Absolute smallest viable size for a colony.

[Fyraltari]

((The other thing we're ignoring is that it is highly likely that the new planet and its native lifeforms will be biologically incompatible with us. Good news, we probably won't die from the local microbes. Bad news, the local produce is essentially indigestible.))

Since the all powerful alien is all powerful and does not want the settlers to die, he probably would have teleported some Earth flora and fauna before-hand. That’s what happens in the Omale series and is the main clue that the whole thing is deliberate rather than some kind of dysfonctionnement.

[Rogar Demonblud]

Not in Traab's setting conditions, so cannot be used. The alien moved some humans and some basic tools. That's it. To be strictly fair, Traab didn't even specify that all of the humans speak the same language, although I'm not sure if that's a plus or a minus.

[Fyraltari]

Not in Traab's setting conditions, so cannot be used.

Isn’t it, though?

a vast forest full of edible plants and creatures.

[Kashem]

Given the primitive conditions: I'd guess somewhere around 10. The real trick is the process of preserving as much knowledge as possible for the next generation as possible before the first generation dies off. The higher the technology level they manage to keep, the more likely it is that the group can keep the following running:

a) Some kind of functional, non-dictatorial government
b) Very careful breeding practices that prevent inbreeding as much as possible
c) Enough skills and equipment to produce the minimum supplies needed for the community to function.

In general, I'd probably take around 5 people who were highly-trained survivalists, a Farmer (Crops), another Farmer (Livestock), a Chemist, A Mechanical Engineer, and a Blacksmith.

Too many people:

Under these conditions, I'd also say that you likely won't have a lot of success if you send too many more than that. During the first year or two, the colony is going to only be able to subsist on what they can forage and hunt. Since you're dropping them on a theoretically non-earth world, they aren't going to know what is edible and what is not, which is going to make life really rough for them right off the bat. They aren't going to have any domesticated animals that they can rely on for basic food production (If you give them a couple of chickens and/or a couple of cows, you have a completely different picture) People are going to get poisoned, repeatedly, as they try and figure out what is edible and what isn't. If you have too many people, you are going to exhaust the resources nearby too quickly, and extending the distance you have to travel for basic supplies will break a settlement. If you were to send 50 people, you'd want to split them into 5 settlements and space them out, while having them know where the others are.

Surviving the weather:

Assuming the world you are putting them in has seasons, that is going to matter too. If you drop them in winter, it probably doesn't matter how many you drop, most people will freeze to death before they manage to get a proper shelter built. If you drop them in Summer or Fall, they likely won't manage to have enough food stored for winter. If you drop them just before or during monsoon season, they might die of exposure before they manage to build a good enough shelter.

The best bet would be to drop them in very early spring or late winter, when it is still chilly, but not too bad. This will give the Farmer (Crops) some time to hopefully figure out some edible things to try to grow it in time to plant them for the season, though realistically it'll probably take him several years to have a solid harvest of any kind. During that time, the Survivalists have to manage to forage enough food for everyone while the Farmer (Livestock) tries to figure out something he can domesticate or at least breed quickly for meat (think Rabbits).

Location, Location, Location:

The whole settlement will need to be somewhere very close to a spring or river, or other fresh water source. A river would also provide fish, a farmable and ready food-source. If the planet also has salt-water oceans, then dropping them not too far from that would be best; Salt is super useful in both preserving food for winter, and as a basic nutritional need for humans.
What kind of building materials are available matters a lot:
If they are near a Bamboo (or like material), then they have nature's most wonderful and functional building material. They'll likely have bamboo houses constructed within a month. They'll have water troughs, pipes, canteens, etc. right there waiting to be cut down. Bamboo is like the Babel fish; It is so astoundingly useful that it boggles the mind.
if there is a beech with sand, sand can be a very useful tool for making adobe, which can make some solid housing.
If they have to figure out stone, or they are in redwood forests or something that don't really have small trees, life is going to be a lot harder. Have you ever chopped down a large tree with a hand axe? I have. It took me and 10 other grown men an entire day to get through a 2 foot diameter pine tree, and pine is a soft wood. They'll end up making temporary shelters from fallen branches and such.

