Ask your geography, geology, meteorology, anthropology, and related questions here!

[Roxxy]

The weapons and armor thread (http://www.giantitp.com/forums/showthread.php?347806-Got-a-Real-World-Weapon-or-Armour-Question-Mk-XV) seems pretty successful, so let's try an answer thread for worldbuilders to use in creating their masterpieces. Here, questions can be asked about why certain areas have certain climates, how those climates intersect with each other, why certain types of terrain are located where they are, how cities work and develop (including why certain types of infrastructure, such as bridges and rail links, may have been done as they were), how civilians lived in past times and places, how societies develop, and other things that go into making a new world, or modifying an existing one. Though we can consider how magic and hypothetical technologies may effect things (and this is in fact one point of the thread), the only reliable geoscience answers we can give are those based on real world science. As with the weapons and armor thread, anyone is free to answer questions, but it is asked that people can cite sources if asked, and acknowledge that the experts very often don't agree, and that there will be debate.

[Oneris]

Finally! I figured there had to be a world-building analogue to that thread, but I couldn't find one for the life of me.

First Question: What would be the effect of killing almost all of the plant and animal life in a relatively humid location analogous to Switzerland? Would desertification set in, and wind patterns change to produce a small enclosed desert, or would it simply retain its present level of annual rainfall and instead become a huge mud pit?

[sktarq]

First Question: What would be the effect of killing almost all of the plant and animal life in a relatively humid location analogous to Switzerland? Would desertification set in, and wind patterns change to produce a small enclosed desert, or would it simply retain its present level of annual rainfall and instead become a huge mud pit?

Things that would kick in:
major increase in the speed of erosion as root systems that hold back water and topsoil disappear.
precipitation would decline somewhat-but much of local losses would simply migrate up the mountainsides as both the vegetation cover and altitude are major factors in causing that part of the water cycle.
most of the local cloud cover does come from the Atlantic rather than local sources (so general water imputs wouldn't be too heavily effected as altitude factors would still dominate) but the area that would see the largest change would be the northern slopes of the southern ranges of the nation. As for being a mud pit....seasonally it may be for a few years but with erosion and the like (if plants were prevented from returning) it would turn stony very quickly (in geologic time at least). If plants were not prevented from returning lichen and other montane plants would quickly re colonize (as they need very little topsoil) and the mud fields that would surround the lakes in the valley floors would act as nuclei for new ecologies within only a few years.

[Tzi]

Deserts, Deserts, and more Deserts. So I am basing a world LOOSELY on a game of Civ5.

The heart of this campaign world is ideally a sprawling Arabia-Esque Empire that the game did in fact spawn me in the arid region for. In terms of resources this is a people whom have lots of gold, gold mines abound as do horses and iron. Though obviously very little productive agriculture outside of a few coastal bogs. I am curious what sort of defenses would cities or city states within this region have and if gold would carry the same preciousness with it being so abundant. Does gold carry the same value in across cultures?

As for climate and meteorology. The region is cast in MAYBE a rain shadow. To its immediate north is a vast mountain range, tall rocky peaks rich with minerals. And a mostly strip of desert with some plains and marshes on the coast, and a narrow inland sea/gulf allow for some access to fishing. I am wondering though what produces you're Sahara like sand dune deserts versus say a rocky Sinai peninsula or American South west?

[Oneris]

As for climate and meteorology. The region is cast in MAYBE a rain shadow. To its immediate north is a vast mountain range, tall rocky peaks rich with minerals. And a mostly strip of desert with some plains and marshes on the coast, and a narrow inland sea/gulf allow for some access to fishing. I am wondering though what produces you're Sahara like sand dune deserts versus say a rocky Sinai peninsula or American South west?

I'm guessing probably an area that was historically once part of an ocean floor, like the Sahara and what eventually became the Dust Bowl in the American Midwest. Places with sandy soil like dry river and lakebeds for ergs, or sandy deserts, as opposed to places with clay soils which for regs, or desert pavements.
Also, rocky deserts are probably more common in places with volcanic activity.

[sktarq]

Deserts, Deserts, and more Deserts. So I am basing a world LOOSELY on a game of Civ5. ... I am wondering though what produces you're Sahara like sand dune deserts versus say a rocky Sinai peninsula or American South west?

If working in this kind of mono-environment I'd recommend that you look as "sub environments" Scrub forest (see the pinyon pine/juniper/mesquite forests of the American SW or the thorn-brush forests of Angola), erg, rocky badlands, volcanic badlands, pebble seas, riparian and flash riparian regions, fog bank life zones (see the skeleton coast of Namibia for the best example), For deserts see the Darksun various editions to mine for ideas. Oneris is right on the seafloor mostly leading to ergs but regs can come in several forms from various actions. Also the older a desert is the more sandy it will be as wind erosion produces sand and dust. Wind produces ergs far more than erosion from flash flood water.
On defenses. Cites in the desert are well suited to defend themselves using walls, towers, and other things that drive their opponents to siege tactics. Food and water has to be stored and controlled anyway. Opponents will have a hard time supplying sieging troops by either wagon-train or forage. The desert is usually a region of a few widely scattered locations of very high relative value, oasis, mines, etc.

as for Gold-can they trade it to others for a wide variety of goods? If ships come from far away to load up on gold in this region it would probably still be highly valued. One of the major drivers of gold as value holder had been the way it endures and doesn't corrode-deserts are mostly low corrosion environments so that would be less valuable and still very heavy. A question to ask in a metal rich region with little plant material is what fuels the smelting fires.

[Roxxy]

As for climate and meteorology. The region is cast in MAYBE a rain shadow. To its immediate north is a vast mountain range, tall rocky peaks rich with minerals. And a mostly strip of desert with some plains and marshes on the coast, and a narrow inland sea/gulf allow for some access to fishing. I am wondering though what produces you're Sahara like sand dune deserts versus say a rocky Sinai peninsula or American South west?Sand dunes are created by wind moving sand across the desert over long periods of time. So, you need lots of loose (which will by dry) sand upwind. As mentioned, dry river beds work well. It can take about a million years to form something like in Arabia, and the older the desert the more sand has accumulated from erosion.

The rain shadow will be partially determined by dominant wind direction, since that moves clouds, so if the region was in a rain shadow with mountains directly north, a northwards rotation would be realistic. It would, however, mean that the setting itself has a fundamentally different understanding of geography than we do, because a compass would read polar north or south, but a northward rotation would mean that the poles are to the east and west. So, polar direction is divorced from cartographic direction. Would make navigation a right pain. Confusing enough to explain and useless enough for any practical purpose that you might just rotate the continent or move the mountain range if you want a rain shadow over the whole region. If the planet is rotating westwards, the rain shadow will be narrower, since the mountains are preventing clouds coming from the north, but not necessarily from the west. This is important, because for sand dunes you want a rain shadow so that it stays dry.

[Tzi]

Sand dunes are created by wind moving sand across the desert over long periods of time. So, you need lots of loose (which will by dry) sand upwind. As mentioned, dry river beds work well. It can take about a million years to form something like in Arabia, and the older the desert the more sand has accumulated from erosion.

The rain shadow will be partially determined by dominant wind direction, since that moves clouds, so if the region was in a rain shadow with mountains directly north, a northwards rotation would be realistic. It would, however, mean that the setting itself has a fundamentally different understanding of geography than we do, because a compass would read polar north or south, but a northward rotation would mean that the poles are to the east and west. So, polar direction is divorced from cartographic direction. Would make navigation a right pain. Confusing enough to explain and useless enough for any practical purpose that you might just rotate the continent or move the mountain range if you want a rain shadow over the whole region. If the planet is rotating westwards, the rain shadow will be narrower, since the mountains are preventing clouds coming from the north, but not necessarily from the west. This is important, because for sand dunes you want a rain shadow so that it stays dry.

I may rotate and adjust the continents. I'm trying to stick with the map from this Civ game just because it's IMHO otherwise perfect. It's hard to describe but I make a lot of world maps for fun and I've really gotten into playing with ones generated by game algorithms and it was a very nice world.

[Oneris]

New Question!

Is there, or can there be, a neurological disease or syndrome that causes seizures or migraines specifically when the patient actively thinks?

For those who read Girl Genius, something similar to what Agatha goes through in the first chapter whenever she tries to spark, though that was specifically headache-inducing sound frequencies caused by her locket.

[Stellar_Magic]

Now that's a theoretical question.

Neurons (the thinking part of our brain) don't register pain so much a interpret it... For a pain response for synaptic activity (thinking) would be a rather specific and unique evolutionary pattern. Most diseases with a neurological element (Syphilis, Rabies...) work by changing brain chemistry or degrading activity. Our understanding of seizures and migraines is rather limited.

I honestly don't know... and I don't think scientists know either, as they're just now starting to publish research identifying a possible 'pain center' in the brain.

[Murk]

Not sure if this falls under geography enough, but I was wondering how certain meteorological and especially tidal effects would work on a moon. Let's say we have a planet much like earth, but instead of having a moon, it is a moon of a much bigger planet (say, Jupiter).
I know tides would probably be more intense, but if it is just like our moon - rotating around the planet as fast as the planet rotates around its own axis so you only see one side - would there actually be any tides, or would currents just become one big mess?
Of course there are other questions: how would such a big planet influence light, for example? Nights on which the planet is visible should be much lighter, I guess, but it would also block out the sun more often. Is there a simple standard graph for lighting, or is it all depending on size/rotation/location/etc.?

Many thanks in advance ;)

[Stellar_Magic]

The short answer... It depends.

The long answer... Tidal locking between an Earth-like moon and it's Jovian buddy is very likely but not guaranteed, and as tidal locking isn't an instantaneous occurrence, it would also be dependent on the age of the solar system involved. When tidally locked the part of the world facing it's orbital companion would effectively always be at high tide, as water would be drawn there.

Tidally locked like this, day length would be equal to the orbital period of the satellite. Say if its in an orbit like Europa, one 'day' would be around three and a half terrestrial days. On top of this, the world would probably be occulted by the gas giant at least once a day, roughly around high noon for the part of the world that faces the gas giant. Occultation is when the world passes into the shadow of the gas giant. Overall giving the world a rather weird solar cycle on that side.

Because days are longer then a terrestrial day, expect temperatures to rise much more and fall much more during the day/night period, though this would be less severe on the side of the world facing the gas giant due to daytime occultation effects. Weather patterns would be bizarre due to tidal effects and lack of Coriolis effects, so I'd expect the winds to move toward the gas giant or away from it, depending on the time of day.

All other things being equal... the side facing the gas giant will be wetter and cooler then the side facing away. Tidal locking is why all the moon's oceans are facing our side and so forth.

[Roxxy]

Not sure if this falls under geography enoughIt does, it's just that once orbits get involved, things get really complicated. It's fine to ask, or to ask something about biology as was done above, it just may be hard to find someone who's able to answer. I'm glad Stellar_Magic was able to answer both, because neither falls within my knowledge base.

[Murk]

I'm glad Stellar_Magic was able to answer both.

Indeed! Many thanks. I think it'll make for a nice setting somewhere somehow.
(Stellar_Magic, where did you get such a diverse base of knowledge?)

[Stellar_Magic]

Indeed! Many thanks. I think it'll make for a nice setting somewhere somehow.
(Stellar_Magic, where did you get such a diverse base of knowledge?)

Lots of reading various stories... I write Sci-Fi so... Kind of useful to know.

[Reiver Party]

I have some questions for a near-future setting. Let's call it about 80 years in future.

Assuming ice sheets etc continue to melt & the sea level rises by 1m:

Does that even partially mitigate ocean acidification?
Does that noticeably affect ocean salinity?
Does that noticeably affect weather patterns?

[Roxxy]

I have some questions for a near-future setting. Let's call it about 80 years in future.

Assuming ice sheets etc continue to melt & the sea level rises by 1m:
Does that even partially mitigate ocean acidification?You'd get a slight reduction in the rate of increase, but it would still be increasing, and still be bad.

Does that noticeably affect ocean salinity?I'm not sure, but I would hinge towards not by too much.

Does that noticeably affect weather patterns?And how. The coldness of freshly melted ice won't be enough to undo the trend of rising ocean temperatures, and warmer ocean water means hurricanes and typhoons can travel further north. Air temperature is derived form land or water temperature, and water takes longer to heat or cool. So, higher average temp means higher air temp. This in turn means evaporation is increased, but it takes more water to saturate the air enough for rain to occur. This means that coastal areas can see more rain, higher temperatures, and worse storms, while some lakes and rivers dry up and many areas get less rain and bad droughts. More water on the coast and worse storms also means a greater risk of flooding.

[sktarq]

Does that noticeably affect ocean salinity?
yes and no. in the long term term it would be yes but by a pretty negligible amount. Scientist would care, boats may sink a inch or two (as the water is less bouyant) but it would still be undrinkable, most sealife would fine as the new norm would still be within or close to normal variances seen in the ocean today. In the short term however (and by short it could be up 100 years) it can affect it locally. A major infusion of fresh water can take a long time to mix into the water system in the right conditions. Basically the newly liquid fresh water floats on the salt water and the currents that normally drive mixing stay under the fresh water letting it still sit there. That can cause all sorts of issues. Surface zone animals can easily be poisoned, bacteria, and plankton ecologies go haywire and the food chain gets buggered and can insulate parts of the water current system which could disrupt things. The idea that such insulation of the Atlantic current could bring Europe much colder temperatures (more like say NY than the Med for Rome) is a very real one. It wouldn't last and as soon as the water mixed the normal system would kick back in again but as you're only 80 years later it could well be the systems haven't recovered. Now none of the above is really relevant on a large scale for a 1m rise. That is the result of a total collapse the major Ice sheets and 10-15m rise.

[Stellar_Magic]

I should also point out that methane gases among other greenhouse gases are being released as the permafrost melts throughout arctic regions. In the last month or so, three sinkholes have been discovered in Siberia, the largest of which was nearly 100 meters across. Each sinkhole was created by the permafrost beneath the ground melting and releasing various gases and water, creating an immense sinkhole.

As climate temperatures warm, other non-human sources of greenhouse gases become more active, and while we'll never get a true Venus style runaway greenhouse, the increases in CO2 especially will have a significant impact.

Oddly, increased CO2 in the carbon cycle may actually improve plant growth, which in turn will increase global oxygenation... which will encourage animal growth.

Total global ice melt (a very unlikely scenario) would result in a 100 meter sea level rise, at most. Moreover, increased sea levels also increase the size of one of the worlds largest CO2 sinks... the Ocean. A lot of CO2 is trapped in the ocean and ultimately deposited in Limestone, thus removing it from the atmosphere.

Overall the Earth's ecology tends to correct for sudden changes in CO2 and water supply, ultimately stirring the planet toward a rough balance. This process takes a lot of time, usually in the thousands of years. Depending on how far into the future you're going to put your setting, it's likely people and the globe will have adapted to higher CO2 and average temperature levels.

If you're doing near term, then you should also consider complimentary effects on society and people from things like increased energy demand, decreased oil supply, increased food demands, and so forth. There are a whole litany of issues we'll face in the 2030-2040 period that will make it a very challenging time, not the least of them the unpredictable weather patterns created by global climate change.

[Reiver Party]

Thank you, your answers have been very helpful.

I've got another question that's been bothering me.

Say that Amazonian deforestation continues and that the land is poorly utilised. Without vegetation to anchor down the shallow topsoil, the topsoil blows away and you get an Amazonian Dust Bowl.

Does that dust bowl have international consequences? I remember reading something that predicted such a scenario would have very bad consequences for North American farming. But I don't know if it was reasonable and evidence-backed or just hyperbolic speculation.

[Stellar_Magic]

For it to be a true dust bowl, not only will the deforestation need to continue but you'd need a major drought. Mud doesn't exactly get picked up by winds all that easily.

Particulate dust levels increasing would encourage cloud formation. Keep in mind that the prevailing winds and trade winds would direct any dust generated in the Amazon basin to the north-west and south-east. Thus dumping most of the dust into the mountains, eastern Brazil, and the southern Atlantic. Global effects of a dust-bowl tend to be that of a 1-2 degree dip in global temperatures overall, sort of like the effect of a volcanic eruption.

Keep in mind a large portion of the Amazon river flows backwards due to parts of the interior having very low elevations. A 1 meter rise in sea level will likely see a corresponding increase in the Amazon of water levels, and large swaths of the Amazon coastal regions are only around 1.6 meters or less above sea level. While higher elevations would dry out in a drought and begin to blow around, the lower elevations would likely flood with the rising sea levels. Farmers would not try and farm sections where the rising sea has turned the area more and more brackish and unusable, and I would figure that mangrove swamp environments would likely slowly supplant any cleared farm land or remaining rainforest in the coastal regions.

Keep in mind, Manaus, a city in the heart of the Amazon Basin is only 35 meters above sea level. While a 1 meter sea level rise would not effect it, a 30-40 meter rise would likely flood it and large sections of the Amazon basin. A sea level rise of 100 meters or so (requiring a near total melt of all glacial ice) would flood about half the entire Amazon Basin creating a vast inland sea.

[bulbaquil]

Okay. Suppose I want a planet where one hemisphere (say the northern) is constantly in winter, while the other (say the southern) is constantly in summer - basically, the planet is tilted relative to its sun much like Earth on February 1, but while it rotates on its own axis, it doesn't orbit the planet - it just... stays fixed, as does the sun. (We're handwaving solar gravity here.)

The sun thus is at a constant declination of about -18 degrees. North of 72°N latitude, the sun never rises; between 72°N and the equator, nighttime is always longer than daytime; between the equator and 72°S, daytime is always longer than nighttime; and south of 72°S the sun is always up. Day length is a function of latitude, but is constant throughout the year.

What I want to know is: Assuming an Earthlike planet at Earth's distance from a Sunlike star, with Earth's day length, about how hot would the permanent-summer side get, and about how cold would the permanent-winter side get? I know:

1. The extremes would likely be milder than they would on a fully tidelocked planet.
2. The north pole would almost certainly have a very thick and large ice cap, while the south pole would almost certainly lack any sort of ice cap at all.
3. Coriolis forces and Hadley cells would still be a thing.

[Stellar_Magic]

This would get rather complex... as the actual continental arrangement and sea currents would have a profound effect on how cold the various parts of the planet would get. Antarctica is so cold in large part due to the currents that flow around it while Arctic regions at the same latitudes have taiga forests and tundra, Antarctica is dominated just by glacial ice.

A perpetual summer and a perpetual winter would ultimately have similar effects to tidal locking... and might actually be geologically possible if somehow the planet's procession (wobble of the axis) was somehow in sync with it's orbital period, perhaps due to a 'mass concentration' of heavy metals around the -18 degree mark.

The average hottest day of the year in the Northern Hemisphere is usually around July 24th, while the longest day is June 21st. This is because heat sticks around and continues to build up for quite some time after the longest day of the year. If summer is perpetual, I'd expect the temperatures recorded in the summer latitudes to be substantially warmer.

The highest temperature ever record was 134 degree Fahrenheit or 56.7 degrees Celsius. The lowest temperature ever recorded was -135.8 degrees Fahrenheit or -93.2 degrees Celsius. These two temperatures would likely be around the average temperatures to expect in the hottest and coldest part of the zones with a world like this and I would expect the extremes to be as high and low 15-20% more extreme then those values.

The zone at -18 degrees is going to be extremely hot, probably inhospitably so except at coastal regions where water currents can mitigate the effects. This heat will rise, and essentially shift the flow pattern of the trade winds southward, as the air is usually rising from the -18 degree line instead of the equatorial effect we have on Earth today. This would also shift the tropics southward around the same amount. The most profound effect in the south will be the constant day near the south pole. As the south pole would essentially be locked in an early evening/morning light level it would be a rather moderate environment.

It's likely you'd be looking at forested areas there with an average temperature around or below the freezing mark, sort of like Summer in the southern parts of Alaska. This more moderate effect will make it so the trade winds south of the -18 degree mark are significantly weaker then those north of the -18 degree line, making trade easier to conduct in the north then the south.

[Yora]

In my setting, there is a country that lies between a very high mountain range and a smaller range of rugged hills, forming a relatively flat land of alpine tundra and lots of marshland. On the other side of the hills the land is lower and covered by large cool and temperate forests.
The highland is inhabited by isolated groups of barbarians, who occasionally come to raid in the lowlands and really don't like visitors. But I still have the unanswered question why they are living in such an inhospitable place, when the forests look much more inviting. I think they may be in some way comparable to the people who settled in Tibet and the mountains of Norway. Possibly even Monolia, but that seems to be more smooth grassland and I don't think horses would do well in a land that is either stony rubble or bogs.

What kind of culture would settle in such a place?

[Stellar_Magic]

The issue is probably that you decided to go with marshlands in an highland environment, which is a rather rare occurrence naturally. Marshlands are almost exclusively a lowland environment and normally occur around lakes, rivers, and river deltas. You can get them in valleys between mountains where they would usually form a marshy grassland like a wet prairie or bog. In this case the majority of the environment would be alpine tundra.

If the alpine tundra is a dominate feature expect a culture to arise that reflects that like the Scottish Highlanders, Tibetans, and so forth. Normally alpine tundra doesn't support much in the way of large wild animals outside of smaller deer, mountain goats, and elk, but it could support sheep and goats among the domesticated animal life making nomadic cultures revolving around sheep herding more likely.

[Yora]

The exact nature of the ecosystems isn't that important. I am mostly looking to have an elevated plateau that is relatively flat with poor draining of water. Not quite sure how realistic it is to have two mountain ranges running paralel, but I've come up with this fairly plausible arangement (http://spriggans-den.com/wp-content/uploads/2014/08/Ancient-Lands-WM.jpg). The area in question is in the very north.
During an ice age claciers flattened the whole area. There are two outlets in the southeast and southwest. The southern mountains and hills would be very smoothed down from glaciers, like you see in norway.

Iceland comes to mind as another land with similar environment conditions and that was also settled. Though as far as I know, conditions were much more favorable during the colonization time than they are now.
Goat and yak herding seem like good primary sources for food and clothing. The main question is why they settled down there to begin with. As a fantasy setting, I think of adding a strong relationship to local spirits. The leaders of the highlanders are witches with a sinister reputation. If they don't go along well with the spirits of the forests, but have come to some kind of understanding with those of the highlands, it would be one incentive for their people to remain in that area, even if it's not economically optimal.

[Aergoth]

Assuming the section you're referring to is the top-most region of blue-green an easier assumption is simply that this is a natural trough created by receeding glaciers, and that the underlying rock is similar to that of the Canadian Shield, which sees regions like what you're describing, though without the other mountains. The rocks don't allow a lot of drainage, the quality of the soil is poor which is why what you see growing in this area is mostly boreal forest, lots of pine trees, lichen and mosses.
Because of the nature of the rocks here, the mineral value of the area is quite high, where it's not covered by rivers and bogs, which could provide a reason to set up shop in the area. Ice ages will have worn away a lot of the harder rocks above fairly rich deposits of silver, gold, nickel and copper, as well as diamonds. (Some of this is likely related to the fact that the actual shield has some fairly large impact craters, but ignoring that).

So your bog-dwelling folks might be able to subsist in a boreal forest, probably functioning as native north americans or scottish highland tribes did. Fishing in some of these areas tends to be pretty good, you get substantial populations of things like elk or moose which can swim or walk through the boggier regions, which attract other predators (bears, wolves) . Assuming your magic types can do something about the soil (pine trees do not make for good soil) you might be able to indulge in agriculture, particularly if you were near a fairly consistent river with fairly solid banks (in essence a cold version of the nile valley).

That said, you'd be dealing with flooding and all kinds of nastiness during spring thaws, so it could be that your bogdwellers actually reclaim sections of the marshlands with manmade constructions which could give you some fairly fertile land to grow things on. Think Holland.

[sktarq]

Yora, you have options.
Seasonality is important. If the area is high latitude the impact of growing seasons will drive the people pretty hard away from agriculture and into pastoralism or hunter gatherer lifestyles. If it more tropical and the drawing from examples of the Andes and Himalyas crops that can deal with an off season storm and last well like potatoes and buckwheat would be preferred. Also if their local crops are tightly adapted to this particular habitat (or your own creations that are) it could be that their forms of agriculture don't work well at lower altitudes in the surrounding region. (leads to something like an island effect and why a place like the inland valley of Papua New Guinea was so developed while the coast was very thinly settled).
Also fishing could be quite good and since there are opportunities to draw water off some areas of bogland could be drained by human action if you want to have the locals have that level of technological advancement. Those draining actions could well leave regions that are more fertile than the surrounding forests, Altiplano, etc which could be comparatively ideal for intensive agriculture. local intensive agriculture, and stone/earthworks would be a good basis for having mines and with all that a pretty developed place that won't travel well.
Another option is that the place is pretty poor and frightened place. Ridge-top keeps and crannogs are both good defensive locations. Give them an enemy to hide from that they can ride out in these swamplands and who make the lower slopes problematic to them. It wouldn't have to be something that hits every year just enough that it punishes those who set up elsewhere.
If you do go for a pastoral system keep an eye on salt. Depending on the geology an presence/lack of uplifted ocean floor hunting salt for the dairy and animals would be a significant issue.

[jqavins]

What would be the effect of killing almost all of the plant and animal life in a relatively humid location analogous to Switzerland? Would desertification set in, and wind patterns change to produce a small enclosed desert, or would it simply retain its present level of annual rainfall and instead become a huge mud pit?
Things that would kick in:
major increase in the speed of erosion as root systems that hold back water and topsoil disappear.
precipitation would decline somewhat-but much of local losses would simply migrate up the mountainsides as both the vegetation cover and altitude are major factors in causing that part of the water cycle.
most of the local cloud cover does come from the Atlantic rather than local sources (so general water imputs wouldn't be too heavily effected as altitude factors would still dominate) but the area that would see the largest change would be the northern slopes of the southern ranges of the nation. As for being a mud pit....seasonally it may be for a few years but with erosion and the like (if plants were prevented from returning) it would turn stony very quickly (in geologic time at least). If plants were not prevented from returning lichen and other montane plants would quickly re colonize (as they need very little topsoil) and the mud fields that would surround the lakes in the valley floors would act as nuclei for new ecologies within only a few years.
(I added the underline.)

Pardon me for jumping in late. Since the question was about killing most of the plant and animal life, not all of it, wouldn't plant populations bounce back fast enough to avert major erosion? Dead root systems hold soil as well as live ones for a little while, and they'd be replaced by new ones as fast as they rotted away. The large amount of rotting plant matter would mean the new plants are practically growing in a compost heap, and with most of the the animals that munch them gone they'd recover like gangbusters. Then the plant munchers, with most of the predators gone, would recover just as fast only a little later, allowing the predators a rapid though even further delayed recovery. The ripple effects would last for years and probably decades.

[jqavins]

Is there, or can there be, a neurological disease or syndrome that causes seizures or migraines specifically when the patient actively thinks?
Now that's a theoretical question.

Neurons (the thinking part of our brain) don't register pain so much a interpret it... For a pain response for synaptic activity (thinking) would be a rather specific and unique evolutionary pattern. Most diseases with a neurological element (Syphilis, Rabies...) work by changing brain chemistry or degrading activity. Our understanding of seizures and migraines is rather limited.

I honestly don't know... and I don't think scientists know either, as they're just now starting to publish research identifying a possible 'pain center' in the brain.
Again, I added the underline and please forgive my jumping in late.

We know that conditions we perceive mentally or emotionally can have effects that we think about neurologically. High stress can bring on migranes or make one more likely. Interesting bit of tangentially related data: I had a neice with a pretty bad concussion affecting a particualr part of her brain such that her doctor told her not to think while recovering. No kidding, she couldn't read or watch TV, and had to try not to ponder while lying in bed; it was hell. Point is, even just thinking can stress the brain under certain circumstances, according to her doctor.

New research is forever finding new causes of siezures. Could damage to a specific part of the brain, either congenital or due to injury (and injury can include damage done by an infectious agent) create a susseptibility to siezures or migranes that are triggered by thinking-induced neural stress? Mmm, maybe.

So, does such a disease exist? Not that I've ever heard of. Is such a disease plausible? Sure, close enough for gaming it is.

[jqavins]

Not sure if this falls under geography enough, but I was wondering how certain meteorological and especially tidal effects would work on a moon. Let's say we have a planet much like earth, but instead of having a moon, it is a moon of a much bigger planet (say, Jupiter).
I know tides would probably be more intense, but if it is just like our moon - rotating around the planet as fast as the planet rotates around its own axis so you only see one side - would there actually be any tides, or would currents just become one big mess?
(Still busy catching up.)

Well, if the moon is tide locked then planet-induced tides would be static. But don't forget their star. Here on Earth, the solar tides are nearly half as strong as the lunar tides. As seen from Luna, the terran tide would be static, but the solar tide is not to be ignored.

Now, if you want to get funky with this, add a second mood to the system. They'd have different orbital periods around the plannet, the two moons and the planet would move into and out of alignment. Also,the other moon's distance from the game setting would change, so the strength of its tides would change a lot (tidal strength is inversely proportional to the cube of distance.) And the changing direction of this tide would not be a simple round-and-round either. There's lots of fun to be had with this, if you want.

[jqavins]

2. Does that noticeably affect ocean salinity?
I'm not sure, but I would hinge towards not by too much.
"Not much" can be "too much." There's a theory that polar ice melt could reduce ocean salinity sufficiently to mess with the thermohaline circulation (https://en.wikipedia.org/wiki/Thermohaline_circulation), which would in turn have radical weather effects.


3. Does that noticeably affect weather patterns?
And how. The coldness of freshly melted ice won't be enough to undo the trend of rising ocean temperatures, and warmer ocean water means hurricanes and typhoons can travel further north...
The effect on the weather of rising sea level and reduced salinity frompolar melting would be - no, will be impossible to separate from the other effects of the rising global temperature that lead to said melting. They are important factors in any model attempting to make predictions, but such models require supercomputers.

