Problem of Aliens: The Fermi Paradox

[Mr. Mask]

I was considering running a an early space faring game, and was considering how to implement aliens in a reasonable way. In particular, I'm concerned with the Fermi (https://www.youtube.com/watch?v=RF4D4k2AVLA) Paradox (http://en.wikipedia.org/wiki/Fermi_paradox).

The short version is: If there are aliens, Earth should have found their radio signals, or they should have found Earth's, assuming alien civilizations are spreading out at all. Extra Credits goes into a few explanations for why they mightn't be found which could be elaborated upon for a setting. Namely: 1) They're staying home and not colonizing other planets. 2) They don't exist. 3) They're hiding their presence. Or 4) The government is hiding their presence.


Since the idea is to include aliens, 2 can be ignored. To get into some other ideas of why aliens haven't been discovered...

The universe, or intelligent life, is young. If either hasn't been around for long, that can justify alien life hasn't spread out enough to be noticed.
Similar is if alien sentience was figured to develop at a similar rate to humans. That would deny very advanced aliens.

There are no aliens in our galaxy. By the time any aliens were advanced enough to reach our galaxy, they're likely to develop technology that doesn't announce their presence from light years away on even extremely primitive sensors like Earth has, explaining why they haven't been sighted. Also, it leaves the possibility that while they are advanced, they're not at a level yet where they're willing to colonize a second galaxy, where communications would likely be so poor between the two galaxies that their colonies would form a separate, possibly competing space empire. With that theory, exploration of this galaxy and the chances of finding humans seems low.

Mass Effect's Version. There were aliens, but they all got wiped out. Allows for alien ruins to be discovered, which is fun.


Those are the ideas which spring to mind. A combination of factors is probably the best idea. What ideas have you used for your settings, or in the stories or rulebooks you've read?

[The Oni]

I guess the question is how much do you want the species to interact?

For example, you could have a situation wherein the aliens have incredibly slow space travel. But, they could have comparatively fast communication. So the aliens can't pop over to Earth in a week or so, but they can send a message that gets here in about a day, leading to a very weird sort of pen pal relationship.

Which could be interesting if there are other, less-friendly aliens who can travel much faster...

[Esprit15]

We haven't looked long enough/in the right places. Maybe they use frequencies/wavelengths that we don't normally look at.

[Mr. Mask]

Smeagle: I like the idea of diverse aliens. Some might be like pen-pals, others might be like a threat that's zooming over to stomp Earth into space dust. Of course, to make for an interesting game, you need the mix to result in having a fighting chance, and a logical reason for why you're discovering them recently. Of course, a plot-twist where humanity is destroyed by an unstoppable alien menace as soon as they were noticed could be interesting, particularly if there are some human survivors who take shelter with friendlier aliens.

For the early parts of the game of an early space faring setting, you probably want to focus on human conflict, with elements of mystery as to alien life, building up to an encounter near the end.


Espirit: As mentioned, alien life may well be operating at a level human sensors aren't able to detect. I mean, with current Earth tech, space war would be as stealthy as sending your enemy big neon signs elaborating your plan a week in advance of enacting it, which is to say that space war is a pretty lousy prospect at this time. Aliens will want to change that, if they want to have any decent war capability whatsoever.

If the aliens were in another galaxy, I don't think there are any signals they could send powerful enough for Earth to detect them.

[Mr Beer]

If the aliens were in another galaxy, I don't think there are any signals they could send powerful enough for Earth to detect them.

Depending on their tech, sure there are. It just seems extravagant to communicate via gamma ray bursts.

[Storm_Of_Snow]

IIRC, it's theorised that there's a relatively short period of time that a civilisation would be detectable via picking up transmissions, as they eventually become either more guarded, or simply more efficient (narrower beam radio communications that use less power, don't interfere with other signals and are less able to be intercepted, non-broadcast methods like fibre optics and so on), and so less signal leaks out that can be detected.

I think we ourselves are actually getting to that point at the moment.

There's also signal attenuation - even if they're effectively shouting as loud as they can, by the time it arrives at your receiver, there simply might not be enough of a signal left to pick out against background radiation.

[Mr. Mask]

Beer: Communicating like that, you're either the big fish in the galaxy, or terminally insane.


Snow: I asked someone about how far Earth's radio traffic can be seen from. They reckoned it would be hard to sport outside of the solar system... which is basically no communication distance at all, compared to distances within the galaxy.

[Millennium]

We haven't looked long enough/in the right places. Maybe they use frequencies/wavelengths that we don't normally look at.

We haven't looked long enough/in the right places. Maybe they use frequencies/wavelengths that we don't normally look at.
Organizations like SETI tend to use the concept of a civilization's radiosphere: when a civilization begins to use radio above a certain level of power, the signals start to expand outward from that world in a roughly spherical shape, and can in theory be detected by other civilizations in the order they were sent, if only the signal comes in at the right time.

But there's a hole in this theory: its assumption that once a civilization develops radio, that technology is never replaced. It's held so far on Earth, but the earliest documented discoveries and/or predictions of radio are only about 130 years old: in a historic sense, we haven't actually been using it all that long. Already our scientists are starting to look at possible ways to overcome radio's most serious limitations, and our artists were imagining possibilities well before science caught up to them. It could be that civilizations to not have radiospheres so much as "radio bubbles": a shell of radio signals that starts when radio starts to be used, but tapers off and eventualy vanishes as radio is replaced.

This is important for organizations like SETI, because it means that each civilization can only be detected for a limited window of time using radio. In order for that to happen, the searchers must also be using radio at just the right time. For example, let's imagine an alien civilization that lives 200 light-years away from us. It would take that civilization's radio signals 200 years to reach us, so if they started using radio 200 years ago, we would only be just starting to receive the very first signals they had ever sent. If they'd started 400 years ago, then we'd receive signals from 200 years ago, because that's how long it takes radio to travel 200 light-years.

But let's imagine something slightly different. The alien civilization started using radio about 1000 years ago -a time we'd have called 1000 CE- and used it for about 300 years before replacing it with some other technology (ansibles, perhaps). The first signals from this civilization would have started to reach us around the year 1200, when humanity was in no condition to listen. Radio might still have been at its peak in the alien civilization at this time, and they continued sending signals for another hundred years, but then -in what we'd call the year 1300- they invented the ansible and stopped using radio. Signals continued to come to us for another 200 years, as the old signals continued to arrive.

But around 1500 they stopped, and this was still long before we ever invented radio. That civilization could still be out there, but our radio detectors will never notice. They just weren't there when they needed to be.

[Mr. Mask]

And that's assuming you can make them out against all the background noise.

[Eldan]

And then, of course, there's the problem that SETI et al simply:

a) Can't watch the entire sky all the time so might miss a transmission
b) Can't analyze all the data they produce properly, so might not even realize they found something

[Elderand]

Other problems, space is ridiculously big, our own radio transmission haven't spread all that far even on a galactic scale. Anything farther than 110 light years away isn't being reached yet. Our galaxy alone is 1200 000 light years accross.

[Storm_Of_Snow]

Snow: I asked someone about how far Earth's radio traffic can be seen from. They reckoned it would be hard to sport outside of the solar system... which is basically no communication distance at all, compared to distances within the galaxy.

And even then, what would you actually pick up? Would it be intelligible fragments, or just garbage mixed with a lot of static?


And that's assuming you can make them out against all the background noise.
Plus our detection gear is basically a small series of dots under an atmosphere that can absorb and scatter electromagnetic signals, on a spinning sphere with it's own electromagnetic fields (the Van Allen belts) that's orbiting a massive electromagnetic radiation emitter (the sun) at a relatively close proximity, with other spinning spheres scattered at various points inside and outside that orbit, trying to pick up electromagnetic signals across x light years emitted by pin point emitters from civilisations that are themselves on spinning spheres closely orbiting massive electromagnetic radiation emitters, with other massive EMR emitters of various size and activity scattered around, and the whole lot's orbiting the centre of the galaxy.

And we're kind of guessing at what we're looking for, based on our understanding of physics and a bit of "well, it's what we'd do if we were trying it...".

Here's a large number of fields full of haystacks, there may or may not be a needle in one of them. :smallwink:

[Eldan]

Here's a large number of fields full of haystacks, there may or may not be a needle in one of them. :smallwink:

Also, some of it probably isn't hay, but made of needle-like objects and you aren't allowed ot search the stack, only to make three photographs, then take them home for analysis.

[Segev]

I'm a fan of the idea that, given the age of the universe and the probabilities of sentient life occurring, we actually beat the odds. We're early. So there aren't other sentient beings out there, most likely.

Why do I like this idea? Because it ties in nicely to the "aliens had a big advanced civilization, but it's gone now, and their relics are all that's left behind" idea: we are the antecedent race. We are the "ancients," in our own infancy today.

If you wanted to use this in conjunction with an "early space exploration" setting, perhaps you could have a large colony group head out at ludicrously relativistic speeds to set up in some distant part of the galaxy. In the time that passes on Earth during the time-dialated transit of these explorers, mankind actually arises to a great height and expands across the stars by technologies as much beyond the ken of the colonists as they will be of the aliens that will come about in the billions of years of the colonists' relativistic travel.

The world and system they colonize was preserved by the ancient human civilization, who honored and revered the colonists exploratory spirit but knew that simply hopping aboard to say "hi" and hand off tech millenia beyond them would be a disservice. So they arranged for their exploring ancestors to find their destination an ideal place to set up, and protected it from all outside comers. Some of the only deliberate relic sites, with primers and automated systems designed to recognize the exporing colonists, exist in that system, intended for them to find and unlock as they grow and expand. Highly primitive compared to the troves other aliens find in teh unintentional relic sites (since those were just abandoned or the like, not deliberatley set up), but still advanced compared to "early space" tech, and useful to defend themselves and help them ratchet up.

When the colony world, using "early space exploration" tech, extends beyond the system that was preserved and reserved for them by the machinations of their descendent humanity that achieved such great heights, they find the more traditional sci-fi galaxy full of advanced races. Being "early space faring" in tech, the colonists are a bit behind, at first.

However, it was human culture and human language - even with the many generations of drift - that was behind the "ancient relics" of the "lost, hyperadvanced civilization." Thus, through a combination deliberate primers left behind for these revered explorers from the ancient civilization, and a simple cultural familiarity that is best served by a study of how it evolved from what our explorers remember of their own cultures they left behind, our "backwards" human colonists discover not only that these advanced alien races are younger than they are, objectively, but that they have an advantage when it comes to deciphering and controlling and even identifying and finding the "ancient relic" devices that are still far more advanced than anything anybody else has.

[Jacob.Tyr]

Organizations like SETI tend to use the concept of a civilization's radiosphere: when a civilization begins to use radio above a certain level of power, the signals start to expand outward from that world in a roughly spherical shape, and can in theory be detected by other civilizations in the order they were sent, if only the signal comes in at the right time.

But there's a hole in this theory: its assumption that once a civilization develops radio, that technology is never replaced. It's held so far on Earth, but the earliest documented discoveries and/or predictions of radio are only about 130 years old: in a historic sense, we haven't actually been using it all that long. Already our scientists are starting to look at possible ways to overcome radio's most serious limitations, and our artists were imagining possibilities well before science caught up to them. It could be that civilizations to not have radiospheres so much as "radio bubbles": a shell of radio signals that starts when radio starts to be used, but tapers off and eventualy vanishes as radio is replaced.

This is important for organizations like SETI, because it means that each civilization can only be detected for a limited window of time using radio. In order for that to happen, the searchers must also be using radio at just the right time. For example, let's imagine an alien civilization that lives 200 light-years away from us. It would take that civilization's radio signals 200 years to reach us, so if they started using radio 200 years ago, we would only be just starting to receive the very first signals they had ever sent. If they'd started 400 years ago, then we'd receive signals from 200 years ago, because that's how long it takes radio to travel 200 light-years.

But let's imagine something slightly different. The alien civilization started using radio about 1000 years ago -a time we'd have called 1000 CE- and used it for about 300 years before replacing it with some other technology (ansibles, perhaps). The first signals from this civilization would have started to reach us around the year 1200, when humanity was in no condition to listen. Radio might still have been at its peak in the alien civilization at this time, and they continued sending signals for another hundred years, but then -in what we'd call the year 1300- they invented the ansible and stopped using radio. Signals continued to come to us for another 200 years, as the old signals continued to arrive.

But around 1500 they stopped, and this was still long before we ever invented radio. That civilization could still be out there, but our radio detectors will never notice. They just weren't there when they needed to be.

This, seriously. If they're only a few hundred years ahead of us, then we wouldn't have overlapped enough to notice. Between advancing beyond using radio, civilization dying out, signal degradation, and minimal monitoring you can easily work around this "paradox".

I'm debating the validity of this for space horror, now. Echoes of dead civilizations, mysterious communication blips picked up now and then by travelers and colonists, etc. Throw in some sci-fi space time anomalies that obscure the time/location of sending for added mind-f!@#, and this could be a great thing for some first time colonists in a new system to encounter.

[Spore]

Sooo.....*adjusts tinfoil hat*

I'd go for the needle in a haystack approach. They may have noticed you but this doesn't mean they can notify you or even reach you before their civilization ends. Cellular life is around for some millions of years. Humankind is around for several tenthousands of years and we have the technology for travel to the moon for about 50 years now. We send "items" to several celestial bodies in our solar system and yovagers out of there. So my guess is that the average highly intelligent civilization not only is rare, depend on specific constant planetary situations (we nearly got killed by an ice age, and those things pop up every so often) but also have to develop efficient interplanetary travel (by what is effectively teleport, all this warp stuff) to reach us in a life-time. So you'd introduce a quick way to travel (Warp Drive for Star Trek, Mass Effect Engines for Mass Effect, Lightspeed for Star Wars). Your advanced aliens monitor earth until we're "ready" which is basically the development of our own hyper drive and what not.

So the typical development goes:
- survive cellular phase
- have sufficient ecosystem to support multicellular life
- have CONSTANT ecosystem to support life
- develop quickly enough to create the technology for that
- not have your homeplanet destroyed/inhabitable by celestial events
- find a way to get to Earth within one life cycle
- not screw up this mission as normal signals could take millenia to reach back to home planet
- not have a society like ours that heavily believes that every investition towards discovering new species is wasted resources (read: money)

Those are A LOT of variables.

[Jeff the Green]

I'm a biologist, so my answer leans towards 2) but isn't quite there. Intelligent life is incredibly rare. For that matter, multicellular life is incredibly rare. Evolution is historically constrained and dominated by chance events with natural selection only filtering what gets produced by mutations. And really, natural selection isn't going to favor intelligence anyway because it's metabolically expensive and not particularly useful for propagating genes (compare our population size to that of gnats, or worse, bacteria). So the most complex organisms you're likely to see are comparable to earth invertebrates.

Of course, this does mean that your players' interactions with alien life will mostly consist of getting it on their boots, but that's the sacrifice we make for biological plausibility. :smalltongue:

[Elderand]

I'm a biologist, so my answer leans towards 2) but isn't quite there. Intelligent life is incredibly rare. For that matter, multicellular life is incredibly rare. Evolution is historically constrained and dominated by chance events with natural selection only filtering what gets produced by mutations. And really, natural selection isn't going to favor intelligence anyway because it's metabolically expensive and not particularly useful for propagating genes (compare our population size to that of gnats, or worse, bacteria). So the most complex organisms you're likely to see are comparable to earth invertebrates.