The First year:
The Survivalists will Hunt, Fish, and provide food and water for the group. The Mechanical Engineer will provide some kind of basic housing. The Farmer (Crops) will try to find something edible he can plant, and will attempt to plant a LOT of things to see if anything will grow. The Farmer (Livestock) will try and find anything he can breed for meat, and, god willing, will try and trap/breed some kind of bird that has edible eggs. The Blacksmith will try to set up a forge and find any kind of raw materials available, because even though you have given them basic hand tools, they have to maintain those tools, so that means they need metallurgy as soon as they can get it. Likely the best they will manage is cast-iron.

So why did I send a chemist?

The chemist's job is to make paper. Once things settle down, the most important job will be for all of the inhabitants to start writing down their knowledge as much as they can and as fast as they can. For that, they'll need a durable ink, and some kind of durable paper. They'll need to start recording what is edible and what isn't. What can be domesticated, what can be grown, where things are, maps. Before they die, the Engineer should write texts on advanced mathematics, physics, geometry, and the basic processes of invention and engineering and the scientific method. The farmers should write texts on selective breeding techniques, crop rotations, soil qualities, and all of the things that they learn about the land. The Chemist should write books on advanced chemistry, atomic and molecular structure and biology. The Blacksmith should write books on metallurgy, smelting, mining, and blacksmithing. The survivalists should write texts on the basics of human survival, and the steps that they took. They should also keep a history of the settlement, write books on politics, society, etc. so that future generations can keep having functioning social structure.

Why didn't I take a Doctor?

Because most of a doctor's training has nothing to do with wilderness survival. These people are going to be reduced to basics; they aren't going to have medications, and they aren't really going to be able to even get a start on any kind of medical practices beyond basic first-aid for several generations. The best you'd get out of a doctor would be some really detailed medical texts, which would be great, but likely aren't going to apply as well as you might think anyway. The kind of medical knowledge that will actually be useful here is going to be known by all of the survivalists.

Anyway, those are my thoughts. I'm a survivalist myself, as well as a software engineer who works closely with both mechanical and electrical engineers, so that's the point of view I'm coming from.

[Storm_Of_Snow]

If these are the parameters, I'm going to say what I said in the other thread: A working steam engine inside of a year is easily possible. Provided they don't have to invent anything - they just need to scrape together the raw materials, and build it.

If only it were that simple.

Let's take your steam engine - it's not just a matter of putting some steel plate together and chucking a match in, you've got to locate and dig the ore out of the ground, refine it, smelt it, get the chemical composition right when you make the steel, forge it and get it structurally strong enough to hold the pressure of the steam. Then build whatever mechanism you're going to use the steam engine to power.

Each of those steps involves a whole series of sub-steps and supporting technologies - smelting requires refactory bricks to make the blast furnace, a fuel source (at a minimum coke, which is itself not an easy process to create, and gas if you can get it), the protective clothing and tools for the worker to be able handle it, skim off the slag (and it's an idea to have dark tinted glass to allow someone to do that without being permanently blinded by the light from the molten metal) and so on.

And even if you do get all of that, you need food, clothing, medicine and everything else that keeps the colony alive.

[Traab]

If only it were that simple.

Let's take your steam engine - it's not just a matter of putting some steel plate together and chucking a match in, you've got to locate and dig the ore out of the ground, refine it, smelt it, get the chemical composition right when you make the steel, forge it and get it structurally strong enough to hold the pressure of the steam. Then build whatever mechanism you're going to use the steam engine to power.

Each of those steps involves a whole series of sub-steps and supporting technologies - smelting requires refactory bricks to make the blast furnace, a fuel source (at a minimum coke, which is itself not an easy process to create, and gas if you can get it), the protective clothing and tools for the worker to be able handle it, skim off the slag (and it's an idea to have dark tinted glass to allow someone to do that without being permanently blinded by the light from the molten metal) and so on.