[jqavins]

The main question is why they settled down there to begin with.
"'Cause no one else was there" is answer enough. On Earth we have people who've settled in tundra, swamps, deserts, jungles, you name it. People go everwhere. The question, then, is less "why did they go there?" than "How did they manage to make a go of it?" On the latter, you've already received more and better advice than I can offer.

[jqavins]

OK, now my question. What's a good source for the basics of determining climate based on geography? I don't want to ask "What should the climate be on my world, with continents X,Y, and Z, and mountains here, there, and here" etc. That's both too general in some ways and too specific in others. I'll do the work myself, but I need some guiding principles. Can anyone reccommend a book or article on the subject for the scientifically literate non-climatologist?

[Stellar_Magic]

Well for Earth analogs I don't know of any articles or books, but some general rules of thumb apply.

1. Equatorial zones are usually tropical environments.
2. Arctic zones exist in areas more then 60 degrees from the equator.
3. Desert belts are located around 15-25 degree.
4. Temperate environments span from 30-60 degrees from the equator.
5. Westerly winds dominate in temperate zones. Easterly trade winds dominate in the Tropics.

Raising or lowering the temperature effects how far north and south the zones exist, with raising the temperature high enough creating an equatorial desert belt continuing to raise it you'll eventually get total desertification. Lowering the temperature will cause ice to move from the poles until you get total glaciation if the temperature is low enough.

[sktarq]

(I added the underline.)

Pardon me for jumping in late. Since the question was about killing most of the plant and animal life, not all of it, wouldn't plant populations boun... The ripple effects would last for years and probably decades.

It depends on the area. Especially how much sunlight and rain is available to generate plant growth. However unless it is an area that is ideal for fast plant growth the answer is no as in 95% of the time no. Look at effects of clear cutting forests (which leaves the root systems, undergrowth and lots of mulch) or overgrazing (which can lead to extremely fast erosion effects).

[Jendekit]

I have a question for which the most closely related field would be anthropology, but without the anthro-. I am working on a race of aliens for a science fiction setting that are very similar to Earth's spiders. Eight limbs, eight eyes, exoskeleton, produce silk, etc. what I am trying to figure out is what kind of culture would develop from a species that doesn't have the social drive that humans have wired into them.

Physically they are about half-again the size of tarantulas and their front set of legs have developed into pincers almost like scorpions, but rather than a large strong claw it is more like two hooks that have the ends pressed against each other.

Thoughts?

[MrConsideration]

Surely they wouldn't have familial or state-based social structures at all? T

It would just be individuals going about their lives, meeting to mate (possibly consuming their mate afterwards) and birthing hundreds of children who are abandoned into the same life cycle.


The difficulty here is (in Sci Fi terms) how such a species ever becomes sufficiently advanced without sharing and preserving knowledge and technology. If we hand-wave that, maybe each is a highly individualistic producer in their economy, using whatever self-taught skills they have to produce things for their own gain, perhaps bartering or exchanging them with others. With no family unit, young individuals probably exist socially on the margins until they can drag themselves up by their eight bootstraps to produce something worth exchanging. Such a species would have minimal interest in collective action of any kind so a 'Tragedy of the Commons' might be the result of any kind of industrialisation on their homeworld - conversely, their lack of social drive or need to impress anyone probably makes them unlikely to engage in anything decadent or luxurious - especially as they probably need to eat seldom like Earth spiders - I can imagine them being thrifty and spartan. Are they competitive?

The culture would probably value the individual over all, and looking at human culture their stories would mainly be about individual heroism, success or emotional development. Maybe every single spider-creature is an artistic being, spending its leisure time using silk to produce art similar to China Mieville's Khepri species? Spiders with a lot of time in between economic pursuits could produce vast silken epics about their personal development.

Maybe they are individuals on an increasingly over-populated planet, incredibly frustrated as space to be themselves dramatically decreases with every generation, leading to spiraling violence and crime-rates.

Just my 2p.

[sktarq]

I have a question for which the most closely related field would be anthropology, but without the anthro-. I am working on a race of aliens for a science fiction setting that are very similar to Earth's spiders. Eight limbs, eight eyes, exoskeleton, produce silk, etc. what I am trying to figure out is what kind of culture would develop from a species that doesn't have the social drive that humans have wired into them.

Physically they are about half-again the size of tarantulas and their front set of legs have developed into pincers almost like scorpions, but rather than a large strong claw it is more like two hooks that have the ends pressed against each other.

Thoughts?
Well you said what they are physically. But the rest? How social are they? Do they invest a lot of effort into each youngling (and thus will develop systems (like strong pair and group bonding) to protect these high value children) or do you produce swarms ?(which would devalue the individual). How long to they take to become adult (which would be key to how they tie into their families. If they have a lot of near genetically identical siblings does the uncle effect drive them to be more open to providing and even dying to protect genetic group and possibly a social group that has stepped into that at some point in their societal development? What do they eat? (Humans being omnivores have a pretty wide variety of food sources and as different societies that are tied to those different survival techniques). With both manual manipulators and silk I could see a control of ones environment being a big thing-even the main way they think to solve challenges. If problem solving and showing off helped drive the human brain development (and things like art, religion, etc) then what drove these in your aliens, if anything.

[jqavins]

Why assume no social drive? No familial drive I can see. Some might still discover that hunting and building in groups is more effective than doing so alone, and evolve a drive to form partnerships. With no concept of family there is no incentive for long term growth of communities (since the reason to build a community is to aid one's decendants) but that doesn't mean there couldn't be a society built around friendship clusters that form, operate, and die in a single lifespan.

[sktarq]

possible but a longer term society would find that to be unstable and thus not one that would be useful in drawing patterns from for DM usage in presentation to players. Also it is still the decision how to get there that needs to be made first. If the decision is none then a whole "where do you go from here" questions open up.

[jqavins]

Perhaps "a culture built on..." would have been a better choice of words.

[Jendekit]

Regarding the questions asked, they produce batches of about fifty eggs which are then implanted into the bodies of larger lifeforms to serve as food for the soon to be hatched young after fertilization. After hatching it takes about ten years for them to start to produce silk of their own, and until such time they rely on group hunting with their hatch-mates before they break off to find their own areas to set up their webs. The mating process takes place over about a two day period and males attract mates by the elaborate patterns, designs, complexity, and practicality of their webs. A web that is elaborate and complex simply for the sake of such is seen as wasteful, it must also be able to catch a supply of food worthy of the complexity.

Diet-wise, they are primarily carnivorous, but in desperate times they can squeeze by on plant material. They can only barely digest it, and must consume nearly three times as much in order to avoid starvation.

One thing that I am debating is something that I read about in the book Aliens and Alien Societies where the author mentioned an experiment where a group of flatworms traversed a maze, were then ground up and fed to other flatworms. These new flatworms then traversed the same maze without having to learn it like the last ones did. Later attempts of duplicating the results failed, but still the idea of passing on knowledge through means beyond just a long childhood I found interesting. If this ends up being used, then some eggs would be implanted into the males and those would hatch with the knowledge that their father had. Would this include memories? Doubtful but possibly.

Now on social structures, upon reaching adulthood they still keep in contact with their hatch-mates. This is partially to avoid inbreeding and partially because doing so is advantageous. If one hatch-mate learns that Afzuka lizards are having a population boom then the other hatch-mates know to keep an eye out for the predators. In extreme cases they will gather together again to deal with whatever has gained their attention. Sometimes hatch-mates will organize their webs so that the corner of one overlaps the others, forming what is effectively a village made out of webs. At the center of such web villages the entire group will form a large structure to protect all of them should the need arise (such as a very powerful storm). On not uncommon occurrences, new members from younger hatchings will be invited to join the web village and set up a new web that connects to the old ones.

Now this is just a generalization of their equivalent of our hunter-gatherer tribes. An idea of where they began as a society.

[Tzi]

Lets talk Underdarks, subterranean mama-jama's.

So I've decided in my world to include a race of (LA GASP) Dark Elves. Driven underground during a cataclysmic ancient war among the Elves, this stalwart survivors burrowed deep, hiding in the deep dark places, crevices and crags and near the flows of volcanic activity ect.

My question is how likely are vast cavern systems and networks and huge chambers naturally occurring or would they all need to be mostly drilled a dug. I could go either way, for example these Elves built settlements akin to Zion (Alla Matrix) and various interconnecting caverns, other vaulted chambers and basically creating a sustained web (Get it, web? Dark Elves, Drow? Spiders.... ) of interconnected cities ect.

What sort of ecology could form there? Say would vast mushroom forests be a thing? Glowing iridescent forests sound appealing to me.

What dangers would this society have?

[Everyl]

Lets talk Underdarks, subterranean mama-jama's.

So I've decided in my world to include a race of (LA GASP) Dark Elves. Driven underground during a cataclysmic ancient war among the Elves, this stalwart survivors burrowed deep, hiding in the deep dark places, crevices and crags and near the flows of volcanic activity ect.

My question is how likely are vast cavern systems and networks and huge chambers naturally occurring or would they all need to be mostly drilled a dug. I could go either way, for example these Elves built settlements akin to Zion (Alla Matrix) and various interconnecting caverns, other vaulted chambers and basically creating a sustained web (Get it, web? Dark Elves, Drow? Spiders.... ) of interconnected cities ect.

What sort of ecology could form there? Say would vast mushroom forests be a thing? Glowing iridescent forests sound appealing to me.

What dangers would this society have?

I can't say how likely large cave systems would be to form on their own, but you should probably assume that most of the caves the dark elves live in were originally natural. Any tunnels or caves that are manually dug would require huge amounts of earth and stone to be hauled somewhere, probably the surface, because keeping it underground would just fill more space than the newly-excavated cave. Artificial tunnels and caves no doubt exist, but would not be trivial to make in the deep underground.

And as for the ecology, cave ecologies are sparse. Nearly all of the energy in a real-world cave ecosystem trickles down from the surface. Bat guano, runoff carrying nutrients, and the like are about the only way for local life to get food. Even fungus needs something to grow from, and geothermal energy isn't nearly as generous as solar power. Deep sea vent ecosystems only support small clusters of life around the vent itself; geothermal power would have great difficulty supporting a complex, sprawling ecosystem that fills an Underdark-style cave network.

Most settings I've seen that concern themselves with the "realism" of Underdark ecology resort to some form of magical handwave. Something like, "Underdark fungi/plants feed on a unique background magical field only found deep below the surface, the rest of the ecosystem is built on eating those fungi/plants and/or creatures that do so." There are plenty of such workarounds available, you just have to choose one that fits the metaphysics/cosmology of your setting.

[Tzi]

I can't say how likely large cave systems would be to form on their own, but you should probably assume that most of the caves the dark elves live in were originally natural. Any tunnels or caves that are manually dug would require huge amounts of earth and stone to be hauled somewhere, probably the surface, because keeping it underground would just fill more space than the newly-excavated cave. Artificial tunnels and caves no doubt exist, but would not be trivial to make in the deep underground.

And as for the ecology, cave ecologies are sparse. Nearly all of the energy in a real-world cave ecosystem trickles down from the surface. Bat guano, runoff carrying nutrients, and the like are about the only way for local life to get food. Even fungus needs something to grow from, and geothermal energy isn't nearly as generous as solar power. Deep sea vent ecosystems only support small clusters of life around the vent itself; geothermal power would have great difficulty supporting a complex, sprawling ecosystem that fills an Underdark-style cave network.

Most settings I've seen that concern themselves with the "realism" of Underdark ecology resort to some form of magical handwave. Something like, "Underdark fungi/plants feed on a unique background magical field only found deep below the surface, the rest of the ecosystem is built on eating those fungi/plants and/or creatures that do so." There are plenty of such workarounds available, you just have to choose one that fits the metaphysics/cosmology of your setting.

magic handwave might be necessary. Within the "cosmology," or metaphysics of the world, planets generate magic. Akin to the geomagnetic fields a regular planet generates, natural magical energy is generated or somehow concentrated by planets. Explaining the array of magical crystals and how stones can be used for magic rituals ect as amplifiers.

The other option is to have these vast underground vaults either be magi-tech fortress cities, or provide for above ground areas they can go to for food.

But I might do the magically charged ecology. Perhaps even using it to explain the strange appearance of the denizens of the deep dark cities. After all the stereotypical Drow/Dark Elf/Night Elf ect physiology is rather odd. Considering their lack of light exposure you'd imagine they would simply be an unearthly pale white color, yet they are not. Vast caverns and subterranean vaults with strange magically fueled ecologic systems might work. But I might also have some mega-fauna above ground, and deep within the roots lay some settlements as well.

[jqavins]

magic handwave might be necessary.
I'd say certainly will be necessary. The longest known cave system on Earth (https://en.wikipedia.org/wiki/Longest_caves) is Mammouth Cave (https://en.wikipedia.org/wiki/Mammoth_Cave) in Kentucky, USA. Its length is listed at 652 km. It has some very impressively wide chambers (I've been there) still most of it is narrow passages, and a lot of that has low ceilings. The natural floor area suitable for building wouldn't support a large village, let alone an underground kingdom.

Large caves form most in rock that is both strong enough and water soluble, and that most often means limestone. Therefore, a cave system extends only as far as the limestone formation, so there's only so big one can ever get.

Digging comes with the problems or removing material as Everyl pointed out, and also is likely to require shoring; just look at mines, which are the quintessential artificial caves.

As with mines, ventilation is essential. Toxic and/or explosive gasses are problems in some areas more than others, but even without those ventilation is required to provide a renewing supply of oxygen; plants that live on ambient magic might produce oxygen in a manner analogous to photosynthysis, but not nearly enough. Also as with mines, water removal will be a constant chore.

IMHO, an underdark simply couldn't evolve naturally. The only way to have a subterrainian environment of any substantial size is to start with magically powerful settlers who create it, such as the losers in the great ancient elf war. The dark elves would expand on natural limestone caves using magic for excavation, shoring, ventilation, and water removal. They would either create magiphagic plants or cultivate naturally occurring ones, and they would be followed in by varieties of vermin and monsters that previously lived in natural caves then thrived in the artificial megacaves. The existance of new sorts of plants and animals that evolved down there would require that the dark elves moved in and created the megacaves a very long time ago, or some sort of evolutionary accelerator.

[Tzi]

I'd say certainly will be necessary. The longest known cave system on Earth (https://en.wikipedia.org/wiki/Longest_caves) is Mammouth Cave (https://en.wikipedia.org/wiki/Mammoth_Cave) in Kentucky, USA. Its length is listed at 652 km. It has some very impressively wide chambers (I've been there) still most of it is narrow passages, and a lot of that has low ceilings. The natural floor area suitable for building wouldn't support a large village, let alone an underground kingdom.

Large caves form most in rock that is both strong enough and water soluble, and that most often means limestone. Therefore, a cave system extends only as far as the limestone formation, so there's only so big one can ever get.

Digging comes with the problems or removing material as Everyl pointed out, and also is likely to require shoring; just look at mines, which are the quintessential artificial caves.

As with mines, ventilation is essential. Toxic and/or explosive gasses are problems in some areas more than others, but even without those ventilation is required to provide a renewing supply of oxygen; plants that live on ambient magic might produce oxygen in a manner analogous to photosynthysis, but not nearly enough. Also as with mines, water removal will be a constant chore.

IMHO, an underdark simply couldn't evolve naturally. The only way to have a subterrainian environment of any substantial size is to start with magically powerful settlers who create it, such as the losers in the great ancient elf war. The dark elves would expand on natural limestone caves using magic for excavation, shoring, ventilation, and water removal. They would either create magiphagic plants or cultivate naturally occurring ones, and they would be followed in by varieties of vermin and monsters that previously lived in natural caves then thrived in the artificial megacaves. The existance of new sorts of plants and animals that evolved down there would require that the dark elves moved in and created the megacaves a very long time ago, or some sort of evolutionary accelerator.

I'm thinking of magically powerful, or even just technically very innovative people building mostly subterranian structures. Possibly later expanding to the surface under vast root systems for large mega-forests. Think Nausicaa and the Valley of the Wind. Beneath those poison jungles sitting cavernous areas in the tangled and petrified roots.

[Yora]

A really big problem with Underdarks is the issue of drainage. Large caves below sea level just don't work, especially if there are passages that link them to the ocean. It would simply flood.
My solution is to make it actually part of the spiritworld. Many very deep caves have portals to the spiritworld, and the place where you come out on the other side is subterranean as well. Even a regular underdark is weirder than most spiritworlds ever get, so it doesn't really change things, and such pedestrian things as drainage and ventilation don't apply there.

Anyone of you familiar with tropical winds? I have a country located in a position similar to Venezuela (which happens to be the only place on earth with an east-west coast and the sea on the pole-side and the hinterland on the equator side in tropical latitudes), and I am trying to figure out at what time of the year the winds would help ships to sail upriver.
The idea being that there is a trade season where merchant ships from other countries arrive to sell their goods in the capital city deep inside the jungles.

[Tzi]

A really big problem with Underdarks is the issue of drainage. Large caves below sea level just don't work, especially if there are passages that link them to the ocean. It would simply flood.
My solution is to make it actually part of the spiritworld. Many very deep caves have portals to the spiritworld, and the place where you come out on the other side is subterranean as well. Even a regular underdark is weirder than most spiritworlds ever get, so it doesn't really change things, and such pedestrian things as drainage and ventilation don't apply there.

Anyone of you familiar with tropical winds? I have a country located in a position similar to Venezuela (which happens to be the only place on earth with an east-west coast and the sea on the pole-side and the hinterland on the equator side in tropical latitudes), and I am trying to figure out at what time of the year the winds would help ships to sail upriver.
The idea being that there is a trade season where merchant ships from other countries arrive to sell their goods in the capital city deep inside the jungles.

I'm now somewhat torn on perhaps having semi-above ground, semi-below ground city complexes/natural caves used as bunker settlements.

One idea being perhaps cities like, to borrow from WoW, Dire Maul/Eldre'Thalas. Vast ruined complexes with underground areas inhabited by stalwart survivors who burrowed deep and have begun to recolonize their wrecked settlements.

The only other idea is having cities built, in burrowed cave systems and mine shafts, akin to dwarven fortresses or I guess Zion of the Matrix series.

[sktarq]

Anyone of you familiar with tropical winds? I have a country located in a position similar to Venezuela (which happens to be the only place on earth with an east-west coast and the sea on the pole-side and the hinterland on the equator side in tropical latitudes), and I am trying to figure out at what time of the year the winds would help ships to sail upriver.
The idea being that there is a trade season where merchant ships from other countries arrive to sell their goods in the capital city deep inside the jungles.
Well according to a couple sailing magazine sites I looked at for you (like it anyway) the Oct-Dec season seems to be the recommended time to leave Europe/West Africa if heading to the West Indies and mostly don't think it will take more than a month or so from the Canaries. So basically early "Winter" id say.

[Yora]

That would be wind from Northeast to Southwest, right? That would work for my purposes, thanks.

[sktarq]

That would be wind from Northeast to Southwest, right? That would work for my purposes, thanks.

They actually recommend against a strait line. Leave Europe in Aug-Oct hop and futz around south until the Canaries/Cape Verdes at least and then turn west to get better winds with far less effort and greater reliability.

[Yora]

But straight east to west wind won't be much help. Best thing would north to south.

But it seems that summer monsoons always go from sea inland, regardless of location, as the land heats up during summer, causing the air to rise and pull cold air from the sea surface after it. That would be exactly what I am looking for.
It also means massive rain, but I am not sure what that means for river travel. Potentially stronger river currents that might cancel the effect. :smallconfused:

[jqavins]

But straight east to west wind won't be much help. Best thing would north to south.

But it seems that summer monsoons always go from sea inland, regardless of location, as the land heats up during summer, causing the air to rise and pull cold air from the sea surface after it. That would be exactly what I am looking for.
It also means massive rain, but I am not sure what that means for river travel. Potentially stronger river currents that might cancel the effect. :smallconfused:
As long as the wind isn't directly out of the south, sailing ships can go south. Sailig cross-wind works at least as well as sailing downwind. Even as little as 20 or 30 degrees off windward is doable. If you want a limited season for sailing up river, I'd look more to the current than the wind. During spring runoff, you could have very strong currents that make the trip impractical. Then you could have a summer dry season where the river is too low to sail. That leaves a late spring or early summer window of opportunity.

[sktarq]

As long as the wind isn't directly out of the south, sailing ships can go south. Sailig cross-wind works at least as well as sailing downwind.
This assumes the technology of triangular sail is available which it wasn't until the late middle ages in Europe (and in the local stone age elsewhere). Square sails are only really good for a downwind run. also equatorial Rivers flow rate over the course of the year is highly variable. If it is fed by a high altitude snowpack then spring melts are a thing but if it is fed by by the year round rains of the equatorial belt then it could be quite steady. If the river crosses the equator then this is a decently high possibility (look at the Congo which crosses the equator twice and has a very low flow variance at its mouth. Also "spring" and "summer" don't really matter at that latitude-it is more a matter of wet and dry cycles which may have a 12 or 6 month period.

[...]

What is a threat that can send entire races running for the underdark, but still have an underdark and have most (if not all) of the race members left?

[NyuBomber]

Ello!

Two questions, as they relate to the setting I'm developing (linked in my sig). The gist of the fantasy world is that it's humans vs other-dimensional spirits, in a heavily medieval China-based time period. Humanity was close to the brink of extinction, after a now-lost golden age, until the tide was turned by extraordinary heroes, shen-lieren, who continue to defend from spirits. The breathing room has allowed humanity to reconstruct and continue establishing itself, though there's still much to learn/re-learn/explore.

- How small/big should this world be to facilitate a global monarchical government? The idea is that the monarchy has a standing army of mundanes to generally handle of mundane threats (going after barbarians and slavers, protection of trade routes, etc.), which combines with each continent's own defenders, both mundane and shen-lieren, to keep structure and order. There's also a nascent shen-lieren police force that operates more on a local level and tackles local crime (or tries to, anyway).

- NothingButCake, in the discussion thread, had the (what I think, anyway) brilliant idea to make the edges of the map (spoiled below, also in info thread) be the arctic regions, with things generally getting warmer the closer to the center you go. I think I can safely handwave the logistics of how the meteorology works, but if I can get a theory on how to logically reconcile the following environments with the idea of an "arctic edge," I'd love to. So the question is, how to do so, if possible?

http://i.imgur.com/UyzxA7K.png

Central: Temperate weather; plains and grasslands, very hilly but not mountainous
North: Ranges southern from tropical islands to northern harsh weather w/ stormy season potential throughout; idyllic beach islands to rough and mountainous largest island
East: Humid, strong seasonal shifts; heavy forest, jungle, wetlands and marshes facilitated by multiple waterways in a very hilly-to-mountainous
South: Dry, hot days and cold nights; desert and barren flats, occasional precious oases, many harsh plateaus
West: Below-moderate to cold temperature; flat flat flat, grasslands and tundra

Note: The Howling Mountains are the largest mountain range, but not the only one.

Thank you for any help!

[Tzi]

What is a threat that can send entire races running for the underdark, but still have an underdark and have most (if not all) of the race members left?

I can comment on what would drive people underground...

Generally it is either the threat OF or the actual act of something truly globally cataclysmic. The best example is the network of bunkers and survival shelters built during the Cold War period between the US and the USSR. In my own worldbuilding this is actually the theoretical idea behind the very existence of the Underdark.

The ancestral population of the Dark Elves or Drow had tunneled deep underground building vast structures, largely in secret or masking them as something else with magic. Then at some date a conflict was triggered that erupted into the equivalent of a global nuclear war. Across the planet great and terrible weapons were used to devastating effect. Other Elven nations used shielding spells and other magic to spare some of them, but only the Drow had built and developed a network of bunkers, some the size of cities, to ride out the ensuing apocalyptic winter and general devastation of the surface.

Though in my world, the actual Underdark is largely the artificial creation of Elves, not a natural place.

But you get the idea. The most likely things to drive people underground are things like a nuclear holocaust, an asteroid or comet impact, maybe even a star dying too close to the planet. Or some other creative disaster.

[Stellar_Magic]

Ello!

Two questions, as they relate to the setting I'm developing (linked in my sig). The gist of the fantasy world is that it's humans vs other-dimensional spirits, in a heavily medieval China-based time period. Humanity was close to the brink of extinction, after a now-lost golden age, until the tide was turned by extraordinary heroes, shen-lieren, who continue to defend from spirits. The breathing room has allowed humanity to reconstruct and continue establishing itself, though there's still much to learn/re-learn/explore.

- How small/big should this world be to facilitate a global monarchical government? The idea is that the monarchy has a standing army of mundanes to generally handle of mundane threats (going after barbarians and slavers, protection of trade routes, etc.), which combines with each continent's own defenders, both mundane and shen-lieren, to keep structure and order. There's also a nascent shen-lieren police force that operates more on a local level and tackles local crime (or tries to, anyway).

- NothingButCake, in the discussion thread, had the (what I think, anyway) brilliant idea to make the edges of the map (spoiled below, also in info thread) be the arctic regions, with things generally getting warmer the closer to the center you go. I think I can safely handwave the logistics of how the meteorology works, but if I can get a theory on how to logically reconcile the following environments with the idea of an "arctic edge," I'd love to. So the question is, how to do so, if possible?

http://i.imgur.com/UyzxA7K.png

Central: Temperate weather; plains and grasslands, very hilly but not mountainous
North: Ranges southern from tropical islands to northern harsh weather w/ stormy season potential throughout; idyllic beach islands to rough and mountainous largest island
East: Humid, strong seasonal shifts; heavy forest, jungle, wetlands and marshes facilitated by multiple waterways in a very hilly-to-mountainous
South: Dry, hot days and cold nights; desert and barren flats, occasional precious oases, many harsh plateaus
West: Below-moderate to cold temperature; flat flat flat, grasslands and tundra

Note: The Howling Mountains are the largest mountain range, but not the only one.

Thank you for any help!

1.) How big a land area can a single monarchy handle... Well, that depends on tech level, but for this... I'd say you're looking at a 'world' that's not bigger then China or the Roman Empire, as that seems to be the upper limit for a fantasy world's tech level.

I'd say 1,500 to 2,000 miles in each direction would fit. This would reduce your 'world' to a small continental area... which leads me to my next answer.

2.) How about this... draw a line from the 'south-west' corner to the 'north-west' corner. This is around where a latitude line would be with the distribution of environments you described. South-east of the line the environment is more tropical... effectively being the equivalent of moving south in the northern hemisphere on earth. North-west of the line the environment moves toward being more temperate with the western lands probably being so cold due to a polar current.

One simply way to explain why the map doesn't line up with the latitude is that the locals use magnetic north for their maps, and where they are the magnetic pole is around 45 degrees off from the actual pole.

[...]

I can comment on what would drive people underground...

Generally it is either the threat OF or the actual act of something truly globally cataclysmic. The best example is the network of bunkers and survival shelters built during the Cold War period between the US and the USSR. In my own worldbuilding this is actually the theoretical idea behind the very existence of the Underdark.

The ancestral population of the Dark Elves or Drow had tunneled deep underground building vast structures, largely in secret or masking them as something else with magic. Then at some date a conflict was triggered that erupted into the equivalent of a global nuclear war. Across the planet great and terrible weapons were used to devastating effect. Other Elven nations used shielding spells and other magic to spare some of them, but only the Drow had built and developed a network of bunkers, some the size of cities, to ride out the ensuing apocalyptic winter and general devastation of the surface.

Though in my world, the actual Underdark is largely the artificial creation of Elves, not a natural place.

But you get the idea. The most likely things to drive people underground are things like a nuclear holocaust, an asteroid or comet impact, maybe even a star dying too close to the planet. Or some other creative disaster.

Yeah, I'm just going to go with my first idea. :P It seems to fit the mold quite well.

[NyuBomber]

1.) How big a land area can a single monarchy handle... Well, that depends on tech level, but for this... I'd say you're looking at a 'world' that's not bigger then China or the Roman Empire, as that seems to be the upper limit for a fantasy world's tech level.

I'd say 1,500 to 2,000 miles in each direction would fit. This would reduce your 'world' to a small continental area... which leads me to my next answer.

2.) How about this... draw a line from the 'south-west' corner to the 'north-west' corner. This is around where a latitude line would be with the distribution of environments you described. South-east of the line the environment is more tropical... effectively being the equivalent of moving south in the northern hemisphere on earth. North-west of the line the environment moves toward being more temperate with the western lands probably being so cold due to a polar current.

One simply way to explain why the map doesn't line up with the latitude is that the locals use magnetic north for their maps, and where they are the magnetic pole is around 45 degrees off from the actual pole.

I love you.

That all sounds great, thank you!

[NyuBomber]

Ello again,

Was further pondering what you were trying to tell me, SM, and now I have a clarification request.



2.) How about this... draw a line from the 'south-west' corner to the 'north-west' corner. This is around where a latitude line would be with the distribution of environments you described. South-east of the line the environment is more tropical... effectively being the equivalent of moving south in the northern hemisphere on earth. North-west of the line the environment moves toward being more temperate with the western lands probably being so cold due to a polar current.

One simply way to explain why the map doesn't line up with the latitude is that the locals use magnetic north for their maps, and where they are the magnetic pole is around 45 degrees off from the actual pole.

Did you mean a "vertical" latitude line like so:
http://i.imgur.com/1C7uJbp.png

I'm having trouble reconciling your explanation with the given latitude line direction. Did you, in fact, mean "south-west to north-EAST" corner, like so:
http://i.imgur.com/fSBY27z.png

Also, would your explanation keep the "entire arctic edge," or did you picture it making the planet have north and south polar (EDIT: Well, northwest and southeast) arctic regions?

[Stellar_Magic]

I meant south-west to north-east.

At 1,500-2,000 miles for the land area... This area would be a bit small to be the whole planet. I figure that with a north-west arctic zone, and the south-east area being roughly tropical and close to the planet's equatorial region you can just say most of the rest of the planet is water.

So no, I'm not going with the edge of the whole map being arctic. I'm going with that diagonal line being around 30 degrees north of the equator. The south-east corner would roughly be around the -30 degrees south of the equator. This seems to roughly fit the climate distribution you have in the regions.