Of course, this does mean that your players' interactions with alien life will mostly consist of getting it on their boots, but that's the sacrifice we make for biological plausibility. :smalltongue:

You have a data sample of 1 here, you can't make any sort of claim about what is rare or not in the universe.

[Larkas]

I'm a fan of the idea that, given the age of the universe and the probabilities of sentient life occurring, we actually beat the odds. We're early. So there aren't other sentient beings out there, most likely.

Why do I like this idea? Because it ties in nicely to the "aliens had a big advanced civilization, but it's gone now, and their relics are all that's left behind" idea: we are the antecedent race. We are the "ancients," in our own infancy today.

If you wanted to use this in conjunction with an "early space exploration" setting, perhaps you could have a large colony group head out at ludicrously relativistic speeds to set up in some distant part of the galaxy. In the time that passes on Earth during the time-dialated transit of these explorers, mankind actually arises to a great height and expands across the stars by technologies as much beyond the ken of the colonists as they will be of the aliens that will come about in the billions of years of the colonists' relativistic travel.

The world and system they colonize was preserved by the ancient human civilization, who honored and revered the colonists exploratory spirit but knew that simply hopping aboard to say "hi" and hand off tech millenia beyond them would be a disservice. So they arranged for their exploring ancestors to find their destination an ideal place to set up, and protected it from all outside comers. Some of the only deliberate relic sites, with primers and automated systems designed to recognize the exporing colonists, exist in that system, intended for them to find and unlock as they grow and expand. Highly primitive compared to the troves other aliens find in teh unintentional relic sites (since those were just abandoned or the like, not deliberatley set up), but still advanced compared to "early space" tech, and useful to defend themselves and help them ratchet up.

When the colony world, using "early space exploration" tech, extends beyond the system that was preserved and reserved for them by the machinations of their descendent humanity that achieved such great heights, they find the more traditional sci-fi galaxy full of advanced races. Being "early space faring" in tech, the colonists are a bit behind, at first.

However, it was human culture and human language - even with the many generations of drift - that was behind the "ancient relics" of the "lost, hyperadvanced civilization." Thus, through a combination deliberate primers left behind for these revered explorers from the ancient civilization, and a simple cultural familiarity that is best served by a study of how it evolved from what our explorers remember of their own cultures they left behind, our "backwards" human colonists discover not only that these advanced alien races are younger than they are, objectively, but that they have an advantage when it comes to deciphering and controlling and even identifying and finding the "ancient relic" devices that are still far more advanced than anything anybody else has.

Wow, I REALLY like this! :smalleek:

[HighWater]

And really, natural selection isn't going to favor intelligence anyway because it's metabolically expensive and not particularly useful for propagating genes (compare our population size to that of gnats, or worse, bacteria).

Hold on, that's an argument against large lifeforms, not necessarely an argument against intelligence. Intelligence of the human form is very beneficial: human population is several orders of magnitude larger than it should be when compared to organisms of similar size. By cellular count, large organisms do alright, though the microbial masses are teeming everywhere (and necessarely so, or the rest of life would die). Calling large organisms "more adapted" than single celled life would, of course, be an error, but they certainly fill a rich niche. High intelligence is indeed metabolically expensive, so it only works if you can use it to your advantage. Basically, if you can make it worth the costs.

I reject the use of intelligence in this context anyway, as lots of animals score at least reasonably well in the intelligence department. It is not completely unthinkable that one of these would've served as the progenitor of another civilisation-building species. The thing that sets humans apart, and the thing we need alien civilisations to have, is sufficiently advanced technology. Intelligence may be a prerequisite, but it's not enough.

More on topic:
The Great Filter is a possible explanation for the Fermi Paradox (either somewhere in our past, or somewhere in our future lies hurdle that eliminates (almost) 100% of contenders, which is why the universe seems so empty of civilisation). Another is that other civilisations stop transmitting (like we are reducing transmission) and just happen to not have colonised our solar system yet (as far as we know). Another one is that some other civilisation never started transmitting, because they are so fundamentally different from us that their preferred method of communication has nothing to do with long-range signals we could pick up...

[Thrudd]

I was considering running a an early space faring game, and was considering how to implement aliens in a reasonable way. In particular, I'm concerned with the Fermi (https://www.youtube.com/watch?v=RF4D4k2AVLA) Paradox (http://en.wikipedia.org/wiki/Fermi_paradox).

The short version is: If there are aliens, Earth should have found their radio signals, or they should have found Earth's, assuming alien civilizations are spreading out at all. Extra Credits goes into a few explanations for why they mightn't be found which could be elaborated upon for a setting. Namely: 1) They're staying home and not colonizing other planets. 2) They don't exist. 3) They're hiding their presence. Or 4) The government is hiding their presence.


Since the idea is to include aliens, 2 can be ignored. To get into some other ideas of why aliens haven't been discovered...

The universe, or intelligent life, is young. If either hasn't been around for long, that can justify alien life hasn't spread out enough to be noticed.
Similar is if alien sentience was figured to develop at a similar rate to humans. That would deny very advanced aliens.

There are no aliens in our galaxy. By the time any aliens were advanced enough to reach our galaxy, they're likely to develop technology that doesn't announce their presence from light years away on even extremely primitive sensors like Earth has, explaining why they haven't been sighted. Also, it leaves the possibility that while they are advanced, they're not at a level yet where they're willing to colonize a second galaxy, where communications would likely be so poor between the two galaxies that their colonies would form a separate, possibly competing space empire. With that theory, exploration of this galaxy and the chances of finding humans seems low.

Mass Effect's Version. There were aliens, but they all got wiped out. Allows for alien ruins to be discovered, which is fun.


Those are the ideas which spring to mind. A combination of factors is probably the best idea. What ideas have you used for your settings, or in the stories or rulebooks you've read?

Post-physical evolution is the norm in the universe, at a certain point most intelligent species evolve beyond the restriction of physical form. The chances of two species that are evolving at roughly the same time and are in close enough proximity to one another to detect and interact with each other is very low. If there is even as little as a million years (possibly less) between the rise of one species and another, they likely will have no chance or desire to interact. The younger species may barely be able to perceive the existence of the older, if at all, and the older be so far advanced that communicating with the younger would be akin to our interactions with invertibrates.

That said, even within a single galaxy the number of planets capable of supporting life is so great that there must be hundreds or thousands of intelligent species evolving at roughly the same time. Most of those species, however, will plateau at certain technological levels due to the vagaries of their particular biology and environment, or will go extinct for one reason or another. There will still remain many that continue evolving and develop space travel. The problem is, the interstellar distances are so great that radio signals and technology working only on the Newtonian-level (propelling physical vessels through space at less than c) will never be a viable option for meaningful contact or interaction.

At some point, however, those signals will come flooding in, and this will be a significant event in human history. The technology of the species who originated the earliest radio signals, including ourselves, will at that point be significantly advanced enough to overcome the c-barrier with probably some meaningful advancements toward post-physical ascension (teleportation, true AI, manipulation of quantum effects) and will initiate contact. Travel and communication will likely be more along the lines of stargates/wormholes, or vessels which use this sort of effect. Each civilization will likely have colonized or at least fully explored and exploited their own solar systems for resources by that point.
Also, by this point, these civilizations will start becoming aware of the existence of post-physical species. Most such species will likely not engage in much contact, but even awareness of them could inspire research and accelerated advancement.

[Slipperychicken]

Maybe the aliens were largely avoiding Earth because it doesn't support life as they know it.

[LimSindull]

Since it hasn't been brought up, the government hiding the alien activity would be a very good option.

First, what type of government would be in control during this Expansion Era? Would there be a United Solar Empire where the ruler(s) of Earth decide the best course of action for all of humanity? If so, then, having the government not only hide, but make it illegal to look for alien vessels/technology would be an option.

Or you could go old Sci-Fi and make the aliens communicate telepathically and already be here hiding themselves.

If the government is a loose coalition of planets and colonies, they may not get along very well. This could allow one or two planets to know of and even have tried to communicate with alien presence, while the group could be from a planet or group of civilizations that have not had any communication from the aliens.

Last, an alien force could be jamming any signals coming into our solar system (or galactic civilization) for whatever reason. (They may view our destructive nature of a danger to all life or they may want to cripple and enslave/eat us.)

I hope you find this helpful.

[Grinner]

Those are the ideas which spring to mind. A combination of factors is probably the best idea. What ideas have you used for your settings, or in the stories or rulebooks you've read?

You should read this (http://www.gregstolze.com/fiction_library/TRANSMIT.pdf).

[Jeff the Green]

You have a data sample of 1 here, you can't make any sort of claim about what is rare or not in the universe.

Millions, actually. Every species whose lineage has been around since the beginning of life on earth (i.e. all of them) and that isn't capable of building advanced technology (i.e. all of them - 1) is a data point. (And before you mention it, no, it wasn't necessary for 4 billion years of evolution to pass before sapience evolved.)

Seriously, if you want to know about the likelihood of extraterrestrial life, ignore astronomers. Read (http://praxtime.com/2013/11/25/sagan-syndrome-pay-heed-to-biologists-about-et/) biologists (http://scienceblogs.com/pharyngula/2006/10/24/a-little-pessimism-about-extra/).


Hold on, that's an argument against large lifeforms, not necessarely an argument against intelligence. Intelligence of the human form is very beneficial: human population is several orders of magnitude larger than it should be when compared to organisms of similar size. By cellular count, large organisms do alright, though the microbial masses are teeming everywhere (and necessarely so, or the rest of life would die). Calling large organisms "more adapted" than single celled life would, of course, be an error, but they certainly fill a rich niche. High intelligence is indeed metabolically expensive, so it only works if you can use it to your advantage. Basically, if you can make it worth the costs.

First, cell count is irrelevant. In the context of ecology and evolution you use either biomass (unicellular organisms have 10 times the mass) or effective population size (unicellular organisms not only dwarf multicellular organisms, they make them negligible). Second, yes, we have a much larger population size than expected for our size now. For most of our evolutionary history, our population size was less than 1 million, at points dropping below 10,000. It's only by chance that we survived; one plague or natural disaster at the wrong time would have entirely extinguished our line. Finally, the issue isn't whether multicellularity or large brains can be beneficial, it's whether the intermediate steps can survive. Which is rarely true, and, as I mentioned before, it's currently believed that the only reason multicellularity evolved in the first place is a ridiculously small population size that resulted in a whole bunch of detrimental mutations that, when the population survived by chance, were repurposed to form the backbone of the eukaryotic genome.

[Storm_Of_Snow]

Millions, actually. Every species whose lineage has been around since the beginning of life on earth (i.e. all of them) and that isn't capable of building advanced technology (i.e. all of them - 1) is a data point. (And before you mention it, no, it wasn't necessary for 4 billion years of evolution to pass before sapience evolved.)

Seriously, if you want to know about the likelihood of extraterrestrial life, ignore astronomers. Read (http://praxtime.com/2013/11/25/sagan-syndrome-pay-heed-to-biologists-about-et/) biologists (http://scienceblogs.com/pharyngula/2006/10/24/a-little-pessimism-about-extra/).

Define "advanced technology".

For instance, some of the corvids can use tools and solve problems. Or spider web silk, which is stronger than steel wire of the same thickness, and is used by some species of spider to fly from one place to another (and would probably be the equivalent of us extruding a 100 foot pole and using it to fly across the atlantic). Do they count?

As for ignoring astronomers in favour of biologists, whilst I'm a biologist at heart too, I'd rather hear what all sides have to say on the matter. :smallwink:

[Mastikator]

You have a data sample of 1 here, you can't make any sort of claim about what is rare or not in the universe.

Sure you can, we orbit an average star and live on an average planet and are made of average elements. By all accounts we're normal and average and it's not unreasonable to assume others will be like us.

If we take a peek at the timeline of life (http://en.wikipedia.org/wiki/Timeline_of_evolutionary_history_of_life), it took a billion years for life to emerge on the planet, for the first billion years there was no photosynthesis, so no oxygen in the atmosphere, then over one and a half billion years passed after photosynthesis started before multicellular life emerged, then within the last 500 million years animals emerged, then maybe a million years ago highly intelligent life forms emerged.

So if we look at a random earth like planet then it's: (rounding HEAVILY here)
20% chance no life, just a lifeless rock
20% chance life, but not breathable atmosphere
35% chance life with breathable atmosphere
15% chance life with plant like life is most complex life form
9% chance life with animal like life as most complex life form
0.9% chance life with intelligent animals as the most complex life form, probably civilization and somewhere between stone age and spacefaring
0.1% chance life with animals so intelligent we can't even guess what they are like OR post apocalyptic planet

[Thrudd]

We can resolve the biological improbability problem with intelligent design/progenitor species. Yes, the odds of biological life surviving through all the stages to attain interstellar civilization are shockingly low, but it only needed to happen once in the life of the galaxy, possibly only once in the whole universe.

One single intelligent species evolved and survived early in the life of the galaxy, billions of years before earth had even formed. They have since made it their mission to ensure life spreads and survives throughout the galaxy, seeding life based on their own DNA tailored to all manner of environments. Perhaps they eventually went extinct, or ascended to post-physical existence. They may still check in and assist their many experiments and offspring, or they may simply spread life and allow nature to take its course. But once intelligence reaches a certain point, its spread and continued existence are assured, barring total galactic annihilation.

Intelligent life may be seeded and evolve on every planet capable of supporting it, or its locations may be carefully selected so that no two species can interact with each other too early in their development. The reason we have not yet encountered any extra-terrestrial intelligence is by design.

Read Arthur C Clarke for stories on this theme, the Space Odyssey series and Rama series with Gentry Lee both present version of this.

[NichG]

First, cell count is irrelevant. In the context of ecology and evolution you use either biomass (unicellular organisms have 10 times the mass) or effective population size (unicellular organisms not only dwarf multicellular organisms, they make them negligible). Second, yes, we have a much larger population size than expected for our size now. For most of our evolutionary history, our population size was less than 1 million, at points dropping below 10,000. It's only by chance that we survived; one plague or natural disaster at the wrong time would have entirely extinguished our line. Finally, the issue isn't whether multicellularity or large brains can be beneficial, it's whether the intermediate steps can survive. Which is rarely true, and, as I mentioned before, it's currently believed that the only reason multicellularity evolved in the first place is a ridiculously small population size that resulted in a whole bunch of detrimental mutations that, when the population survived by chance, were repurposed to form the backbone of the eukaryotic genome.

I'm surprised you'd say this. Biofilms, for example, are incredibly common and pretty much span the gap between unicellular and multicellular modalities. Often they can toggle that as a response to environment. You can get anything from genetically heterogeneous films where the composition is semi-faithfully reproduced to monoclonal films with internal structures, spore-based replication, and 'altruistic' cellular behavior (e.g. some of the film-scale function is managed by cell suicide, such as the necking-off behavior in the aforementioned sporulation.

So it seems rather that multicellularity is (perhaps surprisingly) easy to find.

As far as large brains, I don't think that's any stranger than e.g. evolving transcriptional regulation of genes. Both are a form of biologically-mediated computation that allows the organism to respond to changes in its immediate environment on scales shorter than its lifespan, and also to adapt more smoothly to longer-term changes (e.g. ~20-30 generations) without requiring an overly high mutation rate that would otherwise be generally harmful.