And even if you do get all of that, you need food, clothing, medicine and everything else that keeps the colony alive.

I agree that steam engines in a year is bizarrely fast, however, I will add that one thing that will be a major time saver in going up the tech tree is the knowledge that these things can exist in the first place. There is no crazy person just trying things till something works, the colony will KNOW that steam boilers are a thing that can be built, that they are very useful, and some of the pitfalls surrounding them. Yes it will still require all that other stuff you mentioned, but, for example, they will know that you can turn iron into steel. With some solid record keeping they may even know what it will take. So its going to happen MUCH faster than the way it first went down. Instead of going, "I just invented this new thing! Clearly thats the new highest tier of power!" Its, "I just managed to figure out how to make this new thing! Now we can apply it to all these important milestones!" Instead of a bronze age, an iron age, etc, it will be an bronze generation, an iron generation, etc. Because the existence of the next step will be known as will the general guideline of how to get there. The push to advance rapidly will be there because of the knowledge that these better items will make things easier in the long run will always be there as well. "Yeah we could settle down with these iron tools, but steel will be so much better if we can get it setup!"

[Rogar Demonblud]

But you likely can't. For just one example, iron mines are not found near coal mines, as the geologic processes are completely different. So before you get a steel age, you need a massive transportation revolution.

[Fyraltari]

a) Some kind of functional, non-dictatorial government
b) Very careful breeding practices that prevent inbreeding as much as possible

That's a contradiction right there.
and even then, no careful breeding practices will save a colony of ten from genetic drift. Give them a few generation and they're all jusst as good as siblings, genetics-wise. Not to mention how fragile that group would be.
One person dies from food poisonning? Boom, there goes 10% of your genetic pool. One guy makes a bad fall and injusre his hip? Now you've got a mouth that can't contribute anything. A pack of local predators show up? Good luck fending them off without getting a single injury on your mere twenty working arms and twenty working legs. Someone gets space-flu? Well they're all dead.

Also the pregnancies (and taking care of the children) are also going to divert a lot of energy from the food-gathering and infrastructure building.

Assuming the world you are putting them in has seasons, that is going to matter too. If you drop them in winter, it probably doesn't matter how many you drop, most people will freeze to death before they manage to get a proper shelter built. If you drop them in Summer or Fall, they likely won't manage to have enough food stored for winter. If you drop them just before or during monsoon season, they might die of exposure before they manage to build a good enough shelter.

The best bet would be to drop them in very early spring or late winter, when it is still chilly, but not too bad.

O you know, in a tropical or equatorial region, where season are more of a concept than a reality.

[Grey_Wolf_c]

Or you know, in a tropical or equatorial region, where season are more of a concept than a reality.

Instead, you'd be dealing with a panoply of infectious diseases that'll absolutely decimate the colony over and over again, if it doesn't kill it outright, and a permanent 100% air humidity that really impacts the ability of storing food for any reasonable length of time. Also, IIRC, the soil tends to be rather terrible for growing crops. Although if you do use the burn-plant-move on cycle, at least you never stay in one place long enough for the :ahem: "nightsoil" to build up enough to cause problems.

Grey Wolf

[factotum]

Instead, you'd be dealing with a panoply of infectious diseases that'll absolutely decimate the colony over and over again, if it doesn't kill it outright, and a permanent 100% air humidity that really impacts the ability of storing food for any reasonable length of time.

Stuff like that doesn't apply to the tropics as a whole? Just to give one obvious example, the Sahara Desert lies at least partially within the tropics, and it's definitely not 100% humidity there! Vast portions of India are in the tropics, too, and they've somehow managed to get more than a billion people to live there.

Part of it comes down to acclimatisation, of course. British folks posted to India during the Raj would die far faster of disease or heatstroke than the local populace, simply because they (a) weren't used to the climate and (b) didn't know how to avoid the most obvious disease areas. It takes time to acclimate and get the knowledge of what's safe, but once you have that, there's no reason why you'd be any more likely to die in the tropics than anywhere else.

[Kaptin Keen]

If only it were that simple.