The north-west corner would be very close to the North pole.

[NyuBomber]

I meant south-west to north-east.

At 1,500-2,000 miles for the land area... This area would be a bit small to be the whole planet. I figure that with a north-west arctic zone, and the south-east area being roughly tropical and close to the planet's equatorial region you can just say most of the rest of the planet is water.

So no, I'm not going with the edge of the whole map being arctic. I'm going with that diagonal line being around 30 degrees north of the equator. The south-east corner would roughly be around the -30 degrees south of the equator. This seems to roughly fit the climate distribution you have in the regions.

The north-west corner would be very close to the North pole.

Got it, thank you!

[Stellar_Magic]

We need more questions...

Okay, this is one more for debate but... What do you see as the ultimate long-term effects of human created global warming? I'm not talking about 100 years into the future but 500 or a 1000.

[Aergoth]

Not sure how this works out on the thread. I've considered handwaving it as "it is so" but since the thread is here.
Elves in my homebrew setting are passengers on a sort of biological magitech-space-ark (yes it sounds silly) that broke up over the northern hemisphere of the campaign setting as it entered the atmosphere. How far would the fragments of this craft conceivably be scattered, assuming a roughly earth-sized world and that the bulk of the ship landed on a latitde analagous to midwestern north america?

[NyuBomber]

Not sure how this works out on the thread. I've considered handwaving it as "it is so" but since the thread is here.
Elves in my homebrew setting are passengers on a sort of biological magitech-space-ark (yes it sounds silly) that broke up over the northern hemisphere of the campaign setting as it entered the atmosphere. How far would the fragments of this craft conceivably be scattered, assuming a roughly earth-sized world and that the bulk of the ship landed on a latitde analagous to midwestern north america?

Assuming the pieces and people therein survive the descent and assuming the implication that the break up happened pretty high=up, I'd say it'd be reasonable for the parts to have a relatively wide area.

Let's say it broke up over the Kansas/Nebraska border. Depending on trajectory, I'd have it so pieces could land in the vicinity of the Utah/Colorado border, middle of Texas, Illinois/Indiana region, and/or North & South Dakota border.

Just me though.

[Roxxy]

Could any of you guys help me figure out a reason why a modern technology, wealthy, industrialized nation, geography roughly similar to Canada, might have a large city within the arctic circle?

[jqavins]

Could any of you guys help me figure out a reason why a modern technology, wealthy, industrialized nation, geography roughly similar to Canada, might have a large city within the arctic circle?
Mining town. Hot planet.

[Stellar_Magic]

Murmansk

http://en.wikipedia.org/wiki/Murmansk

That's a military port and city of around 300,000 that's about as far north as you can possibly get (68 degrees north).

Other possible reasons... A relatively ice free port (due to current patterns) with oil fields in the nearby land area for export the oil, fishing industry... I'm sure there's more possible reasons.

[avr]

Refugees from some apocalyptic war or disaster perhaps. I think World War Z had zombies being unable to continue moving in subzero temperatures.

There's the Canberra/Washington DC answer too; the other places the country capital might be placed were deadlocked in competition against each other and this was a compromise site which couldn't rise to challenge the existing cities/states.

Alternately perhaps it's the Mecca for some religion.

[Corneel]

Could any of you guys help me figure out a reason why a modern technology, wealthy, industrialized nation, geography roughly similar to Canada, might have a large city within the arctic circle?
Apart from what has already been said before, and actually in combination with some of it - especially as mining town: site for internal banishment/exile Gulag-style (example: Vorkuta (http://en.wikipedia.org/wiki/Vorkuta)).

[CavemanDan]

I've got an idea for a setting where the sun goes around the planet (as many cultures used to think) rather than the other way around.

To make it a slightly more interesting (or needlessly complicated), I've decided that the sun doesn't merely orbit the planet in a circle but actually goes through the world - erupting out of an impossibly high mountain every dawn (called the World Spire), 'orbiting' one side of the planet every day and being dragged into a fanged maw every sunset (called the Pit).

The next day it would rise through the World Spire and descend down the planet further across its longitude (about the same as a time zone).

To help visualise all of this, I present the WORLD'S WORST MICROSOFT PAINT ARTTM:

http://i952.photobucket.com/albums/ae4/torsoboy016/TheWoundedEarthorbit.jpg

I'm sorry for subjecting your eyes to that but I'm much more comfortable with traditional media (and not just rubbish at drawing, honest :smallbiggrin:).

Anyway, my question(s) are how would this affect how the world works?

I'm going to presume this sun is not as hot as a real one (and may even be a flaming ball of rock to make it interesting) and so wouldn't just melt and/or explode the planet (because insert magical handwave here).

The rough changes I can think of are:

There will be a light side and a dark side every day.
The dark side will see the sun for a brief period at dawn if you are in the northern hemisphere (the World Spire side) or for a brief period at dusk if you are in the southern hemisphere (the Pit side).
There won't be seasons in the traditional sense because the sun's path is constant.
Different climates will be dependent on what latitude you are at in the world with cold climes on the side of/the base of the World Spire, temperate climates as you travel south to the equator and deserts/volcanic hell on earth as you head towards the Pit.
Societies would have to get used to living in prolonged periods of light that get progressively dimmer until they experience long periods of darkness when the sun's orbit is one the other side of the planet.
Any moon(s) would spend most of their time not being illuminated and so would often be new moons (unless they emitted their own light rather than reflected it - which I'm tempted to do).


That's all the big stuff I can think of. I'd be grateful for any comments or suggestions about the obvious things I've missed.

[Everyl]

I've got an idea for a setting where the sun goes around the planet (as many cultures used to think) rather than the other way around.

To make it a slightly more interesting (or needlessly complicated), I've decided that the sun doesn't merely orbit the planet in a circle but actually goes through the world - erupting out of an impossibly high mountain every dawn (called the World Spire), 'orbiting' one side of the planet every day and being dragged into a fanged maw every sunset (called the Pit).

The next day it would rise through the World Spire and descend down the planet further across its longitude (about the same as a time zone).

To help visualise all of this, I present the WORLD'S WORST MICROSOFT PAINT ARTTM:

http://i952.photobucket.com/albums/ae4/torsoboy016/TheWoundedEarthorbit.jpg

I'm sorry for subjecting your eyes to that but I'm much more comfortable with traditional media (and not just rubbish at drawing, honest :smallbiggrin:).

Anyway, my question(s) are how would this affect how the world works?

I'm going to presume this sun is not as hot as a real one (and may even be a flaming ball of rock to make it interesting) and so wouldn't just melt and/or explode the planet (because insert magical handwave here).

The rough changes I can think of are:

There will be a light side and a dark side every day.
The dark side will see the sun for a brief period at dawn if you are in the northern hemisphere (the World Spire side) or for a brief period at dusk if you are in the southern hemisphere (the Pit side).
There won't be seasons in the traditional sense because the sun's path is constant.
Different climates will be dependent on what latitude you are at in the world with cold climes on the side of/the base of the World Spire, temperate climates as you travel south to the equator and deserts/volcanic hell on earth as you head towards the Pit.
Societies would have to get used to living in prolonged periods of light that get progressively dimmer until they experience long periods of darkness when the sun's orbit is one the other side of the planet.
Any moon(s) would spend most of their time not being illuminated and so would often be new moons (unless they emitted their own light rather than reflected it - which I'm tempted to do).


That's all the big stuff I can think of. I'd be grateful for any comments or suggestions about the obvious things I've missed.

I'd think that the lands around the World Spire would be warmer than you're guessing. The sun might not get as close as it does around the equator, but assuming a roughly constant "orbital" speed, it shines on the Spire a lot longer than anywhere else. The southern hemisphere/Pit, meanwhile, spends most of its time in darkness, punctuated by brief, intense blasts of heat and light.

I suppose if you account for atmospheric thinning around the Spire, much of it would be cold simply for altitude reasons. That gets into interesting questions that I'm not equipped to answer, though - namely, just where would the center of gravity in an irregularly-shaped planet like that be? Your illustration, perhaps because it is rough, implies that gravity in this world would feel like it's pulling toward somewhere on the Spire side.

There are probably better art programs you could get as freeware, though as a non-artist, I can't tell you which ones. I used GIMP to make my avatar for this site, but that's more of a Photoshop substitute, not a drawing one.

[jqavins]

To help visualise all of this, I present the WORLD'S WORST MICROSOFT PAINT ARTTM:

http://i952.photobucket.com/albums/ae4/torsoboy016/TheWoundedEarthorbit.jpg

I'm sorry for subjecting your eyes to that but I'm much more comfortable with traditional media (and not just rubbish at drawing, honest :smallbiggrin:.)


There are probably better art programs you could get as freeware, though as a non-artist, I can't tell you which ones. I used GIMP to make my avatar for this site, but that's more of a Photoshop substitute, not a drawing one.

How about using the "traditional media" you're comfortable with (I assume that means paper) then scanning the picture so created?

Anyway, I can't see any picture on my work computer, so I'll have to look at it later. Based on the description alone, I'd say one implication is that there are active gods. I'm pretty sure that there is no way of getting even close to the orbital behaivior you describe using real gravity and a little magic handwaving; you're going to need a truckload of magic handwaving, and that means gods. Highly active, even activist, gods. And that means all sorts of other things are possible; you could have a downright Seussian world here, if you want it, with no more handwaving than is already required.

[CavemanDan]

How about using the "traditional media" you're comfortable with (I assume that means paper) then scanning the picture so created?

Anyway, I can't see any picture on my work computer, so I'll have to look at it later. Based on the description alone, I'd say one implication is that there are active gods. I'm pretty sure that there is no way of getting even close to the orbital behaivior you describe using real gravity and a little magic handwaving; you're going to need a truckload of magic handwaving, and that means gods. Highly active, even activist, gods. And that means all sorts of other things are possible; you could have a downright Seussian world here, if you want it, with no more handwaving than is already required.

I haven't got access to a scanner and just wanted a rough thing to help explain my ramblings.

On the gods note, I was going to make the sun a god that had sacrificed themselves to provide light and heat to the world (much like Aztec mythology).

[Carl]

You probably get away without extending the planet like that if you wanted, i could mock it up in wings 3d to check, (well i think i can, shouldn't really be hard), if you like.

An underdark probably isn't geologically impossible, but it would be very difficult to have form and would be restricted to one geological area, and would be very much dependent on local geological conditions remaining stable, but there is a sort of basis for that so yeah, plausible, just really, really, bloody unlikely. Like "secret colony of undiscovered dinosaurs in the modern world" unlikely at a minimum, maybe much more so. I can go into details for the curious if you like but so far everyone discussing it seems to have gone for the "magic handwave lol" route since it is kinda easier.

[D2R]

Hi everyone ! I hope this is a proper place to ask several world-building related questions I've got...

The first question concerns Geography and Climatology for the most part.

Real World phenomena:

http://upload.wikimedia.org/wikipedia/commons/1/18/Map_prevailing_winds_on_earth.png

As you may know, on planet Earth there are the so-called "prevailing winds", which constantly blow from one general direction. That includes the equatorial Trade Winds, which blow from the west toward the east in the middle latitudes, and the Westerlies, which blow in the opposite direction in higher latitudes. The prevailing winds largely form the climate of the world, e.g. the Trade Winds literally suck all the moisture out of the Sahara region, forming the immense desert - and simultaneously create the rain-forests in equatorial Africa by transferring water from the Indian ocean.

On most of the Earth, the prevailing winds are strongly affected by the continental landmasses they cross, which significantly limit the wind-speed and change the direction of the wind.

There is one exception, however: in the Southern Hemisphere, there's almost no continental landmass in the high latitudes. This vast oceanic expanse creates a natural phenomena know as the Roaring Forties (http://en.wikipedia.org/wiki/Roaring_Forties) - a region between 40 and 50 degrees latitude in the Southern Hemisphere which is characterized by constant anomalously strong Westerly winds and very frequent storms, of anomalous power as well.

In the Age of Sail, this phenomena was widely used for travel, most famously - the Clipper Route between England and Australia / East Indies. Strong constant winds sped up the ships significantly, making such course extremely attractive for the captains, while also dangerous, especially for low-tech sailing vessels of the past.

The so-called Furious Fifties and the Shrieking or Screaming Sixties lie further towards South and have similar, but stronger conditions.

The Idea:

Now, let's imagine a generally Earth-like world with all the continental landmass concentrated around the Poles - no large continents along the Equator.

If I'm right about that, in this case we're going to have anomalously strong Trade Winds blowing along the Equator and forming a region of very frequent tropical storms between maybe 5 and 30 degrees latitude in both hemispheres - the Roaring Thirties, the Furious Twenties and the Shrieking Teens (well that sounds ambiguous...), if you wish.

Now, finally, the question(s):

If the above-mentioned assumption correct, how would such phenomena affect the development of the local civilizations ?

First of all - can the strength of the wind and the frequency of storms be such that the hemispheres would be almost completely separated from one another - until sufficiently developed technology comes to use (steamers that do not rely on wind for propulsion ? maybe even submarines which are unaffected by the surface storms ?) I mean, is it possible without making the planet almost uninhabitable by human beings ? As far as I understand it, the strength of the Trade Winds is mostly affected by the amount of heat the planet receives from its Sun; so, to make the winds stronger, we'll have to tinker with solar radiation in tropical areas. However, I don't want my world to be too hot (not to mention to make its inhabitants a little crusty !) - I want mostly temperate-to-subtropical climates and at least small ice caps on the Poles...

Or, maybe, the problem is mostly psychological, and even in Earth-like conditions the growing-ever-stronger winds and lack of any land along the equator would be enough to prevent the attempts to go "beyond the edge of the world" until the civilization gets enough self-confidence and reaches a certain level of tech ?

I imagine that in such a world the theory of "flat Earth" (or maybe "hemispherical Earth" ?) would last for much longer than in our own world, and the only way to disprove it would be through astronomical observations (other planets are spherical and move around the Sun just like our own planet, so our planet is also most likely spherical, too).

Another thing I can predict is the use of our "Roaring Thirties" (the least extreme of the three regions) as a sort of Fast Travel System - even more useful than the Earth's Roaring 40's, as they would be much closer to the inhabited areas. In such a world, seafaring would be a very fast and convenient (while not completely safe) way to travel, connecting all coastal regions in a hemisphere as soon as sufficiently seaworthy sailing ships are developed. I guess steam-powered vessels (or even modern-day Diesel-powered ships) would be of much less use in such a world, as "clippers" or resembling advanced sailing ships would be more efficient for long-distance travel and cargo shipping (my world has roughly late-XIX... mid-XX century stage of development). Also, due to the lack of land along the equator, there would be much less opportunities to refuel en-route, and even highly developed steamships hat to refuel very often [in my world, there may be an "artificial island" floating base(-s ?) on the equator, specifically built to refuel ships en-route from one hemisphere to another; that's a spoiler, however]. Maybe steamers would be restricted almost entirely to coastal navigation and war.

One more concern - how would the lack of continental landmass in the low latitudes affect the climate and other characteristics of the planet ? E.g., the ocean currents; would we have a local Gulf Stream that makes the North-Western corner of Eurasia a much more comfortable place to live ? It seems that we are going to have some east-to-west "Circumequatorial" current, but I just can't see the rest of the pattern.

All in all, that gives some very intriguing world-building opportunities... by the way, I assume I'm not the first to discover that ? Was such a concept used anywhere in fiction ?

[Carl]

I'm probably missing several important factors here but a key part of the sea vs land phenomena is that the ocean is far better at absorbing the suns energy that the land. So once air hits the land the maximum energy level the terrain below can support drops drastically.

In addition rates of temperature change have an effect, that's a big part of why things actually get more severe as you go south not less AFAIK. the south is actually a lot cooler and less energetic than the 40's. But the suddenness of the change creates some weird current effects, (and is even further from land), that lead to that.

The situation your describing would probably lead to a continuous chain of equatorial super hurricanes. They'd be able to build with far fewer limits, in fact you'd probably get seasonal movement of storms and if you got an really big ones you might get stable systems similar to Jupiters great red spot whose outer edges would stretch overland battering coastlines on a regular yearly, or possibly multi-yearly cycle. Certainly the coastlines can expect to receive regular and harsh batterings, so i'd expect local coastal communities to have to develop vessels and sailing techniques to survive it. So whilst i think it's would slow things down a lot, (mostly navigation issues, a stable compass that was unaffected by rolling of the ship would be a requirement), i don't think it would be quite as bad as the severity would suggest.


Also regarding the spider civilization earlier:


1. A species of hyper social spiders. (http://en.wikipedia.org/wiki/Anelosimus_eximius)

2. A species of vegetarian spider's, (well technically omnivores, but it's 90% veg). (http://en.wikipedia.org/wiki/Bagheera_kiplingi)

Ridiculously Cute Picture.

http://i.stack.imgur.com/3vNXb.jpg

[D2R]

I'm probably missing several important factors here but a key part of the sea vs land phenomena is that the ocean is far better at absorbing the suns energy that the land. So once air hits the land the maximum energy level the terrain below can support drops drastically.

In addition rates of temperature change have an effect, that's a big part of why things actually get more severe as you go south not less AFAIK. the south is actually a lot cooler and less energetic than the 40's. But the suddenness of the change creates some weird current effects, (and is even further from land), that lead to that.

The situation your describing would probably lead to a continuous chain of equatorial super hurricanes. They'd be able to build with far fewer limits, in fact you'd probably get seasonal movement of storms and if you got an really big ones you might get stable systems similar to Jupiters great red spot whose outer edges would stretch overland battering coastlines on a regular yearly, or possibly multi-yearly cycle. Certainly the coastlines can expect to receive regular and harsh batterings, so i'd expect local coastal communities to have to develop vessels and sailing techniques to survive it. So whilst i think it's would slow things down a lot, (mostly navigation issues, a stable compass that was unaffected by rolling of the ship would be a requirement), i don't think it would be quite as bad as the severity would suggest.

Thanks for the reply !
I'm not sure yet whether this is what I want or not...

from one point - that seems a bit too much as in my world there are supposed to be relatively calm sub-equatorial and tropical waters for marine nomad cultures to prosper...
[however, IRL Moken "sea gypsies" habit the Andaman sea area which is notorious for the most destructive hurricanes in the world, so that seems not to be critical]

from another - I wanted to have some catastrophic floods in particular regions, too, and you great red spot-like megahurricane idea seems to be a good way to organize that...
such megahurricane, even if not permanent but lasting for several decades, can have a major impact on the civilization, an just in the way I want for the setting

...but anyway you gave me some very interesting directions for further research on the subject

[Carl]

Your welcome, and yeah, to get calm waters you need a stable year round temperature with enough land to break up the monster storms. You can't really have stable tropical conditions and no landmass's there. That said a nomadic civilization out on the open ocean would have real issues finding ways of keeping it's "ship houses" maintained, they'd need some form of sheltered anchorage to put into for repairs and whilst you can create artificial one's given enough effort, they aren't something a nomadic society would be able to do. You'd be fine if their where periods of calm, just not if it's constant battering sea's, which it largely would be with no major landmass's.

[D2R]

...by the way - looking at the hurricane basins map -

https://upload.wikimedia.org/wikipedia/commons/d/d6/7_zones_dels_ciclons_tropicals.jpg

- I noticed that there is no hurricane basin in the Southern Atlantic, to the east from South America.

Wikipedia tells that


South Atlantic tropical cyclones are unusual weather events ... strong wind shear (which disrupts cyclone formation) and a lack of weather disturbances favorable for tropical cyclone development make any hurricane-strength cyclones extremely rare

And strong wind shear in this area seems to be a direct result of lack of land in the Southern Hemisphere.

So, it seems, strong winds do not let cyclones to be formed ? And there would be no or very few tropical hurricanes in a world without much land along the equator, because they would be literally blown off by strong trade winds before being completely formed ?

[Carl]

Bear in mind that earths wind flows are heavily influenced by the lands and weather patterns to the north and south as well as east and west. It's certainly possible certain patterns of land and sea could preclude hurricanes on your world, but i wouldn't bet on it. Winds flowing in opposite directions play a very strong role in hurricane formation and a landless equator would be perfect for that as wind north of the equator flow the opposite way from lands south thereof. But those patterns are affected by a lot of factors.

I'd have to look into it as it's a while since i recall hearing it, but i believe the south american mountain chains disrupt the flow over them effectively placing the entire ocean on their sidea behind a windbreak, (land normally slows the winds down, but doesn't usually stop it short of mountain's), and this creates a lack of winds in one direction which affects things. Also a bit of quick research brings up the humboldt current as causing a sharp drop in sea temperatures of western south America, which would also affect things since that effectively kills the heating effect which drives storms on that side and there's a similar current off the African coast as i recall. It's certainly responsible for the deserts on the western side of the Andes.

Need to do more research, but basically don't write it off as a normal part of the situation, if it was you'd never get hurricanes at all because the trade wind's are everywhere they're not blocked by mountains. Certainly the trade winds probably are the cause here, but there's a reason they have that effect here and not elsewhere and it's important to understand why. I just can't remember the specifics off the top of my head with any degree of confidence, I've heard various stuff at various times on the odd climate there but i'm having trouble finding anything detailed on it.

[D2R]

That said a nomadic civilization out on the open ocean would have real issues finding ways of keeping it's "ship houses" maintained, they'd need some form of sheltered anchorage to put into for repairs and whilst you can create artificial one's given enough effort, they aren't something a nomadic society would be able to do. You'd be fine if their where periods of calm, just not if it's constant battering sea's, which it largely would be with no major landmass's.

Well I imagined it more as a shallow-water region with a lot of small islands covered with evergreen forests (too small to support agricultural communities) and coral reefs - much like the Aegean sea or the Mergui Archipelago where the Moken "sea gypsies" actually live, but much larger in area. In vicinity from the continental landmass, most likely - along its coastline, so that the nomads could play the same role as the Central Asian steppe nomads in the history of Eurasia - transmitters of technologies and ideas from East to West and vice versa, powerful foes or allies of sedentary civilizations playing a major geopolitical role, inventors of many military technologies and tactics. In no case I'm going to place the boat-dwelling nomads into open sea without any possibilities to maintain or renovate their fleets.

Colonies (mostly resource-developing or food-producing) in open sea in this world are supposed to be a product of industrial development of sedentary civilizations, who once derived advanced sailing and navigating technologies from the nomads just as the Europeans inherited armored cavalry from the nomads of the steppes. And that happends in the Age of Steam, of course, with sufficiently advanced technologies such as steel/concrete shipbuilding and advanced navigational equipment including mechanical computers and "wireless telegraph".

All in all, I would be pretty happy with Earth-like hurricanes, or even somewhat more severe - I just need the above-mentioned relatively safe water area where the nomadic civilization could develop, it pretty much can be shielded from the most severe storms by a landmass. And the landmass may and actually *should* be subject to periodic hurricanes and flooding. So far I've sticked to the Netherlands model, with a very low territory and rising sea, but tropical hurricanes can work even better, especially combined with the former factor.

[Carl]

Shallow water area's would have a huge effect on currents and you'd almost certainly see up-welling around them that would produce disruptive currents that would disrupt storm formation. They're a big affector as my last post pointed out. So potentially they'd have a huge affect on storm formation creating clear area's where they're cold water flow disrupts traditional solar heating effects. It's uniform heating that could create true monster storm conditions. This is what Jupiter experiences (albeit from internal rather than external heat sources), and results in it's incredibly active hurricane system. Though even it gets some up-welling producing relative dry spots for them.

I was thinking entirely in terms of deep ocean when your first asked. Sharp changes in ocean depths and the affect that has on currents would greatly change things. You'd still see much more intense storms when they occurred, but they wouldn't be nigh constant.

[D2R]

Yeah, I see there is some misunderstanding, and I'm mostly the one to blame. Now I'm stating it clearly that we're dealing with one HUGE (~85 million sq. kms, that's roughly Eurasia, North America and Australia combined) continent (THE Continent here, as there is few landmass other than this in the world), with it's core landmass around a pole (Northern or Southern - that does not matter) and it's "appendages" reaching as far as 20...15 degrees latitude. It is divided into the "core" landmass, the "appendages" and the Subcontinent, which is partly wrapped by one of the appendages, and there are many small islands in the strait between them which is roughly 1000 kms wide. The continental landmass is not one peace, there are many epicontinental (inland) seas, much like the Mesozoic or early Carboniferous Earth continents.

Something like that

http://media-1.web.britannica.com/eb-media/47/136147-004-A931BD62.jpg

- but without / with smaller Lavrussia and multiple islands between it and the main continent

Now I'm struggling to shape this Continent to give its parts the properties I need. And what I want is mostly uninhabitable core landmass in 60+ latitude, and comfortable, but relatively overpopulated temperate to tropical areas, some of which is subject to periodic flooding at the shoreline.

[Citrakayah]

Anthropology question!

What are/were the different regions in North America called by Native Americans? For instance, did the Hopi have a specific name for the southwestern region?

[Ninjadeadbeard]

My question is two-fold: Is the following map accurate as far as climate goes? (I am friends with sticklers :smallsmile:)

And, Would the map be improved/better/more interesting if the lower two continents were merged?

http://i153.photobucket.com/albums/s231/sithlord7/physCassiri_zps4f89102c.png

[Yora]

The deserts don't seem to make much sense. Generally you get deserts to the east or the west of mountains, depending on what direction the winds blow. If you'd move one of the mountain ranges on the northern continent to the west coast, you'd have a configuration like the Rocky Mountains, justifying the desert. The eastern part of the desert seems to be in a similar location like Texas, and even though I don't know why Texas is dry, it's obviously a situation that does happen in real life, so it works.

On the south-central continent, it would probably be more plausible if the desert runs north-south along the mountains, instead of east-west.

On the small eastern continent, I'd switch the desert and the jungle around, unless on your planet the wind patterns move in the opposite direction as they do on earth. Or just remove the desert entirely. If you want to keep the desert, add another mountain range along the coast and make the desert an elevated plateau, that would also work.

I'd personally move the two southern continents around a bit, because now the seas that separate the three continents seem to be of almost the same uniform width, which does stand out as looking a bit artificial. Moving the western one a bit more to the west and the eastern one a bit to the south for example, should take care of that.

[Ninjadeadbeard]

The deserts don't seem to make much sense. Generally you get deserts to the east or the west of mountains, depending on what direction the winds blow. If you'd move one of the mountain ranges on the northern continent to the west coast, you'd have a configuration like the Rocky Mountains, justifying the desert. The eastern part of the desert seems to be in a similar location like Texas, and even though I don't know why Texas is dry, it's obviously a situation that does happen in real life, so it works.

I was predominantly following the Horse Latitude (30+ degrees) for desert creation, and then modifying them by assuming hot and wet westward winds at the equator and cool dry eastward winds at the poles. I believe Texas is arid due to being on the Horse Latitude despite also being on the coast. Climates are weird.

I will move some of the mountains westward, to form a more "Rocky Mountain" thing, but with the mountains still near the east coast, would there be a desert in the center of the continent?


On the south-central continent, it would probably be more plausible if the desert runs north-south along the mountains, instead of east-west.

I was assuming an antarctic wind would hydrate the southern reaches...but perhaps that was mistaken? Would there still be that little strip of arid country in the North West of the continent, assuming the aridity goes from north to south and the northern peninsular mass would block the tropical winds?


On the small eastern continent, I'd switch the desert and the jungle around, unless on your planet the wind patterns move in the opposite direction as they do on earth. Or just remove the desert entirely. If you want to keep the desert, add another mountain range along the coast and make the desert an elevated plateau, that would also work.

I...was under the assumption that wind went from East to West at the equator (unless XKCD is a damn liar...)? The mountains, while not tremendous, contribute to the Horse Latitude effect, leading to a more tropical climate on the windward side of the mountains, and a more arid (not necessarily desert!) territory. Was I correct in that assumption, or are I dumb?


I'd personally move the two southern continents around a bit, because now the seas that separate the three continents seem to be of almost the same uniform width, which does stand out as looking a bit artificial. Moving the western one a bit more to the west and the eastern one a bit to the south for example, should take care of that.

I am quite troubled with what to do with the southern continents. I thought of merging them together, but something tells me that would mess up all the climate work I am doing. What would you think of moving the SE Continent more eastward? This would also necessitate shifting the other islands east as well, and it would start to look more Indonesia-y. Thoughts? I am using "I" waaay too much. I might be some sort of egomaniac!

[Yora]

I will move some of the mountains westward, to form a more "Rocky Mountain" thing, but with the mountains still near the east coast, would there be a desert in the center of the continent?
If you have mountains in the east and the west, the land between them would still be arrid. Once the moisture has been dropped at the west coast, it's gone and doesn't replenish itself without crossing a large body of water.


I was assuming an antarctic wind would hydrate the southern reaches...but perhaps that was mistaken?
Arctic winds would be quite cold, which means it wouldn't have much moisture, even if it travels over the ocean. Even if you can get lots of evaporation during the antarctic summer, the cold air just can't carry much water to the north.


I...was under the assumption that wind went from East to West at the equator (unless XKCD is a damn liar...)? The mountains, while not tremendous, contribute to the Horse Latitude effect, leading to a more tropical climate on the windward side of the mountains, and a more arid (not necessarily desert!) territory. Was I correct in that assumption, or are I dumb?
That is correct, but from the map it looks to me as if the big island in the east is north of the tropics, and there you have wind blowing the other way. It's a bit hard to judge the latitudes without earths continents overlaid for reference.


I am quite troubled with what to do with the southern continents. I thought of merging them together, but something tells me that would mess up all the climate work I am doing. What would you think of moving the SE Continent more eastward? This would also necessitate shifting the other islands east as well, and it would start to look more Indonesia-y. Thoughts?
I don't think it would change much, weather-wise.

I suggest you make a version of the map on which you overlay the wind patterns. Can be as simple as this (http://www.classroomatsea.net/general_science/images/wind_patterns.jpg). Once you have reference lines where the tropical winds change to temperate ones, and the temperates to arctic ones, it's probably going to be a lot easier to see where rain would fall.