[Storm_Of_Snow]

Any alien advanced enough to be starfaring probably thinks of us in the same way that Columbus thought of New World monkeys. An interesting evolutionary path (if you're a botanist), but hardly something you'd want to stop and talk with.
Or if you're studying animal behaviour, someone you might want to work out how to talk with, same as we do with chimps and dolphins.

Alternatively, maybe an advanced alien species can't do something we can (maybe they're from a planet around a hotter star, so can see more in the blue-ultraviolet range, but can't see green to red like we can), and aren't rude enough to just grab a few of us and chop them up to find out how we do it.

Or maybe their starfaring technologies are way more advanced than ours because, for whatever reason, they focussed on them, but another technology is a lot less advanced - say, their medical sciences are roughly equivalent to what we had in the early roman empire, or they stuck with valves and never developed the transistor, meaning their computers are massive machines that take 99% of the volume of the ship, but have less processing capability than a laptop.

[Beleriphon]

Or maybe their starfaring technologies are way more advanced than ours because, for whatever reason, they focussed on them, but another technology is a lot less advanced - say, their medical sciences are roughly equivalent to what we had in the early roman empire, or they stuck with valves and never developed the transistor, meaning their computers are massive machines that take 99% of the volume of the ship, but have less processing capability than a laptop.

That reminds me of a sci-fi story where the aliens developed anti-gravity technologies (its appearently very easy, but we never figured it out), but never moved beyond black powder weapons. So they show up on Earth think that they're all Hernan Cortez and we're the cavemen, only to have an unfortunate turn of circumstance where humans fusion bombs something the aliens didn't even realise was possible. Of course this happens in the first chapter, and humans promptly figure out how the spaceships work and functionally take over the universe.


Or maybe their starfaring technologies are way more advanced than ours because, for whatever reason, they focussed on them, but another technology is a lot less advanced - say, their medical sciences are roughly equivalent to what we had in the early roman empire, or they stuck with valves and never developed the transistor, meaning their computers are massive machines that take 99% of the volume of the ship, but have less processing capability than a laptop.

You know, the funny thing about using cathode ray tubes, or even valves effectively make a computer hack proof without actually having access to the system itself. You can't override the control system with physically inputing new instructions. It would be intersting if it didn't even work on binary to boot.

[HighWater]

First, cell count is irrelevant. In the context of ecology and evolution you use either biomass (unicellular organisms have 10 times the mass) or effective population size (unicellular organisms not only dwarf multicellular organisms, they make them negligible).
10x isn't that bad. Multicellular life is in some ways quite restricted by its dependence of unicellular organisms. You'll see similar ratios when looking at relations between predators and prey in foodchains for instance. None of it is very relevant for the question at hand.

We deal with one single question here: "How can I make intelligent alien specie(s) appear in my Sci-fi setting in spite of the Fermi Paradox?"
One possible answer to the Fermi Paradox is the Great Filter, your explanation is essentially one example of the Great Filter: the emergence of intelligent life that could turn into a galactic spacefaring civilisation is so severely limited that we've beaten pretty much impossible odds, provided we ever make it to that stage ourselves. This is not an interesting answer for the Topic Starter, but a short reply is still in order:
Multicellular life has arisen on several occasions (if I recall correctly that includes: red algae, brown algae, plants, insects and animals as separate incarnations of complex multicellularity). It may be an accident, but one that has happened more than once. Intelligence (and presumably sapience as well) is a gliding scale, not a binary one. Quite a few animals on earth qualify for at least some of our "intelligence requirements". High intelligence is certainly energy intensive, some luck is possibly needed to make it past the post where it starts to really pay off in a planet-dominating manner. It has certainly paid off for humans, at least so far, even when we've faced extinction in our past. It's hard to tell the odds on any of these events: the Earth dataset is incomplete (our records are not yet exhaustive) and a single planet with spacefaring intelligent life is both proof for the hypothesis that spacefaring life is very abundant, and that spacefaring life is extremely rare. (It only proves it's possible.)


Finally, the issue isn't whether multicellularity or large brains can be beneficial, it's whether the intermediate steps can survive. Which is rarely true, and, as I mentioned before, it's currently believed that the only reason multicellularity evolved in the first place is a ridiculously small population size that resulted in a whole bunch of detrimental mutations that, when the population survived by chance, were repurposed to form the backbone of the eukaryotic genome.
Got an article on that? I'd be interested in reading it.

Back to the actual Topic:
Be creative, try to think of something really out-of-the-box (perhaps technological advancement shows to a crawl at a certain tech point we haven't reached yet, rather than everlasting accelleration, diminishing returns quickly take over! Suddenly a headstart of a million years doesn't have to be insurmountable.) Or instead use some well-intended recycling (seeding-spacefarers, for instance). Some nice suggestions have been made within this thread.

[Frozen_Feet]

Since it hasn't been brought up, the government hiding the alien activity would be a very good option.

I'm going to posit a variant of this:

The governemt is hiding alien activity... and doing a really poor job.

You say there's no evidence of alien life? Put a few search words in Google, and you will find tens of thousands of people swearing they've seen one and detailing extremely contrived scenarios.

Of course, you think they're all nuts... but do you think they're nuts because you actually went over the evidence, or because someone else told you so?

Reality check: most of everything you've ever learned, including of science and history, is something you've accepted on faith that people are not lying to you. It is simply impossible for a single human to go over and prove or disprove even all the provable claims posited by UFO theorists.

So if you want to get over the Fermi paradox and have a setting with aliens, it's easy to do! You just have to say that something you thought was bunk was correct all along! Maybe Martians really did built the pyramids! Maybe crop circles really were made by aliens!

This isn't the same as saying every crackpot theory out there is correct. In fact, it's best if that isn't the case. Just go and find one even remotely plausible series of UFO sightings that hasn't been definitevely debunked, and then say aliens did it. The rest can still be humbug.

[Storm_Of_Snow]

Be creative, try to think of something really out-of-the-box (perhaps technological advancement shows to a crawl at a certain tech point we haven't reached yet, rather than everlasting accelleration, diminishing returns quickly take over! Suddenly a headstart of a million years doesn't have to be insurmountable.) Or instead use some well-intended recycling (seeding-spacefarers, for instance). Some nice suggestions have been made within this thread.
Or they get to the point where they can no longer do what Newton did, and stand on the shoulders of giants.

Basically, a lot of our high end technology is built by groups, who individually only know very small parts of it (for instance, a computer processor's is designed by a team, who then pass that design to another team to build, who take the results of experimental work by teams of materials scientists to identify the best available materials to make it out of, and the processor then goes to a team of people who program in the underlying system code).

If something happens that causes either some of the underlying knowledge to be lost, or to become unavailable, then that technology could still be there, but slowly degrading and completely unreproducable - the Imperium in 40k is a fictional example, but you could also look at tech level of the Dark Ages compared to the height of the Roman Empire.

[russdm]

We deal with one single question here: "How can I make intelligent alien specie(s) appear in my Sci-fi setting in spite of the Fermi Paradox?"

Have you considered the possibility that the Fermi Paradox is actually erroneous or false? It is based on two very flimsy arguments that aren't capable of removing any possibility of alien life if you actually think about it.

Point 1) Any existing civilization should have already contacted us: This presupposes that we have the technology to hear and understand they are contacting us and can respond to the message if any appears.

Point 2) We would discover anything or they would receive our messages and contact us: This presupposes that we can actually contact with the distance that our radio signals have actually traveled and that our telescopes are powerful enough to detect the required molecules. Our instruments are improving but still quite haven't reached the proper point.

This entire idea is based on the a concept that puts humans first and foremost and uses us the primary binding glue. Another species may do things completely differently and we don't know how they act.

[Hiro Protagonest]

I'm going to posit a variant of this:

The governemt is hiding alien activity... and doing a really poor job.

Or a really, really good job. In which case Xanatos is in charge of it.

[Grinner]

This isn't the same as saying every crackpot theory out there is correct. In fact, it's best if that isn't the case. Just go and find one even remotely plausible series of UFO sightings that hasn't been definitevely debunked, and then say aliens did it. The rest can still be humbug.

Cracked posted some good ones (http://www.cracked.com/article_18690_5-ufo-sightings-that-even-non-crazy-people-find-creepy.html).

[veti]

I can't believe no-one has linked to this (http://xkcd.com/1377/) yet.

All the aliens are hiding. And if we're neither very, very careful nor very, very lucky, we will shortly find out why.

[Jeff the Green]

Define "advanced technology".

For instance, some of the corvids can use tools and solve problems. Or spider web silk, which is stronger than steel wire of the same thickness, and is used by some species of spider to fly from one place to another (and would probably be the equivalent of us extruding a 100 foot pole and using it to fly across the atlantic). Do they count?

I like crows as much as anyone (I helped out in a study of their ability to recognize human faces), but I was thinking "technology capable of transmitting our existence to the stars".


I'm surprised you'd say this. Biofilms, for example, are incredibly common and pretty much span the gap between unicellular and multicellular modalities. Often they can toggle that as a response to environment. You can get anything from genetically heterogeneous films where the composition is semi-faithfully reproduced to monoclonal films with internal structures, spore-based replication, and 'altruistic' cellular behavior (e.g. some of the film-scale function is managed by cell suicide, such as the necking-off behavior in the aforementioned sporulation.

I probably should have specified "complex multicellular organisms," which is what multicellularity refers to in the vernacular (that is, the language biologists and biology students use in everyday conversation and not in papers). Biofilms are cool, but they're not complex. You can run a biofilm off of not significantly more genetic material than already exists in most prokaryotes. The same is not true of complex organisms with multiple tissue types and complex behavior. Which, again, cannot evolve without low population sizes which are rare in unicellular eukaryotes. Rarer still in prokaryotes.


Got an article on that? I'd be interested in reading it.

Hmmm. I will look (tomorrow, when I'm not about to fall asleep at my desk), but I learned it in class rather than an article. You could try reading The Logic of Chance, particularly chapters 3 and 4, though it's a textbook and meant for people who already have a basic background in genetics and evolution. The Kindle version was at one point free, but no longer. :smallannoyed: I do know there's a pdf version available maybe kind-of legally, though I'll abstain from linking due to forum rules and not being sure of its copyright/license status.

[Talya]

We've been transmitting radio signals for a little over 100 years...and those early signals weren't very strong or aimed into space, ever. Let's say 60 years seriously.

Within 60 light years doesn't even make much of a visible dot on a map of our galaxy, which is about 120,000 light years in diameter. even assuming signal strength doesn't deteriorate (which is wrong. The radio signal scatters and becomes less noticeable the further it gets), we haven't been transmitting long enough for very much of the galaxy to notice us.

Likewise, any advanced alien civilization that might exist even in our own back yard could literally be 10,000 light years away and if they came to technology 6,000 years ago, we still won't receive their signals (assuming they didn't deteriorate again, which they will) for another 4 millenia.

If anyone ever develops a means of "FTL" travel (which is almost necessary if species are to become truly spacefaring) it's highly likely we'd encounter them BEFORE we ever detected their planetary radio signals.

[Frozen_Feet]

On the same subject, there have been numerous calculations done on the hypothetical number of other civilizations out there who are within the technological window to pick up our transmissions. Even very optimistic estimations place the density of such civilizations at "one every 200 light years". So we'd actually have to wait for another hundred years to notice them, or three hundred for them to notice us and for them to respond.

[Eric Tolle]

The real question in the Fermi Paradox isn't "Where Are They?" but "Where Were They?" Interstellar travel, while slow, isn't impossible. At even the speeds we can manage (say, 1% light speed), the time to colonize the galaxy is a tiny fraction of the lifespan of the galaxy. So, the aliens should have encountered Earth back when it only had single cell life, and converted the solar system for their use. Obviously, they didn't. So to this question, there are only three answers:

1. Technological intelligence is incredibly rare, so much so that we are effectively the only intelligent race in the galaxy.

2. Interstellar travel is so much more difficult than we think it is, that it is effectively impossible.

3. Something else is happening to keep interstellar colonization from happening. Note: this thing has to apply to pretty much ALL intelligent life.

So cynical me, here's my theory: intelligent, technological life is inherently self destructive.

The idea being, the function of intelligence is to allow greater control over and utilization of the environment. The more intelligence, the more resources from the environment become available. However, intelligence is not oriented toward perceiving and dealing with the side effects of resource utilization. Where resource acquisition is a first order effect, consequences are second and third order effects and dealing with them often is not as obvious, or conflicts with the primary resource acquisition function of intelligence.

The end result is that intelligence will modify their environment without an obvious understanding or concern with the consequences. As a result, inevitably, intelligences will modify their environment to the point where technological civilization is no longer possible, and possibly drive the intelligent species extinct.

If one discards the idea of "natural balance", and looks at all the situations where the introduction of a new species or trait, caused a catastrophic ecological change, then this result looking more and more likely. In short, technological intelligence is not sustainable long enough for start flight to happen. The demonstration of this hypothesis is currently ongoing.

[Frozen_Feet]

You forgot option 4: Panspermia is a thing and we are partially or completely offspring of creatures who spilled their seeds on this stone ages ago.

[Eric Tolle]

You forgot option 4: Panspermia is a thing and we are partially or completely offspring of creatures who spilled their seeds on this stone ages ago.

That's because panspermia a) begs the question of the origin of life, and b) doesn't actually answer the Fermi Paradox.

[Talya]

3. Something else is happening to keep interstellar colonization from happening. Note: this thing has to apply to pretty much ALL intelligent life.



I'd use a modified approach to this one.

It takes life a long, long time to develop.

The first single-celled species developed on this planet about 3.5 billion years ago. While multicellular life may have developed shortly afterward, the first plant life didn't make its way out of the oceans until almost 500 million years ago, and the first animals took another 100 million years to follow. The earliest fossils belonging to Homo Sapiens we've discovered are at most 200,000 years old, and we've found earlier homonin ancestors that were clearly NOT human yet at about a million years ago.

This 4,550,000,000-year-old, 5,973,600,000,000,000,000,000-tonne ball of iron we call Earth has had life on it for about 77% of its existence, and only in the last 70 years have we been able to seriously contemplate space travel in a rational manner.

We estimate that, barring human misadventure, Earth will remain habitable to us for another 10 million or so years before the warming star we orbit is hot enough that most of the planet becomes uninhabitable (This has nothing to do with the death of the sun...the sun will continue to warm throughout most of its remaining 4 billion years before it exhausts its supply of fuel). That means that life used up 99.7% of its available time on this planet getting to a stage where we can even think about getting off. That's cutting it close, and we may still not make it. And if we happened to be close to a gamma ray burst, or another big astroid struck, life could be set back millions more years.

The odds are against any given origin for life advancing fast enough to get out of its environment before that environment ceases to be able to sustain it, even assuming that life doesn't destroy its own habitat.

[Elderand]

2. Interstellar travel is so much more difficult than we think it is, that it is effectively impossible.

This is pretty much true, people don't realise how bat****ingly difficult interstellar travel would really be.

You need shielding against radiation, armor strong enough to resist microimpacts, a power source that will last a very long time, artificial gravity, pack enough people to offer a geneticly diverse sustainable population and ways to grow food for them.

At our current level of technology going anywhere outside our own solar system is damn near impossible.

And then there is the fact than not every inteligent specie might see a point to it short of their original system being rendered uninhabitable.