Let's take your steam engine - it's not just a matter of putting some steel plate together and chucking a match in, you've got to locate and dig the ore out of the ground, refine it, smelt it, get the chemical composition right when you make the steel, forge it and get it structurally strong enough to hold the pressure of the steam. Then build whatever mechanism you're going to use the steam engine to power.

Each of those steps involves a whole series of sub-steps and supporting technologies - smelting requires refactory bricks to make the blast furnace, a fuel source (at a minimum coke, which is itself not an easy process to create, and gas if you can get it), the protective clothing and tools for the worker to be able handle it, skim off the slag (and it's an idea to have dark tinted glass to allow someone to do that without being permanently blinded by the light from the molten metal) and so on.

And even if you do get all of that, you need food, clothing, medicine and everything else that keeps the colony alive.

Neither of those steps you mention are difficult if you know how, and have access to the raw materials.

The premise here is: You know how, and have access to the raw materials.

Hence, it's not a problem. You need time and manpower. You can do it within a year. It won't be the greatest steam engine the world ever saw (well, in literal fact it will), it won't be pulling any trains, but it will give you production power, on which you can quickly build more production power - so you can skip the 'digging in the dirt' colony phase, and get on with becoming a stable, secure place to live.

It is absolutely essential. Getting past the dirt farmer stage is more important than anything else.

[factotum]

Neither of those steps you mention are difficult if you know how, and have access to the raw materials.

The premise here is: You know how, and have access to the raw materials.

"Have access to the raw materials" is the bit you're just kind of skimming over, though. There's nothing in Traab's setting conditions to indicate that iron ore is provided, which means the colonists will first have to find the stuff, then mine it--all while using presumably primitive tools because they don't have iron yet. And only when they've got the stuff can they start thinking about actually smelting it, which itself is a bit of a task--there's a reason human civilization went through thousands of years of Bronze Age before getting anywhere near iron, and that's because copper and tin are far easier to smelt than iron is.

[Traab]

"Have access to the raw materials" is the bit you're just kind of skimming over, though. There's nothing in Traab's setting conditions to indicate that iron ore is provided, which means the colonists will first have to find the stuff, then mine it--all while using presumably primitive tools because they don't have iron yet. And only when they've got the stuff can they start thinking about actually smelting it, which itself is a bit of a task--there's a reason human civilization went through thousands of years of Bronze Age before getting anywhere near iron, and that's because copper and tin are far easier to smelt than iron is.

This. They have "access" to ore in that they have been planted in a mineral rich area but they have to build the tools to mine and refine it. They have the knowledge of how to do these things due to the education of the initial colonists which would save time in a large way because, to use your example, iron is well known to be superior in quality and they know how to make it so would be willing to push forward as fast as they reasonably can. But its still going to be a large time gap to get that far as they have to use stone tools, to reach bronze tools, to reach iron tools, etc etc etc. (Not sure what steps might be in between there, you get my drift though)

[Grey_Wolf_c]

Stuff like that doesn't apply to the tropics as a whole? Just to give one obvious example, the Sahara Desert lies at least partially within the tropics, and it's definitely not 100% humidity there! Vast portions of India are in the tropics, too, and they've somehow managed to get more than a billion people to live there.

Yes, I assumed that when Fyraltari suggested "tropical or equatorial region" he was not suggesting dropping them in the middle of a hot desert.

India is endemic to a large number of infectious diseases, including Malaria. The warm, humid environment makes great breading grounds for mosquitoes, a common vector. So yes, that stuff does apply to the tropics as a whole.

As to India's population numbers, I don't think these group of colonisers will have the ability to develop medicine to keep up with the diseases (or drain all nearby marshes, which is how Europe got rid of their own Malaria).

Grey Wolf

[factotum]

As to India's population numbers, I don't think these group of colonisers will have the ability to develop medicine to keep up with the diseases (or drain all nearby marshes, which is how Europe got rid of their own Malaria).

India has been populated for in excess of 30,000 years, long before any sort of "medicine" was available...the point I was making is that the people seem to be able to not only live there but to thrive, despite local diseases and apparent inability to store food. I don't think those problems are as big as you're making them out to be.