[jqavins]

My question is two-fold: Is the following map accurate as far as climate goes? (I am friends with sticklers :smallsmile:)

And, Would the map be improved/better/more interesting if the lower two continents were merged?
Just an observation, really; I don't know if this has any relavence but perhap it will spur some useful thoughts in otheres. The mountain range down the middle of the northern continent likely implies two previously separate continents pushing into one another and raising these mointains, like the Himalayas. If this was geologically recent then these would be tall, jagged mountains, again like those same Himalayas. If this was longer ago, then they could be any size. More potentially interesting is what this may imply for the motions of the other continents, since all three mojor continents are so close together. But just what this may imply, I don't know. Maybe there's a converging current in the magma that means the two sothern continents are heading for a collision of their own? Or maybe there's an outflow of magma from the collision zone caused by the converging motion (like glue squeezing out of a joint as the clamps are applie) that would carry the southern continents away from each other? The northern one separating from the southern two as a pair would seem to make sense, but I could be al wet. I don't know what this means, it just seems like it probably means something. (It's as if the mountains have a big blue paw print on them yelling "A clue! A clue!")

[Ninjadeadbeard]

http://i153.photobucket.com/albums/s231/sithlord7/Cassiri4_zps2749bae7.png

@Yora. This is the map as it stands. I moved the SW continent a bit more S and W, and I touched up some climate spots I wasn't happy with. I also made the northern shore of the SW continent look more like it "fit" into the northern one. I moved the South-Central continent further East to break up the ocean distances, and I modified some of the climate zones.


I suggest you make a version of the map on which you overlay the wind patterns. Can be as simple as this (http://www.classroomatsea.net/general_science/images/wind_patterns.jpg). Once you have reference lines where the tropical winds change to temperate ones, and the temperates to arctic ones, it's probably going to be a lot easier to see where rain would fall.

I was originally working from such a wind map:
http://i153.photobucket.com/albums/s231/sithlord7/WIND_zps46b993d5.png

This one is fairly basic, but I believe relatively accurate(???). At least with this you have some frame of reference for my diseased mi- I mean my choice of placement for climates.


Just an observation, really; I don't know if this has any relavence but perhap it will spur some useful thoughts in otheres. The mountain range down the middle of the northern continent likely implies two previously separate continents pushing into one another and raising these mointains, like the Himalayas. If this was geologically recent then these would be tall, jagged mountains, again like those same Himalayas. If this was longer ago, then they could be any size. More potentially interesting is what this may imply for the motions of the other continents, since all three mojor continents are so close together. But just what this may imply, I don't know. Maybe there's a converging current in the magma that means the two sothern continents are heading for a collision of their own? Or maybe there's an outflow of magma from the collision zone caused by the converging motion (like glue squeezing out of a joint as the clamps are applie) that would carry the southern continents away from each other? The northern one separating from the southern two as a pair would seem to make sense, but I could be al wet. I don't know what this means, it just seems like it probably means something. (It's as if the mountains have a big blue paw print on them yelling "A clue! A clue!")

That is an interesting theorem. Unfortunately, I wasn't clever enough to consider it. :smallredface: I originally did intend for the central mountains on the Northern Continent to be volcanic, but this would be due to Magic as opposed to geography. When the Smith God needs a Volcanic forge, he ain't moving far from his comfy chair.

[jqavins]

I originally did intend for the central mountains on the Northern Continent to be volcanic, but this would be due to Magic as opposed to geography. When the Smith God needs a Volcanic forge, he ain't moving far from his comfy chair.
Well, yes, gods work too. (And I haven't proven anything, so it's not a theorem, but a theory at best; "conjecture" would be an even better term.)

[thethird]

Hi there everyone!

I have a couple of questions, first of all does anyone know of a source of how earth would look in a really long time? I'm thinking of writing a sci fi piece where the original homeworld has been lost in the memory of the space faring civilization and it is now colonized again. I'm personally partial to the Pangaea ultima theory thing, because Madagascar is in such a perfect place to be the capital of the Empire and wreck a space ship... but other ideas would be pretty great.

On the same vein what would have to a planet without a moon? I know that moon has influence in tides and stuff. What happens with more than a moon?

Finally one thing that I find pretty cool is the fact that the moon is always facing the earth with the same side, would it be possible to have two planetary objects (moon + planet or planetoids) facing each other all the time? What would be the effect on their clima and stuff?

---

On an unrelated note how do you guys think sea navigation and orientation would have evolved if stars were not a valid point of reference (i.e. there are several space ships moving above the planet making it hard to have fixed points)

[Everyl]

On an unrelated note how do you guys think sea navigation and orientation would have evolved if stars were not a valid point of reference (i.e. there are several space ships moving above the planet making it hard to have fixed points)

I'm sure other can help you better with the other questions, but for this one, I feel confident in answering - "several" space ships would not affect the development of navigation in the slightest. The world already has several "stars" that don't behave like the others, which we call "planets." The fact that a few dots in the sky don't behave like the others didn't stop our ancestors from figuring out how to use the sky for navigation, and I can't imagine that orbiting space ships would be any harder to ignore when navigating. It would take quite a few "rogue stars" cluttering the sky to the point where it's hard to keep track of the "fixed" ones to cause any problems. Given how many stars are visible on a clear night in a place with no light pollution, I'd guess it would take dozens, more likely hundreds or even thousands, of ships, all large enough to be visible from the surface with the naked eye, to really complicate navigation...

[avr]

As to what the world will look like in the future, can you put any boundaries on that very long time? Centuries, a million years, more?

On navigation even if the stars were somehow blotted out you could do a lot with the sun, moon and the wind direction. Stars let you know north more precisely and more rapidly but you can maintain an approximate heading without them, and on cloudy days you have to do without them anyway.

[jqavins]

On the same vein what would have to a planet without a moon? I know that moon has influence in tides and stuff. What happens with more than a moon?
The planet's sun would still cause twice daily high and low tides. On Earth, the Sun's contribution to the tides is about 44% as strong as the Moon's. This means that when those contributions add, which happens when the Sun, Moon, and Earth are in a line (i.e. at full moon and new moon) the tides are 144% of average (spring tide) and when the contributions subtract, which happens when the Sun and Moon are separated by 90 degrees as seen from Earth (i.e. at first and third quarters) the tides are only 56% of average (neap tide.) And you thought tides were simple. (Actually, the land masses and variations in ocean depth make the matter even more complicated still.)

So, if the Moon were not there, tides on Earth would be about 44% as strong as their average in reality. Tides would also be a great deal simpler. But the tides on the real Earth were not too complicated to keep real earthlings from figuring out the patterns in them centuries ago; I'd bet that the need to figure it out probably helped spur our understanding of the solar system.

If there were multiple moons, each would have its own contributions to the tides, with strength proportional to its mass divided by the cube of its distance from the planet, and each one's period would be different based on its orbital period around the planet. It's most likely (I think) that only one or two whould be massive enough to have a large effect, so I'm confident that human-like people would figure it out well enough for navigation with the same ease we did, and the fine details just might give them clues to figure out their solar system all the sooner.
http://oceanservice.noaa.gov/education/kits/tides/tides06_variations.html
Complex tides won't stifle early development of navigation. 10 or 20 artificial sattelites visible to the naked eye won't stifle early development of navigation. If you want them stifled, try an opaque atmosphere, i.e. eternal dense overcast. If they never see the moon or stars and only barely see that one patch of the day sky is brighter than the rest, that'll hold'm in sight of shore.

[thethird]

Thanks for your answers guys! You are great. Let me go back and set what I've decided till now :smallsmile:

The story is going to be set 250 million years in the future, this is such a long time that it might as well be a totally different timeline. I'm going to go with the pangaea ultima map.

http://img2.wikia.nocookie.net/__cb20131012001500/speculativeevolution/images/2/24/Pangea-ultima.jpg

http://1.bp.blogspot.com/-y0l9s973h30/UOje-dprFcI/AAAAAAAAAa8/M53wOpKVoQk/s1600/Pangaea+Proxima4.jpg

The story, at first will focus in what now is Madagascar which should be more or less centered on the central mass of water. Due to your reasons, which are good for me, I've decided that the starships above aren't a problem per se to navigation but there is still interest in them (astrology will be relatively advanced due to that). I've also done some research and the lack of moon would also destabilize the orbit, of the planet, at least it does so in Mars, so I'm going to leave that out (for now) the moon though is further away and smaller than it is currently.

History wise, please make any comment that would impede anything:
-As I'm picturing it Madagascar should have plenty of water around it and resources thus it's people would have thrived at some point.
-A ship faring empire would have formed.
-Since a megacontinent makes the clima more arid main cities/trade points would be formed in river basins (or close to). So the area around the indic ocean is "civilized" (air quote the term civilized, ala Roman Empire)
-A catastrophic event (someone breaking the first directive) happened. A whole space ship fell on Madagascar getting destroyed in the process.
-The nuclear reactors of the ship detonated forming a nuclear winter around the island that greatly impeded navigation for three years.
-This caused the colonies to fragment and start forming independent kingdoms. And for them to believe that the place was cursed (it was highly radioactive).
-Eventually Madagascar was safe again but was still presumed cursed. It served as the base of pirates and other rogue elements that raided the different kingdoms.
-Several merchants and wealthy individuals from the kingdoms either joined the pirates or decided to put a stop to them, but Madagascar ended being a brewing pot of individuals from the different cultures.
-The looted technology from the fallen space ship jump started an industrial revolution, at first with material science (using the fallen debris, because they are purer and better alloys) or energy science (some reactors should have survived the fall).
-This jump in technological level (nothing to large) would have put the people from Madagascar at odds with the other kingdoms.

Does this make sense? Any ideas?

[jqavins]

The story is going to be set 250 million years in the future, this is such a long time that it might as well be a totally different timeline. I'm going to go with the pangaea ultima map.

The story, at first will focus in what now is Madagascar which should be more or less centered on the central mass of water.
From what I've been able to find, Madagascar is expected to disappear on the way to Pangea Ultima. Am I missing something?


History wise, please make any comment that would impede anything:
...
-The looted technology from the fallen space ship jump started an industrial revolution, at first with material science (using the fallen debris, because they are purer and better alloys) or energy science (some reactors should have survived the fall).
-This jump in technological level (nothing to large) would have put the people from Madagascar at odds with the other kingdoms.
What's the tech level before the wreckage is looted? It takes some pretty good science and no small amount of technology to analyze and replicate an unknown alloy or to take advantage of a mysterious power source. If you gave a nuclear reactor or a bunch of, let's say, aluminum-titanium alloy to the fines minds of the age of sail they would have no idea what to do with it.

[thethird]

I've found maps with Madagascar on it and since it isn't definitive either way (because it's something that may happen far far in the futre) let's go with it being helpful to the plot and thus existing. (I like islands)

Technological level before the crash should be a mix between bizantine and chinese empire but by the time it is resetled we are in the late "age of discovery". Note though that when the roman empire fell it was by being taken by "extrangers" in this case the Empire falls because the capital is destroyed thus the knowledge of the province is more or less intact. The ensuing war among the terrritories forces them to apply all the theories they can think of.

While replicating/understanding the alloy or the source of power is going to be impossible I can see them trying to use it. Trying and failing to smelt the metal into a cannon and deciding to use the material as is (in swords, bullets or the foundation of a palace). It might be called magic (or close enough). I particularly want to explore what happens when that line is messed with, a cargo cult based on a wrecked and looted space ship.

Does that make more sense?

[jqavins]

While replicating/understanding the alloy or the source of power is going to be impossible I can see them trying to use it. Trying and failing to smelt the metal into a cannon and deciding to use the material as is (in swords, bullets or the foundation of a palace). It might be called magic (or close enough). I particularly want to explore what happens when that line is messed with, a cargo cult based on a wrecked and looted space ship.

Does that make more sense?
Honestly, not really. But I don't want to be the big bad party pooper; "doesn't make sense to this guy" doesn't mean it can't make for a good read. I'm really not out to be discouraging, so you might want to stop reading now.

Still reading? Sorry. The reactor would provide what, electricity? At the end of the Age of Discovery there were no electrical devices to power with it, and basicly no experiments going on with electricity to be accelerated by it. From Wikipedia, the Age of Discovery lasts, at most, through the end of the 17th century. Even the most elementary understanding of electricity did not dawn until a good half century later, with actual applications not coming until the early 19th century. Granted things could be different in your world; in the real world, a thing that amounts to a magic inexhaustable voltaic pile of great power would have been nothing more than a paper weight to the like of Isaac Newton.

Scraps of a mysterious metal would be just that, scraps. I used a titanium-aluminum alloy as an example, but you might have something else in mind. With my example, even in the early 20th century it would have been all but impossible to melt for recasting and downright impossible to weld, braise, or solder. Other candidates for a starship alloy would probably pose similar problems, or different ones just as major. And how much of it is there? Large enough scraps could be hammered, cut, and ground into useful shapes (like blades) but once the supply of such scraps is gone, you're done. How do you get an inustrial revolution out of that?

The history of science and technology is that each development in one depends on earlier work in both; science provides the basis for technology, but technology provides the tools that let science advance. If a foreign (or alien) culture introduces some advanced technological artifacts into a society that is not ready for them, those artifacts would only be usable as tools if they are not very much advanced, and will only spur progres if the society was pretty nearly ready for them to begin with.

[SirKazum]

Oops... I made a new thread (http://www.giantitp.com/forums/showthread.php?378944-Weather-patterns-in-a-tidally-locked-world) without knowing there was already this excellent thread where questions such as mine are answered by a lot of people who seem to know their stuff. So I'll re-post it here, spoilered for size.

tl;dr version: How do wind patterns (and, consequently, weather patterns) work in a tidally-locked world? I'm asking for my D&D as Sci-Fi (http://www.giantitp.com/forums/showthread.php?368609-The-Haliburn-Galaxy-D-amp-D-(3-5)-as-Sci-Fi-WIP) setting, namely the planet New Eugeron (the fourth one in this post (http://www.giantitp.com/forums/showsinglepost.php?p=17999864&postcount=2)).

Original post: In my D&D as Sci-Fi campaign setting (http://www.giantitp.com/forums/showthread.php?368609-The-Haliburn-Galaxy-D-amp-D-(3-5)-as-Sci-Fi-WIP) that I'm developing, there are a number of planets, and while most are easy enough to figure out how they work, there's one that stands out because I've decided it's tidally locked. (It's New Eugeron, the fourth planet in the planets list here (http://www.giantitp.com/forums/showsinglepost.php?p=17999864&postcount=2).) That means the planet has one side continuously facing the sun, and the opposite side always in darkness, because the duration of its day (one revolution around its axis) is exactly equal to its year (one lap around its sun). This synchronicity between day and year is "locked" due to tidal forces, which is why it's called "tidal locking".

Anyway, in such a planet, the side that's hit by the sun would be unbearably hot, and the dark side would be extremely cold. I figured there could be factors mitigating that difference - wind and sea currents, and maybe a small greenhouse effect - but there would still be an enormous temperature differential between the two sides. Most civilization would be huddled around the "twilight belt", the area near the imaginary circle that separates the two sides, and which would physically look from the surface like a typical planet during dusk or dawn, but there could be outposts in the hotter and colder areas. (It's home to creatures that are equivalent to D&D's devils, which have fire immunity and resistance to cold, and some of them also have cold immunity.)

Anyway, I figure that wind patterns would be quite important in this world, for propagating heat from the sunlit side to the dark side. So I set to researching how wind patterns work in our world, and how they might work differently in a tidally-locked world. So it seems that, in the broadest scope (before you figure in things like mountains and oceans), the two biggest things that influence wind patterns are temperature and the Coriolis effect. (This page (https://people.hofstra.edu/geotrans/eng/ch1en/conc1en/globalwindpatterns.html) has a pretty straightforward schematic explaining how it works.) In our world, the equator is the hottest zone and the poles are the coldest, which dictates the basic wind pattern in the left-hand picture; then, wind-circulation cells are formed (the outer part of the right-hand picture), probably because the temperature and pressure differentials aren't enough to carry air all the way from the poles to the equator and back, so another cell with "reversed" direction (the Ferrell cell) is formed in the middle, making the different cells spin like cogs in a gear mechanism; and finally, the Coriolis effects twists the wind toward the east and west, creating the currents seen in the interior of the right-hand picture.

In a tidally-locked world, things would work quite differently. For one, the temperature differential is between the "midday point" (the point where the sun strikes the planet directly, at a 90-degree angle), which is the hottest, and the "midnight point" (the opposite point in the planet), which would be the coldest. Those two points would be fixed relative to the planet, and stand along the equator. (I'm assuming the axis of rotation is not tilted relative to the axis of translation.) While the sun appears to stay in the same point relative to the planet at all times, the planet is still rotating, so the Coriolis effect is still in place (though maybe weaker, since the planet's rotation would have to be much slower). But you cannot apply the same logic we have here to this planet, especially because the temperature gradient and the axis of rotation are in quite different positions relative to one another than in the Earth. Here, the temperature isometrics (the bands along which the temperature is the same) are parallel to the equator; in a tidally-locked planet, however, the isometrics are perpendicular to the equator, completely changing the way the Coriolis effect interacts with the temperature differentials. Also, while on Earth you have two coldest points (the poles) and one hottest band (the equator), in the tidally-locked planet you have one coldest point, one hottest point, and bands of varying temperature in-between. There's also the fact that, in our Earth, aside from the temperature differential between the poles and the equator, there's also a variation between day and night; in the tidally-locked world, there's no day-night cycle (nor yearly seasonal cycle either).

I've tried working out a few preliminary schematics of how this might work, but first, I'd like to know if anyone here has any experience or knowledge about this. Tidal locking is a staple of science fiction, so it's quite likely that much smarter minds than mine have already worked on this problem in the past. Anyone knows how the wind might blow in such a world, and how weather patterns might work? (aside from the obvious temperature differential, of course.)

[Carl]

The effect would be that the planet would probably be an orbiting cloud of plasma or an airless rock. Tidal locking is about the relative gravitational strengths of the two object's. Unless it was both close i wouldn't be tidally locked. Getting close enough without turning into a ball of plasma probably isn't doable unless your mass is so small that you'll have no appreciable magnetic field and thus wouod lose any atmosphere it started with,

The closest you could reasonably get would be to have it arranged like Uranus, laid on it's side. But even then as it orbited over the half year the pole facing the sun would change.

[SirKazum]

I was thinking the planet might be really close to its sun, which on the other hand would be rather small. So maybe having a much smaller orbital radius than Earth, though still with a comparable amount of sunlight, to make tidal locking easier. Or then again maybe it's just a rather old solar system - from what I've researched, tidal locking is actually inevitable for any two given orbiting bodies, given a sufficient amount of time (which in some cases may be so long that the star in question would die first or whatever, but in other cases is manageable enough). Anyway, from what I've been reading, the general sense I've been getting from expert opinions is that "tidal locking isn't nearly as bad as you think it is". But I'd still like to know how it would play out in practical, day-to-day terms...

[Carl]

Things like the habitability are decided by energy per unit area which is a simple factor of the distance from the sun, (changes with the square thereof), being smaller won;t let you get closer without turning you into a cinder burned to a crisp and it will remove your gravity giving you a thinner starting atmosphere and the weaker magnetic field and greater solar wind power will eventually obliterate your atmosphere.

Also if weird orbital interactions apply it's possible for tidal locking to be avoided in the long term, but even if it isn't, for something large enough to be habitable, and far enough away to not be cindered your talking far longer than the lifetime of a star.

As for what would hypotheticlly happen. Well Air flows from hot to cold so you'd have strong winds flowing away from the sunny side to the artic side. Depending on exact ocean arrangements you'd get similar current patterns in the sea as well. The area of most extreme weather would probably depend on exact ocean vs land layouts, but you can expect the hot pole to be rough weather regardless just from the amount of energy dumped into it.

[thethird]

snip

Don't worry about being the party pooper taking your time to write a response makes me think about different things.

As for energy output I was thinking heat, heat is an easy power outlet and probably a by product of a reactor. I'm not intending for them to use it "right" just to get use from it. Steam engines should be withing the technological level even if they are not efficient due to size. Having a small source of heat could be convenient. Yes the resulting technological leap would be dependent on the few available reactors, but since those are the most complicated to produce I think that pipe miniaturization is doable. It just gives them an edge, a jump start, even if the reactors they could create are ages from it. Their reliance on those alien pieces could work as a plot device, they will need to keep them safe, out of reach from the other nations. At the most basic they could work as cortexs from Warmachine/Iron Kingdoms. I'm also not totally against taking notes from The General (by David Drak and S.M. Stirling) in which a benevolent A.I. ends in a backward planet and helps to technologically rise the cultures there, step by step.

Similarly with the metal. "Magic swords" (or titanium alloy or valirian steel or mithril or whatever you want to call it) could give the nation a distinctive edge.

---

Let me paraphrase.

A star fell from the heavens on the capital as divine retribution for their sins. It darkened the world in three years of night. That was the age of ending. The Empire fell. It was destined to fall. It's corpse ravaged by opportunistic vultures, the capital just a grim reminder of men's hubris. But human arrogance knows no limits. As the story and it's moral dimmed in memory more and more adventurers reached for the star carcass. They tore it apart unlocking powerful magics that were beyond their control. Many died but more came after them. Eventually they were able to unlock the fire power from the star's core and subjugate it to their will.

It is now "magic"

[SirKazum]

I was thinking about the Goldilocks Zone (http://en.wikipedia.org/wiki/Circumstellar_habitable_zone). The less bright a star is (which is more or less a function of its size, though of course it also depends a lot on what type of star it is), the closer a planet should be to it in order to be habitable. And that makes a lot of difference - from the formula here (http://en.wikipedia.org/wiki/Tidal_locking) (check out Timescale), the time needed for an orbiting small body to become tidally locked to the larger body it's orbiting is directly proportional to the sixth power of their average distance. White dwarves have very little luminosity, compared to a main-sequence star of similar mass (which means any habitable planet orbiting one would have to be reeeally close), and they also appear rather late in a star's lifetime (giving plenty of time for tidal locking), so our planet could orbit one. Or maybe it's just a rather small main-sequence star - they tend to live longer than bigger ones anyway. There's also the factor of how fast the planet was spinning to begin with when it was formed - maybe it wasn't spinning so fast. Maybe a large meteor already slowed it down. There are countless possibilities. Honestly, I don't really see the existance of a tidally-locked habitable planet with an atmosphere and liquid water as particularly problematic.

I'm more interested in how things would play out in practice. I know that hot air would flow from the sunny side to the dark side in upper altitudes, and cold air would flow from dark to sunny in lower altitudes, at least in principle... though, say, on Earth, that overal flow gets broken into smaller cells (with a "reverse" Farrel cell in the middle, acting as the middle wheel in a gear mechanism), and the Coriolis effect further messes it up, and that's even before taking into account relief and oceans. In our tidally-locked planet, those effects would be rather different, due to the considerably different geography involved, as I commented in my above (extended) post. Has anyone here studied this problem before? Any thoughts?

[zabbarot]

*snip*
I found this pretty interesting so I went and did my own research. Also read your setting post and looked at your maps.

So specifically for the map you have, that world is probably not habitable. You have the right idea with the winds mostly. You don't have much of a Coriolis effect because the rate of rotation is fairly low. I think that means the leading and dragging sides of the planet have a larger effect on the wind patterns than the Coriolis effect would. Other than that you mostly have the hot air moving away form the subsolar side, and the cold air being drawn back. If you were to simulate the winds they'd look pretty chaotic, but eventually they'd find a pattern. I'm not sure that there is a good way to figure what that patten would be other than to simulate it over and over and pick the average though :smallconfused: Regardless your habitable zone (assuming you have one) is likely wracked with tornadoes and other cyclic storms.

But it doesn't matter much because that planet as you have it is probably inhabitable. Air isn't the best material to transfer heat, and it's likely that the planet would be lost to run away green house effect. Here's a good explanation of why (http://www.space.com/13950-habitable-alien-planets-tidal-lock-life.html). There's a 'fix' though. Give that planet waaay more surface water. Water circulates heat quite well, and supposedly a 'water world' could sustain temperatures of -33 C under it's antisolar icecap. And hey, water planets are cool too right?

[jqavins]

I was thinking about the Goldilocks Zone (http://en.wikipedia.org/wiki/Circumstellar_habitable_zone). The less bright a star is (which is more or less a function of its size, though of course it also depends a lot on what type of star it is), the closer a planet should be to it in order to be habitable.
I think you've got this basicly right, except that "small" in your earlier post wasn't really the right adjective; say rather "dim" meaning low in total output, which is a function of both temperature and size. And I think you've got the right idea with a white dwarf. Those are the stacked, blonde bimbos of the cosmos; really hot, but not very bright.


I'm more interested in how things would play out in practice. I know that hot air would flow from the sunny side to the dark side in upper altitudes, and cold air would flow from dark to sunny in lower altitudes, at least in principle... though, say, on Earth, that overal flow gets broken into smaller cells (with a "reverse" Farrel cell in the middle, acting as the middle wheel in a gear mechanism), and the Coriolis effect further messes it up, and that's even before taking into account relief and oceans. In our tidally-locked planet, those effects would be rather different, due to the considerably different geography involved, as I commented in my above (extended) post. Has anyone here studied this problem before? Any thoughts?
Yours is as complete a discussion of the topic as I personally have ever seen. I think you can pretty safely ignore the coriolis effect completely; since the planet's rotation rate is so small it would be in the noise. The double-shell convection would be modified by terrain as you note, and that's probably all you need in order to be close enough for gaming. The prevailing wind should be slower at the terminator (the day/night line) than at the sub-solar and anti-solar points, because it can occupy a wider "channel," but if the depths of the layers change then I could be wrong. The perpetual updraft at the subsolar point and downdraft at the antipolar could have noteworthy consequences for aerial creatures and aviation technology, if such exist and survive the temperatures.

Suggestion: add a bit of axial tilt. That would cause the terminator to oscillate annually as seen from the surface. It wouldn't move at the equator and would swing a fair amount out at the poles. This gives you the sort of climate you originally figured near the equator, good habitat for nomads in the middle lattitudes, and extremophiles at the poles.


There's a 'fix' though. Give that planet waaay more surface water. Water circulates heat quite well, and supposedly a 'water world' could sustain temperatures of -33 C under it's antisolar icecap. And hey, water planets are cool too right?
Remember, Earth is 71% ocean to start with, so I don't know if "waaay more" is even possible. Earth's particular arrangement of continents would be a real hinderance to the kind of circulation you want, with two land masses each stretching nearly pole to pole. But giving your tide-locked planet as much as half the land Earth has might very well be fine, as long as it's not arranged so badly.

[SirKazum]

(...)But it doesn't matter much because that planet as you have it is probably inhabitable. Air isn't the best material to transfer heat, and it's likely that the planet would be lost to run away green house effect. Here's a good explanation of why (http://www.space.com/13950-habitable-alien-planets-tidal-lock-life.html). There's a 'fix' though. Give that planet waaay more surface water. Water circulates heat quite well, and supposedly a 'water world' could sustain temperatures of -33 C under it's antisolar icecap. And hey, water planets are cool too right?

Hmm... That "water world" is not quite what I was picturing, but I'll keep this possibility in mind in case the original, drier world really can't work at all. I was prepared for an extreme variation in temperature between the two sides (as I said in the spoilered post, this world is home to beings that can survive extremely hot and extremely cold temperatures), as long as there is a band around the terminator that "normal" humans can live in more or less normally. But if weather effects stemming from the tidal locking make that impossible, I'll look into this water world alternative.

I was thinking, maybe have the planet on a relatively "cold" region (in terms of distance from its star vs. the star's brightness), but with a runaway greenhouse effect bringing the temperature back up to a nice level? I considered that possibility because a "greenhouse" planet sounds like it should have a less varied temperature. Is that right?


The prevailing wind should be slower at the terminator (the day/night line) than at the sub-solar and anti-solar points, because it can occupy a wider "channel," but if the depths of the layers change then I could be wrong. The perpetual updraft at the subsolar point and downdraft at the antipolar could have noteworthy consequences for aerial creatures and aviation technology, if such exist and survive the temperatures.

Interesting... I've seen people around the web saying the winds would be extremely fast near the terminator. Yours seems to be a pretty good point though.


Suggestion: add a bit of axial tilt. That would cause the terminator to oscillate annually as seen from the surface. It wouldn't move at the equator and would swing a fair amount out at the poles. This gives you the sort of climate you originally figured near the equator, good habitat for nomads in the middle lattitudes, and extremophiles at the poles.

Huh... I thought the stability provided by the tidal locking would do away with the axial tilt, which is why I chose not to have any. But if you can have both, then yeah, that might provide not only some nice variety to the weather, but also some temperature and daylight variation to help mitigate the effects of the tidal locking.


Remember, Earth is 71% ocean to start with, so I don't know if "waaay more" is even possible. (...)

I think the "waaaay more" refers to the map I posted, which has very little surface water actually. It's in the link in my first post in this thread (or, hey, here (http://www.giantitp.com/forums/showsinglepost.php?p=17999864&postcount=2) - it's the 4th planet).

[zabbarot]

(truncated)
I think the "waaaay more" refers to the map I posted, which has very little surface water actually. It's in the link in my first post in this thread (or, hey, here (http://www.giantitp.com/forums/showsinglepost.php?p=17999864&postcount=2) - it's the 4th planet).

Yes, I was referencing your map. There's a study I found that said an earthlike (water:dirt ratio) planet would be habitable, but basically the more water the less extreme the temperature variance gets. Also surface water prevents that soil erosion that leads to the run away greenhouse effect.

I had a question though. I might have missed it in your main thread, but I'm assuming these planets are in different star systems? Paint me interested : P I'll be dropping by your discussion thread at some point.

[SirKazum]

Yes, each planet orbits around a different star. These people don't have that much in the way of terraforming technology, and I thought it would be unlikely to find more than one planet with good living conditions around each star. There might be small domed outposts in moons and other planets though.