Hell the more a specie advance technologicly (as far as we can envision it) the less there would be any need for interstellar travel in the first place.

[DM Nate]

Why would aliens WANT to contact us?

They've spent centuries or millennia building an advanced civilization that can literally span the stars, and they find a planet of backwater primates barely out of the trees, that in the few years they've learned to harness technology have allowed their selfish, short-sighted, bigoted, self-ingratiating, prejudiced behavior push their planet to the brink of the next great extinction.

Deciding to drop out of the sky and say "HEY WE'RE HERE GUYS HERE'S HOW WARP TECH WORKS" makes about as much long-term sense as handing a chimpanzee a hand grenade and telling him to be careful with it.

The way I see it, the aliens already have their own cliques and we're just the noisy, socially inept nerds in the back of the school lunchroom. They're hoping if they ignore us long enough, we'll just go away.

[Grinner]

They've spent centuries or millennia building an advanced civilization that can literally span the stars, and they find a planet of backwater primates barely out of the trees, that in the few years they've learned to harness technology have allowed their selfish, short-sighted, bigoted, self-ingratiating, prejudiced behavior push their planet to the brink of the next great extinction.

Who said anything about advanced, for whatever definition of advanced you wish to use? If we're speculating, there's no absolute reason to assume they know what they're doing anymore than we do.

[DM Nate]

Who said anything about advanced, for whatever definition of advanced you wish to use? If we're speculating, there's no absolute reason to assume they know what they're doing anymore than we do.

Advanced = whatever it takes to build a civilization across stars without triggering those pesky mass extinction events on one's home planet

[Grinner]

Advanced = whatever it takes to build a civilization across stars without triggering those pesky mass extinction events on one's home planet

Halo and District 9 come to mind.

[DM Nate]

Halo and District 9 come to mind.

Which aspect of Halo? As for District 9, I wouldn't exactly call the aliens a star-spanning civilization if they can't even get to their destination alive.

[Grinner]

Which aspect of Halo? As for District 9, I wouldn't exactly call the aliens a star-spanning civilization if they can't even get to their destination alive.

While occupying a Covenant warship, Cortana notes that the reactors, while quite powerful, only output a fraction of the power they should be able to. She then realizes that the Covenent don't actually understand what they're doing. Their "engineering" consists of jury-rigging together Forerunner technology into a basically cohesive whole. In spite of their ineptness, they're still able to overpower the humans, and they do so with extreme prejudice, exterminating every human colony they run across.

They meet your criteria for being advanced, but they are far from achieving any kind of enlightenment. On their own, they hold no merit.

As for District 9, imagine this: you're driving along a desert road when you pop a tire. You pull to the side of the road and find that you've parked next to a small town. What luck! So what do you do? In this case, you sit in your car for months, wallowing in your own filth. Eventually, the town's inhabitants, curious about this strange car, cut open your car with a blowtorch and drag you out.

It's hard to say anything definitive about the prawns, given the circumstances we see them in, but seeing how only a few of them actually know how to work their own technology, they are fairly comparable to humans in that regard. Still, they do also meet your criteria.

[Segev]

The idea being, the function of intelligence is to allow greater control over and utilization of the environment. The more intelligence, the more resources from the environment become available.I agree with you up to here.

However, intelligence is not oriented toward perceiving and dealing with the side effects of resource utilization. Where resource acquisition is a first order effect, consequences are second and third order effects and dealing with them often is not as obvious, or conflicts with the primary resource acquisition function of intelligence.This may seem believable when examined on a first glance, but a more in-depth look at how humanity has behaved over the course of its history demonstrates this to be flawed. It assumes a singular intellect with monolithic goals and centralized observation and imagination. "Centralized" is not a good thing in this context, because it is the sort of macro-view that fails to actually witness precisely the sort of second, third, and even 10th-order effects that stem from the central decision-making.

But man is not a centralized being. Men exist at the implementation level. We may not always predict every consequence of our actions, but we do learn and adapt, and we do so "on the ground" in ways that let us keep our systems not only running but thriving.


The end result is that intelligence will modify their environment without an obvious understanding or concern with the consequences. As a result, inevitably, intelligences will modify their environment to the point where technological civilization is no longer possible, and possibly drive the intelligent species extinct.This is both an arrogant view (that intellect could modify an environment so completely that no force could resist it, not even that intellect's own later efforts) and one lacking evidence.

The history of man is one of making mistakes and then recovering from them. The history of the Earth is one of disaster beyond anything men can inflict and recovery from the same. The history of technology is accelerating advancement as one new technology obsoletes another and opens doors to the next ones. Resources that we could not tap nor of which we could even conceive have opened up to us in the last century. The same is not unreasonable to expect as a continuing trend, unless we foolishly stop our efforts at progressing our understanding of and ability to exploit nature.

Recall that "nature," contrary to D&D's mystical treatment of it as a divine force, is itself a system of systems that revolve around mutual exploitation. The power of intellect is that it permits deliberate experimentation rather than a "throw of the dice;" where evolution without intelligence relies upon totally random chance potentially finding something that works a little better, intelligence permits deliberate study of what does and does not work, and permits focus on areas of design which have a higher probability of being an improvement over what came before.

Exploitation of itself is what nature does. That is why intellect is so strong a tool; it is a part of that natural engine of exploitation which is capable of increasing the efficiency with which resources are exploited. Efficiency is a good thing; the alternative is wasted resources. Exploitation is a good thing; the alternative is stagnation and more wasted resources.


If one discards the idea of "natural balance", and looks at all the situations where the introduction of a new species or trait, caused a catastrophic ecological change, then this result looking more and more likely. In short, technological intelligence is not sustainable long enough for start flight to happen. The demonstration of this hypothesis is currently ongoing.
You hit on a good point when you mention discarding "natural balance" as a fixed point. The idea that things exist in delicate balance and are the same forever because of it is silly. Nature changes all the time. It gets better all the time, as those things which upset the existing equilibrium cause changes in the rest of the environment which produce newer, better things. Sometimes merely different, but even that difference supports that which came in and upset the balance by, itself, being better in some way.

Intellect is the one property of this kind of disruptive innovation which can permit preservation of what came before. Intellect enables not just memory, but deliberation and action to devote resources to preservation, generally for later exploration. Nature's normal course is to lose what it had before, with the hazard that it will have to rediscover it when it proves useful again. Intellect permits the preservation of such things for later study and use when they become useful again.

It is not the natural course for intellect to self-destruct. Intellect permits the system to strengthen and grow faster.

[tomandtish]

Beer: Communicating like that, you're either the big fish in the galaxy, or terminally insane.


Snow: I asked someone about how far Earth's radio traffic can be seen from. They reckoned it would be hard to sport outside of the solar system... which is basically no communication distance at all, compared to distances within the galaxy.

Well, according to NASA (http://helios.gsfc.nasa.gov/qa_sp_en.html#radiosig), radio waves do disperse over distance. So the vast majority of earth's radio noise has probably faded into meaningless gibberish and background noise not all that far out. And even focused deliberate attempts may not get all that far (relatively speaking).

Heck, the simple answer to the Fermi Paradox? They went the other way first. Space is HUGE. There's so many interesting directions to go and things to look at. What are the odds that they'd actually come in our direction first?

"Yeah, there's some small POC planet 3rd out from its sun half a billion light years from here with some slightly elevated electromagnetic readings".

"Meh, let the next survey team check it out. My 2 week vacation starts soon".

[Madeiner]

I'm a fan of the idea that, given the age of the universe and the probabilities of sentient life occurring, we actually beat the odds. We're early. So there aren't other sentient beings out there, most likely.

Why do I like this idea? Because it ties in nicely to the "aliens had a big advanced civilization, but it's gone now, and their relics are all that's left behind" idea: we are the antecedent race. We are the "ancients," in our own infancy today.

If you wanted to use this in conjunction with an "early space exploration" setting, perhaps you could have a large colony group head out at ludicrously relativistic speeds to set up in some distant part of the galaxy. In the time that passes on Earth during the time-dialated transit of these explorers, mankind actually arises to a great height and expands across the stars by technologies as much beyond the ken of the colonists as they will be of the aliens that will come about in the billions of years of the colonists' relativistic travel.

The world and system they colonize was preserved by the ancient human civilization, who honored and revered the colonists exploratory spirit but knew that simply hopping aboard to say "hi" and hand off tech millenia beyond them would be a disservice. So they arranged for their exploring ancestors to find their destination an ideal place to set up, and protected it from all outside comers. Some of the only deliberate relic sites, with primers and automated systems designed to recognize the exporing colonists, exist in that system, intended for them to find and unlock as they grow and expand. Highly primitive compared to the troves other aliens find in teh unintentional relic sites (since those were just abandoned or the like, not deliberatley set up), but still advanced compared to "early space" tech, and useful to defend themselves and help them ratchet up.

When the colony world, using "early space exploration" tech, extends beyond the system that was preserved and reserved for them by the machinations of their descendent humanity that achieved such great heights, they find the more traditional sci-fi galaxy full of advanced races. Being "early space faring" in tech, the colonists are a bit behind, at first.

However, it was human culture and human language - even with the many generations of drift - that was behind the "ancient relics" of the "lost, hyperadvanced civilization." Thus, through a combination deliberate primers left behind for these revered explorers from the ancient civilization, and a simple cultural familiarity that is best served by a study of how it evolved from what our explorers remember of their own cultures they left behind, our "backwards" human colonists discover not only that these advanced alien races are younger than they are, objectively, but that they have an advantage when it comes to deciphering and controlling and even identifying and finding the "ancient relic" devices that are still far more advanced than anything anybody else has.

Definately a very interesting setting. I think the players would need to gather a series of more and more convincing clues that what they are looking at is "too similar" too themselves, before finally realizing that its been humans all along. And when they realize that, its when you introduce the classic sci-fi scenarios.

[Segev]

Definately a very interesting setting. I think the players would need to gather a series of more and more convincing clues that what they are looking at is "too similar" too themselves, before finally realizing that its been humans all along. And when they realize that, its when you introduce the classic sci-fi scenarios.

Indeed. There's also the possibility of running a lot of "mysterious first contact" stuff.

Start with them colonizing, and maybe even having small interplanetary travel from colony-world-prime to sub-colonies or mining stations or the like. First, they discover one of the first deliberately-left caches of stuff, but it is also one of the ones with the least tech and the most "be aware of the hazard of your local space" type of information. Possibly more cryptic than needs be due to actually being one developed very near the end of the great human empire's time. Hence it being as accurate as it still is.

Then, as they're developing some handle on the way some of the new tech can help them, perhaps timed with an expectation by the Ancients that warfare with these new weaponizable techs is inevitable, a "crack" in the defenses they set up to preserve this place for the explorers develops, letting a neighboring alien race or two reach out and contact them.

Potential for hostilities and a presentation of defenses using the newly-acquired tech (still at least decades behind whatever the local aliens have, but enough) provides impetus for remaining united and not infighting.

Classic sci-fi scenarios involving first contact and careful invitation to visit a friendlier neighbor and see some of the galaxy from their perspective may be appropriate. Perhaps the friendly neighbor has a certain amount of arrogance regarding this "young, foolish" race they've found, so are cryptic, themselves, but at least it's a glimpse.

Weave the classic sci-fi exploration with some newer tech into the beginnings of the joining of hunting for relic sites.

The colony system, preserved for the humans, has an unusual amount of relic sites, which makes it grow more important in the local galactic arm. That leads to more politics, more "they come to us" exploration, opportunities for tech trades that are more understandable (and yet more alien) due to the presence of aliens who can actually help explain the tech and its uses... And starts great hunts through their system (plus struggles to defend the colonists' rights to them) which can lead to the mystery of "humans all along" as a mid-game twist.

[russdm]

Heck, the simple answer to the Fermi Paradox?

That Fermi was an idiot.

Scientific advances have already proven that Fermi simply got it wrong. We have a spacecraft at the edge of our solar system or having crossed over about now. That spacecraft requires time in the span of hours or days to receive messages from us and about the same amount of time to send them back.

Both NASA and other scientists have already determined that the light we receive from other planets are centuries old. It will take time for any change in light to be perceived by us since it has to appear before we notice.

Aliens could have visited our planet, found nothing interesting and left. The aliens might not have been capable of communication anyway.

Fermi works on the idea that we are the certain of the universe and that any aliens who exist must land on our planet and do something. It forgets the fact that 1) We have had radio technology a short time, and 2) That radio technology may not deliver clear messages across vast distances.

Spotting a message is basically like shining a flashlight at someone who already has bright lights shining in their eyes. They won't be able to notice or see the flashlight. If it was a red laser pointer, they may catch glimpses of it from time to time. This is courtesy of the background radiation, which may swallow any messages up, rendering them undetectable. Fermi does not account for this at all. It assumes that contact is always possible even if it isn't.

Fermi also follows solely along our technological development rather using what we have learned about in nature. Bees, birds, whales, and dolphins can communicate in a way or language we simply cannot comprehend or translate. Fermi doesn't account for that point either. How would we be able to talk with bees? or birds? or even whales or dolphins?

Employing Fermi's own stupidity, the ancient Chinese would never viewed the Mayan as existing because the two had never had contact ever. Continuing with that, if we solely used the ancient Chinese, then the Mayans never existed and despite our finding ruins, we would never label as a civilization because the ancient Chinese were unable to communicate with them in any way then.

Until we have actually tested Fermi employing proper scientific methods on at least 100 other solar systems with probes or actual human visitors, Fermi is an unproven concept and not one that should be used for determining anything.

I personally prefer other outlooks than this idiocy.

Do what you want with aliens, because nothing we have currently can actually prove or disprove the existence of them anyway and Fermi is not the answer at all.

[hymer]

That's because panspermia a) begs the question of the origin of life, and b) doesn't actually answer the Fermi Paradox.

It does answer it, if all life was seeded around the same time. It could be very Master of Orionesque.

[Talya]

I agree with you up to here.
This may seem believable when examined on a first glance, but a more in-depth look at how humanity has behaved over the course of its history demonstrates this to be flawed. It assumes a singular intellect with monolithic goals and centralized observation and imagination. "Centralized" is not a good thing in this context, because it is the sort of macro-view that fails to actually witness precisely the sort of second, third, and even 10th-order effects that stem from the central decision-making.

But man is not a centralized being. Men exist at the implementation level. We may not always predict every consequence of our actions, but we do learn and adapt, and we do so "on the ground" in ways that let us keep our systems not only running but thriving.

This is both an arrogant view (that intellect could modify an environment so completely that no force could resist it, not even that intellect's own later efforts) and one lacking evidence.

The history of man is one of making mistakes and then recovering from them. The history of the Earth is one of disaster beyond anything men can inflict and recovery from the same. The history of technology is accelerating advancement as one new technology obsoletes another and opens doors to the next ones. Resources that we could not tap nor of which we could even conceive have opened up to us in the last century. The same is not unreasonable to expect as a continuing trend, unless we foolishly stop our efforts at progressing our understanding of and ability to exploit nature.

Recall that "nature," contrary to D&D's mystical treatment of it as a divine force, is itself a system of systems that revolve around mutual exploitation. The power of intellect is that it permits deliberate experimentation rather than a "throw of the dice;" where evolution without intelligence relies upon totally random chance potentially finding something that works a little better, intelligence permits deliberate study of what does and does not work, and permits focus on areas of design which have a higher probability of being an improvement over what came before.