[Grey_Wolf_c]

India has been populated for in excess of 30,000 years, long before any sort of "medicine" was available...the point I was making is that the people seem to be able to not only live there but to thrive, despite local diseases and apparent inability to store food. I don't think those problems are as big as you're making them out to be.

Ok, and I am telling you they are. Malaria is like a really bad two-week flu, that you get twice a year and that leaves permanent damage. All the other various fevers and infectious diseases are about as bad. I've seen what Malaria does to people without access to mosquito nets for their beds, and it is not pretty. India did not "thrive" - like most pre-industrial societies, they muddled through by having many children and hoping that the weather would work out fine... and starving when it did not. India did have the massive advantage of spices, which meant lots of foreigners giving them money for the local plants. (North India has the rivers and good soil, but they are not tropical, and do have seasons)

But a small group, dropped in South India, and told to survive without outside help? They'd be dealing with a panoply of infectious diseases that'll absolutely decimate the colony over and over again, if it didn't kill it outright. And the spices will make for slightly better food, but they won't have anyone to trade with.

Grey Wolf

[Kaptin Keen]

This. They have "access" to ore in that they have been planted in a mineral rich area but they have to build the tools to mine and refine it. They have the knowledge of how to do these things due to the education of the initial colonists which would save time in a large way because, to use your example, iron is well known to be superior in quality and they know how to make it so would be willing to push forward as fast as they reasonably can. But its still going to be a large time gap to get that far as they have to use stone tools, to reach bronze tools, to reach iron tools, etc etc etc. (Not sure what steps might be in between there, you get my drift though)

If I was your all-powerful alien - and I wasn't aiming for creating a tribespeople mucking about in the dirt for millenia - I'd drop them somewhere where they could develop basic ironworking quickly.

I feel those are the options available: Have iron inside months, and steampower inside of a few years maximum ... or become famous plains people, ride wild horses bareback and unshod, shoot arrows at muffalo.

If you do not establish an industrial base, you lose the ability to do so. You become a tribe, living hand to mouth. Or, sure, you maybe become farmers instead, living .. field to mouth. Shaves off some millenia, but that's hardly attractive. Have production ability quickly - or lose your technical know-how, and ... worship the sky and the sun, thunder and earthquakes. You cannot maintain unused knowledge over generations.

But ... this is all hypothesis. Anyone's guess is as good as mine. But that's how I'm convinced it has to go.

[Rogar Demonblud]

Your farmers aren't going to have access to John Deere tractors, Cargill seeds or Monsanto chemicals. Heck, the ground rules don't even give the colonists draft animals to pull the non-existent iron plows. You will be living hand to mouth with subsistence agriculture. Prepare to lose a third of your population with a bad harvest.

Mining iron without the modern machinery will take thousands of people to dig, carry, crush rock, carry some more, pre-refine and carry yet again to get to the smelting stage. It is actually easier to work the iron than it is to mine it. Oh, and you'll need trained geologists to recognize the ore when they see it--better hope they don't die in the first few decades of this project.

[Kashem]

. You cannot maintain unused knowledge over generations.

This is absolutely not true; you simply have to be willing to do what it takes to keep it.

First generation will need to work out some form of paper, papyrus, or another easy writing mechanism (We're talking NOT chisels and stone tablets here). That generation writes down their information as well as they can. They raise their kids with an expectation that the children will literally set those works into stone, word for word, so they can be used later. They designate a Librarian for the tribe, who has the responsibility to be as educated as possible, and educate everyone else in the tribe, and to make sure that the knowledge is kept safe by making sure that there are multiple copies of the books in addition to the chiseled into stone versions. The Librarian should be revered as much as a religious leader, so that the books themselves start to be studied like religious works, with each generation "re-discovering" new parts that continue to be useful to them. Think of the "Librarian" being treated with the same respect that one would treat the Pope.