[jqavins]

Interesting... I've seen people around the web saying the winds would be extremely fast near the terminator. Yours seems to be a pretty good point though.
They'd surely be extremely strong everywhere; I thought less extremely so at the terminator, but as I said I'm really not sure.


Huh... I thought the stability provided by the tidal locking would do away with the axial tilt, which is why I chose not to have any. But if you can have both, then yeah, that might provide not only some nice variety to the weather, but also some temperature and daylight variation to help mitigate the effects of the tidal locking.
Huh back at you. I failed to consider that. Considering it now, I don't know. You seem to have done more research than I, so take my input with several grains of salt. I'll try to stop talkig out my backside now.


I think the "waaaay more" refers to the map I posted, which has very little surface water actually. It's in the link in my first post in this thread (or, hey, here (http://www.giantitp.com/forums/showsinglepost.php?p=17999864&postcount=2) - it's the 4th planet).
Ah. The picture is blocked on my computer at work and the thread is failing to load on my tablet right now. I'll have to go downstairs to my real computer. Zabbatot, no offense meant.

(It seems I'm backpedaling lots of stuff here; maybe I should just cal it a day.)

[SirKazum]

Huh back at you. I failed to consider that. Considering it now, I don't know. You seem to have done more research than I, so take my input with several grains of salt.

Not about the relation between tidal locking and axial tilt, I haven't. That was just an off-hand assumption. I also similarly assumed the orbit would have very little eccentricity, for the same reason, but now I'm not sure.

[Carl]

@SirKazum: As far as the theory, i think i hit everything i really can on that front, though the strong updraft and downdraft conditions at the extreme's might actually be enough to produce a notable air pressure change and atmosphere height difference.

Regarding using a dwarf star, i did consider that, but before it become a dwarf and star goes through a red giant phase, anything out to the habitable orbit of the star pre-red giant gets vaporized, their wouldn't be anything left to of the world.

Regarding runaway greenhouse effects. Venus was virtually 100% water coverage, the problem is steam is actually a really good greenhouse gases so if evaporation beats precipitation bam, runaway greenhouse, Venus's atmosphere is only CO2 now because it has no atmosphere and thus the solar wind broke it down into oxygen and hydrogen, the hydrogen evaporated off into space and the oxygen reacted with the carbon on the surface.

The water point is important for preventing seasonal effects and night time from creating too large a variance in temperature to be habitable. it can't stop a planet getting really really hot because it's too close to it's star.

[...]

If people lived on mars for 300 years without leaving, would their skin change color?
If so, to what?

[Carl]

Nope, try a few million. Evolution takes an insane amount of time. Humans and Chimpanzees diverged about 5-7 million years ago for an idea of the time scale.

[Citrakayah]

Except that we are different species with many distinct traits. Skin color already varies, so a change in allele frequency wouldn't necessarily take all that long. The real question there is what factors would be influencing any change?

[Carl]

Well to be fair a few million was an exaggeration to make the point. 300 years simply isn't long enough, period.

[brian 333]

If people lived on mars for 300 years without leaving, would their skin change color?
If so, to what?

Actually, yes, it would. You see, Mars receives about the same solar radiation at the surface that Earth does, due to the much reduced atmosphere of Mars. Therefore people would have to remain indoors unless wearing full body pressure suits. Therefore people would only receive ultraviolet light via their daily sunlamp baths. Therefore everyone, no matter his ethnic background, would become paler almost immediately because a large factor in skin color is tanning. Within a year paleness would dominate every racial skin tone. Africans on Mars would be dark-skinned, but not as dark as an African who grew up on Earth and had daily sun his whole life. Russians, on the other hand, might only look a little paler than their Earthly comrades.

Of course, vampires would love life on Mars. Everyone in closed spaces incapable of finding safety in sunlight? The problem there would be that very soon everyone would be a vampire. Well, there is no Utopia, apparently.

[Carl]

Therefore everyone, no matter his ethnic background, would become paler almost immediately because a large factor in skin color is tanning.

I assumed he was asking about genetics style skin color changes, tanning should i hope be obvious...

[Yora]

Genetic changes are rather unlikely. Useless traits don't disappear from a species genes until they are replaced by a more advantageous trait. Unless decreased melanin production provides any improved chances to survivial and reproduction (and the survival of the populations young, an often overlooked factor in evolution), the genetic information will remain the same, and any future individuals that move to earth will most likely gain the same color as people who never left. (Or at the very least, their Earth-born children will. Not being exposed to sunlight as children could hypotheically cause the mechanism for tanning to never correctly develop in a person.)

[Corneel]

Hi there everyone!

I have a couple of questions, first of all does anyone know of a source of how earth would look in a really long time? I'm thinking of writing a sci fi piece where the original homeworld has been lost in the memory of the space faring civilization and it is now colonized again. I'm personally partial to the Pangaea ultima theory thing, because Madagascar is in such a perfect place to be the capital of the Empire and wreck a space ship... but other ideas would be pretty great.

<snip>

Maybe a bit late but you could have look at "The Future is Wild" site, which looks how life on earth might evolve 5 million, 100 million and 200 million years in the future (and in the absence of humans). It also shows how the continents rearrange.
Wikipage (http://en.wikipedia.org/wiki/The_Future_Is_Wild)
Homepage (http://www.thefutureiswild.com/)

ETA: it seems they drastically reduced available content on their site, so I add the wiki (http://thefutureiswild.wikia.com/wiki/The_future_is_wild_wiki)

[thethird]

Maybe a bit late but you could have look at "The Future is Wild" site, which looks how life on earth might evolve 5 million, 100 million and 200 million years in the future (and in the absence of humans). It also shows how the continents rearrange.
Wikipage (http://en.wikipedia.org/wiki/The_Future_Is_Wild)
Homepage (http://www.thefutureiswild.com/)

ETA: it seems they drastically reduced available content on their site, so I add the wiki (http://thefutureiswild.wikia.com/wiki/The_future_is_wild_wiki)

Awesome, thanks! I happened to find the series so I'll make sure to look at it.

[zabbarot]

@ SirKazum

I just want to clear somethings up here...

Regarding using a dwarf star, i did consider that, but before it become a dwarf and star goes through a red giant phase, anything out to the habitable orbit of the star pre-red giant gets vaporized, their wouldn't be anything left to of the world.
I just want to point out that not only are there planets orbiting red dwarf stars, but there are earth-like planets orbiting red dwarfs, and red dwarfs are one of the best hopes for finding life.


Regarding runaway greenhouse effects. Venus was virtually 100% water coverage, the problem is steam is actually a really good greenhouse gases so if evaporation beats precipitation bam, runaway greenhouse, Venus's atmosphere is only CO2 now because it has no atmosphere and thus the solar wind broke it down into oxygen and hydrogen, the hydrogen evaporated off into space and the oxygen reacted with the carbon on the surface.

The water point is important for preventing seasonal effects and night time from creating too large a variance in temperature to be habitable. it can't stop a planet getting really really hot because it's too close to it's star.

First off, only trace amounts of water have been found on Venus and there is nothing to suggest it had 100% water coverage. It might have had oceans, but that's speculation. And the greenhouse effect is a quite a bit more complicated than you're putting it. Here is a really in depth explanation of what we think happened to Venus (http://www.skepticalscience.com/Venus-runaway-greenhouse-effect.htm). Venus not having water in it's atmosphere now is because the atmosphere became warm enough that it didn't precipitate and instead reached the upper atmosphere where solar radiation broke the H2O down and basically blew the hydrogen away. The traces we find that even suggest water are deuterium which is just a bit to heavy to easily escape the atmosphere.

But these things don't directly effect a tidally locked planet because unlike Venus, this planet has a massive ice cap that won't be so easily overcome because it never sees the sun. The wind patterns that you've discussed help negate the loss of gaseous water to the upper atmosphere because of the cooling effect from that icecap, and in turn help keep the water cycle stable. Also, again, we aren't assuming that this planet is really close to a star like Sol, we're assuming a much dimmer red/brown dwarf(on the large end for brown).

Really you need water. It's the easiest way to write of one of the other major hurdles for tidally locked planets which I mentioned earlier. Basically only one point on your planet is weathering (the land at the subsolar point), and this can lead to incredibly unstable temperature variations. In the end the planet swings wildly from one end to the other and eventually either loses all it's atmosphere or ends up with a superheated, dense atmosphere like Venus. You don't have to make it a water world, I just thought that would be neat, but if you make it a desert it will be Mars (no atmosphere at all. probably).

[Carl]

I just want to point out that not only are there planets orbiting red dwarf stars, but there are earth-like planets orbiting red dwarfs, and red dwarfs are one of the best hopes for finding life.

Care to source that. he fact that the sun will expand past or approximately to earths orbit, (there's still some debate on that), is well established. There's simply no way for an earth like planet, (assuming by earth like you mean in the habitable zone), could survive that. Grav Capture could do it, but that would be astonishingly rare.


First off, only trace amounts of water have been found on Venus and there is nothing to suggest it had 100% water coverage. It might have had oceans, but that's speculation. And the greenhouse effect is a quite a bit more complicated than you're putting it. Here is a really in depth explanation of what we think happened to Venus. Venus not having water in it's atmosphere now is because the atmosphere became warm enough that it didn't precipitate and instead reached the upper atmosphere where solar radiation broke the H2O down and basically blew the hydrogen away. The traces we find that even suggest water are deuterium which is just a bit to heavy to easily escape the atmosphere.

I'm simplifying down to bare basics and explaining what is the best regarded theory, though i meant to say magnetic field and ozone layer (which I've heard stated as key points in the breakdown process), not atmosphere on the "no X" comment, tired when writing that, sorry. I do have a number of sourcebooks on this stuff btw, i just rarely bother to get more technical than i have to unless asked specifically for it or it requires a really technical answer.

Your point on the tidal lock may be valid. But i'm not convinced. Planets are fairly complicated things, but traditionally heat radiation rate is a factor of temperature differential and the composition of the radiating object. An icy pole would radiate more slowly than a hot one basically, and a dark side shouldn't radiate any faster because it's rotating than it should since it's tidally locked.

Runaway greenhouse quite simply is about getting the absorption rate to exceed the radiance rate.

The other point is that he was talking of placing it in the habitable range for a dwarf star. That's going to be really close, without looking up specific values i'm not sure on the precise value's, but i'd guess quite a bit closer than Venus is today.

[zabbarot]

Care to source that. he fact that the sun will expand past or approximately to earths orbit, (there's still some debate on that), is well established. There's simply no way for an earth like planet, (assuming by earth like you mean in the habitable zone), could survive that. Grav Capture could do it, but that would be astonishingly rare.

There are other ways for dwarf stars to form. Yes, all large stars eventually collapse into, but not all stars start out large. Brown dwarfs in particular never even have the critical mass necessary to start the Hydrogen fusion reaction that powers our sun. Here's a source (http://www.space.com/14659-red-dwarf-stars-planets-habitable-zones.html) for my statement about red dwarfs being a good source to look for life, though I guess I should clarify that that is partially because it's easier to find planets that orbit red dwarfs because of their shorter orbits.


I'm simplifying down to bare basics and explaining what is the best regarded theory, though i meant to say magnetic field and ozone layer (which I've heard stated as key points in the breakdown process), not atmosphere on the "no X" comment, tired when writing that, sorry. I do have a number of sourcebooks on this stuff btw, i just rarely bother to get more technical than i have to unless asked specifically for it or it requires a really technical answer.
And that's fine, but you can simplify things until they are no longer correct.


Your point on the tidal lock may be valid. But i'm not convinced. Planets are fairly complicated things, but traditionally heat radiation rate is a factor of temperature differential and the composition of the radiating object. An icy pole would radiate more slowly than a hot one basically, and a dark side shouldn't radiate any faster because it's rotating than it should since it's tidally locked.

Runaway greenhouse quite simply is about getting the absorption rate to exceed the radiance rate.
We're arguing two different things here I think. I was saying that the ice cap helps keep gaseous water from reaching the upper atmosphere because it can cool it and force precipitation. This has the effect of keeping the water cycle moving, and not letting too much water get trapped in the atmosphere. Also water has a very high specific heat so the more there is the better the planet should do as the water currents cycle from the day side to the night side.

If you really want to get into thermodynamics heat radiation based on difference of temperature is a function of closed systems, which the planet isn't. The thermal energy is being radiated into space as infrared radiation. Yes, at it's base the greenhouse effect is just about absorbing more heat than you can get rid of, but like you said, "planets are fairly complicated."


The other point is that he was talking of placing it in the habitable range for a dwarf star. That's going to be really close, without looking up specific values i'm not sure on the precise value's, but i'd guess quite a bit closer than Venus is today.

A tidally locked planet orbiting a red dwarf in the habitable zone would have an orbit smaller than Mercury's around our sun. This isn't relevant to your point though, because the reason the habitable zone is that close to the star is because the star radiates that much less heat and light than our star. It isn't going to be hotter than Mercury just because it's closer. It's like the difference between standing a foot from a bonfire versus a foot from a candle.

[brian 333]

I would like to point out that planets may not need water on them originally to have water on them now. One way water could have been introduced after a planet has formed is via cometary bombardment.

The total volume of Earth's oceans is a sphere about 420 miles in radius, which is smaller than Charon, but about the size of the largest known centaur, (supermassive comet.) A single massive hit after the sun collapsed from red giant phase upon a tidally locked inner planet may have resulted in both altering its orbit and providing it with the water and hydrocarbons it needed to begin the evolution of life. I prefer several hits by smaller objects, and orbital capture and decay as opposed to direct strikes, but that is my preference.

One thing not mentioned in this discussion is the effects of solar radiation upon a world with no magnetosphere. Much of the stellar radiation is deflected by Earth's 'force field', the effects of which can be seen in the Aurora Borealis and Aurora Australis. I didn't reflect on it in my original thesis, mostly because I wasn't thinking about the star itself, but the world. But water is a great insulator and it is also a very good means of absorbing radiation and deflecting sub-atomic particles. I hypothesize the volume of water vapor in the upper atmosphere acts as a radiation shield and heat sink, allowing the sun's heat to be more evenly distributed. It would also, by capturing charged particles from the solar wind, drag them from pole to pole, creating a small magnetosphere which would further deflect and capture particles which would strengthen the magnetosphere. (Rather than Earth's internal dymano core, this world would rely upon an external linear accelerator effect to charge its iron core.)

Edited because someone can't tell his diameter from his radius.

[SirKazum]

While that "water vapor shield" idea sounds interesting, I don't know if the atmosphere would have that much water vapor going around unless the planet's temperature was way too high to begin with. Otherwise (with a livable temperature), it would simply precipitate and rain down. Then again, we are talking about a planet with a huge temperature differential... maybe the water simply evaporates in the sunward side, generating vapor in the sunlit area, which helps shield against solar radiation, and then gets carted off to the colder parts of the planet by the wind currents, where it precipitates as rain or snow.

There's still the problem of snow falling on the "night" side and the moisture just staying there, essentially forever, as ice, thereby reducing the total amount of freely-circulating water on the planet, which would make everything worse... but then again, maybe that's exactly what's happening. Maybe that's why there's so little liquid surface water on the planet and such a massive ice shelf (as per the map (http://worldlinecollapse.files.wordpress.com/2014/08/eugeron.gif)); maybe life evolved in this planet ages ago, under more favorable conditions, but then this trapping of moisture as "night-side" ice has been making the planet's weather worse, and it will be completely unlivable in a few million years (or maybe even sooner), barring some terraforming. That raises some interesting possibilities...

That would mean, of course, that something changed more or less recently, in geological terms anyway. Maybe the tidal locking itself is relatively recent, with days growing longer and longer over time, until the planet's rotation finally "locks" in with its yearly period. Even a very long apparent day (as in the period the sun takes to move around the sky, from the ground's perspective, which in this case would be different from the planet's rotation period) would still allow for more varied weather, so maybe the water-trapping runaway effect wouldn't take place until the tidal lock really set in for good. Which would allow us time for life to evolve in a planet that's fast on the way to becoming unlivable. That make any sense?

(btw, in this setting, the main population in the planet in question came in from elsewhere, but there had to be intelligent life in there before... as their method for finding habitable planets involves using psychics to detect intelligent life in outer space.)

[brian 333]

Ice is a wonderful insulator, which is why Eskimos build igloos. Ice is also very heavy and not very strong. When it gets stacked over a certain height, compression and friction generate heat. This occurs in Antarctica where the ice sits on rock, and it occurs more quickly beneath moving glaciers. A mountain of ice will not grow beyond a certain size before it forces itself to squeeze away from its center or melt from beneath due to the crushing weight above it and the lack of tensile strength of the ice itself.

In my proposed scenario the ice cap was surrounded by an ocean, almost certainly formed by the ice itself scraping away at the rock over the eons. This ocean would have the dual role of transporting warm surface waters into the frigid zone and allowing the transport of nearly frozen meltwater away from beneath the ice cap, creating a more or less upper limit to the mass of the ice which would grow and shrink based on periodic solar variability.

Note that we know of exactly one other waterworld: Europa. While what we know is as yet mostly speculative, we do know that Europa has a liquid ocean beneath its ice crust, which is six miles thick. The ocean is another 60 miles or so deep. Since Europa has almost no atmosphere, all liquid water either freezes or sublimates when exposed to the surface, and is then split by stellar radiation into hydrogen and oxygen. The hydrogen blows away almost immediately leaving a tenuous oxygen envelope around the moon. Gravity on Europa is somewhat less than on Earth's Moon.

[zabbarot]

Brian makes some good points. With enough water I think your planet will be stable and habitable for a very long time, so the tidal locking doesn't need to be recent, even on a geological time scale. Glaciers and just the weight of the ice forcing it to melt should be enough to keep all the water from accumulating on one side of the planet. It adds some neat features to your habitable ring around the planet too. You have this advancing glacial wall that breaks and melts as it reaches the warmer side of the planet. It's pretty cool.

I still suggest a water world, but that's mostly because I think it's awesome. If you've got around 70% water coverage like earth, it should be pretty stable, hellish at times, but stable.

[Carl]

@zabbarot:

1. Ok went digging through the wiki. looks like i need to go update my stellar sourcebooks, (admittedly they are rather old, dating mostly from between 80 and 90, fortunately my solar systems ones are rather newer). They only talk about stars down to the range where they do go through a red giant phase, albeit only a hydrogen based one.

Fair's fair on that one. There is a narrow range of red dwarf's that burn without a reg giant phase and that burn long enough at a stable radiance that you could get the tidal locking effect.

2. Aside from a typo nothing i said about venus was actually inaccurate.

3. Your missing the point there. All the ice in the world mans nothing because if that ice isn't re-radiating all the excess heat it absorbs via that cooling of the air moving around the planet from the hot pole. If it can't it eventually melts. Or more likely never forms since in the early planet formation the star will likely have lit off before the planet properly cools from the early bombardment phase.

Also complicated doesn't mean violates laws of physics. Heat Differential and reflective properties are going to set an upper limit on heat transfer off the planet. There isn't really any purely physics advantage to the tidal lock setup, or given solar radiation isn't hitting it at all, all the ice. Basically if the system isn't heat stable without the water and ice then they're just giant heatsinks that will eventually be overloaded.

[avr]

A tidally locked world is most stable when the mass is concentrated about the poles facing directly towards and away from the star, i.e. any oceans are most likely to be around the terminator.

One feature of tidal locking which doesn't get mentioned a lot is libration. Tidal locking isn't an all or nothing affair, even once the day and the year become the same length there can be some rocking back and forth - the terminator isn't quite fixed. Libration is barely detectable on Earth's Moon but could be more significant on an alien world. It would be most noticeable on the equator and zero at the poles.

[zabbarot]

@Carl:
Here you go, a peer reviewed paper from the Journal of Advances in Modeling Earth Systems (http://www.clidyn.ethz.ch/papers/tidally_locked.pdf). If you still have reason to argue after reading this, I bow to your superior desire to be right.

[SirKazum]

I remember the explanation of rivers running out from under the glacier due to crushing-generated heat in the thread I inadvertently made about this. That's a cool idea, and I'd definitely like to use it.

I didn't know about the libration effect... and it shows that both eccentricity and axial tilt are definitely possible in a tidally-locked body. Hmm, seems New Eugeron will have some luminosity variations close to the terminator after all.

Again, thanks all for the feedback! You guys are awesome.

[brian 333]

I remember the explanation of rivers running out from under the glacier due to crushing-generated heat in the thread I inadvertently made about this. That's a cool idea, and I'd definitely like to use it...

If your glacier sits on land the meltwater will be in huge, blue-white rivers which chew their way through mountains and deserts to make their way to the sea, (or evaporate before they get to it.) These rivers will quickly pick up debris, dirt, and virtually anything which stands in their way, rapidly becoming colored by the soil through which they travel, and by the life which thrives in their violent channels. As they wend their way through river basins they carve meandering courses which over time chew up the land until it is a flat plain loaded with fertile soil and organic debris. If they do not ever reach a sea, you can look to the Okavango Delta for an example of the terrain they would create as the last of the powerful river's waters evaporate.

In this scenario you would see little in the way of floods in an annual cycle, but perhaps the evolving underside of the ice traps vast lakes which generate massive floods when they break free, or perhaps the river's source finds another outlet and the original river system is abandoned leaving a chain of oxbow lakes like Australian billabongs.

I have already described the situation if the glacier were situated on or in a sea in my original post on this topic.

The paper cited above brings up an important point, in that a planet rotating a star will still have a rotating atmosphere which will distort the winds and currents to a degree depending upon the speed of its orbit. I had assumed a moonless planet more-or-less in the range of Earth from a Sol-like star in my original thesis. However, according to that paper the temperature variations from dark-side to light-side will range from about -30F (-33C) to 116F (47C) assuming the same amount of stellar energy Earth receives from Sol. Aside from radiation affects, humans could survive there.

[Ursus the Grim]

I think this is a pretty simple thought experiment, at least compared to some of what's been asked.

Premise: This setting takes place on an island/continent roughly the size, latitude, and longitude, of the USA East Coast, from New England (Maine) to Florida. However, there is no land West of the Appalachians. How would the climate change? What might your typical vanilla D&D setting have cause to war over? My geology is incredibly neglected, so I should have been able to figure this out, but if the rest of North America never formed, how close to the Appalachians could the pacific get?

[Jendekit]

...there is no land West of the Appalachians...if the rest of North America never formed, how close to the Appalachians could the pacific get?

I can't answer the climate questions, but for the last question you already answered it. If there's no land west of the Appalachians, then the Pacific ends on the west side of that mountain range.

[brian 333]

The Eastern US is a forest. One single forest. The reason it is a forest is that this is a very wet region of the planet.

In a nutshell, here is what happens:
Coriolis winds flow from West to East across North America. The Rocky Mountains are high enough to create a Rainshadow, and this after the Cascades and Sierras create a Rainshadow along the Pacific Coast. This generates a situation in which either sub-polar jet streams meander South, or sub-tropical jet streams meander North across the Great Plains.

The wetter sub-polar air brings rain, (or more often snow,) while the sub-tropical air brings heat and on an annual monsoon cycle, vast thunderstorms. These storms sweep from West to East across the Great Plains creating vast counter-clockwise rotations in the atmosphere. This is where the good part comes in.

You see, right on the boundary between the Western flowing tropical air mass to the south and the Eastern flowing temperate air mass that dominates central North America, there is the relatively shallow and very warm Gulf of Mexico. Heat and warm water generate a lot of water vapor in the air over the Gulf, and as counter-clockwise rotating storms sweep East, they suck air northward along their 'front'. This air is heavily laden with moisture, which cools and precipitates along the frontal boundary from the Gulf Coast to Canada. Basically, anything East of the Mississippi River is going to get a crapload of rain on an annual average.

This results in a differential of about 30 inches of rain a year between the Western states and the Eastern ones, (30 inches or less in the West, and 60 or more inches in the East.) Some parts of the Gulf Coast receive over 100 inches of rain, (my hometown of New Orleans being in that region,) and relative humidity all along the region is horrendous as compared to the West. Only the Northern Pacific Coast gets more rain, and this is caused, as I said earlier, by the Rainshadow effect of the Coastal Ranges.

What Rainshadow is is that when an air mass is shoved upwards it cools, and warm air holds moisture better than cool air. Any vapor in the air condenses and precipitates out, and what goes over the mountains is dry air. So on the windward side of mountains you have very wet conditions, and on the leeward side of mountains you have very dry conditions. Eastern and Western Washington are effectively two different states due to this.

So, we apply it to your proposed continent. If its terrain is exactly like North America, with a thick, broad chain of low, weathered mountains with flat river valleys between them and an ancient forest of scrub oak dug into its crown, it will be only a marginally effective rainshield. Most of the Appalachian Chain is simply too low to effectively generate a rainshadow. However, it does generate enough of an effect to cause turbulence which results in frequent showers, which would tend to maintain aquifers which are the headwaters of rivers, (unless farmers have learned to pump the aquifers out for crop irrigation...)

Now the real questions begin: does your Western Ocean have a cold arctic current running south along it? Is there a massively cold sub-arctic zone just north of it which can generate a temperature differential large enough to maintain a polar ice cap? Is there a warm shallow sea south of it to generate a massive volume of water vapor in the air? All of these conditions are required for the wetness of the Eastern Seaboard of the US. Consider that New Orleans receives 100+ inches of rain in a dry year, while Cairo Egypt receives less than 1, (yes, that's ONE inch of rain a year!) and both lie 30 degrees North of the Equator. (Egypt and New Orleans have another thing in common, and that is that the Sahara Desert affects both of their climates, but I'll let you discover the connection on your own!)

So, to answer your question: the climate of any region is dependent upon many other factors, including the climates of the regions around them and of the world overall. There was a time, in the Carboniferous Period, when the land mass which was to become North America was about the size you want, but it was lodged firmly in the Tropics in a much warmer and wetter world. This was the age of America's great coal deposits, and vast forests and swamps covered the land as the continents collided to create Pangea, (and incidentally to create some of the mountain groups which are now known as the Appalachians.)

[Melzentir]

Hello,

I'm making typical D&D world though with slightly less magic (there's still wizards and dragons) and more GoT-style political depth and gruesome combat (permanent injuries). I want to divide a Kingdom in about a half- to a dozen provinces and have some very basic economy going on between each of them, both over land and sea.

I'm planning on implementing about 15 different resources (iron, wheat, cloth, leather, fish and so on). A pine-filled mountainous province may produce for example 2 units of iron, 1 fur and 2 logs. I'd much like to know where my dwarves will be digging up coal, copper, iron, silver and gold. Instead of each mine just pumping out 20% of each, I want at least some vague semblance of realism to know where each of these materials come from. I've played Minecraft and Dwarf Fortress, but this thread seems quite promising.


TLDR: Where and how deep can I find coal, copper, iron, silver and gold? Info will be used for inter-kingdom trade and also dungeon and location design. Possibly player crafting.

P.S. this entire thread is much appreciated, thank you all for partaking in it.

[avr]

I think this is a pretty simple thought experiment, at least compared to some of what's been asked.

Premise: This setting takes place on an island/continent roughly the size, latitude, and longitude, of the USA East Coast, from New England (Maine) to Florida. However, there is no land West of the Appalachians. How would the climate change? What might your typical vanilla D&D setting have cause to war over? My geology is incredibly neglected, so I should have been able to figure this out, but if the rest of North America never formed, how close to the Appalachians could the pacific get?
The Pacific ocean ridges have been creating new crust for a very long time. They can easily fill the gap you describe with oceanic crust.

Now, if that oceanic crust is being subducted beneath the Appalachians they will be quite a bit taller and more volcanic than in RL.

There are already minerals in those mountains D&D-landers might war over, a few volcanoes and more rising and folding of the terrain will only make that more so.

[Ursus the Grim]

First, thanks Brian. I am mostly going with this idea because its easier to me modify and existing thing than forging a whole world.


The Pacific ocean ridges have been creating new crust for a very long time. They can easily fill the gap you describe with oceanic crust.

Now, if that oceanic crust is being subducted beneath the Appalachians they will be quite a bit taller and more volcanic than in RL.

There are already minerals in those mountains D&D-landers might war over, a few volcanoes and more rising and folding of the terrain will only make that more so.

There's an interesting idea. Would higher Appalachians change any of the results Brian suggested? I would assume a yes. . . .

[avr]

Hello,

I'm making typical D&D world though with slightly less magic (there's still wizards and dragons) and more GoT-style political depth and gruesome combat (permanent injuries). I want to divide a Kingdom in about a half- to a dozen provinces and have some very basic economy going on between each of them, both over land and sea.

I'm planning on implementing about 15 different resources (iron, wheat, cloth, leather, fish and so on). A pine-filled mountainous province may produce for example 2 units of iron, 1 fur and 2 logs. I'd much like to know where my dwarves will be digging up coal, copper, iron, silver and gold. Instead of each mine just pumping out 20% of each, I want at least some vague semblance of realism to know where each of these materials come from. I've played Minecraft and Dwarf Fortress, but this thread seems quite promising.


TLDR: Where and how deep can I find coal, copper, iron, silver and gold? Info will be used for inter-kingdom trade and also dungeon and location design. Possibly player crafting.

P.S. this entire thread is much appreciated, thank you all for partaking in it.
You can get those minerals at any depth. Even when they form lower they can be brought to the surface by higher terrain being eroded and/or faults folding blocks of rock over or raising them up.

Copper you can get in so many places that it's the availability of tin (to make bronze) which is the real limit, at least without modern technology creating a demand for good electrical conductors. Good tin ore is relatively rare as I understand it.

Gold can be found where volcanoes have been heating groundwater - maybe not recently! Look for volcanic rocks in general.

Silver can be found in similar places to gold or mixed into some lead or copper deposits. Often it's the silver content which makes mining lead or copper economically viable.

Coal is found in old sedimentary rock. Unless there's a local shortage of wood (because of a shipbuilding boom or an industrial revolution) it will normally only be mined when it's close to the surface.