Exploitation of itself is what nature does. That is why intellect is so strong a tool; it is a part of that natural engine of exploitation which is capable of increasing the efficiency with which resources are exploited. Efficiency is a good thing; the alternative is wasted resources. Exploitation is a good thing; the alternative is stagnation and more wasted resources.


You hit on a good point when you mention discarding "natural balance" as a fixed point. The idea that things exist in delicate balance and are the same forever because of it is silly. Nature changes all the time. It gets better all the time, as those things which upset the existing equilibrium cause changes in the rest of the environment which produce newer, better things. Sometimes merely different, but even that difference supports that which came in and upset the balance by, itself, being better in some way.

Intellect is the one property of this kind of disruptive innovation which can permit preservation of what came before. Intellect enables not just memory, but deliberation and action to devote resources to preservation, generally for later exploration. Nature's normal course is to lose what it had before, with the hazard that it will have to rediscover it when it proves useful again. Intellect permits the preservation of such things for later study and use when they become useful again.

It is not the natural course for intellect to self-destruct. Intellect permits the system to strengthen and grow faster.


I would like to agree with all of this. It's a very positive outlook, and properly rejects the flawed concept of natural balance, and places humans in our place - which is a rather insignificant one.

However, it misses one issue, that for all our intelligence, we still tend to behave like bacteria in a petrie dish, multiplying exponentially and rapidly consuming all available resources until we die off. Our intellect may allow us to circumvent this eventuality, but it will require some hard choices that we thus far seem unable to make.

[Segev]

I would like to agree with all of this. It's a very positive outlook, and properly rejects the flawed concept of natural balance, and places humans in our place - which is a rather insignificant one.I'd disagree about the insignificance; powerlessness in the face of the raw might and majesty of nature does not make us insignificant. It merely makes us small, and nature vast.

As the only known (to us, admittedly) intelligence in the universe, we are arguably, by this outlook, extremely important. We represent the acceleratory catalyst of that self-advancement in which nature engages, because we can guide our own (and that of the rest of nature's) development through our ability to direct and design the focus of the things which will represent potential advances.


However, it misses one issue, that for all our intelligence, we still tend to behave like bacteria in a petrie dish, multiplying exponentially and rapidly consuming all available resources until we die off. Our intellect may allow us to circumvent this eventuality, but it will require some hard choices that we thus far seem unable to make.
The false premise - that we consume resources until they're irreplaceably gone - is what leads to that depressing outlook. We don't; we never have. The so-called "non-renewable" resources are still out there in such abundance that we keep finding MORE than we have yet to consume every time we get anywhere near thinking about exhausting the known reserves. You can argue that we'll eventually run out, but when our science does not yet know for certain how it was created (and we keep finding reasons to doubt the theories we already have), that's not really founded.

We have enough known resources in just North Dakota to continue consuming at our current exponential rate of growth for the next century and a half, and that's assuming we find no technologies to make our exploitation of those resources more efficient, nor more reserves, nor new technologies that utilize other resources in that time.

We can infinitely utilize wood-burning, if nothing else, as we have more forests today than there were 100 years ago, and largely due to the activities of the intelligently-directed industries that make their business the harvest of wood.

We have more space on this planet unexploited than exploited, so we're in no danger of running out of room, whether for physical occupation or for food production or anything else. In fact, we produce more food on less land today than was possible 100 years ago, and, if we expanded to fill the planet with the same ratio of people-to-land-cultivated, we'd be able to support millenia of population growth just on Earth alone...and that's assuming no further advances in agricultural technology.

Our intellect and technology keeps increasing our expected-time-to-running-out of every single resource we use. While it's possible Earth might be "used up" one day, by the time that happens, it would have been long since used-up without intelligent design managing and exploiting its resources. I do not expect that would be within many millennia, and I also suspect we'd have long since moved off-world. (Given the nature of urbanization and imports, if the planet is still livable at all just from being a rock ball, we'll probably import so many resources to it before then that nobody will notice it BEING 'used up.')

There just isn't evidence in history to support the idea that technology and intellect leads to exhaustion of a region; it instead leads to growth of productivity of that region, and even problems that DO arise are later fixed because the intelligence does not wish to have such unpleasantness in its presence.



I'm a Computational Intelligence expert, so this is a subject near and dear to my academic heart. That intelligence works hand in hand with nature to inevitably improve it (unless the intelligence is so perverse as to deliberately want to cause harm to itself and its environment). And even in that parenthetical case, the intelligence is not mighty enough to fight the overwhelming behavior of the vastness of nature. And it is not in the nature of intelligence - nor of life in general - to be so perverse, so such perverse intelligences are, themselves, the less-fit-to-survive and will be wiped out by nature, while those that are not so perverse will thrive as they direct successful advances.

It is honestly those who seek to somehow stop advancement and promote "natural balance" that are closest to falling into the trap of being a perverse, self-destructive intelligence. They seek to fight nature rather than exploit nature's bounty, and that is why they lose.

Nature WANTS to be exploited (if you'll permit the anthropomorphization). It exploits itself. Being better at exploiting it advances the same goals as are advanced by nature left to its own course...only faster and more efficiently.

[Jeff the Green]

The false premise - that we consume resources until they're irreplaceably gone - is what leads to that depressing outlook. We don't; we never have. The so-called "non-renewable" resources are still out there in such abundance that we keep finding MORE than we have yet to consume every time we get anywhere near thinking about exhausting the known reserves.

Not true. There are at least two resources I can think of off the top of my headthat we've entirely depleted: Middle Eastern cedar and sylphium (ironically two that would most likely be classed as renewable at a glance). Thousands of years ago, much of what is now desert in the Middle East was forest or grassland. Rather than climatic shifts (which were not all that dramatic once the last ice age was over c. 10,000 ya), they were clearcut/overgrazed long ago (up to 12,000 ya) and desertification kicked in, permanently rendering swaths of land unsuitable for human habitation.

Sylphium is the famous seed used by the Romans as birth control, which was driven to extinction by the time of Nero.

We could also add in various extinct megafauna, but it's hard to prove humans had anything to do with it.

Besides, we don't need to deplete them to die out because of overuse. We can use exactly 1/5 of known fossil fuel reserves and not have civilization as we know it collapse in the next century.

[Slipperychicken]

Besides, we don't need to deplete them to die out because of overuse. We can use exactly 1/5 of known fossil fuel reserves and not have civilization as we know it collapse in the next century.

To paraphrase someone who's name does not come easily to mind:

"The Stone Age didn't end because humanity ran out of stones, the Iron Age didn't end because we ran out of iron, and the Oil Age won't end because we ran out of oil".

[Elderand]

Not true. There are at least two resources I can think of off the top of my headthat we've entirely depleted: Middle Eastern cedar and sylphium (ironically two that would most likely be classed as renewable at a glance). Thousands of years ago, much of what is now desert in the Middle East was forest or grassland. Rather than climatic shifts (which were not all that dramatic once the last ice age was over c. 10,000 ya), they were clearcut/overgrazed long ago (up to 12,000 ya) and desertification kicked in, permanently rendering swaths of land unsuitable for human habitation.

Sylphium is the famous seed used by the Romans as birth control, which was driven to extinction by the time of Nero.

We could also add in various extinct megafauna, but it's hard to prove humans had anything to do with it.

Besides, we don't need to deplete them to die out because of overuse. We can use exactly 1/5 of known fossil fuel reserves and not have civilization as we know it collapse in the next century.

And then there is always the matter of the dodo.

[Jeff the Green]

And then there is always the matter of the dodo.

...are dodos a resource? According to sailors they were so disgusting they'd eat almost anything but them, and it's not like they had nice plumage to put in hats or whatever.

[ReaderAt2046]

Or if you're studying animal behaviour, someone you might want to work out how to talk with, same as we do with chimps and dolphins.

Alternatively, maybe an advanced alien species can't do something we can (maybe they're from a planet around a hotter star, so can see more in the blue-ultraviolet range, but can't see green to red like we can), and aren't rude enough to just grab a few of us and chop them up to find out how we do it.

Or maybe their starfaring technologies are way more advanced than ours because, for whatever reason, they focussed on them, but another technology is a lot less advanced - say, their medical sciences are roughly equivalent to what we had in the early roman empire, or they stuck with valves and never developed the transistor, meaning their computers are massive machines that take 99% of the volume of the ship, but have less processing capability than a laptop.

There's an interesting Brandon Sanderson short called "Defending Elysium", where part of the premise is that most races develop FTL travel (which in this verse is powered by psionic energies) very early on, with one race inventing FTL before they developed the steam engine. The fact that humans are so technologically advanced but don't have FTL really worries and confuses the alien races.

[Talya]

To paraphrase someone who's name does not come easily to mind:

"The Stone Age didn't end because humanity ran out of stones, the Iron Age didn't end because we ran out of iron, and the Oil Age won't end because we ran out of oil".

True. We will stop using oil long before we run out. We'll stop using it because demand will exceed supply and the price will become so prohibitive we're forced to wean ourselves off of it. That WILL happen, and probably sooner rather than later. The only question is how much economic pain will result.

[Segev]

True. We will stop using oil long before we run out. We'll stop using it because demand will exceed supply and the price will become so prohibitive we're forced to wean ourselves off of it. That WILL happen, and probably sooner rather than later. The only question is how much economic pain will result.

Nonsense. We'll stop using it because we wil lfind something better. Cheaper, more abundant, more useful.

[Talya]

Nonsense. We'll stop using it because we wil lfind something better. Cheaper, more abundant, more useful.

Peak resource production is an accurate economic model for any (virtually) non-renewable resource that is accepted by just about every economist and oil-industry insider in the world. I tend to think they're still estimating Peak-Oil too close, (most view the peak to be prior to 2020, and anything beyond 2030 to be highly unlikely, but they've underestimated it before). We won't even be close to running out of oil, but sometime within the next 16 years, most believe, we will hit the peak for oil production, where oil production is as high as it will ever get. After that point, it will slowly drop off. (And no, there's no such thing as abiotic oil production on earth. Our oil was formed from the vast accumulation primordial trees that existed before life forms had evolved that could break down and consume dead wood.)

Except our oil usage is still increasing rapidly, especially with the growing industrialization of Asia. The instant demand outstrips what we can produce, the cost will start to jump.

If we've moved away before then (which doesn't appear likely to happen, because we're nowhere close to that type of energy breakthrough), peak oil won't matter, as demand will be dropping rapidly. If we're still heavily reliant on oil, oh, demand will still eventually drop until equilibrium is reached, as the poorest nations that can't afford it pretty much all starve to death.

Ironicly, the best thing that could happen for our species' future would be a culling of over half our world population, so it won't hurt us in the long run. But the short term pain could be nasty.

[Jeff the Green]

Ironicly, the best thing that could happen for our species' future would be a culling of over half our world population, so it won't hurt us in the long run. But the short term pain could be nasty.

Depends on how it was carried out. I'd be worried about some nasty allee effects (http://en.wikipedia.org/wiki/Allee_effect).

Also, forget oil. The bigger problem is coal and natural gas. We're not going to hit peak on those any time soon, and they make up nearly 60% of greenhouse gas emissions from burning fossil fuels. More if you count natural gas leaks, which are constant, inevitable, and more potent than burning it. There will be starvation in developing nations due to global warming well before peak oil. (Actually, it's already happening.)

[Elderand]

Depends on how it was carried out. I'd be worried about some nasty allee effects (http://en.wikipedia.org/wiki/Allee_effect).

Also, forget oil. The bigger problem is coal and natural gas. We're not going to hit peak on those any time soon, and they make up nearly 60% of greenhouse gas emissions from burning fossil fuels. More if you count natural gas leaks, which are constant, inevitable, and more potent than burning it. There will be starvation in developing nations due to global warming well before peak oil. (Actually, it's already happening.)

And funnily enough the much touted green solution of biomethanization is actually making thing worse.
Sure it might emit less CO2 (except it really doesn't when one take into account the whole production chain rather than just car exhaust) but it also uses up space that could be devoted to growing food for peoples.

[Storm_Of_Snow]

This is pretty much true, people don't realise how bat****ingly difficult interstellar travel would really be.

And even those of us that think they do are probably nowhere near the mark. :smallwink:



You need shielding against radiation, armor strong enough to resist microimpacts, a power source that will last a very long time, artificial gravity, pack enough people to offer a geneticly diverse sustainable population and ways to grow food for them.

Plus system redundancy, enough spare parts and the ability to manufacture new items as you need them, the ability to manufacture medical supplies and pharmaceuticals, massively efficient bio-waste recycling (some of which might be taken care of with bio-domes), and a whole lot else.

Although IIRC, the minimum starting point for a genetically diverse society isn't actually that large - it's a few 10s of people. Plus there's the possibility of using donated ova and spermatozoa.

In fact, you could potentially just send cryogenically stored genetic materials, automatically mix them when the craft a little way short of the target planetary system, grow them in an artificial support environment and have some system that cares and educates the offspring.

[Elderand]

And even those of us that think they do are probably nowhere near the mark. :smallwink:


Plus system redundancy, enough spare parts and the ability to manufacture new items as you need them, the ability to manufacture medical supplies and pharmaceuticals, massively efficient bio-waste recycling (some of which might be taken care of with bio-domes), and a whole lot else.

Although IIRC, the minimum starting point for a genetically diverse society isn't actually that large - it's a few 10s of people. Plus there's the possibility of using donated ova and spermatozoa.

In fact, you could potentially just send cryogenically stored genetic materials, automatically mix them when the craft a little way short of the target planetary system, grow them in an artificial support environment and have some system that cares and educates the offspring.

Which end up with a host of other problem because whitout people to do stuff in case of emergency you are even more at the mercy of power failures, glitches and a host of other things.

Essentialy the safest way to travel through space is to be on a planet but those are a bitch to steer. :P

[Jeff the Green]

Although IIRC, the minimum starting point for a genetically diverse society isn't actually that large - it's a few 10s of people. Plus there's the possibility of using donated ova and spermatozoa.

In fact, you could potentially just send cryogenically stored genetic materials, automatically mix them when the craft a little way short of the target planetary system, grow them in an artificial support environment and have some system that cares and educates the offspring.

Depends. With genome sequencing and sufficient knowledge of gene function, you could eliminate deleterious recessive alleles from your starting population. Then the problem will be maintaining diversity to resist pathogens. This could be accomplished by a diverse starting population and a controlled breeding program similar to what we use for endangered species.

[NichG]

I probably should have specified "complex multicellular organisms," which is what multicellularity refers to in the vernacular (that is, the language biologists and biology students use in everyday conversation and not in papers). Biofilms are cool, but they're not complex. You can run a biofilm off of not significantly more genetic material than already exists in most prokaryotes. The same is not true of complex organisms with multiple tissue types and complex behavior. Which, again, cannot evolve without low population sizes which are rare in unicellular eukaryotes. Rarer still in prokaryotes.