The Chiseled into stone versions should be chiseled into cave walls, where they won't be damaged, and once the original texts have been dutifully copied, they would be entombed somewhere for safe keeping.

People often are of the opinion that humans inevitably lose technology and knowledge, simply because we have at so many times. But the reasons that we've lost technological advancement are because of the Dark ages, and because of political and religious wars, and because of societies that flat out just didn't do a great job of writing things down in ways that last forever.

The people that you put on this world will be starting with one thing that has screwed up humanity for a really long time: a common language and alphabet. While they will eventually develop dialects, they will likely have advanced pretty far long before there is enough drift for them to have any difficulty communicating or reading each other's works.

[Rogar Demonblud]

You're assuming they will have a common language. Nothing the OP has stated backs that (or opposes, to be honest). And you have it backwards. Dark Ages don't cause loss of information. Loss of information causes Dark Ages, and they're also generally not that dark to begin with.

Your books will only last until the first time people have to choose between survival and hunks of dead tree that serve no useful purpose. Then they go into the campfire to fuel making supper.

The unspoken premise included in all this is that your alien has selected people who can survive without constant infusions of technologic assistance. That pretty much means we aren't talking first world humans here--which means your odds of literacy just took a big hit.

[GrayDeath]

Can I as the advanced alien use genetically engineered humans with all recessive genetic defects removed? Because that would definitely change the inbreeding problem for the first few centuries.

Ok, so since this has gotten to the point of ridiculousness, lets reel the parameters back in. This alien is transporting humans to another world. They start out with the clothes on their back, and a set of basic tools to start. By which I mean they have axes, shovels, knives, hammers, etc. The tools they need to create more tools and so forth as they rise up the tech tree. They are dropped in an area that is bordered by mineral rich mountains on one side, a river leading to an ocean on the other, a vast plain in the third, ideal for farmland, and the 4th is a vast forest full of edible plants and creatures. The goal is to create a permanent self sustaining colony and he is able to bring whatever number of men women and children he needs to create it. With all that in mind, and no interference beyond what I listed from the alien, how few could he get away with while making the odds of long term survival, barring inexplicable natural disaster or some such thing, nearly certain? Assume he is able to gather a mix of people with the skills and knowledge needed to survive and thrive in this setting as well. So hunters, farmers, doctors, survivalists, construction workers, etc etc etc.

And why, pray tell, does the unmnamed super powerful alien want to rip thousands of people out of thier lives and drop them in a situation that is somewhere between "barely surviving" and "a back to the nature Idealists Dream" with near to NO chance of them keeping their culture, technology (even written) or other things?


Assuming you change it in a way that includes tools up to the latest Rennessaince age, and "access to" means "already established mines", and the semitropics are either free of agressive diseases or the colonists are made immune, I`d say a few hundred can work fine (obviously with a strong overfocus on women, say 1 to 4 men/women tos tart off the population growth).

However, this overlooks a massive problem

Government.
People who have nothing in common and are simply drtopped in such a situation WILL experience horrible things, from total anarchy and "law of the Djungle" to either extinction or a form of stable Dictatorship.

So the question is again: is this just an experiement to show how "evil" Humans are if worst comes to worst or what does this Alien want?



Now if they simply wanted to remove viable numbers of humans from human culture/dsseed them to avoid their extinction, they would have (or be considered truly evil) make sure that they have basic early industrial tech, are all kinda willing (for example delete their memories like in the Safehold setting) and set up a kind of "overwatch" for their government (say some very powerful artificial intelligences) that are able to softly steer them away from the worst stuff.

and even then its gonna be hard (unless its a preengineered south sea paradise^^).

[Kaptin Keen]

This is absolutely not true; you simply have to be willing to do what it takes to keep it.

It absolutely is. No, really.

If you do not get off the ground, it doesn't matter than you assign half your workforce to being monks, writing down volumes and volumes of their knowledge on animal hides or whatever. A flood will come, or a brush fire, or a child will chew on it, or rats will get in it, or some other disaster - and then you truly are trapped riding bareback for millenia. Hell, teaching one kid how to build a combustion engine takes two people (kid and teacher) at least 10 years, working full time. You don't have that kind of time.