[Jendekit]

In a campaign setting that I am currently running for Pathfinder, I have introduced a new race that has an animistic, tribal culture and a deep seated hatred for dragons. As in, they hat dragons just as much if not more than dwarves hate orcs. I have their naming convention (basically that of the Avvar from Dragon Age), origin myth, racial stats, and a few different cultural features (such as having no concept of permanence and the use of tattoos to denote outsiders as worthy of respect). Since I mentioned them, I'll provide naming convention and origin myth.

In any case, what I am basically looking for are ideas to further flesh out the culture beyond just dragon hunting. Ideas?


Personal names tend to be single syllable, and are followed by ba/bo (son of/daughter of) *mother's personal name* bi (child of) *clan/tribe name*. So Yok ba Tie bi Vorkka would be Yok son of Tie child of the Vorkka clan.

Long ago, in an era before time was time, there was nothing. From this nothing, there was a flash of light and a clap louder than the loudest thunder. At the center of the flash and clap, the world began. This early world was not like the world today. The ground roiled, the water boiled, the air was poison, and the rain burned like liquid fire. It was in this world, that the first spirits arose.

These early spirits breathed in the poison air, and kept the poison within them when they breathed out. For age after age the world continued as such. But as it did, it slowly began to change. The world cooled, the earth settled, and the spirits unknowingly were bringing about their own end. The early spirits needed the poison in the air to live, but with each breath there was less poison in the air. Eventually, there wasn’t enough left to support the first spirits.

As the first spirits died, new ones took their place. New spirits that learned from the mistakes of their predecessors. They breathed the cleaned air, and made sure to return more of what they needed than they took. As these new spirits arose, something else new arose with them. The plants and animals that you see around you are the descendents of those that were born in this time. The plants and animals of today are not the plants and animals of that time, for all things change in time.

Ages passed, creatures were born, they lived, they bred, they died. They spirits came, lived, then went. Then, something happened unlike anything that had happened in the history of the world. A creature did something that nothing before it had done, it asked why. Building from that first intelligence, came all thinking things. Even the hated dragons owe their ability to think to this first thinking creature.

[brian 333]

There's an interesting idea. Would higher Appalachians change any of the results Brian suggested? I would assume a yes. . . .

When they were in their formative years, (as Pangea was being formed, and all the continental collisions which accompanied that event,) the Appalachians were probably the height of the Rocky Mountains. They've worn down quite a bit over the ages since. This is why they have broad flat river plains between the mountain peaks.

As to what climactic features change, this depends on the regional climate. Assume a cold Western ocean with a polar current running south along the coast: this would lend itself to a coastal rainforest similar to modern day coastal Washington/Oregon.

Immediately beyond the coastal ridges would be dry valleys. If we assume some kind of mountainous terrain to the north this dry zone might extend Eastward as far as the mountains go due to the sub-polar air mass being trapped north of this barrier. If, on the other hand, we assume no barrier, we may well have a glaciated North coast similar in appearance to modern Norway.

The south faces similar issues. Is there a warm shallow sea, or a deep cold ocean? Warm and shallow means we get more active and wetter weather, while deep and cold means we get milder temperatures and more sunshine. A deep and cold ocean south of our landmass would mean there is no Gulf Stream to bring warm waters up along the coastline both to moderate winter weather and to increase the bounty of the northern seas.

So, your proposed East Coast may well be a rainshadow desert similar to the Namib or Atacampa deserts. Look at Madagascar for an example of this kind of climate. Or it may well be very much the same as it is today with warm sub-tropical winds carrying rain Northward along the leeward flanks of the West Coast Range in the summer and cold sub-polar winds carrying freezing ice southward in the winter.

In short, it is difficult to project a continental climate because climate is a global phenomenon. To have a warm wet climate in the North is utterly dependent upon a warm shallow sea to the south. (Gulf of Mexico and Mediterranean.) In places where no such body of shallow warm water exists you have Siberia's climate in the north. In order to have drastic cold winters you must also have an ice cap. This almost certainly requires either a land-locked sea or an actual landmass upon which the ice sits, or the ice cap will be small and probably melt in summer. (Note that for most of its history Earth has had no ice caps primarily due to this feature.)

One must not forget the impact of north-south continents in the disruption of weather patterns as well. Water will tend to flow around a globe in patterns similar to the atmosphere, leading to isolated cells in the far north and south, with very slow migration over the horizontal bands. North-south continents force that water to find paths other than simple bands around the planet. It is this feature which brings the warm Gulf Stream into Ireland and Northern Europe, without which Northern Europe, and most of the northern globe, would be sheathed in ice year round. Without something to force currents to go North and South we would have very cold poles and very warm tropics with little exchange of heat between them. This would lead to a dryer atmosphere overall, and far less violent weather. Land would be mostly desert outside of the coastal zones, (like Australia.)

[Melzentir]

You can get those minerals at any depth. Even when they form lower they can be brought to the surface by higher terrain being eroded and/or faults folding blocks of rock over or raising them up.

Copper you can get in so many places that it's the availability of tin (to make bronze) which is the real limit, at least without modern technology creating a demand for good electrical conductors. Good tin ore is relatively rare as I understand it.

Gold can be found where volcanoes have been heating groundwater - maybe not recently! Look for volcanic rocks in general.

Silver can be found in similar places to gold or mixed into some lead or copper deposits. Often it's the silver content which makes mining lead or copper economically viable.

Coal is found in old sedimentary rock. Unless there's a local shortage of wood (because of a shipbuilding boom or an industrial revolution) it will normally only be mined when it's close to the surface.

Thank you very much! I'll be sure to include tin as the limiting factor to bronze, as well as making gold more common in volcanic areas. I'm actually planning on making a volcanic desert (http://www.dahabescape.com/uploads/1/7/5/7/17578043/3981030_orig.jpg) mixed race kingdom of humans, dwarves and perhaps some dragonborn, all ruled over by an ancient dragon. The desert used to be a volcanic, highly fertile jurassic park-like area, but after thousands of years of exploitation eventually turned to what it is today. Gold being prevalent in such areas? Bingo.

Mixed deposits is another interesting thing. I will do something with that. I'll combine it with the fact that only the largest of forges in barren areas will be using coal. Unless magma forges buried deep within the Dwarven Holds take over production. But that would be an enormous undertaking to construct. Talk about being economically viable.

In any case, thanks! And perhaps someone somewhere will find this link useful: http://www.minecraftforum.net/forums/minecraft-discussion/discussion/118450-building-a-realistic-medieval-world

[jqavins]

A pine-filled mountainous province may produce for example 2 units of iron, 1 fur and 2 logs. I'd much like to know where my dwarves will be digging up coal, copper, iron, silver and gold.
Sounds like Dragons of Catan.:smallwink:


Copper you can get in so many places that it's the availability of tin (to make bronze) which is the real limit, at least without modern technology creating a demand for good electrical conductors. Good tin ore is relatively rare as I understand it.
As I understand it, bronze was (either) discovered (or invented, depending on your point of view) due to deposits that bore both copper and tin and were thus actual bronze ores. But those are rare and it was not long before it was found that the two metals could be smelted from separate ores and mixed afterword. That quickly became the common practice as tin ores, although less common than copper, are a lot more common than bronze ores.


Silver can be found in similar places to gold or mixed into some lead or copper deposits. Often it's the silver content which makes mining lead or copper economically viable.
It's really rather common for more than one metal to come from the same rocks or rock deposites, and methods have to be found to separate them, which can mean separating the different minerals before smelting, separating the metals afterward, or smelting in a manner that only yields one at a time. I've occasionally wondered if the use of magic and magicaly successful alchemy would make this enough easier to spur greater progress in metalurgy and metals production at a lower tech level than occurred in the real world, and what the industrial implications of that might be.

On another tangent, there is an interesting D&D connection to the problem of finding good ores for silver, particularly a problem faced in Germany. A different metal would foul the ore, and the miners attributed its presence to mischievous creatures, and named this nuisance metal after them. The creatures we know as kobolds, and the metal, this "kobold metal," we now call cobalt. But I digress.


Coal is found in old sedimentary rock. Unless there's a local shortage of wood (because of a shipbuilding boom or an industrial revolution) it will normally only be mined when it's close to the surface.
This may be more detail that you really want. As a general rule, the deeper coal is found the higher grade it will be*, with the stuff on the surface most often (but by no means explusively) being either lignite or peat (which is actually a coal precuror, but similar to coal as a fuel for heating.) If there is accelerated progress in metalurgy as I suggested above, there might be accelerated demand for higher grades of coal, as these are often used in refining metals.

* Higher grade means harder and closer to pure carbon. Lignite is about half volatile organics.

[Melzentir]

In a campaign setting that I am currently running for Pathfinder, I have introduced a new race that has an animistic, tribal culture and a deep seated hatred for dragons. As in, they hat dragons just as much if not more than dwarves hate orcs. I have their naming convention (basically that of the Avvar from Dragon Age), origin myth, racial stats, and a few different cultural features (such as having no concept of permanence and the use of tattoos to denote outsiders as worthy of respect). Since I mentioned them, I'll provide naming convention and origin myth.

In any case, what I am basically looking for are ideas to further flesh out the culture beyond just dragon hunting. Ideas?


Personal names tend to be single syllable, and are followed by ba/bo (son of/daughter of) *mother's personal name* bi (child of) *clan/tribe name*. So Yok ba Tie bi Vorkka would be Yok son of Tie child of the Vorkka clan.

Long ago, in an era before time was time, there was nothing. From this nothing, there was a flash of light and a clap louder than the loudest thunder. At the center of the flash and clap, the world began. This early world was not like the world today. The ground roiled, the water boiled, the air was poison, and the rain burned like liquid fire. It was in this world, that the first spirits arose.

These early spirits breathed in the poison air, and kept the poison within them when they breathed out. For age after age the world continued as such. But as it did, it slowly began to change. The world cooled, the earth settled, and the spirits unknowingly were bringing about their own end. The early spirits needed the poison in the air to live, but with each breath there was less poison in the air. Eventually, there wasn’t enough left to support the first spirits.

As the first spirits died, new ones took their place. New spirits that learned from the mistakes of their predecessors. They breathed the cleaned air, and made sure to return more of what they needed than they took. As these new spirits arose, something else new arose with them. The plants and animals that you see around you are the descendents of those that were born in this time. The plants and animals of today are not the plants and animals of that time, for all things change in time.

Ages passed, creatures were born, they lived, they bred, they died. They spirits came, lived, then went. Then, something happened unlike anything that had happened in the history of the world. A creature did something that nothing before it had done, it asked why. Building from that first intelligence, came all thinking things. Even the hated dragons owe their ability to think to this first thinking creature.


Okay, just going to spew out some chunks brainstorming style:

There must be a reason why they hate dragons more than any other. Perhaps the dragon's ideals are diametrically opposed to that of the people. Since dragons view themselves as deserving of fortune, possess great greed and are both manipulative and egocentric, perhaps your people's ideals will be sharing, self-sacrifice for the greater food and community-based decisions. Perhaps every step of their daily life will be a contribution not to themselves, but to the community as a whole. Perhaps they will strongly depend on eachother because of this. Is there an environmental reason this dependence has arisen (such as extreme cold/warmth)? Or could that be the dragons?

Why would banding together give them an edge over the dragons instead of fleeing as every man for himself? Perhaps they have a way of repelling the dragons which only works in unison, since they hate them so much. Perhaps they have enclaves which are safe from dragons due to many of their people being there at once and all protecting it using the same technique. Perhaps something to do with spirits or psionics or magic or a primal emotional bond or somewhat. I feel like I'm running dry on that trail, so let's read your question again.

Dragon hunting. That is quite a bit different from repelling or exterminating them. So if they hate them so much, they probably hunt them for that reason. If they'd actually benefit from hunting them you could slip some native american bison philosophy in there, but that would constitute too much respect and love for dragons since your people hate them.

Tattoos huh? Do these tattoos have magical properties that bestow powers? Do the tattoos signify status, such as certain elite warriors or a cabal of shaman having them? Can a tribesman 'catch them all' like the Game of Thrones Maesters gather chains? How do they make those tattoos in the first place? Do they use ink, or something else (burning it in, a spell ritual, spirit binding into the skin)? Is that in some way related to the dragons?

In what kind of environment do your people live? A tropical, densely overgrown archipelago? An arid wasteland of sand and rock? Something else?

Okay, that's it. Deleted some of the poorer ideas since this post got bigger than I thought.

[Melzentir]

Sounds like Dragons of Catan.:smallwink:

Exactly. Civ 5 was my main inspiration, though I want to keep it as simple as it can be.



...tin ores (...) are a lot more common than bronze ores.


...the use of magic and magicaly successful alchemy would make this enough easier to spur greater progress in metalurgy and metals production...




...the miners attributed its presence to mischievous creatures, and named this nuisance metal after them. The creatures we know as kobolds, and the metal, this "kobold metal," we now call cobalt.




If there is accelerated progress in metalurgy as I suggested above, there might be accelerated demand for higher grades of coal, as these are often used in refining metals.

Here's a summary of my take on it:

Some metals are mixed and shouldn't be.
Some metals aren't mixed while they should be.
On top of that, kobolds taint metal to the point it only yields dirt-tier fragile rubbish. How is yet unknown, but the extracted impurities have qualities of their own...


I am now picturing a dwarven city that has vast alchemical sweat shops. On top of that, the city council wants to dig into a nearby a volcano so that they can use the infinite heat, removing the necessity for coal. Of course, the coal merchants will do everything they can within the law to stop it. And then some. Enter the player characters.

Wow, this thread surpassed my hopes. Thank you.

[Jendekit]

Okay, just going to spew out some chunks brainstorming style:

There must be a reason why they hate dragons more than any other. Perhaps the dragon's ideals are diametrically opposed to that of the people. Since dragons view themselves as deserving of fortune, possess great greed and are both manipulative and egocentric, perhaps your people's ideals will be sharing, self-sacrifice for the greater food and community-based decisions. Perhaps every step of their daily life will be a contribution not to themselves, but to the community as a whole. Perhaps they will strongly depend on eachother because of this. Is there an environmental reason this dependence has arisen (such as extreme cold/warmth)? Or could that be the dragons?

Why would banding together give them an edge over the dragons instead of fleeing as every man for himself? Perhaps they have a way of repelling the dragons which only works in unison, since they hate them so much. Perhaps they have enclaves which are safe from dragons due to many of their people being there at once and all protecting it using the same technique. Perhaps something to do with spirits or psionics or magic or a primal emotional bond or somewhat. I feel like I'm running dry on that trail, so let's read your question again.

Dragon hunting. That is quite a bit different from repelling or exterminating them. So if they hate them so much, they probably hunt them for that reason. If they'd actually benefit from hunting them you could slip some native american bison philosophy in there, but that would constitute too much respect and love for dragons since your people hate them.

Tattoos huh? Do these tattoos have magical properties that bestow powers? Do the tattoos signify status, such as certain elite warriors or a cabal of shaman having them? Can a tribesman 'catch them all' like the Game of Thrones Maesters gather chains? How do they make those tattoos in the first place? Do they use ink, or something else (burning it in, a spell ritual, spirit binding into the skin)? Is that in some way related to the dragons?

In what kind of environment do your people live? A tropical, densely overgrown archipelago? An arid wasteland of sand and rock? Something else?

Okay, that's it. Deleted some of the poorer ideas since this post got bigger than I thought.


Well in answer (and I'm making these up as I go), they hate dragons because for a long period of time (a couple generations) dragons saw them as a decent source of food/test subjects for magical experimentation. It is through those experiments that the curses of lycanthropy and vampirism originate in this setting.

They stay in groups because, despite a penalty to Charisma, they are a social race. Much like how isolation is an unhappy prospect for most people, it is the same for them. The fact that groups means the ability to pool resources and skills also gives them an edge. The primary reason why they haven't been hunted to extinction by the dragons yet is partially because they pickup and move to a new place about once a month, and partially because the dragons of this setting are embroiled in their own conflict. A rough analogy would be the issue of Dany and her dragons by the people of Westeros during the War of Five Kings. Is there an issue with this Targaryan girl with three dragons, yes but we've got bigger problems right now.

In regards to benefits of hunting dragons, beyond improving one's individual prestige, the resources that come from the dragon's corpse, and the fact that there's then one less dragon in the world, there's not a whole lot else. They have little use for gold, jewels, or large pieces of artwork due to their need to keep moving. So a dragon's horde has little of interest to them outside of practical magic items, and that's a very small fraction of the horde. Those three things I listed are the main reasons (along with vengeance and that sheer burning hatred I mentioned in the original post) they have for hunting dragons.

Most of the tattoos are just that. Nothing magical about them. The ones that the PCs received last session are basically a way of identifying the PCs as wyvern-slayers and lowlanders worthy of respect. There's no mechanical benefit, but it makes the PCs more likely to get aid from other groups of the race. Regarding the materials used, it's a basic black ink mixed with blood from the wyvern that the PCs killed. Now that you have brought it up however, I do like the idea of some specific tattoos having special significance. Must think more on this.

Home terrain: Mountainous. They live on the coastal slope of the widest and longest mountain range in the known world. Certainly wider than the Sierra Nevadas or the Rockies. Geologically I'm picturing the range as the result of two plates crashing into each other, like the Himalayas. Temperature wise, they live in a temperate zone, and there's a desert about a month+ travel on foot (exact distance to be determined) to the south west (due to difficult terrain).

[Jendekit]

A buddy of mine asked me a question today about world building. Since he doesn't have easy internet access, I'm relaying his question for him.

"How would a world be affected beyond sun rise and sunset if the magnetic north/south was parallel to the host star rather than perpendicular? The planet still spins in the same way that Earth does, but the poles aren't on the 'top' and 'bottom' of the planet."

Anyone with more knowledge in the subject than me wish to have a go at it?

[BladeofObliviom]

A buddy of mine asked me a question today about world building. Since he doesn't have easy internet access, I'm relaying his question for him.

"How would a world be affected beyond sun rise and sunset if the magnetic north/south was parallel to the host star rather than perpendicular? The planet still spins in the same way that Earth does, but the poles aren't on the 'top' and 'bottom' of the planet."

Anyone with more knowledge in the subject than me wish to have a go at it?

Well, the first important thing to note is that what's being suggested is impossible without some kind of magic being involved. The magnetic field of Earth is generated by a natural dynamo within the Earth's core; Earth's direction of rotation causes sloshing of the fluid outer core in a certain direction, which is the reason the magnetic poles are where they are. It's like asking how fast a car would go if its axles were rotating perpendicular to the wheels.

In this hypothetical situation, though, I woudn't expect to see much practical change, excepting perhaps that compass-based navigation gets a little weirder. The magnetic cores already wander somewhat over time and can suddenly reverse with minimal effect on the efficacy of the field as a whole. In general the magnetic field is stronger near the poles than it is at the equator, so this spinning dipole would result in a slightly stronger field wherever the current poles happen to be and a somewhat weaker field near the real-life poles.

This is basically insignificant as far as I know.


So pretty much the big change here is that compasses now lead to some arbitrary point roughly around the equator instead of some arbitrary point roughly around the arctic circle.

[darklink_shadow]

Other the coping out that the scenario presented is physically impossible, due to the fact the the magnetic poles are caused by rotation, I guess I can't answer. However, magnetic north and south are caused by the way the world spins. The only explanation I can come to is that the world does not orbit a sun, but rather spins around independent of a sun that orbits the world. This would mean that the sun is much, much smaller than the world.

[avr]

If the north magnetic pole was in Zaire, you'd get some great auroras over half of Africa. And another bunch over the mid-pacific ocean.

Navigation over long distances would be a bit easier; magnetic north combined with latitude (which you could get from the stars) would give you an approximate location.

It's not impossible BTW but I don't think it's a stable state and would probably change within a few years.

[Yora]

I had a thought yesterday about creating alternative family structures for fictional cultures. Having looked at forms of social organizations all over the world from many different periods, I think that marriage is primarily an economic arangement, not an interpersonal relationship. Most of the time you can and do have both between the same two people, but the descision to marry and who is separate from the descision who to have a relationship with. Many cultures didn't have marriage as we understand it, and rich men who married for politics always had the option to have concubines. Very powerful rulers with dozens of wives probably didn't even know most of them that well, but had much more closer relationships with just one or two. Even today, two people can live together their whole live and raise their children without actually being married. But it's often highly beneficial to do so because of taxes. Two of my friends had decided to marry, but waited for five more years because the government supports parents whose children are still in education or training until the age of 27. Once they had married, she would be regarded as living on her husbands income and no longer requiring the government support, so they waited until she was no longer eligible for it.

Marriage seems to fulfil two purposes: Provide clear rules of inheritance, and ensure that the partners without an economic income is safely supported once they leave the household of their parents. That's really the two things any model of family structure and marriage has to cover. Avoid inheritance conflicts and make sure nobody ends up on the street with no money.
Many cultures have the option of divorce and in that case it's important that the wife has some kind of wealth of her own, which she will keep after she leaves her husband. That's the whole reason behind dowries. In the western world we don't have that anymore, and instead have a legal system in which she combined wealth of the couple is split somewhat evenly between them.

When it comes to inheritance through the male line, everyone wants to avoid fighting over who is the legitimate heir, so it's very important that there is absolute certainty over the identity of a childs father and whether he is legally married to the mother or not. He could still have children with other women like a concubine, but the law is clear that those don't inherit anyway, so it's not really important who their father is.
But let's assume you have a king and queen who married for political reasons and go along reasonably well, but are not each others partner of choice. Now if the king has some bastard children of his own, it doesn't really matter. If the queen had children of uncertain fatherhood, that would be a problem, so she can't have a personal lover by the side. But let's say she and the king already have three healthy sons. That means the question of who gets to inherit the throne is already pretty safely secured and any further children by the queen wouldn't get the throne anyway. So with "her duty performed", the king could be quite okay with her finding a man for herself.
Or take the Roman emperors, who in theory formed a long dynasty, but the position of Emperor pretty much never went from father to son. Quite often the successor would be a nephew or close advisor who had shown great qualification for the job. In such an arragement, it would also not be politically relevant who is actually the father of the children of the rulers wife.
On the other end of the power-spectrum, you could have a society in which people live in kin-groups of 20 to 30 people, who are ruled by the patriarch and everyone else is theoretically equal. The groups would exchange either your men or women between them to avoid inbreeding, and each group works simply as one big family. The only thing that matters is who is going to be the next patriarch, but other than that nobody needs to keep track precisely of who is related to who. There's no inheritance anyway, since everything stays inside the group, and when a relationship between to people breaks up they are still part of the family. Such a culture wouldn't need any formal system of marriage at all.

So, when you try to create a society with different models of family and marriage and keep it realistic or at least plausible, these two things need to be covered: Who inherits property after the death of the head of the family, and how is it ensured that no partner or children are left without support after the end of a relationship.
If you have answers to those, the system could plausibly work.

[Hytheter]

Hey guys, just found this thread. I'd like to talk about Tidal locking.

Specifically, I want some thoughts about what would happen if the Earth or earth-like planet suddenly (magically) became tidally locked with the sun so that one side is always day and the other always night.

Obviously "noon" and "midnight" (which are now geographical locations rather than times of day) become extremely hot/cold respectively, with a more moderate section in between. But just how extreme are they? Can anything survive in the twilight zone in between, or is the day/night cycle too important to currently living creatures? If life can survive, how large will the habitable zone be?

Assuming they survive, how do you think human societies would cope with the change? How would their culture be affected?

Obviously this is highly speculative, but I'm curious as to what your thoughts and opinions are.

For the purpose of this exercise, I'm only interested in effects from the constant position of the sun (from our perspective), and not from the sudden large scale changes in momentum from abrubtly changing the speed of the earth's rotation (which I'm assuming would just kill everyone if not destroying the planet utterly). Like I said, the change would be magical in nature and said magic would be used to mitigate such consequences. (If you're wondering, my idea is that the event is caused by a new God as a show of power)

[darklink_shadow]

Well, if the atmosphere was thick enough, and the planet far enough away, it would help make the heat transfer better. But the Noon side would probably not be livable above ground. However, the midnight side might be bearable. However, the twilight zone should be very livable. There are a few physics papers on this matter floating around, and, more interestingly, the Twileks, from Star Wars, actually hail from a planet (http://starwars.wikia.com/wiki/Ryloth)much like you've described.

The fact of the matter is, if one side is very hot, and the other side is freezing cold, there must be a band around the twilight zone that is warm/cool, comparatively.

[brian 333]

There was a paper cited earlier in this thread and the scientific students involved in its creation determined that the hottest places would be around 116 F and the coldest -30F, assuming a sufficiently dense atmosphere like Earth's.

Basically, everything in shadow would freeze. Without sunlight it would be a very short time before the available food would be used up on the darkside, and life there would be dependent upon the migration of life from brightside to dark.

[BladeofObliviom]

There was a paper cited earlier in this thread and the scientific students involved in its creation determined that the hottest places would be around 116 F and the coldest -30F, assuming a sufficiently dense atmosphere like Earth's.

Basically, everything in shadow would freeze. Without sunlight it would be a very short time before the available food would be used up on the darkside, and life there would be dependent upon the migration of life from brightside to dark.

So, basically a less extreme Mercury? Huh.

[brian 333]

As a side note: Earth itself cannot tidally lock. Solar and lunar tidal stresses will continue to flex the planet in it's elliptical orbit, which would serve to induce spin if somehow the entire world were locked in place momentarily.

Currently these same forces (http://www.abc.net.au/science/articles/2012/11/28/3642932.htm) are acting to slow the rotation of Earth.

[brian 333]

So, basically a less extreme Mercury? Huh.

Mercury's day is about 58 Earth days and its year is about 88 Earth days, so it is not tidally locked.

Well, actually, it's day is not 58 days: that is its rotational speed relative to fixed background stars. Because it is rotating in the same direction as its orbit it takes two orbits for one rotation relative to the sun. So a day actually takes two Mercurian years.

[BladeofObliviom]

Mercury's day is about 58 Earth days and its year is about 88 Earth days, so it is not tidally locked.

Well, actually, it's day is not 58 days: that is its rotational speed relative to fixed background stars. Because it is rotating in the same direction as its orbit it takes two orbits for one rotation relative to the sun. So a day actually takes two Mercurian years.

I meant more in the sense of "One side hot, other side cold, relatively comfortable twilight band in middle."

Though in retrospect that was sort of stating the obvious.

[Hytheter]

The fact of the matter is, if one side is very hot, and the other side is freezing cold, there must be a band around the twilight zone that is warm/cool, comparatively.

Well yes, that much is obvious. But temperature alone doesn't determine whether things can survive. Do you think animals could survive without a day/night cycle? Humans could probably cope, but that doesn't matter if the rest of the world dies around them.


There was a paper cited earlier in this thread and the scientific students involved in its creation determined that the hottest places would be around 116 F and the coldest -30F, assuming a sufficiently dense atmosphere like Earth's.

Yeah I found another paper (http://arxiv.org/pdf/1001.5117v1.pdf) which had similar, and in fact even milder, results. It's a much lower maximum temperature than I expected - there are plenty of real places that can get that hot (although not as constantly, of course). I guess that means that a normal day (in summer, closer to the equator) already heats that area close to as hot as it can possibly be. But even where temperatures are relatively mild, the fact that they are constant might be important in terms of what can survive.

A bigger, according to the paper I found, would be precipitation. At the noon point you'd get huge amounts of rain, but most of the rest of the sunny side evaporates faster than it recieves water. In other words, it's basically desert everywhere. I'm not sure whether that would actually evaporate the oceans though or if they would remain. If they do remain, most aquatic species could probably survive, and humans in coastal areas maybe could survive on diets of fish. But if they are evaporated off... well hell, that could create some cool (but deadly and terrifying) environments, huge deserts where there once were oceans and massive ravines that were once deep sea trenches.

The paper also has a section on wind speeds but I don't really understand it or what it's implications might be.

Plus, I imagine geography can effect all of these factors darmatically. Areas closer to the sun but in the shadow of a mountain range might be cool enough to survive in?

[darklink_shadow]

Animals would find a way to survive, even if that meant they'd all be burrowing. Nature is unstoppable.

[jqavins]

A buddy of mine asked me a question today about world building. Since he doesn't have easy internet access, I'm relaying his question for him.

"How would a world be affected beyond sun rise and sunset if the magnetic north/south was parallel to the host star rather than perpendicular? The planet still spins in the same way that Earth does, but the poles aren't on the 'top' and 'bottom' of the planet."

Anyone with more knowledge in the subject than me wish to have a go at it?What exactly does your buddy mean by "parallel to the host star?" Nothing is parallel or perpendicular to a sphere (or to a point that approximates a distant sphere.) Probably he means parallel to the ecliptic (since it's the ecliptic to which Earth's magnetic and rotational axes are approximately perpendicular) but that is not a sufficient description. If he means parallel to the star-planet vector, i.e. always pointing toward the star, then the poles travel around the equator daily. Other responders have assumed the poles are at fixed points on or near the equator, which means the axis rotates daily relative to the star-planet vector. The two cases would be very different in their effects on magnetic navigation (both artificial and what many animals use) and shielding against the solar wind.

Sunrise and sunset are dictated by the planet's rotation, not by its magnetic field, so I don't understand what he means by "beyond sunrise and sunset." It seems likely that your buddy is laboring under more misconceptions than just the feasibility or likelihood of radically separating the magnetic and rotational axes. Perhaps if he would explain just what he means by "beyond sunrise and sunset" and "parallel to the host star" those misconceptions (or mine) would be exposed.

[Jendekit]

What exactly does your buddy mean by "parallel to the host star?" Nothing is parallel or perpendicular to a sphere (or to a point that approximates a distant sphere.) Probably he means parallel to the ecliptic (since it's the ecliptic to which Earth's magnetic and rotational axes are approximately perpendicular) but that is not a sufficient description. If he means parallel to the star-planet vector, i.e. always pointing toward the star, then the poles travel around the equator daily. Other responders have assumed the poles are at fixed points on or near the equator, which means the axis rotates daily relative to the star-planet vector. The two cases would be very different in their effects on magnetic navigation (both artificial and what many animals use) and shielding against the solar wind.