Well yeah, biofilms are transitional examples, so they're at the lowest end of what one'd potentially consider multicellular. They have internal structure, but its generally something like two or three layers of differentiated cells (though some have circulatory systems, like rusticles (http://www.dbi.ca/Ocean/Titanic/graphics/diag5.gif)). The main thing is that it seems as though loss of individualized germline is actually not that hard to find, and thats the primary and most overtly disadvantageous step to evolving multicellularity (in that cells have to give up their reproductive identity and rely on kin selection and things like that to propagate). Once you've gotten that, I'm not sure why one would necessarily assume that evolving multiple tissue types or complex behavior would be initially strongly deleterious. If its not deleterious initially, you don't need small populations (and generally if you're hoping to find something good down the line, that small population is going to be more of a hindrance than a boon).

There's at least two other ways to make genetically large jumps without tiny populations. One is things like the SOS response where a sub-population of cells will kick up their mutation rate for a brief time in response to stress. The idea being that if the stress is likely to kill the cell population anyhow, the higher mutational load is worth paying for the (small) chance to find an innovation that helps some part the population survive. Or in other words, if you're going to get shot at dawn anyways, there's no reason not to play russian roulette for your life - statistically its an average benefit. The other is horizontal transfer, which can make significantly non-local moves in genetic space.

The interesting thing, I think, is how quickly multicellular evolutionary mechanisms have proceeded despite the massively lower population sizes compared to e.g. bacteria. This suggests some sort of refinement or advantage of evolutionary process in multicellulars compared to the single-celled case - either a large vacuum in the niche space of multicellulars that basically just filled as quickly as genetic variation could accumulate, or possibly that one of the bottlenecks to sophisticated multicellulars emerging was the development of a framework similar to genotype-phenotype mapping which made individual forms of genetic variation more efficient at sampling the space of possible shapes. That is to say a specific framework for morphogenesis that allowed individual mutations to permute the organism's resultant shape in a generally non-lethal way needed to be refined somewhat first before things could really take off, similar to the evolution of transcriptional regulation would have been to unicellulars. If you have a mapping such that adding or removing a protrustion can be done without e.g. most of the time damaging the protein responsible for forming protrustions in general, then things can move along much faster.

Anyhow, this is probably a bit far off of the Fermi Paradox question at this point. So to return to that, my money's on the separation of timescales between geological time and the rate of advancement of civilization, combined with the fact that signal detection is actually a seriously non-trivial problem. So far, human history has spanned timescales on the order of 10k years. Human history that involves transmission of information that can be detected in other star systems has spanned on the order of 100 years. Evolutionary history on earth has spanned on the order of gigayears. If civilization start times are Gaussian processes due to the addition of a number of random delays, then we can expect that the variation in start times scales like 4 gigayears divided by the square root of the weighted sum of the various evolutionary transitions needed to get to this point (weighted because some transitions are fast and others are slow). So even if there are quite a few of those we can still expect that that timescale of the variation in start-times could be millions of years (for 1 million 'difficult' and distinct evolutionary transitions) - several orders of magnitude bigger than the history of civilization. I think its more likely that the number of distinct, absolutely essential evolutionary transitions is something like 100s than 1 million, which would make the start-time variation about 100 megayears.

Now, if the time to develop some sort of different transmission technology is comparable to the timescale of the development of radio communication, we're looking at a couple centuries, maybe a millennium of highly visible radio chatter from any given civilization. So just based on those stats, we'll only be at the right time to detect 1 in 1000 alien civilizations. So instead of the nearest alien civilization being 200ly away, we have that the nearest alien civilization that statistically we're lucky enough to detect is 200 * 1000^(1/3) = 2000 lightyears away. Add that at those ranges our ability to detect radio signals and to scan the right part of the sky is pretty far from 100% and you might find that the nearest civilization we'd be lucky enough to detect would be 20k lightyears away. So thats a significant distance across the Milky Way from us.

So it doesn't seem all that unlikely that our inability to find technologically advanced life out there is not strongly indicative of whether there actually is or not.

[Segev]

As others have alluded to, we're already using so many things other than oil that we're not really in danger of losing it. If oil DOES reach a peak production capacity...
Though I doubt it is likely to despite what "most" economists say. Most economists said we'd run out decades ago back when Pennsylvania was the primary source of oil in the world; then we discovered vast new reserves in the oceans and in Arabia. Even now, we've developed Fracture Mining in the last few years, and it's BOOMING in North Dakota. It gets natural gas more than oil, but it does also get oil. And as I said, the oil reserves we have unlocked just from knowing how to fracture shale for it are enormous. But, even if we assume the economists who are ignoring the historical trend of a Moore's Law for oil reserves are correct...
...we have natural gas, coal (not our best option, but certainly abundant), and (if we'd get our heads our of our social-scare-tactics hindquarters) nuclear. Missouri, where I grew up, is almost entirely powered on nuclear fission plants. It has some of the cheapest and most reliable energy in the country.

Moreover, while I think this particular branch must have hit some major stumbling blocks as I haven't heard of it in a few years, there was some research being done into producing crude No. 4 from turkey carcasses. It looked promising. I think the big obstacle is that it's more expensive than mining it from the ground. But if oil really does become scarce, research into making that method more affordable will become more attractive, and eventually that WILL be an affordable method compared to mining oil. Prices may rise, but not to catastrophic levels, and the nature of intelligent invention and the economy of scale is such that I expect we'll see those technologies become more affordable as they become more necessary. "Necessity is the mother of invention" may not be a 100% truism, but it conveys a certain truth nonetheless: We tend to invent things we need, even if we also invent stuff we don't just for the heck of it.

Intelligence is a wonderful blessing.

[TheThan]

Ok lets plug some holes in the theory.

it assumes that humans are not unique in the universe and there are other sentient life forms out there.
it assumes that the aliens use radio waves for communication
it assumes that the aliens are close enough to pick up the radio waves
it assumes that the aliens are advanced enough to pick up the radio waves and decipher them
it assumes that the aliens are capable of hearing and deciphering human speech.
it assumes that the aliens have the tech to reach earth from another planet
it assumes that the aliens are even interested in earth in the first place
it assumes that the aliens are corporeal being like ourselves and not something completely different

[Ravens_cry]

I think the last can be ruled out unless evidence suggests otherwise. It has a little too much of the 'Invisible unicorn' to it.
Also, it's not that they are necessarily interested in Earth, it's a simple matter of expansion throughout the universe, even at conservative, well within what is allowable by the laws of physics, rates.
Any growing society is going to need more and more raw materials even if they all uploaded themselves to digital paradise.

[Talya]

it assumes that humans are not unique in the universe and there are other sentient life forms out there.
it assumes that the aliens use radio waves for communication
it assumes that the aliens are close enough to pick up the radio waves

Want to touch on these:


the first is actually highly likely. The bigger issue is whether they'd recognize us as sentient, or see us as just local fauna.
the second point is broader than you let on. There's nothing special about radio waves that make them physically different from microwaves, infrared light, the visible spectrum, ultraviolet light, x-rays or gamma rays. They're just photons, and to even detect that the stars exist, any alien species would need a method of detecting photons. Note that as a species, we're pretty much blind to most of the EM spectrum.... visible light makes up such a tiny part of it. It's entirely possible other species will see different parts of the EM spectrum (even here on earth, many species see into parts of the EM spectrum that humans cannot), and yet we learned to detect and use other parts of the EM spectrum that we cannot see. Therefore, any intelligent alien species that could see the stars would do the same.
We pick up radio waves from other galaxies, even now. The problem is whether they'd be able to distinguish our faint radio waves as somehow different from all the other background noise.

[Elderand]

Any growing society is going to need more and more raw materials even if they all uploaded themselves to digital paradise.

Do they ? Do they really ?

It's entirely possible, whithin the laws of physics to end up with a society so advanced they end up producing matter by converting energy into whatever they need. At that point any need for expansion stops.

And we can't rule out the last one at all. It's actually a very salient point.

What if life elsewhere was, due to a quirk of fate, the result of molecule with reverse chirality to our own ? Thye wouldn't be able to survive in our spot in the universe or benefite from anything in it.

What of life made out of antimatter ? We "think" all the antimatter that existed got destroyed, but can we be sure ? Couldn't isolated pockets of it exist in some far reaches of the cosmos ?

Or even less abstract, even with life similar to ours the form that sapient intelligence can take could so bizarre from our perspective that things we'd consider somewhat viable despite the risk, like interstellar travel could simply be utterly abhorent.

Fermi paradox is only a paradox if you cannot conceive of anything too different form a human like perspective of life and thinking.

And even discarding that you end up with purely technical constraints that are gleefuly brushed under the rug for the sake of the paradox, like space travel at any great distance is really really really difficult and communications get garbled no matter what medium you use.

[Elderand]

and yet we learned to detect and use other parts of the EM spectrum that we cannot see. Therefore, any intelligent alien species that could see the stars would do the same.
[/list]

Objection, generalisation from a sample of exactly one sentient specie. And assuming technology follows a strictly linear path.

That's the fundamental problem with Fermi's paradox, it's rellies on assumptions based entirely on extrapolations from human experience.
There is simply no reason to assume that sentient life would develop to end up thinking or developping technologicly in any way shape or form remotly like we did.

[Talya]

But there really is. It's a logical progression. Knowledge of one is required to unlock knowledge of another.

I mean, it's entirely possible they are primitives, in which case, no, they wouldn't detect us (we wouldn't have detected us 120 years ago, either.) But we're talking about advanced civilizations. The electromagnetic spectrum is a pretty basic part of scientific knowledge. Having a high-tech advanced civilization without knowledge of it would be like having rocketry and space flight without a basic understanding of the laws of motion and gravity.

[Ravens_cry]

Do they ? Do they really ?

It's entirely possible, whithin the laws of physics to end up with a society so advanced they end up producing matter by converting energy into whatever they need. At that point any need for expansion stops.

Even if you can convert matter into energy directly, you still need that energy to come from somewhere. Even a star's output is finite. Besides, by our present understanding, while this is possible, it's woefully inefficient.



And we can't rule out the last one at all. It's actually a very salient point.
How? If we are going to bust the lknown aws of physics that bad, the discussion is effectively over.


What if life elsewhere was, due to a quirk of fate, the result of molecule with reverse chirality to our own ? Thye wouldn't be able to survive in our spot in the universe or benefite from anything in it.
They'd still be able to use the raw materials. Even if they couldn't come to Earth, the rest of the solar system would be their playground, and this would be pretty obvious by now if they were here.


What of life made out of antimatter ? We "think" all the antimatter that existed got destroyed, but can we be sure ? Couldn't isolated pockets of it exist in some far reaches of the cosmos ?
It'd have to be quite far away, as when matter and antimatter interact, the annihilation creates, along with neutrinos, gamma radiation at a specific frequency. Animation between matter and antimatter interstellar medium would create a signature gamma ray glow.


Or even less abstract, even with life similar to ours the form that sapient intelligence can take could so bizarre from our perspective that things we'd consider somewhat viable despite the risk, like interstellar travel could simply be utterly abhorent.

Fermi paradox is only a paradox if you cannot conceive of anything too different form a human like perspective of life and thinking.
We need only one interstellar civilisation per galaxy for the universe to be overrun.


And even discarding that you end up with purely technical constraints that are gleefuly brushed under the rug for the sake of the paradox, like space travel at any great distance is really really really difficult and communications get garbled no matter what medium you use.
That's the best reason so far, in my opinion, though among the most depressing. No one does it because no one escapes their respective solar systems, defeating the mightiest minds various forms of tool using intelligence have to offer.

[Segev]

Touching on the FTL aspect is a fascinating one to me. Obviously, in Star Trek and other such space operas, FTL just works, enabling travel to distant locations while ignoring relativistic effects. Time really does move at the "same pace" everywhere, just as we conceptualize it to do here on Earth. At most, there might be mention of shipboard time vs. planetary time in the vein of time zones and jet lag here on modern-day Earth.

However, the truth is, even if we could achieve FTL, the odd temporal distortions relative to two distant locations would create weird effects.

One of the more extreme ones, to my view, is covered by the concept of the "tachyonic antitelephone (http://en.wikipedia.org/wiki/Tachyonic_antitelephone)." The link goes into some math involving Lorentz transformations, but the meaning boils down to the simple statement that, if you can travel faster than light (or even arrange just for messages to travel faster than light), you can arrange a set of communications between two reference frames (that is, two places moving at significantly different speeds) such that a person in reference frame (RF) A sends a message to a person in RF B, and the message the person in RF B sends in reply arrives at RF A, from the perspective of the person in RF A, before the person in RF A sent the initial message.

While our modern warp drive research (http://www.extremetech.com/extreme/164326-nasa-discusses-its-warp-drive-research-prepares-to-create-a-warp-bubble-in-the-lab) into FTL possibilities, we're using a theory advanced by Stephen Hawking to attempt to cheat our way around the light-speed limit imposed by Einstein's theory of relativity. We do this by never moving faster than light in "local" space, but bending space in a sort of wave so that the space-wave on which our ship is located is moving at FTL speeds. Think of it as a surfer who is never moving much wrt the wave on which he's surfing, but the wave on which he's surfing is pushing him along rapidly through the water.

But even though we're cheating our way around the speed limit by having the road move that fast rather than the car, our warp-driven space ships will still arrive, in theory, with effective faster-than-light travel. This means that they arrive before light from their origin point would get there, and creates the possibility for tachyonic antitelephone-like situations.

Whether these will prove to really be possible remains to be seen, but the math holds up, and if we can't do it in practice, it will mean either adjusting the models or that we've discovered some practical limit. That limit is oft theorized to be "FTL is impossible," but given that the same theories that produce the potential paradoxes don't explicitly forbid FTL, I suspect that the "it's impossible" crowd is really just failing at science. Assuming something is impossible just because the consequences of it happening don't fit your world view doesn't meet the scientific standard. (That said, hypothesizing that it's impossible but being willing to come up with tests to attempt to prove or disprove your hypothesis is perfectly fine as a scientific mindset.)

[Elderand]

Well, here is the most damning evidence to sya fermi's paradox isn't worth the paper it's printed on. Probability.

Go on, I dare you to give me the probability for the following.

Probability of life appearing on another planet
Probability that said life becomes complex
Probability that said complex life get sapience
Probability that said sapient life develop technology
Probability that said sapient life with technology survives
Probability that said surviving sapient life with technology actually wants to make it to the stars

You can't give it any probability, you might say it's probable given how vast the universe is and you'd be right, but you can't give any actual numbers anywhere along the line because we don't have enough data points.

Therefore the end result can be 10 billions spacefaring species per galaxy or 1 per 10 billion galaxies.

All fermi's paradox needs to be worthwile is for 1 spafaring specie per galaxy, that's true, but we have absolutly no way to be sure the odds are even that high.

Fermi's paradox makes for an interesting thought experiment but nothing else, it can't be scientificly discussed because there isn't enough data.

[NichG]

The real question that we should be asking is, if civilizations all do eventually upload themselves to 'digital paradise', what are the optimal sources of the resources they need, and how quickly do they need them, obtain them, and successfully extract them?

Right now, our big priority in looking at other solar systems if we as a species wished to expand would be proximity (having even a piddly 3ly distance to our target would already require the ship to support a society in of itself and have probably at least one if not two generations born on board) and Earth-like conditions on at least one planet in the target system. We also have to look at what motivations would drive us to do this - overpopulation actually isn't one, because its incredibly inefficient to transport significant numbers of people away from Earth. Probably the biggest driving forces would be curiosity (we want to see what other planets are like to more deeply understand the universe and ourselves), ensuring long-term survival of the species (if we have two planets then we've got a backup in case of disaster/self-destruction), and the fact that a subset of our population has a psychological draw towards unstable, isolated, and changeable situations (frontier mentality). Resources in other solar systems are inefficient to transmit back to Earth compared to harvesting things in our own solar system at our current tech level, so that wouldn't be a factor.