You put your knowledge to work, or you lose it. Not from day to day. But it will deteriorate to uselessness before you ever get a chance to implement it.

Or you skip that whole nonsense, and just get to work straight away, building machines. Frankly I don't even see why this is a point of contention. We mucked around in the dirt for more millenia than anyone has any clear count of - then we built a steam engine, and had space travel inside of two centuries. Build the steam engine. Or enjoy the millenia of dirt muckery.

Addendum: None of us know what we're talking about. Zero colonies have been built in space thus far, so it's all just guesswork and opinion. So if I come across as if I'm trying to claim I do know anything about this, that's unintended.

[Traab]

And why, pray tell, does the unmnamed super powerful alien want to rip thousands of people out of thier lives and drop them in a situation that is somewhere between "barely surviving" and "a back to the nature Idealists Dream" with near to NO chance of them keeping their culture, technology (even written) or other things?


Assuming you change it in a way that includes tools up to the latest Rennessaince age, and "access to" means "already established mines", and the semitropics are either free of agressive diseases or the colonists are made immune, I`d say a few hundred can work fine (obviously with a strong overfocus on women, say 1 to 4 men/women tos tart off the population growth).

However, this overlooks a massive problem

Government.
People who have nothing in common and are simply drtopped in such a situation WILL experience horrible things, from total anarchy and "law of the Djungle" to either extinction or a form of stable Dictatorship.

So the question is again: is this just an experiement to show how "evil" Humans are if worst comes to worst or what does this Alien want?



Now if they simply wanted to remove viable numbers of humans from human culture/dsseed them to avoid their extinction, they would have (or be considered truly evil) make sure that they have basic early industrial tech, are all kinda willing (for example delete their memories like in the Safehold setting) and set up a kind of "overwatch" for their government (say some very powerful artificial intelligences) that are able to softly steer them away from the worst stuff.

and even then its gonna be hard (unless its a preengineered south sea paradise^^).

It doesnt matter why the alien does it, the point of the question was to find out how big of a group of people you need to form a permanent viable colony with a reasonably high chance of success. My main goal being to find out how many people you need to eliminate the dangers of inbreeding and its related problems, the worry that a few injuries would doom the colony because you only had the exact amount of people needed to survive and now one has a broken leg and cant pull his weight or a small household got sick and cant help with the colony chores or whatever. I just tossed in the omnipotent alien bit so people could adjust the parameters in ways to fine tune it. Like, the idea of being able to pick and choose skilled labor and well educated on the types of information needed most types, rather than just transplanting a neighborhood at random and seeing what happens. We got side tracked by the argument over how fast tech would be redeveloped and earlier the parameter adjusting went too far with perfect cloning meaning 1 person is all it takes type stuff.

[Rogar Demonblud]

The problem is, you can't answer this question without settling most of the technology issues at the get go. The only examples we have of human colonization are quite clear that the only colonies that survived were equipped with current era technology, whether that's Greeks founding new cities, Polynesians going to new islands or the European expansion into Australia and the Americas. And they needed constant support and a steady influx of new people. Losing the technology you know how to use is a death spiral, because nobody knows how to do all the stuff needed to regain it, let alone supply the massive amount of hidden labor involved in the end product.

[Vinyadan]

The Romans used 300 families to found a colony (city) if it was to be administered directly from Rome, and 2,500 to 20,000 families if it was to be self-administering.

Family in this case means a man and everyone under his authority, so wife, children, and slaves (and, in the strictest/oldest custom, their descendants, too). So the size of a family was very variable.

[factotum]

The problem is, you can't answer this question without settling most of the technology issues at the get go. The only examples we have of human colonization are quite clear that the only colonies that survived were equipped with current era technology

Yeah, but I'm sure there are places which were never "colonies" per se, just places where larger groups of humans tended to gather a few tens of thousands of years ago, that went on to be entirely viable civilisations. Problem is, we don't know what time period these humans are being gathered from or what tech level they would have naturally--a bunch of humans from the African plains twenty thousand years ago is going to survive much better with primitive tech than a group of humans plucked from New York City in 2020.