Sunrise and sunset are dictated by the planet's rotation, not by its magnetic field, so I don't understand what he means by "beyond sunrise and sunset." It seems likely that your buddy is laboring under more misconceptions than just the feasibility or likelihood of radically separating the magnetic and rotational axes. Perhaps if he would explain just what he means by "beyond sunrise and sunset" and "parallel to the host star" those misconceptions (or mine) would be exposed.

It's become apparent that I didn't explain what my friend was asking well, and for that I apologize.

The globe would still spin east-to-west or west-to-east, whichever, it is just that the magnetic poles would be facing the sun once or twice a year. So parallel to the ecliptic. So is that alone not enough to greatly affect the life of the world?

[jqavins]

It's become apparent that I didn't explain what my friend was asking well, and for that I apologize.

The globe would still spin east-to-west or west-to-east, whichever, it is just that the magnetic poles would be facing the sun once or twice a year. So parallel to the ecliptic. So is that alone not enough to greatly affect the life of the world?
Whoa! that's a third option I hadn't though of. The magnetic pole is parallel to the ecliptic and fixed relative to the fixed stars. So it goes around the equator daily and around the star-planet vector seasonally, right? This will take some further pondering.

[Jendekit]

Whoa! that's a third option I hadn't though of. The magnetic pole is parallel to the ecliptic and fixed relative to the fixed stars. So it goes around the equator daily and around the star-planet vector seasonally, right? This will take some further pondering.

If that means the same thing as taking Earth with north as ~90o and moving it so that north's ~0o, then yes :smallsmile:

[jqavins]

If that means the same thing as taking Earth with north as ~90o and moving it so that north's ~0o, then yes :smallsmile:
I'm still not getting through with what my question is.

First, let's define what "north" means and what 90o and 0o mean.

The Earth has two intrinsic axes: its axis of rotation and its magnetic axis (with the magnetic poles at each end) as you know. "True north" is the direction toward one particular end of the rotational axis. Pointing in that direction is called a 0o heading, but the corresponding point on the Earth's surface is 90o lattitude. Moving the magnetic axis wouldn't change this; what I think you meant in the above is "moving magnetic north from ~90o lattitude to ~0o lattitude" where lattitiude is defined by the rotational axis. I know this seems pedantic, but the ultimate answer depends on getting the question exactly right, which is difficut when natural language uses "north" to mean two different things (true vs. magnetic) and also uses 90o to mean two different things (heading vs. lattitude.)

The rotational axis is tilted about 23o from perpendicular to the plane of the Earth's orbit around the Sun, i.e. the ecliptic. It always points very nearly toward Polaris, one of the fixed stars, so it points toward or away from the Sun (or obliquely) at different points of the year, creating the seasons, which you also know.

The magnetic axis is tilted (presently) about 10o from the rotational axis and intersects the surface at two particular points on the surface; the north magnetic pole is presently about 80oN 72oW, which places the south magnetic pole at about 80oS 72oE. (Actually, the magnetic poles are not precisely antipodal, but that's more detail than we need.) Thus, the north magnetic pole's bearing to the Sun varies ±10o around the rotational axis's bearing to the Sun each day (on top of the yearly cycle of the rotational axis's solar bearing.) On the other hand, its bearing to Polaris is always 10o in magnitude, but drawing a daily circle around Polaris without a yearly component. (Well, very close.)

So, here's what I'm trying to get straight. With one magnetic pole's lattitude changing to 0o (let's not call it "north" anymore; let's just call it pole A) does it still have a fixed longitude? That's what the other responders have assumed. Or does it always point toward the sun, i.e. the pole can always be found wherever on the equator it is high noon? That, too, would be a reasonable interpretation of "parallel to the host star." But then you seemed to say it would have a constant bearing to a point among the fixed stars, which would put it wherever high noon is for one day of the year and wherever midnight is half a year later.

[Jendekit]

I'll use the following picture to get my point across and save myself a thousand poorly chosen words.

http://facweb.bhc.edu/academics/science/harwoodr/Geog101/study/images/AxialTilt.jpg

Basically that, but adding 65-70 degrees to the tilt. Does that clear it up?

[brian 333]

We are discussing two different things here: Axial tilt of the planet and the shape of the world's magnetosphere.

Uranus (http://pages.uoregon.edu/jimbrau/BrauImNew/Chap13/7th/AT_7e_Figure_13_06.jpg) is laying on its side and its poles alternately face toward and away from the sun. Aside from a little precession which is common to all rotating bodies, its axis of rotation keeps it fixed pointing toward some star or constellation as a 'North Star' or 'Southern Cross'.

Urnaus' magnetosphere (http://lasp.colorado.edu/home/wp-content/uploads/2010/08/MOP-4Tilts.jpg) is tilted 60 degrees off this axis, which makes it the most radically divergent of the known magnetospheres compared to the planets' axis of rotation.

Now, I am assuming that you are discussing the second. What we would call the North Pole and South Pole lie in the plane of the ecliptic (http://en.wikipedia.org/wiki/Ecliptic#mediaviewer/File:Ecliptic_plane_side_view.gif). The magnetosphere of the world would lie in the axis of the ecliptic (http://en.wikipedia.org/wiki/Ecliptic#mediaviewer/File:Ecliptic_plane_top_view.gif) if it were offset by 90 degrees from the planet's rotation.

This would, in effect, make every magnetic compass a clock. It would actually improve navigation, because metric time was the one key missing from accuracy in navigation until the invention of the escapement allowed spring-powered clocks to work.

We don't really know that birds, fish, and other migratory animals use the Earth's magnetosphere to navigate, but there is some evidence to support such theories. In this case, such animals would be screwed, because their navigation equipment would be pointing to the time of day rather than the location of good feeding grounds! In this case evolution would never have generated such traits, or would quickly suppress them.

Earth's magnetosphere is not stable. (http://en.wikipedia.org/wiki/Geomagnetic_reversal) It flip-flops all the time. While the geological record is fairly clear on the times that polarity is one way or the other, it is difficult to pin down the geological periods in between, so it is still unclear what exactly happens. As such, there are many hypothesis about this.

The last flip-flop was a double-reversal about 40,000 years ago, just as the mega-fauna of the Ice Age began to die off and humankind began to spread over the planet. There is no statistical correlation between magnetic reversals and extinction events, and humanity weathered the last one and the one before that just fine, so it's improbable that such an event would result in more than a need to install inertial navigation equipment on our long range transports and to create a whole new set of Boy Scout Orienteering Manuals.

Given this, it is unlikely that a distortion of the world's magnetosphere from what we consider normal would impact life to any great degree. In the case of axial tilt of 90 degrees, my money would be on the need for most species to be able to deal with long cold periods as a primary evolutionary trait. Various species would migrate, hibernate, or develop cold/hot tolerance in other ways, because at one point or another every part of the world would be directly under the sun, and every part of it would be directly away from the sun.

[Ursus the Grim]

I've been scribbling notes down every time I check this thread.

I've got a new 'what-if' though.

I have two mountain ranges coming together from West and East, meeting together in a volcanic northern range. To the south is water, a bay, I suppose, where the ranges spread further apart. Because most of the precipitation comes from the Northwest, I've created a desert in this little pocket. I imagine that near the bay, this desert would look similar to the Namib desert. Sand seas near the coast, some lichens and succulents scraping out life. Gravel plains a little further north, inland. Then, near the volcanic north, I'd like to have some lava fields, possibly looking a bit like Reykjanes. Its been 500 years since the last eruption (which I know, doesn't really mean the volcanos are dormant), and the lava spread in some unconventional directions, meaning not all of it went into the Desert, because a Dwarf Did It.

Would the wind coming in off the Desert proper be enough to gradually weather some of the lava field? Granted, there has been lava there for longer than 500 years, that was just the most recent event.

The desert is approximately 80 miles long from the Bay to the Volcanoes, and 30 miles at its widest point. If we count from the Bay. . . .
0: Coast
0-10: Coastal Desert. Some vegetation, but not much.
11-30: More arid sands. No vegetation.
31-40: Gravel desert.
41-60: 'Black Gravel Desert'. Oldest part of the lava field, worn down by wind and the rare rainfall.
61-80: Lava fields and foothills.

Does this seem plausible?

Bonus Point: Lava flows downhill. So does water. If we had a river running south, fed by tributaries in the mountains, how would this interact with the volcanic activity?

[jqavins]

This would, in effect, make every magnetic compass a clock. It would actually improve navigation, because metric time was the one key missing from accuracy in navigation until the invention of the escapement allowed spring-powered clocks to work.
Don't forget the effect on the magnetosphere's ability to shield us from the solar wind. This shielding is weakest at the magnetic poles. In Earth's configuration, the incident solar flux is weak at the poles since the megnetic axis is nearly perpendicular to the Sun-Earth vector; the solar wind passes right by the poles tangentially. The Aurorae are caused by solar wind actually guided into the "wells" over the magnetic poles, but the direct incidence is very small.

Now consider a magnetic pole on the equator. The directly incident solar flux is greatest at the equator, right where the gap in the shielding would be. If the magnetic poles have fixed longitudes then their neighborhoods are each rather intensely irradiated for a few hours around noon daily. On the other hand, if one pole always points toward the sun (which is the case that would make compasses into clocks) then the sub-solar spot is always being intensely irradiated, and the entire equitorial region is swept by it daily. On the third hand, if the magnetic axis is constant relative to the fixed stars then the situation would oscillate between the sub-solar hot spot twice a year (when one pole or the other is pointing to the star) and Earth-like a quarter year off from those times, when the incident flux is perpendicular to the magnetic axis (i.e. when the magnetic axis is tangent to the planet's orbit, more or less.) It comes down to this: how much of the equitorlal region gets cooked, how intensely, and how often?

These solar radiation considerations, along with the magnetic clock thing, are why I've been trying to pin the orientation down completely, not satisfied with just the equitorial lattitude, not ready to assume fixed longitude. Then came the post with the picture that seems to state we're talking about tilting the rotational axis, Uranus-like, which is the opposite of what the first post on the question stated. I'm about ready to give up.

[brian 333]

Well, all of the magnetospheres of the Solar System have an axis more or less perpendicular to the plane of the ecliptic so none of them ever point their north or south pole directly toward the sun.

In the example I gave, the world's rotational axis was parallel to the plane of the ecliptic and the magnetosphere was perpendicular. In your example the world's rotational axis is perpendicular to the plane, and the magnetosphere is parallel.

I'm not sure a magnetosphere can exist as described in the second case. While the dynamics of formation of magnetospheres is not fully understood, it is clear that interaction with solar wind is a primary component. Even in the absence of a naturally occurring magnetic field, an atmosphere would induce one as it swept through the ionized particles of the solar wind, and this field would have to be more or less perpendicular to the solar wind. (Mars.) (http://scienceblogs.com/startswithabang/files/2013/11/aspera_solar_wind1.jpg)

The primary magnetic field in any stellar system will be generated by the star in the middle of it. This will skew every other magnetic field in its field of effect, (which is massive.) Magnetic lines of flux try to align to parallel each other, but they are loops and not straight lines, so distortion is common. However, even when bucking phases the tendency is for magnetic fields to attempt to align.

Have you ever played with shaved iron and magnets? When you place two magnets in proximity to one another astonishing patterns (http://c8.alamy.com/comp/BPT8M6/Bar_magnets_with_iron_filings_showing_magnetic_rep ulsion_between_similar-BPT8M6.jpg) emerge in the filings.

[brian 333]

I've been scribbling notes down every time I check this thread.

I've got a new 'what-if' though.

I have two mountain ranges coming together from West and East, meeting together in a volcanic northern range. To the south is water, a bay, I suppose, where the ranges spread further apart. Because most of the precipitation comes from the Northwest, I've created a desert in this little pocket. I imagine that near the bay, this desert would look similar to the Namib desert. Sand seas near the coast, some lichens and succulents scraping out life. Gravel plains a little further north, inland. Then, near the volcanic north, I'd like to have some lava fields, possibly looking a bit like Reykjanes. Its been 500 years since the last eruption (which I know, doesn't really mean the volcanos are dormant), and the lava spread in some unconventional directions, meaning not all of it went into the Desert, because a Dwarf Did It.

Would the wind coming in off the Desert proper be enough to gradually weather some of the lava field? Granted, there has been lava there for longer than 500 years, that was just the most recent event.

The desert is approximately 80 miles long from the Bay to the Volcanoes, and 30 miles at its widest point. If we count from the Bay. . . .
0: Coast
0-10: Coastal Desert. Some vegetation, but not much.
11-30: More arid sands. No vegetation.
31-40: Gravel desert.
41-60: 'Black Gravel Desert'. Oldest part of the lava field, worn down by wind and the rare rainfall.
61-80: Lava fields and foothills.

Does this seem plausible?

Bonus Point: Lava flows downhill. So does water. If we had a river running south, fed by tributaries in the mountains, how would this interact with the volcanic activity?

This question deserves a scientific paper to answer. It seems simple enough, but you get into many different things, like the composition of the lava material itself, the volume of airborne particulates, wind velocity, temperature differential both annually and diurnally, presence or absence of salts and moisture...

But what the heck, let's take a stab at it. Keep in mind I will explore one of many possible scenarios, and it will necessarily be a vague one due to a major lack of details.

Because of the coastal sands and rocky interior I'll assume a slope, with the interior lava plateau being about a mile or so higher than the coastal dunes. I'll further assume peak altitudes of two miles or so for the mountain chains, so mountains in the 10,000 foot (3000m) above sea level range and the plateau itself around 4000 feet (1200m) above sea level. Cold temperatures at this elevation allow accumulation of winter snows which melt into channels and sinks which form the upland head of aquifers beneath the apparently dry, stony moonscape of the lava fields.

However, lava is not as tough a rock as it appears to be, especially tuff and ash which are ejected by volcanic eruptions in much greater quantities than lava itself. While lava flows form dorsal ridges that radiate out from the central caldera, tuff and ash fill the voids between them with what appears to be dust, sand, and rocks from very tiny pebbles to massive boulders, all mixed together sort of like concrete, (but without the cement.)

Water percolates through this matrix, absorbing clays as it passes, creating tiny tunnels that feed down until they reach a lava floor where the water pools or forms underground streams that lead to such pools. Note that this will seldom be cavern systems because the material is not densely packed, and removing a volume of material would only allow upper layers to collapse into the void. Instead, it forms wet sands which allow water flow but do not become displaced by it.

When enough of these flows converge to create a steady stream of water it begins to form a channel with a powerful enough current to clear the debris away, causing collapse of the overlying materials, which also gets carried off until all of the overlying material is carried away, exposing the stream in a gully or canyon (http://upload.wikimedia.org/wikipedia/commons/2/2f/CanyonlandsNP_GreenRiverOverlook.jpg). This ultimately results in broad flat-bottomed canyons with steep sides or even cliffs. Early in the evolution of these canyons they can be quite narrow and bottleneck as debris dams the current for a time, until erosion cuts through and the dam's waters flood, excising the canyon even deeper.

As these streams converge into powerful rivers their meanders cut into the sides of the canyons, widening the floor of the canyon. Sometimes secondary canyons will then be cut into the floor of these broad plains as erosion continues.

The water continues down the path of least resistance towards the lowlands, but it now encounters the more pebbly lands of the intermediate zones, and this forces the currents to begin to break up and diverge. Wide swampy areas form here amid the rocks as the once powerful currents break up and spread out over a wide area (http://en.wikipedia.org/wiki/Okavango_Delta).

Depending upon the volume of meltwater that feeds the channel, the delta may spread out and dry up before it reaches the sea, or it may continue through the sandy belt to the coast. However, sand with low clay content will allow water to percolate through it and what may result is the water traveling beneath the sand to emerge in the sea along the coast, or if confined by a hard rock, (coral reef or limestone, for example,) or clay layer, could emerge miles offshore as fresh water springs most commonly known as blue holes. Otherwise it will form vast sandy deltas such as that formed by the Nile River.

This landscape, aside from the hydrologically active canyon floors and delta regions, will be arid. Because of this, a kind of weathering occurs in which the day-night heating and cooling tends to crack rocks into smaller and smaller fragments, and this leads to a lot of ultra-fine dust which does not get locked into the soil by moisture and biological activity. This kind of weathering is the origin of the Quatarra Depression (http://en.wikipedia.org/wiki/Qattara_Depression). Because these temperature changes also create winds, this ultra-fine material is blown aloft.

The heavier material remains at relatively low altitudes and adds a sandpaper effect to the wind. Windblasting sculpts rock, and adds to the material being blown into the air, speeding up the wind erosion power of the wind as it does. Lighter material lofts higher into the atmosphere and may settle out many miles away as nutrient rich, or poison rich, deposits. This is actually the origin of the Miami sunrise (https://www.google.com/search?q=Miami+Sunrise&client=firefox-a&hs=L66&rls=org.mozilla:en-US:official&channel=fflb&tbm=isch&tbo=u&source=univ&sa=X&ei=7DRZVI25G6PpiQLetYC4BA&ved=0CDIQsAQ&biw=1280&bih=639), as winds loft sediments high into the atmosphere over the Sahara Desert and bring them on the Easterlies to the East Coast of Florida, the Caribbean, and South America, (along with very rich minerals vital to the fertilization process of those regions.) This is also a major contributing factor in the development of hurricanes over the Atlantic Basin as the superheated cells move across the warm Central Atlantic picking up moisture and energy as they head East.

As winds blow West to East over this continental mass sand dunes along the South coast are pushed Eastward forming long chains of coastal dunes. This has the effect of creating shallow sandy bays and salt-lakes along the coast. This tends to increase the local daytime heat as humidity traps the air in local inversion cells during the day and in the night carries it away as humid winds, allowing the sandy soil to radiate the day's accumulation of heat into the night sky. By dawn the chill can become intense, even in summer, and this can generate fog banks as warm water meets cold air. Fortunately for boaters, the bottoms of the bays are almost universally sandy except in coral formations, so running aground is more likely to be an inconvenience than a catastrophe.

[Ursus the Grim]

This question deserves a scientific paper to answer. It seems simple enough, but you get into many different things, like the composition of the lava material itself, the volume of airborne particulates, wind velocity, temperature differential both annually and diurnally, presence or absence of salts and moisture...


Hah, thanks Brian.

I did get my BS in Environmental Science but ended up going into a less geology-focused field (insulating houses, lol) so I remember just enough of my classes to ask obnoxiously complicated questions.

Here I thought I was being easy by not bringing up tidal locking or the magnetosphere. :smalleek:

[jqavins]

In the example I gave, the world's rotational axis was parallel to the plane of the ecliptic and the magnetosphere was perpendicular. In your example the world's rotational axis is perpendicular to the plane, and the magnetosphere is parallel.

I'm not sure a magnetosphere can exist as described in the second case.
All true, but it is what the question was.

[HolyCouncilMagi]

I don't know if this is an entirely appropriate -ology question, but I'll go ahead and ask. I know that one of the things significantly enlarging the average human's necessary calorie intake compared to what another animal of similar mass would need is our brains, which are the heaviest proportionally to our body mass of any animal (though other, much heavier, animals do have larger brains). This is because of (or rather, it partially causes, but that's pedantic) our vast intelligence.

So dragons.

There are some weird things going on with dragons. Somebody else on this site whose name I can't remember based an entire setting on the flavor text that dragons could get more energy breaking down nonorganic material like rocks and gems than it takes to break them down; and they can fly with their wings, which is laughable all on its own, because they're heavy enough to have a crush attack. But I'm choosing to ignore these things for the moment.

So you've got a creature whose mental capabilities are over triple those of the average human, who is vastly larger than a human, and who regularly engages in high-calorie activities like flying for an hour or several hours per day to supervise territory, casting spells (I guess this might be effortless, but hm), and fighting things it doesn't like that enter its territory.

Given those factors, how much hunting territory would a dragon need to sustain itself, depending on location? A mile around in a forest... Fifty in a desert? This is more an ecology and biology question; how many sustainable daily calories could a dragon find in a given area, and what kind of calorie count would be a good rough estimate for a dragon's daily output? I know fantasy keeps us from getting anything exact, but...

[BladeofObliviom]

There was actually a thread about this, though it didn't really reach any usable conclusion. (http://www.giantitp.com/forums/showthread.php?367460-How-Many-Dragons-Could-Live-on-Earth) Might be fun to read anyway.

[brian 333]

Perhaps this is why dragons spend so much time sleeping?

Crocodilia spend a great deal of their time doing nothing but waiting. They make sudden aggressive attacks from a state of rest and after their energetic spurt return to a low-activity state. They eat when food is available and can spend long periods of time between meals. American alligators spend their winters in a nearly dormant state in which they almost never eat, but they are not hibernating and can launch into furious activity if disturbed.

Dragons are not crocodiles, it is true, and one aspect of birds' adaptation to flight is that they have one of the highest metabolisms in the animal kingdom. The adaptation to flight is even more energy consuming than the adaptation to intelligence. So, where does that leave us?

Well, let's back off a second and consider brains. The size of the brain is not really a good indicator of intelligence. Consider a Chihuahua and a Great Dane. There are certainly traits that differ from one breed to the other, but I have never been able to detect a difference in the trainability of a dog based on brain size. Indeed, my sister's Pomeranian was much easier to train than my Boxer, whose brain was probably the size of the Pom's whole body, but then my Boxer was perhaps just a stupid dog, or I was a bad trainer...

But what about birds? Well, African Grey Parrots have an astonishing capacity for word mimicry, and owners swear they know how to use them in context. My own experience with a Ringneck Parakeet informs me they are easily as trainable as my Boxer and perhaps even easier. My Ringneck, for example, would ask for, "Seeds, seeds, you want seeds?" when we sat down to dinner. What he really wanted was handouts from the kids because you could give him his regular seeds or even the sunflower seeds we kept as a treat and he would get mad and scatter them.

So, in my personal experience some birds have the brainpower of a Boxer with a brain the size of the tip of my little finger or even smaller, and there are studies into animal intelligence that support what I have observed. Cats are another example of an animal with a smaller brain than dogs with equal or greater intelligence, and what about ferrets?

Well, now that was a confusing non-explanation, wasn't it?

Assume a dragon's actual brain is no larger than needed to maintain its body, with a segment added on for thought. (Not really how a brain works, but we're not neurologists here.) If we use the bird model we can have a brain that is about the same mass as a humans in comparison to its body size, which would require 1/5 of the dragon's body to be devoted to its brain! (That's one funny looking dragon!) However, elephants have a much smaller, (proportionally,) brain which is 1/50th the elephant's mass, and it gets along just fine. This is more in keeping with the drawings of dragons I've seen.

A proportionally smaller brain would require proportionally less energy to sustain without decreasing intelligence. So a dragon's reliance on a high calorie intake would be reduced when compared to body size. Add in a reptilian metabolism and the ability to store energy for long periods by gorging when feeding then sleeping, and you begin to draw down the energy curve.

Then there's that nasty flight thing. In all real world flying species flight is a high energy adaptation. Dragons would need a power source to fuel this activity, not to mention to power its breath weapon.

Has anyone ever adequately explained a dragon's lust for treasure? Why, exactly, do dragons covet gold when they never spend a copper? Or magic items they cannot wield, for that matter? And why do they make piles of it and sleep on it?

I stipulate that rare metals and magic items have an aura that dragons find irresistible because they draw energy from it. Whether via actually eating the materials or via sublimation or some other means such as radiation, (similar to humans synthesizing Vitamin D in their skins while exposed to ultraviolet light, for example,) dragons make use of this magic field energy, storing it in their bodies over time and calling for it in bursts of activity. (This is why D&D dragons are limited to 3 breaths/day, perhaps? It's the limit of their battery charge.) This would also account for their need to sleep for long periods of time on a pile of treasure.

Such a premise might explain the ferocious marauding of dragons who have as yet not gathered a treasure. They require hundreds of bodies to gather the energy they need if they cannot absorb energy from treasure, and once they have a bed of treasure they can begin to rest to gain the same level of energy over time without marauding. This might also explain their preference for virgin flesh, as virgins might have an aura compatible with a dragon's dietary needs in the same way humans crave sugary foods.

[jqavins]

I don't know if this is an entirely appropriate -ology question, but I'll go ahead and ask.
Yes, completely appropriate.

Here's a quick and dirty approach to the calorie requirements, but I don't have the numbers to employ the approach and crank out an answer. I'll try to find some numbers and get back to it, but for now...


Start by getting a calories per day per pound figure from a range of animals with more or less similar intelligence, none of which fly. Look at the daily caloric intake of, let's say, mice, squirrels, skunks, a few dog sizes, horses, and hippos. Or something like that. Derrive from thses a relationship that lets you guestimate the caloric needs of an average "animal intelligence" creature of a given weight. Or maybe such a relationship can be found in the literature rather than derrived fresh. Such a formula is, of course, very rough, approximate, loosey-goosey, and all other adjectives indicating a low level of accuracy and precision, but close enough for jazz.
Apply this formula to a dragon. The result is the base figure for a dumbed down, grounded dragon. Call this XBASE.
Apply the same formula for human-sized animals (call this Y) and compare the result to a human's actual caloric demand (about 2000 Cal/day.) It is expected that the human's actual demand is greater than Y; as you noted, this difference is attributed to our large brain in comparrison to our overall size. Take the relative difference, (2000 Cal/day ÷ Y) - 1 and call it the Brain Adjustment Factor (BAF). If you want to consider dragons to be, on average, more intelligent than humand then increase the BAF by some arbitrary amount; twice the intelligence, double the BAF, or something on that order.
Compare the caloric intake of a few birds of various sizes to grounded animals of similar weight. Compare this bird to a mouse, that bird to a cat, etc. Again, divide the intakes then subtract 1. Take the average for a few cases if they are scattered around, but if there is a trend (like the larger the bird the larger (or smaller) the ratio) then you might want to extrapolate to a ratio for much bigger flyers. Take your final value of (calories for a flyer)/(calories for a non-flyer of the same weight) - 1 and call that the Flight Adjustment Factor (FAF).
Ignore magic. Unless humanoid spell casters have to eat extra, just consider the cost of the actual casting part of regular life (built into the BAF) and the actual magical energy to be from a separate source.
The dragon's caloric demand is then X = XBASE(1+BAF+FAF).


The whole thing is a super wild WAG. But, to paraphrase the MST3K guys, "Repeat to yourself 'It's just a game, I should really just relax.'"

Relating that to hunting range is likely even simpler. There's got to be lots of data available on the productivity for hunting of various types of terrain in various climates.

[Yora]

Something I've just been pondering, but not having a clear answer to:

In my world, there were only a few small and relatively isolated human tribes living on the borders of the great civilizations, until some of the elven kingdoms started hiring human warriors from the other side of the desert as mercenaries to increase the size of their armies. It worked out pretty well and also established trade links to the lands beyond the desert, so eventually entire tribes settled in the lands of the elves to become vassals to the elven kings. 300 years later, these humans have become a significant minority in the region, with some of the vassal tribes being now minor independent kingdoms.
Those elven kingdoms who have human vassals regard them as quite valuable and want to keep them loyal, while those who never hired human mercenaries understandably see them as intruding barbarians. Some of the minor human kingdoms regained independence when their liege was defeated by other elven kings, and in some cases they saw an opportunity to turn again their former masters, which is still the reason for some bad blood between those former allies. Especially as there are still many elves who remember their defeat and the betrayal of their former subjects.

Now my idea for the regional culture is that blood relationship isn't particularly high valued. Kinship defines everything, but most people regard it as somewhat fluid, and when someone is loyal to the group and follows its customs, it does not make much difference if the person was born into that group or joined it through marriage or adoption by a clan elder.

Now what I am pondering is, in what circumstances one would expect to see the most numbers of half-elves, and where would they be basically nonexistant?
I would imagine that in the very early phases, some of the human mercenaries would have taken local wives, which would have been elves. Though probably of low station. Once whole tribes migrated to the region, a generation or so later, that would probably have been less common. But given the much greater number of humans now being there, the actual number of half-elves being born might very well have remained the same.
But what would have become of these first-generation half-elves, who were basically soldiers children? Would they have had a life with their human fathers or, given these men were mercenaries in a period of intense warfare and constantly shifting alliances, would they remain with the elven families of their mothers, their human blood gradually disappearing in their own children and grandchildren? (Assuming things working similar to human ethnicities, children with only one foreign grandparent don't tend to be distinctly visible as such.) With Europes unglorious colonial history, there should be plenty of precendents for this. Does anyone know how these things generally worked out?
The other question regards the second phase, when whole human tribes became vassals to elven kings: What would be a likely scenario for intermarriage between the vassal and the liege families? I think it would seem plausible that the human chiefs would be very proud to have sons and daughters of elven nobles to marry into their households, with somewhat elven looking features even becoming desirable as seeming more "aristocratic" than the common warriors and farmers. Or would there perhaps be a desire to maintain their own ethnic identity? Pledging your loyalty to a foreign king and moving your whole population would probably indicate a strong desire to benefit from the culture and progress of the new overlord, so I think they would likely embrace it. However, if anyone knows of cases where the opposite happned, I would like to hear those too.
But what about the opposite case? Would the elven nobles want to bring members of the leading human families into their own? Would they regard it as a sign of power to have human nobles as the wives and husbands of their own children and join their courty, or would it be beneath them to personally associate and mix with their foreign mercenaries and vassals? Does anyone know of historic cases that could be comparable?