If on the other hand we were digital organisms, could transmit ourselves via light signals once our automated ship finished constructing the necessary infrastructure, etc then our needs would be different. The travel of individuals to a location would probably be more of a matter of convenience than a matter of exploration or psychological draw - basically, 'where you are' is more malleable anyhow, so living on Earth or Mars or Alpha Centauri II wouldn't make as much of an individual difference. Long-term survival is still a factor but perhaps less-so, since you can make plenty of backups by locating things at different sites in e.g. deep space without the need for a particular planetary atmosphere. I don't know off the top of my head what the ideal location for giant computing platforms would be (heat is a problem in space, as are radiation spikes, but if you're outside of an atmosphere you don't have to deal with weathering of components... so probably the dark side of a tidally locked planet with no atmosphere would be ideal). But also, because of flexible timescales of existence (you can slow down your society's clock rate), resource gathering becomes more of a feasible motivation. You could set up computation platforms in a bunch of solar systems, but then communication lag is a big problem. So its better to take the wastage and years to bring the materials home and expand your at-home computing capabilities.

So the result is that uploaded societies I think would be likely to be slowly hollowing out their immediate neighboring star systems in a slowly-growing outward shell, rather than undergoing a 'polinate and expand' sort of dynamic where they seed far away solar systems and grow exponentially out of those local seeds. The result is that they'd take over the galaxy, but very very slowly. If we assume it takes roughly 2000 years to fully exploit, transmit, and use up the contents of a single solar system back home then it takes them about 4 million years to expand to an empire 50 light years in radius. This time goes up by a factor of 8 for every doubling in radius until they reach the thickness of the galactic disk, at which point it goes up by a factor of 4 for each doubling. This assumes that transportation times aren't a significant factor in the time to exploit an alien system (they send automated ships to process everything and send it back in a lump package, and they set the entire schedule for galactic takeover ahead of time to keep the flow of materials steady). So 4 billion years is enough for them to make a 500 light year radius empire. Thats big, but its small enough that we wouldn't necessarily expect to be overrun in that time.

[NichG]

Well, here is the most damning evidence to sya fermi's paradox isn't worth the paper it's printed on. Probability.

Go on, I dare you to give me the probability for the following.

Probability of life appearing on another planet


I'd guess roughly 10^-5 (1 in 100k) if we count all planets. We're discovering that most star systems have multiple planets, many of them being gas giants. Planets in the habitable zone/etc are also reasonably common (1% to 10% of planets iirc) now that we're gaining the ability to detect smaller ones, and I'd roughly gauge the chemical conveniences of Earth as being about a 1/1000 chance. There's also no guarantee that you have to have precisely Earth-like chemistry for interesting stuff to happen - so that 1/1000 factor may be more like 1/100 or 1/10 depending on how much give there is in the chemistry. If you look e.g. at surveys of artificial chemistries, its pretty easy to find functioning autocatalytic sets (e.g. self-reproducing chemicals) in simulation - things like 1/10 or 1/100 chances (and a given planet has many different localized chemical environments to roll the dice with). Heredity is harder to pinpoint though.

Once you have those initial conditions, life is basically a 100% chance. The evidence is how quickly life first emerged when the Earth was cooling down - basically almost immediately. That suggests that the first steps are pretty easy and given geological timescales they're a certainty if you have the components present.



Probability that said life becomes complex


I'd put this at roughly 1/10, again based on geological timescales versus the age of the universe. It took a few billion years for this to happen on Earth once life originated, which is about an order of magnitude less than the age of the universe. So if start times are distributed based on the age of the universe and the emergence of high-end complexity is distributed based on a 1 billion year timescale, 1/10 seems to be about right as a conservative estimate (likely higher though).



Probability that said complex life get sapience


Basically 100% once you get complex life. Compared to the emergence of multicellularity, sapience was very fast - less than 1 billion years for it to happen.



Probability that said sapient life develop technology


Basically 100%, because this is part of what sapience means. It could be 85% or 95% or whatever due to some odd factors, but basically this is order-1 probability.



Probability that said sapient life with technology survives


My inclination is to say order-1 probability because its really hard to completely wipe a species from a planet without there being something that has succeeded it, but I'll be conservative and say 10%.



Probability that said surviving sapient life with technology actually wants to make it to the stars


Really this question is 'how late in the lifespan of their local resources would we randomly encounter them'. Eventually any technologically active species will use up convenient resources and will therefore have need of things elsewhere (if nothing else, the lifespan of their star is limited). Given infinite time, this is probability 1. But that's kind of unfair, because its not just 'will they eventually want to make it to the stars' but instead 'will they need to make it to the stars long enough before the current time for that drive to be relevant'. This is basically asking the question of 'were humans early to develop or late to develop compared to the average, and if so were they at least 500 million to a billion years late?'. Given that the timescales involved for sapience once multicellularity comes around are about 100 million years in order of magnitude, we can call that 1 sigma. So if we require that humanity be 5 sigma late (e.g. the only reason anyone goes to the stars is that their home star starts to get old) then this is about 1 in 10 million. But I think that's an extreme lower bound, since other resources and reasons can exist much more quickly than a dying star and those would be far earlier drivers. So I'd lean a lot closer to O(1) than O(10^-7).

[Mr. Mask]

Math isn't a good way to prove undicovered matters. You can prove aliens that way simply by the number of reports reckoning their existence, by giving a cynical estimate of the number of poeple who would lie or mistake something, and then be left with a few out of the ten million who must be telling the truth and have seen it correctly. You could also prove bogeymen, yettis, and any religion or major political theory you wished with this mathematical principal.

[Elderand]

Stuff
Every single number you've given after the number of planet in the habitable zone is estimated based on how thing developped here or far too convenient to be anything but a guesstimate based on guts feelings.

They may well be resonable estimate, but that's not hard science.

[Talya]

The concept of Earth and the life on it being somehow "special" is not a scientific one.

[Deophaun]

Namely: 1) They're staying home and not colonizing other planets. 2) They don't exist. 3) They're hiding their presence. Or 4) The government is hiding their presence.
5) They're not stupid enough to try to colonize a planet with technologically-advanced intelligent life already on it.

Think about it for a second. FTL, in all probability, does not exist (remember, all proposals for "realistic" FTL require exotic matter, which is just stuff that physics has yet to prove cannot exist-just like unicorns). Stars in our region of the galaxy are, on average, 7 light years apart and habitable planets, while maybe more abundant than we first imagined, are not abundant enough that you're anywhere likely enough to have intelligent life evolve separately, at near-enough times on neighboring star systems. So, to give a generous estimate, let's say there's a distance of 50 light years between civilizations.

Let's also say that one has only developed radio 50 years ago, while the other is really, really, really advanced: capable of building generation or cryostasis ships that travel at 0.2c. It's going to take 250 years for whatever military force that civilization musters to travel to the young whippersnappers broadcasting their position to them. 250 years. How much progress can occur in that time? Also, keep in mind, there is no stealth in space. It's highly possible they'll detect this force 10, 20, 50, 100 years out. What do you do then? Well, write it off as a loss, that's what.

[HighWater]

All this "do Aliens exist Mathematically/Biologically"-talk is terribly interesting, but it's also an (expected) derailment of the original poster's request:


I was considering running a an early space faring game, and was considering how to implement aliens in a reasonable way. In particular, I'm concerned with the Fermi (https://www.youtube.com/watch?v=RF4D4k2AVLA) Paradox (http://en.wikipedia.org/wiki/Fermi_paradox).

The OP did not pose the question:
"Do aliens exist in our real universe and why haven't we found them if they do?"

But the question:
"Aliens exist in my fictional universe (which is built on our current universe but 'in-the-future'). Please explain why we haven't run into them yet, but will run into them in my setting so I can preserve suspension of disbelief."

To get us back on track, I'd like to ask a few counter-questions (and propose a few solutions) to narrow down what we're looking for:
- The first question you need to ask yourself is this: Will your players actually go ahead and ask you this question? More importantly, and this is the crux, why would you answer it if they do? You can equally say "Maybe you'll find out later!" Giving explanations for story-problems is one way to deal with difficult questions, the other way is to use the problems to feed the mystery. You can make it an actual part of the setting background: suddenly we discovered we were not alone, the universe is teeming with interstellar life on a technologically competitive level. And the scary thing is... WE DON'T UNDERSTAND HOW THAT'S EVEN POSSIBLE OR WHY WE DIDN'T SEE THEM ! Leaves plenty of room for later-story Bigger Fish, Godly Aliens, or whatever you need when you go into Epic. :smallwink: (For instance, every solar system could be surrounded by a sphere of tiny machines that actively hide intelligent signals and stop colonisation attempts of already life-bearing systems. Where did the expanding civs go? Something keeps cutting them down to size? Where did the machinemakers go anyhow?)

- Second question: What is the function of the aliens in your story? Why do you want your players to encounter aliens? Are they antagonists? Mary Sues? Aesops-caught-in-media-res while fixing their Deus Ex Machina?
This has consequences for how we can elaborate on suggestions 1, 3 and 4, as well as new suggestions. Quick reminder:

1) They're staying home and not colonizing other planets. 3) They're hiding their presence. Or 4) The government is hiding their presence.

- What level of existence do the aliens live at? Are they inhabiting the same type of planets and stars that we are, or not? Are they surface dwellers, like a are, or burrowers? Are they purely predatory with very little technology of their own (Alien)? Are they starbusters, way out of Humanity's league? Are they upstart cultures like humanity itself? Are they more primitive than humanity, limited to the surface of their planet(s), because they can't do any spacetravel yet? (And if they've spread regardless, who is responsible?...)


Use your question to spark questions, rather than trying to straight-up answer it. A well-crafted mystery is much more engaging than a complete explanation. If your mystery is crafted well enough, you can get away with never actually answering it (in fact, it may be better if you don't, people will just be disappointed: see Reaper Justification Mass Effect 3).


I hope this helps.

[Mr. Mask]

The main purpose of the aliens would be a mysterious backdrop to the human conflict going on. Hints of alien life and foreshadowing for a close encounter, maybe sinister, overshadowed by wars and rumours of war, tensions at the point of cooling or at the point of exploding among the human race, a precipice between the path of new peace and the descent of destruction.

To hammer home the point, the player's home ought to be somewhere that will basically be taken or outright nuked as soon as a major war started, a place with no hope of defence due to a mixture of strategic importance and comparable irrelevance in a self contradiction. Nowhere is the fear of a conflict felt more than where people know their best hope will be as refugees or as occupied territory, where defence is not a reality that can be mustered into material form.

It is hard to be subtle enough when hinting at aliens in a space setting. Beneath every moon rock will lay inquiries of alien life, of signs, of signs of possibilities, and of possibilities of signs. You can thwart these thoughts while still tickling the sensation through clear let downs. "Your sensors pick up an unidentified craft. Now that it's within range, you can see it's just another mining vessel." "There are signs that someone has drilled in this area prospecting for minerals, but when you check with HQ no one has been cleared to check this zone. There is something strange about the drilled area, and it's missing signs of conventional tools." It turns out to be military turned bandits who must be dealt with, that decided to check for rare minerals despite lacking the proper tools (burned at it a while with a military laser or something).

There are also possibilities for uncertainty. Ships disappear around X nation's territory mysteriously. Aliens? Or government plot involving the much sought after stealth in space? It can be hard to guess at which if not well informed as to authorial intention. Misinformation is recommended.

If asked by players, I would probably say, "aliens don't exist," with a tone so serious it can be anything but. For what they play when they do appear, I'd probably base it on the way the game was going. If everything is being peacefully resolved, consider a message greeting the players in a human voice, "2437, we request docking permission from your ship," which after seeming perfectly mundane leads to the appearance of the alien ship and, "We are the Http, we request peaceful contact," as a karmic reward for the player's success and investigating into the subject, and a plothook for another day. Alternatively, I could ruin a universe that is seeming all too peaceful by having a radio conversation from the military, filled with an unusual number of pauses and evasive wording. The revelation being that humanity has come under alien attack, and the players' home is lost (either destroyed or captured).

Something similar could happen in the case of a humanity poised to war on itself, interrupted by aliens, or more horrifyingly that players discover an alien threat without means to prove it to a degree that will draw necessary attention. A sequel about attempting to find major proof of elusive alien existence could be interesting, and could be filled with hints that the players were mistaken, or that the aliens might be long dead.

After looking more closely at the Fermi Paradox, my options became a lot more flexible for the aliens. I have some ideas for the question of why aliens haven't spread out and colonized every planet a billion years ago.

So far, it seems like radio signals aren't effective for detection for as much as a few light years, but I think you could create some static generators to send out noise alongside your signals and make them gibberish if necessary. Space stealth is trickier to say, since it requires technology that is highly theoretical at best. It's fairly certain that with enough technological advancement, if it is possible it will be found, since stealth is too useful in the application of war, privacy, defence, and etc..

[Segev]

We have at least the means to perform some FTL experiments (http://www.extremetech.com/extreme/164326-nasa-discusses-its-warp-drive-research-prepares-to-create-a-warp-bubble-in-the-lab) with current technology. Notably, the only mention of "exotic matter" is for energy requirements - basically, to be used as fuel - not to actually achieve the space warping itself. I wouldn't say that all FTL theories require things that may not exist in our universe just yet.

[Mr. Mask]

Sadly for unobtainium (exotic matter) storylines, almost nothing appears in space which can't be found on earth. There are a few naturally occurring gasses on some of the planets, but those can be reproduced in a lab easily enough. It might still be reasonable scifi to say planets outside the solar system have undiscovered materials, or perhaps even for the deep recesses of the planets in the solar system (depending on how thorough recent surveys have been).

You could even hazard at materials deep in the earth if you wanted to, going with a mixture of Minecraft/Terraria/Dwarf Fortress logic that the best stuff is deepest and the fact we've only drilled about 7 miles down. What justification you could make for a rare and valuable material deeper than that however, I can't presently imagine.

[Jeff the Green]

The concept of Earth and the life on it being somehow "special" is not a scientific one.

Well, yes and no. Unique, absolutely. Even if there are other intelligent beings in the visible universe, there aren't enough stars to replicate all the random chance that led to humanoid beings. Evolution is entirely historically contingent.

Special's a slippery term, though. I'd be surprised to find habitable planets that didn't have some form of life. Probably even life bound in cells. Almost certainly carbon-based. Likely with amino acids and/or nucleic acids in a key role as catalysts or genomes. At what point is something special, and at what point is everything special so nothing is?

[Ravens_cry]

Isn't that a bit of a tautology? Oxygen is a hideously reactive gas. You don't find it free and floating around in large concentrations on planets in the temperature range considered 'habitable' without something to replenish it, and the best, heck, only way we know so far of doing that on a geological scale is photosynthesis done by life.
I think something that can be described, broadly, as humanoid (two locomotive limbs, upright stance, and two manipulators) would be more likely than a habitable planet that is sterile.