[Rockphed]

Yeah, but I'm sure there are places which were never "colonies" per se, just places where larger groups of humans tended to gather a few tens of thousands of years ago, that went on to be entirely viable civilisations. Problem is, we don't know what time period these humans are being gathered from or what tech level they would have naturally--a bunch of humans from the African plains twenty thousand years ago is going to survive much better with primitive tech than a group of humans plucked from New York City in 2020.

Not least because all the humans from NYC have corona.

[Storm_Of_Snow]

It absolutely is. No, really.

If you do not get off the ground, it doesn't matter than you assign half your workforce to being monks, writing down volumes and volumes of their knowledge on animal hides or whatever. A flood will come, or a brush fire, or a child will chew on it, or rats will get in it, or some other disaster - and then you truly are trapped riding bareback for millenia. Hell, teaching one kid how to build a combustion engine takes two people (kid and teacher) at least 10 years, working full time. You don't have that kind of time.

You put your knowledge to work, or you lose it. Not from day to day. But it will deteriorate to uselessness before you ever get a chance to implement it.

Not only that, but you need to keep educating the new generations of colonists to be able to understand and advance that knowledge, otherwise it becomes ritual and mysticism and you will hit a dark age.

Or you skip that whole nonsense, and just get to work straight away, building machines. Frankly I don't even see why this is a point of contention. We mucked around in the dirt for more millenia than anyone has any clear count of - then we built a steam engine, and had space travel inside of two centuries. Build the steam engine. Or enjoy the millenia of dirt muckery.

The problem then is the actual mechanics of what you're building.

For the steam engine what fuel sources do you have - peat, wood, coke, coal, natural gas? That gives you an upper limit on the temperatures you can reach, which then says how much power you can generate, and how much steam pressure you need to contain, so you need materials that can contain both the pressure and the temperature.

Knowing something is possible to be made means nothing if you don't know how it's made.

Addendum: None of us know what we're talking about. Zero colonies have been built in space thus far, so it's all just guesswork and opinion. So if I come across as if I'm trying to claim I do know anything about this, that's unintended.

True, but we can make reasonable inferences and estimates.

For instance, Kashem mentioned a couple of ways knowledge was lost - the dark ages and wars. Even if everyone's focused on the common good now, there's a chance that this hypothetical colony may wind up splitting into two camps later due to some reason (ambition, a misunderstanding, someone decides on a course of action that others disagree with etc), and you get conflict between them.

Another possibility is linguistic drift - for instance, one of the issues with long term storage of radioactive waste is that future generations may not understand the warnings current generations post about it. If there's information available that you don't understand, it's useless.

[Eldan]

We're not going to get steam engines in a year. That's preposterous.
Humanity has had both primitive steam engines and steel for over 1500 years before someone managed to build one that actually did any useful work. And not for lack of trying. Pressure vessels are difficult. So are pistons. And lubrication. And nozzles that don't corrode from hot steam.

[Kaptin Keen]

The problem then is the actual mechanics of what you're building.

As I read the OP, we have all the knowledge we need.

And the reason building a steam engine is necessary, is because of mechanics. The steam engine is the required first step to build more complicated things, extract and process larger quantities of ore. Everything begins with the ability to switch from muscle power to mechanical power.

Without it, you're a primitive tribesman. With it, you've set foot on the first rung of the technological ladder - all you gotta do it climb.

All that jazz about fuel and material strength? Nonsense. You need the steam engine to begin obtaining better fuel and materials. And while coal doesn't power rocket ships, to this day it powers pretty much everything else. Not exclusively, of course - but it generates heat and electricity, it can be transmogrified into liquid fuel for combustion engines.

Our world rests on a robust foundation of steel, coal and steam. To rebuild our civilisation .... you need steel, coal and steam. If you have to hunt the wilds or even sacrifice half your colonists to starvation to achieve a steam engine - that's still the correct choice. It trumps literally all other concerns.