[Honest Tiefling]

1) What counts as a lower class, as in, what class/profession did these women come from?
2) *cough* You should also perhaps factor in...Ah, relations that are charged by the hour, if you know what I mean, unless the elves don't have this. That would also increase the number of half-elves.
3) Even if more tribes came in, would they be equally male or female, or predominately male still? Many settlers and explorer groups still had a majority of men. Also, they might want some more selection and try to woo elves anyway.
4) How does human marriage differ from elven marriage? Would it be more advantageous (assuming that elven women get to pick their own husbands) to get married to a human or an elf?
5) How healthy are half-elves? If they produce lots and lots of strong children due to not being inbred and its a large enough difference for people to notice, it might catch on...
6) What physical traits are considered attractive in these cultures?
7) Are there factions of elves, in that one could decide to throw their lot in with the humans to get the numbers to oust the other group? Did those nasty humans only rebel against the elves in that region, so other houses don't have as much prejudice?
8) If kinship is so flexible, would they care more about bloodlines, or more about how elven/human one acts?

[Yora]

1.) For this purpose, I would consider everyone "lower class" who isn't part of the aristocracy, that is families with political power whose marriage policies include dynasic considerations.

2.) Of course there would be lots of such half-elf bastards, but for these ones it's already clear that they have no place in "proper society" and are automatically marginalized, so I didn't bring them up specifically.

3.) I think the ratio would be pretty even, or at least similar to what it used to be in the old homeland. In the first phase, it was warriors seeking their fortune, in the second it was tribal leaders making the specific descision to relocate their entire people.

4.) Not quite sure about that yet. I generally favor a system where marriage is primarily an economic, and secondarily a political arrangement for both cultures. What bed everyone usually picks each night is for the people of the household to arrange among themselves. Society and religion don't really have much of an oppinion in that regard. For nobles, who can afford to feed a handfull of concubines without much effort, marriage is often treated more as a nicer way of permanent hostage trade than to keep track of the blood relationship of any children.
In the human clans, the heir of the chief or partriarch is generally any of his children, nephews, or nieces who shows the most qualification. Among the elves succession is often not inherited at all, as things get much too confusing with the long lifespans and large generation gaps. Instead it's the "inner circle" of the former leader who select the successor, often from among themselves (of course, if the old ruler had a favorite, which might well be his childm he would be part of the group).

5.) I like the idea of hybrids being more robust than members of more isolated populations. They would have the same stamina and fortitude of humans, with about half the life-expectancy of elves. But the way I think of elven longevity, that would generally not be a major factor. Death from accident, disease, and battle can take anyone at any time and elves don't plan for anyone to make it for the whole 350 years. If someone is up to a job now, he can be given a task or office. If he stays there for 15 years or 150 is not treated as relevant to an assignment.

6.) I think that generally there would be both plenty humans and elves who would find members of the other race attractice enough to consider as a life partner. I think that half-elves might actually be considered asthetically more attractive than a pureblood member of the other race, as they are only half as unusual looking. How much people would want to be associated with a half-elf is a different question though, and one I am still not decited about.

7.) I think human-elf relationships would be very much case by case based on specific local circumstances. And both races are very highly fractures, with no clear dominant factions. And elves allying with humans to join forces against another elven group was what set the whole situation into motion in the first place.

8.) This is probably one of the trickier things to get right in a way that seems belivable. Everyone makes a very clear distinction between "in-group" and "out-group", but this part of a persons identity depends very much on allegiance. Adopted children are legally full children, and that arrangement is often used to bring a person into the group when marriage is not convenient or possible, regardless of age. However, this works entirely on an individual basis and the person needs to become part of the household and a member of the family, living with them and working with them all day. There isn't really any "integration", but only very strict assimilation. If a person joins a new group, all ties to the old group cease to exist. (With a backdoor in the case of divorce, in which a woman (generally) has a claim to be taken back into the household of her father or his successor.) It's expect that a person who joins a group completely adopts its culture, including language, dress, and customs, and participating in the rituals to the ancestors and local place spirits. (Any forms of personal religion are highly varied between individuals of any group anyway, so that's generally not seen as a source of conflict.)
Most people are generally pretty cool with the customs of other people. If someone is a friend, ally, guest, or enemy depends almost entirely on diplomatic relationships between groups. It's not uncommon that a clan considers a neighboring clan of the same ethnicity their mortal enemies and apply that to every single member of that clan, while a lone wanderer from another part of the world and even a completely different race can be treated as a honored guest. People are not usually racist or xenophobic, but make a huge fuss about alliances and feuds.

[Honest Tiefling]

Perhaps I need to clear up a few questions.

Firstly, if marriage is a contract, then there are stipulations. What are the differences between human and elven marriages for:
1) Freedoms? What can a married woman do and not have to do in these marriages?
2) Property? Does the woman keep her stuff, or has half of the property of the marriage?
3) Brideprice/dowries? Where does it go, who has it, and who benefits the most out of this arrangement?
4) Divorce? People probably don't enter into these with this in mind, but the ability to change your mind without extreme social shunning might sway a few people. Who gets what property

As for the last question, some cultures care more about ethnic then racial identity. I would assume there is a chance that a society that doesn't care about blood to treat a half-elf that acts elven far differently then one that acts human, with the former possibly even being considered elven enough. They could put a greater emphasis on their culture, not their bloodline.

EDIT: Actually, now that I think about it, would there be any reason for elven men to marry the humans? Are there any qualifications an elven man must meet before marriage, and perhaps those who fail instead resort to human women?

[Yora]

1.) The main thing would be that one partner has to permanently move into the household of the other, which means leaving behind your family. If it's within your own clan, that's not such a big deal, but even between allied clans that can easily mean that visits may be almost impossible. However, when we're talking about the aristocracy, that might be a lot easier to arrange, and after all, strengthening diplomatic relations between the two families is the whole point between aranged marriages.
Since chiefs and kings can, and usually do have several wives, but both cultures handle succession based on merrit and not by order of precedence, having the marriage result in any children might often not be neccessary. If one of them wants a sexual relationship but the other is really opposed to it, none of the possible outcomes is probably going to be pretty, with heated legal battles for monetary compensations between the parents being the best case scenario, but this probably doesn't need to be figured out in detail for these purposes. Generally it's prefered to find matches that both of the children to be married agree with, and if both have a preference that is acceptible to what the two families currently need, then even better. If it's a purely political marriage and they come to an agreement to each take a separate concubine, then so be it. In that case, the bride is effectively a permanent hostage, that works out for both families as well. If however one of them takes a lover without the others consent, that's a serious breach of custom and reason for significant consequences. In case one partner loses interest in the others and denies permission to seek love elsewhere, that's also a big no-no. (Not seeing after your partners needs is considered quite a big thing in both old Christian and Islamic texts.)
The partner who joins the others household would also be expected to work in the same way as the other family members of her or his station. Which for famers would be working in the field, or for merchants and nobles to work in administration and household management. Since households are usually large, being wife or houseband to the head of the house doesn't neccessarily mean being the second in comand, as that position may well be held by a sibling, cousin, or uncle, who had been in the business for decades.
Always extremely important, particularly for nobles, would be to adequately represent the household to outsiders. As all of society is build around kinship, it's completely unacceptible for any family members to step out of line. The action of any member will always reflect back on the entire family. If a person who married into a family causes trouble in that regard, she may be confined to the house, or the marriage divorced and she kicked out and send back to her parents household.

2.) With property I think I'd like to keep things as simple as possible. All property except personal possessions is household property, under the management of the head of the family. This means primarily land, livestock, and business. Furniture, cuttlery, farm tools, and so on, also tend to fall under this. A person really only owns clothes, weapons and armor if any, and jewelry. Jewelry would be very important, as it would double as insurance if the household becomes unable to support a bride, for whatever circumstances. I think gold jewelry in India still is extremely popular and important because of that reason.

3.) Now in the case of rich people, I could see a custom of having kind of a "loan" to the other family accompanying the marriage, which would be a kind of tribute. For the honor of having a family member live in the other families household, it would be like a gift of gratitude. If the bride is more of a hostage, then it would be pretty much just plain tribute to a more powerful clan.
If the marriage gets divorced and the bride returns to her parents family, the same value of goods would have to be returned as well. However, the circumstances of the divorce might lead to the family refusing to pay it back, which is the stuff for some great stories about feuds. :smallbiggrin:

4.) I believe most societies do have the option of divorce and in most periods made good use of it. I think it's only in the 18th and 19th century, that it fell out of favor in Europe, and unless I am completely mistaken it's extensively covered in Islamic law as well. And I think it's part of the Code of Hamurabi as well. Where marriage for diplomatic and economic reasons is common, you of course want to have ways to make changes as the need arises. Henry VIII got into a fight with the Pope not because he was divorcing his wife, but because he really went a bit overboard with it. In the early middle ages, I believe there were lots of christian kings who had several wives at the same time. This is really just another case of the Victorians making up blatant lies about everything to make themselves look superior.
I think social stigma would be pretty low, if you can make a good claim that it was you who has been wronged in some way. That applies to both genders, and regardless of if you leave or get kicked out. The main trouble comes from arranged marriages, because several people had gone through quite some work to arrange it in the first place. If it's all for naught, the relationship to the other family ends up even worse than it was before, or you even end up in a battle over the money from the wedding, the parents at home might be seriously angry. And getting kicked out from your family with no other family to take you in would be a really big problem. For poor people, the question might really be primarily how you're going to eat when you divorce.

5.) Specific clan relationships beat ethnic and cultral background here as well. Two families can't make a marriage agreement if their clans are enemies. They both would betray their clan this way by not standing behind their chief on these things. A whole family might get kicked out of the clan for that, and the other clan most likely wouldn't take them in either. However, and this seems like a great opportunity to add some grit here, a family could capture members of enemy clans as slaves. If you had a situation where two people of hostile clans really would want to be together, staging a kidnapping and having that person taken into the household as a slave would formally work. However, if the clans had not already been at open war before, they most probably are now. Unless the patriach of the other family is so furious at his child that he banishes it from the clan forever, refusing to take it back even if it wanted to. And it will still have a bad effect on the relationship between clans. As head of household, you would have to consider it very well to allow any of your children to kidnap their lovers from other families and even if you think you're willing to risk your family, your chief could still punishing you for damaging the reputation of the whole clan, and even risking triggering a war, if the other patriarch has good relations with his chief.

Elves only need to be 24 and have the approval of the head of the household, or live independent and be 32 (the minimum age to be head of a mini-household). I don't see how human partners would be a "cheaper alternative". However, in times of social disruption, the pool of potential new mates would refill with humans faster than with elves. Elven women have a child usually once per decade perhaps, while it's not unheard for humans to have four children in just as many years. After 20 years, there will lots of young humans looking for parners, while the fewer elven children are still growing up.
I think it would seem appropriate to have some cases in which elven populations got severely decimated and they resorted to rebuilding their numbers by taking significant numbers of humans into their clan. That way they will have a good number of warriors again long before the other local elven clans do. It's after all a world in which space is plenty and populations usually rather small.

[brian 333]

Let's back up a moment and examine some base ideas.

Marriage exists for the purpose of property rights. It really has no other purpose. It defines who is eligible to inherit, who is responsible for the care of children, etc. So, what are the base property rights of the elven culture? Since they are presumed the dominant culture in the area, migrating humans would adopt their code of property when interacting with elves.

If women in elven society are full partners and not subordinate socially or legally, then they may well have as much say as males about who they choose for marriage or any other relationship. If women are subordinate, they would not likely be allowed to 'marry down' to unpropertied humans. If a sexual relationship elevates a female to common law marriage status, (such as for the protection of the woman and the insurance of the maintenance of her children,) then elven males would be less likely to 'marry down'.

Rebellious youths would break the social rules, of course, and rape is always a possibility, either way. But freely chosen partnerships across social and economic boundaries are not commonly acknowledged, though they do occur.

If there is no onus upon the father to care for such children, then fathers would be very willing and mothers very unwilling to engage in such relationships. If there is also an imbalance of power, such that the father in this case can compel obedience to his desires, this kind of unequal relationship would be extremely common.

If there were great social and legal pressure applied to fathers to care for such children and their mothers, then the reverse would be true, in that fathers would be reluctant to acquire additional burdens while mothers would be eager to gain a more financially stable partner. If there were also an imbalance of power such that the father can compel obedience, then this would lower the odds of a female attaching herself to such a male.

So, depending on how the dominant race views property rights regarding inheritance and how they regard responsibility toward offspring, we could have a wide spectrum of possibilities with regard to half-elf population.

Then there is social stigma. If there is a negative view of such relationships within a culture it would serve to limit them. If the stigma attaches only to the mother and the child, and there was a power factor in favor of the father, there would be more half-elven offspring, but if the stigma attaches to the father there would be fewer such births.

If half-elves are shunned by both races and their mothers treated as undesirables, mothers would be extremely reluctant to bear such children. Powerful males could compel such relationships, but females would seek protection from this if possible.

I know this doesn't answer your question, but there are many factors involved. Consider these factors in your societies and the answers will begin to pop out.

For example, if humans mistreat women who bear half-elven children and relegate half-elves to a lower caste, but elves accept such women and children, then you may have many elven mothers of half-elves and few human mothers of half elves.

If humans tend to be poor when compared to elves, but elven society demands elven males support their illicit offspring, then many human women will seek to 'trap' an elf into giving them a child, while elven females would be reluctant to bear the children of human males due to their inability to offer support.

[Booper]

A long time ago when I was a kid, I had an idea for a planet with two intelligent species that had no knowledge of each other; until modern tech allowed them to meet. I came up with a world that had tropical poles and an equator too cold for them to cross until the industrial age. To make such a planet possible, I came up with two suns. Rather than orbit around them, the planet kind of sling shotted up and down between them, the gravity of one sun always pulling the planet just enough to never crash into the other.

It made sense when I was little, but now my question is, how can a planet realistically have hot poles and a cold equator? Or is magic the only way to make it work? If it could happen, what would life there be like, if at all possible?

[SirKazum]

I can imagine the two suns orbiting one another, in a binary star system, and the planet caught exactly in the barycenter of this system, between the two suns. For the climate zones to be as you describe, it would have to be tidally locked between the two - otherwise, if it rotates relatively to the two suns (i.e. they rise and set when seen from the planet's vantage point), the whole planet would be heated by them and there would be no ice band. But then there's another problem - the two suns would appear fixed relative to the planet, and both halves would actually have eternal daylight, which would heat them up way too much. I've been actually asking around this very same thread about tidally-locked planets, for my own setting (see my sig *plug*), and it's hard to make it work :smallwink:

I just thought up another possible solution. It appears that you want each half of the planet to experience a day-night cycle, except that each of the two suns would only hit a certain area above the equator. I don't have appropriate graphics tools here with me, but bear with me and see if my descriptions make sense. Okay, let's imagine how it looks from the planet's vantage point. In the, say, northern hemisphere, you have a "northern sun" that "circles" the planet (when observed from the planet's surface) somewhere off toward the planet's north pole, and similarly with the "southern sun" in the southern hemisphere. If, in a regular planet, the sun's trajectory looks like a wide circle around the planet (not *quite* on the same plane as the equator due to the inclination of the planet's axis of rotation), in this here planet the northern sun's trajectory would be a circle way off toward the north pole. The planet wouldn't be in the center of this imaginary circle, as "normal" planets are. If you connected this sun's trajectory to the center of the planet, the resulting shape would be a cone. And the same for the southern sun.

Now, this is the movement of celestial bodies as viewed from the planet. When viewed from the binary system (if you rotate along with the two stars in such a way that the two appear to be standing still), the planet is stranded right in the middle of the two... but it's rotating along a slanted axis. Its axis of rotation would be diagonal relative to the imaginary line that connects the two stars. I don't know how that would happen - maybe an impact knocked it around and tilted its axis of rotation. That should give the effect described in the previous paragraph.

As for orbital movement (or other movement relative to the stars), the planet would have to be smack dab in the middle of the two (in the system's center of mass, which is not necessarily equidistant from the two stars, depending on their relative masses), and the two stars would effectively orbit the planet. (Actually, they're orbiting each other, but since binary orbits are around the system's center of mass, it would look like they're orbiting the planet.) What you described, of the planet wobbling between the two stars, wouldn't really be possible, since gravity is inversely proportional to the (squared) distance between the bodies - therefore, if the planet moved away from star A and toward star B, it would "feel" increasingly less gravitational attraction from star A and more from star B. So it wouldn't ever bounce back, but rather just keep moving toward star B until it's engulfed. Unless it makes a figure-8 trajectory between the two stars, but that doesn't appear to be what you want.

[jqavins]

Not necessarily magic, but an Extraordinary ObjectTM, be it magic, alien or lost civilazation tech, or a really really improbable natural phenominon that happened anyway. Here's the idea:

Start with a planet whose axis is tilted nearly 90 degrees, like Uranus. This makes one pole hot and the other cold. But, add the Extraordinary Object at the planet's L2 point, and make it hot enough to provide about the same incident heat as seen from the planet's anti-solar pole as the solar pole gets from the sun. The equator is then the coldest region.

To make the equitorial region really arctic you'd need the axial tilt to be quite near exactly 90 degrees, much closer that Uranus's. You still might not get as much temperature difference as you originally envisioned, but then "tropical" and "arctic" are in the heat and cold receptor nerve endings of the beholder, so if your people are wimps it could work. (And I'm not sure they need to be wimps at that; I don't know how radical the temperature extremes could get.)

Mind you, this configuration has other implications. There is no night on either side, just twilight in the middle. There are no seasons. If the planet is close enough to the sun for a significant solar tide (on Earth, for example, the Sun's contribution to the tides is nearly half that of the Moon) then this force would always be stretching the planet along its axis, and might actually change the shape from sperical to a noticable degree. And more, I'm sure.

Nope, that doesn't work. The L2 orbit is not stable either. My bad.

[Storm Bringer]

a neater solution would be to have the planet have an orbit between a binary pair (so lit form both sides. managing to sit within both stars habitable zones is really unlikely, but no more unlikely than having life, so meh.). The whole set up is tidally locked (http://en.wikipedia.org/wiki/Tidal_locking), so one side of the planet is always facing "inwards" and one side is always "outwards", like how we only see one side of the moon, because it's turning at just the right speed to keep one side facing inwards.

the hard part is ensuring the outer sun is always their to keep the outer face warm, as normally its further out orbit would mean It would "lag" behind and only light the surface for some parts of the year (and the rest of the year it would be stupid cold. like, colder than anywhere on earth cold).

I think some sort of very Eccentric (non round) orbit around the primary, where the outer sun has a short, high speed pass around the sun and then spends most of it's time on a slow outer loop at roughly the right distance. A sort of natural Molniya Orbit, (http://en.wikipedia.org/wiki/Molniya_orbit)if you will.

getting the orbit to progress so it's always lighting the outside is, again, tricky. like really tricky. I'm not sure it's possible.

but for a sci-fi/fantasy handwave, it's all good.


my understanding of the net result of this set up is detailed below. Note that when I'm talking about the "pole" and "equator", I'm not talking about the actual poles and equator (which are where they have always been), but the points nearest to and furthest away form the inner (primary) sun, and the mid point between them where the terminator for the Inner sun lies.



the Nearside has a large expanse of very hot desert that is uninhabitable, with eternal sun. the near "pole" is going to be very close to or above boiling point. form being lit 24/7. around the edges of this desert is a band of habitable ground, also in permanent daylight, which gets colder the closer to get to the "equator". discounting the effect to the outer sun, their are not really any seasons, so plants will basically grow continuously. the closer you get to the "equator", the lower the suns angle. Any permanent shadow is going to be bear of plants that can't reach clear of the shadow, as they in basically never been in the sun. right close to the "equator", the backsides of whole hills are going to be devoid of plants, on top of being quite cool.

The impassable ice field is going to be slightly "over" the midpoint line, as convection is going to warm it up a little (the winds here are going to be blowing towards the near "pole", in a set of huge convention cells that rise at the pole and drop over the midpoint, warming that area up a bit.)


now, the Farside is generally going to be much cooler, and much less habitable. The sun that warms it is smaller, and not always present. this side is going to see months long "nights" like the polar regions do. the temparture is going to be warmest just before the sun sets and just after it raises, as that's when the sun is closest. the mid point is going to cooler, so the temperature graph is going to look like a "M" shape with a dip in the middle, two spikes and major lows over the sunless period. Most plantlife is going to be tailored to use this cycle, and will bloom at sun up, live while the sun is high in the sky, then flower and die off as the temperature rises again before sunset.


how animal life is going to be adapted to live in either of these "poles" is rather beyond me, apart form hibernation or similar behaviour being common on the Farside to cope with the Long Night.

[jqavins]

What you described, of the planet wobbling between the two stars, wouldn't really be possible, since gravity is inversely proportional to the (squared) distance between the bodies - therefore, if the planet moved away from star A and toward star B, it would "feel" increasingly less gravitational attraction from star A and more from star B. So it wouldn't ever bounce back, but rather just keep moving toward star B until it's engulfed. Unless it makes a figure-8 trajectory between the two stars, but that doesn't appear to be what you want.
She knows that. That's why she's asking for a new solution.


I can imagine the two suns orbiting one another, in a binary star system, and the planet caught exactly in the barycenter of this system, between the two suns.
Problem is, this is unstable for the same reason as the yo-yo planet. The moment the planet's orbit is perturbed the slighted amount - say, by another planet in the system, its own moon, or an asteroid strike - it would no longer be centered and would crash into one star or the other.


For the climate zones to be as you describe, it would have to be tidally locked between the two - otherwise, if it rotates relatively to the two suns (i.e. they rise and set when seen from the planet's vantage point), the whole planet would be heated by them and there would be no ice band. But then there's another problem - the two suns would appear fixed relative to the planet, and both halves would actually have eternal daylight, which would heat them up way too much. I've been actually asking around this very same thread about tidally-locked planets, for my own setting (see my sig *plug*), and it's hard to make it work :smallwink:
Yes, I neglected to mention, that is true of my Extraordinary Object solution as well. And yes, that's hard to work out.

[Booper]

Hmm, its sounding more and more like two suns isn't the answer...Would making the ice band along the prime meridian instead of the equator make any difference? I can't imagine it would, but you all seem to know more about this stuff than I do so I'll ask.

What about a tidally locked planet with one sun, but on the other side is heavy volcanic activity to keep things warm? Plants could be more like the kind found at the bottom of the ocean, feeding off thermal vents rather than sunlight. Although how an ice band could form with so much heat from both sides is beyond me. Maybe its a very big planet and the volcanos are only in the "arctic" circle?

I thought about just making the two species a sort of elemental so they can survive the extreme temperatures, but I decided not to. If possible I'd like them to be more organic than supernatural.

[Carl]

There is one fairly simple way though explaining the orbit would be tough.

Have it orbit in a highly elliptical orbit around a gas giant, one of who's ends always points at a single sun with a rotation rate of half a revolution per orbit. That would mean each orbit around the gas giant would warm a different side of the planet, but the orbit would have to be around 12 hours to produce a day night cycle like ours, which is probably a bit fast for a gas giant orbit.

Alternatively 2 suns and a 24 hour orbit with a rotation locked to it's orbital period would work.

Actually that might be easier on the orbital mechanics aspect, if we assume the planet is a capture rather than natural thing and the gas giant is tidally locked between the two stars un-moving the two stars would keep an eliptical orbit stable, otherwise you have to invoke a lot of other moons for funky stuff.

[Storm Bringer]

I think we can agree that creating the "hot poles but cold equator" set up would require a rather complex and disbelief stretching set up, though not one totally beyond the pale.

so, I would like to ask a variant of Booper's question:

How can we create a world were two independent intelligent races exist, but are separated by a barrier that would take advanced technology to cross?

my initial thoughts are either a genuinely impassable mountain range that you need to fly over, or a really turbulent sea that needed either submarines or iron hulled ships to cross.

[Eldan]

How about a race that lives in the deep (deep, deep) sea, maybe along hydrothermal vents, and one that lives on land? They could, maybe, exchange messages, maybe even trade goods, but due to pressure differentials would never meet face to face.

[jqavins]

Not necessarily magic, but an Extraordinary ObjectTM, be it magic, alien or lost civilazation tech, or a really really improbable natural phenominon that happened anyway. Here's the idea...

Nope, that doesn't work. The L2 orbit is not stable either. My bad.

What might be simplest in terms of orbit handwaving is to go back to the EO at L2, but it can't be natural. Either a magic object or an alien (or lost ancient) tech could have some station keeping mechanism to maintain the unstable position. So it would have to be something like, say, a giant starship with an overactive matter-antimatter reactor. L2 for the Sol-Earth system is about 0.01 AU from Earth, so the EO's output would have to be about 1/10,000 of the Sun's to have the same apparent intensity as seen from Earth. From the previous discussion about tide locked planets, the sun in the system here would be lighter than ours, which makes the ratio even more extreme, so it might be somewhat, if barely, plausible. The station keeping systems would have to be awefully hardy and/or well shielded from the hot reactor. A few tons of antimatter fuel might last the tens or hndereds of thousands of years needed for distinct intelligent species to evolve, but I haven't done any calculation for that yet; I'll get back to it at lunch time.

Physics is a harsh mistress. Even with very favorable assumptions about the mass and luminosity of the star, the OE would have to consume about 10 tons/sec of antimatter. So, I take it all back. Again.

[Jendekit]

a neater solution would be to have the planet have an orbit between a binary pair (so lit form both sides. managing to sit within both stars habitable zones is really unlikely, but no more unlikely than having life, so meh.). The whole set up is tidally locked (http://en.wikipedia.org/wiki/Tidal_locking), so one side of the planet is always facing "inwards" and one side is always "outwards", like how we only see one side of the moon, because it's turning at just the right speed to keep one side facing inwards.

the hard part is ensuring the outer sun is always their to keep the outer face warm, as normally its further out orbit would mean It would "lag" behind and only light the surface for some parts of the year (and the rest of the year it would be stupid cold. like, colder than anywhere on earth cold).

I think some sort of very Eccentric (non round) orbit around the primary, where the outer sun has a short, high speed pass around the sun and then spends most of it's time on a slow outer loop at roughly the right distance. A sort of natural Molniya Orbit, (http://en.wikipedia.org/wiki/Molniya_orbit)if you will.

getting the orbit to progress so it's always lighting the outside is, again, tricky. like really tricky. I'm not sure it's possible.

but for a sci-fi/fantasy handwave, it's all good.


my understanding of the net result of this set up is detailed below. Note that when I'm talking about the "pole" and "equator", I'm not talking about the actual poles and equator (which are where they have always been), but the points nearest to and furthest away form the inner (primary) sun, and the mid point between them where the terminator for the Inner sun lies.



the Nearside has a large expanse of very hot desert that is uninhabitable, with eternal sun. the near "pole" is going to be very close to or above boiling point. form being lit 24/7. around the edges of this desert is a band of habitable ground, also in permanent daylight, which gets colder the closer to get to the "equator". discounting the effect to the outer sun, their are not really any seasons, so plants will basically grow continuously. the closer you get to the "equator", the lower the suns angle. Any permanent shadow is going to be bear of plants that can't reach clear of the shadow, as they in basically never been in the sun. right close to the "equator", the backsides of whole hills are going to be devoid of plants, on top of being quite cool.

The impassable ice field is going to be slightly "over" the midpoint line, as convection is going to warm it up a little (the winds here are going to be blowing towards the near "pole", in a set of huge convention cells that rise at the pole and drop over the midpoint, warming that area up a bit.)


now, the Farside is generally going to be much cooler, and much less habitable. The sun that warms it is smaller, and not always present. this side is going to see months long "nights" like the polar regions do. the temparture is going to be warmest just before the sun sets and just after it raises, as that's when the sun is closest. the mid point is going to cooler, so the temperature graph is going to look like a "M" shape with a dip in the middle, two spikes and major lows over the sunless period. Most plantlife is going to be tailored to use this cycle, and will bloom at sun up, live while the sun is high in the sky, then flower and die off as the temperature rises again before sunset.


how animal life is going to be adapted to live in either of these "poles" is rather beyond me, apart form hibernation or similar behaviour being common on the Farside to cope with the Long Night.

Physics, thou art a heartless bitch.

[Citrakayah]

How about a race that lives in the deep (deep, deep) sea, maybe along hydrothermal vents, and one that lives on land? They could, maybe, exchange messages, maybe even trade goods, but due to pressure differentials would never meet face to face.

That would work well. Diseases also work, though--a suitably deadly disease in one organism that is harmless to another (if I remember correctly, Ebola is pretty much harmless to bats) would make people pretty hesitant to explore an area without antibiotics. Or healing magic, I suppose.

A solution to the issue of magic (which could also deal with physical barriers [teleporation] or pressure differentials [both go to another plane and cast planar adaptation]) is to do what I did for the Southern Basin in Terra Chronos, and have magic be generally wonky in an area. Healing magic doesn't work against the pathogen, because the entire area in question suffered a magical cataclysm in the past, which the pathogen was part of. Since then, the pathogen has spread, but it remains immune to healing magic--perhaps it actually just makes it worse. Antibiotics and normal immune systems work just fine, though.

[SirKazum]

Depending on how magical/fantastic you want the setting to be, you could go the Hollow Earth route and have a whole other world inside the planet, with reversed gravity, and a sun in the center of the planet...

[Eldan]

That would work well. Diseases also work, though--a suitably deadly disease in one organism that is harmless to another (if I remember correctly, Ebola is pretty much harmless to bats) would make people pretty hesitant to explore an area without antibiotics. Or healing magic, I suppose.

A solution to the issue of magic (which could also deal with physical barriers [teleporation] or pressure differentials [both go to another plane and cast planar adaptation]) is to do what I did for the Southern Basin in Terra Chronos, and have magic be generally wonky in an area. Healing magic doesn't work against the pathogen, because the entire area in question suffered a magical cataclysm in the past, which the pathogen was part of. Since then, the pathogen has spread, but it remains immune to healing magic--perhaps it actually just makes it worse. Antibiotics and normal immune systems work just fine, though.

Plus you can dig out another classic and give the underwater race weird magic. Theirs is entirely different from that of the above-water cultures.

[Storm Bringer]

Physics, thou art a heartless bitch.

she ain't heartless, but she plays no favourites. The rules are The Rules, following them is not optional.

in real life, at least. in fantasy? Screw the Rules, I Make Them! (http://tvtropes.org/pmwiki/pmwiki.php/Main/ScrewTheRulesIMakeThem)