[NichG]

Isn't that a bit of a tautology? Oxygen is a hideously reactive gas. You don't find it free and floating around in large concentrations on planets in the temperature range considered 'habitable' without something to replenish it, and the best, heck, only way we know so far of doing that on a geological scale is photosynthesis done by life.
I think something that can be described, broadly, as humanoid (two locomotive limbs, upright stance, and two manipulators) would be more likely than a habitable planet that is sterile.

Because of this I think 'habitable' probably needs to be expanded a bit beyond things that a human could set down on, take off their helmet, and live there. At least for discussion of exobiology.


Every single number you've given after the number of planet in the habitable zone is estimated based on how thing developped here or far too convenient to be anything but a guesstimate based on guts feelings.

They may well be resonable estimate, but that's not hard science.

It gives us a lower bound though. There could be plenty of ways for life to emerge on places that would be totally different than the Earth-like parameters I've used, but that just means that there's more life than these estimates predict, not less. It wouldn't say all that much if the lower bound was so low that its one civilization per galaxy, but when the extreme lower bound is giving us a civilization every ~4000 lightyear radius volume even taking very pessimistic estimates, then that's a useful thing to keep in mind. It suggests that there's something which requires explanation, which is basically the whole point of Fermi's Paradox - it points to some of our observational data that appears to be statistically unlikely in the context of our current state of knowledge.

And that's basically how science is done - you find oddities and things where the explanations you have break down, and then you try to figure out why that is, and how your understanding has to change to make them consistent.


Math isn't a good way to prove undicovered matters. You can prove aliens that way simply by the number of reports reckoning their existence, by giving a cynical estimate of the number of poeple who would lie or mistake something, and then be left with a few out of the ten million who must be telling the truth and have seen it correctly. You could also prove bogeymen, yettis, and any religion or major political theory you wished with this mathematical principal.

This isn't a statement about whether math is good or not, its a statement about applying mathematics incorrectly. In all the examples you give, you're doing the calculation wrong because you're assuming that each observation event is statistically independent. However, that isn't true for at least one major reason: humans can hear of these reports and then have their behavior modified as a result.

In general, math itself is not a wrong way to prove anything so long as you can actually encode the situation properly, but you can always get a wrong result if you make errors in the approach. If those errors exist or you believe those errors exist in a calculation that is being used to show something, then its the errors that must be critiqued, not 'math in general'. Otherwise it's like me saying 'Language isn't a good way to prove undiscovered matters. You can use language to prove anything, including the existence of invisible unicorns.'

[Mr. Mask]

I'm not sure what you can prove with language. You can communicate things you've proven and discovered, and communication is often required to reach discovery and vindication of theories. I don't think you can really prove something with language unless it is a linguistic matter.

And yes, mathematics requires you have sufficient data. We lack the datapoint of likelihood of life on other planets (did we find some bacteria on another planet a while ago?). Thus, as the examples show, it is a misapplication of mathematics.

[Talya]

Isn't that a bit of a tautology? Oxygen is a hideously reactive gas. You don't find it free and floating around in large concentrations on planets in the temperature range considered 'habitable' without something to replenish it, and the best, heck, only way we know so far of doing that on a geological scale is photosynthesis done by life.
I think something that can be described, broadly, as humanoid (two locomotive limbs, upright stance, and two manipulators) would be more likely than a habitable planet that is sterile.

Indeed. We know H2O exists in vast quantities all over our own solar system. Most of it is vapor or ice, but that's just due to Earth being the only planet in the solar system that has lots of water and being in the "Goldilocks Zone" of the star. Water is an incredibly common substance in the galaxy.

Life didn't start in Earth's atmosphere. It was life that terraformed Earth's surface to be habitable for later life (which is just sensible, and really says things backwards. Earth's surface wasn't changed to be suitable for life. Life changed to be suitable for whatever environment existed upon the surface at the time.) Chemistry being what it is,while it's possible that life could form from other elements and other starting conditions, we know that life is highly likely to form in conditions where liquid water existed, and such life ends up likely to be chemically similar to our own. Other chemicals simply do not react together in the same ways. Any life that exists in the universe is likely to be composed primarily of Carbon, Hydrogen, Nitrogen, and Oxygen, just like us. Apart from the chemical reactivity of these substances in relation to each other, there is another reason they are likely to be the elemental building blocks of all life:

They're four of the six the most common elements in the universe. (Helium and Neon lack chemical reactivity and are unlikely to play a huge part in the composition of life, anywhere.)

[Frozen_Feet]

One possibility to consider is that of life consisting solely or primarily of hydrogen and helium. Biological lifeforms are obviously impossible, but entities based on stable layers of plasma might be plausible.

I bring this up, because the Sun has such a layer. I can't say if a stable plasma layer could contain information or facilitate conscious thought, but living stars is something you ought to think of if you want truly alien aliens.

[NichG]

And yes, mathematics requires you have sufficient data. We lack the datapoint of likelihood of life on other planets (did we find some bacteria on another planet a while ago?). Thus, as the examples show, it is a misapplication of mathematics.

You don't need to find a second example of life to address probability questions. That's the whole point in decomposing a composite probability into sub-probabilities which can be estimated with available data. We may not have 'a datapoint of life on other planets', but we have plenty of stellar and exoplanet data, which lets us address: the probability of various star types, the probability of finding an Earth-sized or similar planet per star, the probability that said planet is in the habitable zone, etc.

To figure out the chance that said planet has similar enough composition to Earth chemically to just go ahead and use Earth's statistics is a little trickier, but we know things about the abundance ratios of various elements due to our knowledge of the physics of the lifecycles of stars and our knowledge of nuclear chemistry (that is, the various pathways by which elements interconvert during the lifespan of a star and during supernovae).

What we don't know is if life can occur in some other way than it did on Earth, which is what makes this kind of thing a lower bound (it can only address the probability of Earth-like life, not any life) rather than a complete interval.

As far as the civilization factors go, we have our understanding of the processes and timescales of evolution, the history of Earth's biomass, etc - that isn't a single solitary process, but decomposes into a number of sub-processes each which have similar structure. This is basically the discipline of population genetics. Since its decomposable, we have much more than just a single data point about 'how evolution progresses'.

We also have timescale and spatial information which multiplies our data set quite a bit. There's no evidence that there was a single moment and place where you could flip a coin to decide 'life?' or 'no life?' once Earth cooled sufficiently. Instead, we have a large planetary surface and a long period of time in which that sort of coin flip is going on constantly because those areas and times can be decoupled into statistically independent 'attempts'. How can we know they're statistically independent? We can't exactly, but we have good evidence for it because of the separation of timescales - chemical reactions proceed at a certain speed, as does the production of new energetic compounds via e.g. lightning or geothermal processes and the decomposition of previously-formed energetic compounds. We can estimate within an order of magnitude or so the velocity scale of transport of compounds through water, wind, etc. Putting those two things together gives us an idea of a lengthscale over which the system de-correlates itself, and while I can't give you a distance like '5 miles' I can say that its significantly smaller than the circumference of the Earth, and the timescales are significantly less than a billion years.

So yeah, we have quite a bit of data to use to address this problem, even if it means that at best we're getting lower bounds. There's a lot we don't know, but thats not a reason to discard what we do actually know.

[Ravens_cry]

Indeed. We know H2O exists in vast quantities all over our own solar system. Most of it is vapor or ice, but that's just due to Earth being the only planet in the solar system that has lots of water and being in the "Goldilocks Zone" of the star. Water is an incredibly common substance in the galaxy.

Life didn't start in Earth's atmosphere. It was life that terraformed Earth's surface to be habitable for later life (which is just sensible, and really says things backwards. Earth's surface wasn't changed to be suitable for life. Life changed to be suitable for whatever environment existed upon the surface at the time.) Chemistry being what it is,while it's possible that life could form from other elements and other starting conditions, we know that life is highly likely to form in conditions where liquid water existed, and such life ends up likely to be chemically similar to our own. Other chemicals simply do not react together in the same ways. Any life that exists in the universe is likely to be composed primarily of Carbon, Hydrogen, Nitrogen, and Oxygen, just like us. Apart from the chemical reactivity of these substances in relation to each other, there is another reason they are likely to be the elemental building blocks of all life:

They're four of the six the most common elements in the universe. (Helium and Neon lack chemical reactivity and are unlikely to play a huge part in the composition of life, anywhere.)
Blue Green Algae, or at least their ancestors. Their oxygen output (a waste gas from the production of food from sunlight) killed off much of the anaerobic life in a mass extinction of unrivalled devastation. Some evolved to tolerate and even use the waste gas (ATP can be manufactured much more efficiently using oxygen as part of the process) but, make no mistake, it was devastating.

[veti]

When discussing panspermia, I like to bring up dinosaurs.

These creatures dominated the earth for more than 150 million years. Hundreds, probably thousands, of species, some of them (again, probably) quite intelligent. That right there is a huge counter-example to the assumption that there's something inevitable about sophisticated life giving rise to a technological civilisation.

And then they were (allegedly) wiped out by a meteor, and only then could the 66-million year process of our evolution really begin. So if we'd never had dinosaurs, we might've been where we are now 150 million years ago.

If that meteor was the panspermia seed, then it didn't hit a barren planet and seed life from scratch - it hit one where life was already well under way, and reshaped it. If, on the other hand, the panspermia seed came way before the dinosaurs, then you have to wonder how the progenitors foresaw the second meteor. I guess they could have launched that, too, but that seems an unreasonably long-term way of working; and allowing hundreds of millions of years of unsupervised evolution before your hard-coded second intervention can arrive, seems like a monumental gamble to take.

[Ravens_cry]

Maybe they sent the second asteroid because they didn't like how life was heading. :smalltongue:
I wouldn't say some dinosaurs were 'probably' intelligent, we really have no way of knowing. Some surprisingly intelligent, social behaviour can come from small brains, see ravens and crows, for example, but they also have much smaller bodies to control.

[Thrudd]

When discussing panspermia, I like to bring up dinosaurs.

These creatures dominated the earth for more than 150 million years. Hundreds, probably thousands, of species, some of them (again, probably) quite intelligent. That right there is a huge counter-example to the assumption that there's something inevitable about sophisticated life giving rise to a technological civilisation.

And then they were (allegedly) wiped out by a meteor, and only then could the 66-million year process of our evolution really begin. So if we'd never had dinosaurs, we might've been where we are now 150 million years ago.

If that meteor was the panspermia seed, then it didn't hit a barren planet and seed life from scratch - it hit one where life was already well under way, and reshaped it. If, on the other hand, the panspermia seed came way before the dinosaurs, then you have to wonder how the progenitors foresaw the second meteor. I guess they could have launched that, too, but that seems an unreasonably long-term way of working; and allowing hundreds of millions of years of unsupervised evolution before your hard-coded second intervention can arrive, seems like a monumental gamble to take.

Ayreon knows the answer to that question -

Newborn Race (https://www.youtube.com/watch?v=eshhko4KLW0)
Ride The Comet (https://www.youtube.com/watch?v=fS1OryN8UHk)
The Fifth Extinction (https://www.youtube.com/watch?v=zI6ZuXGiTAI)

:smallcool:

[Mr. Mask]

To figure out the chance that said planet has similar enough composition to Earth chemically to just go ahead and use Earth's statistics is a little trickier, but we know things about the abundance ratios of various elements due to our knowledge of the physics of the lifecycles of stars and our knowledge of nuclear chemistry (that is, the various pathways by which elements interconvert during the lifespan of a star and during supernovae). Only if the event which starts the first nucleotides forming occurs.

[Nightraiderx]

6. They knew where Earth was in case they exhausted their resources and now that they have they
are going to harvest/take over Earth for it's resources.

Edit: Why do we assume that the alien lifeforms will be smarter than humans idk. Now "To Serve Man"

[Talya]

When discussing panspermia, I like to bring up dinosaurs.

These creatures dominated the earth for more than 150 million years. Hundreds, probably thousands, of species, some of them (again, probably) quite intelligent. That right there is a huge counter-example to the assumption that there's something inevitable about sophisticated life giving rise to a technological civilisation.

And then they were (allegedly) wiped out by a meteor, and only then could the 66-million year process of our evolution really begin. So if we'd never had dinosaurs, we might've been where we are now 150 million years ago.

If that meteor was the panspermia seed, then it didn't hit a barren planet and seed life from scratch - it hit one where life was already well under way, and reshaped it. If, on the other hand, the panspermia seed came way before the dinosaurs, then you have to wonder how the progenitors foresaw the second meteor. I guess they could have launched that, too, but that seems an unreasonably long-term way of working; and allowing hundreds of millions of years of unsupervised evolution before your hard-coded second intervention can arrive, seems like a monumental gamble to take.

Ultimately, the differences between humans and dinosaurs were fairly insignificant. You and I share 55% of our DNA with a tree. We know for a fact that if Panspermia is how life spread through the galaxy, it was done very very early in Earth's existence, because we are obviously genetically related to every other bit of life on earth. You and I are distant cousins to bacteria. If life was seeded by some other being, they only set it in motion with that initial abiogenesis. We got to where we are today on our own.

Dinosaurs as we think of them today, ultimately walked the earth for about 135 million years (ignoring the fact that I have a small green feathered dinosaur on my shoulder as I type this. We're going to consider only classical dinosaurs.) Mammals, on the other hand, have existed in recognizable (albeit very small) form for the better part of 170 million years. Humans have only been around for about a million of those years. What's the point of this? Dinosaurs weren't given enough time on this planet to develop the level of sentience you're talking about. It's very possible that without the Cretaceous–Paleogene extinction event, some species of dinosaur would have evolved that would have been as intelligent as humans or more so. Heck, even now, given some time without human interference, several extant species might develop human-like levels of sapience, as they're not far off as it is. But we got there first, and we don't share prosperity easily.

[NichG]

Only if the event which starts the first nucleotides forming occurs.

Because of space- and time-scales you get lots of chances at this, so we can estimate roughly the rate at which that event occurs in prebiotic early Earth conditions (though the order of events may be a bit finnicky here - jumping straight to RNA may or may not be the way it actually happened since there are a number of autocatalytic chemical cycles which occur more readily from Miller-Urey type conditions, such as the formose reaction, which gets you closer to nucleotides). Small molecule chemistry is pretty fast compared to geological timescales, so you have lots of statistically independent 'trials' to get what you need to develop more stuff (although there are a few longer-term effects such as weathering and the development of changes in the composition of the oceans and rocks, etc which make it a little more tangled). So that suggests that the correct distribution to model the formation of early life is a Poisson process or a sequence of several Poisson processes without a strong ratchet. Poisson processes have a standard deviation in time-to-occurrence that is equal to the mean, so if it took 100 million years for it to happen on Earth, its very unlikely that it would take 1 billion years to happen elsewhere given the same environment, surface area, etc.

It gets messy in two places. The biggest is that its unclear how quickly small changes to the environment of early Earth would alter this probability. To try to address that more carefully, one would want to do a survey of conditions on Earth and look at their distribution, and then see whether or not those are stiff or soft degrees of freedom with respect to the properties of things like the formose reaction, citric acid cycle, and other core chemistries related to very old parts of Earth life. This will again be a lower bound because if there's some other set of reactions that'd take over in different conditions that can also lead to life, this sort of survey would almost certainly miss it since its based on what we can see in modern organisms (also, its quite likely that we're missing important chemistry anyhow because we can't see ancient transients by studying the chemistry of modern organisms, so the actual rates of occurrence are more likely to be higher than our estimate rather than lower).

The other messy thing is that different planets are different sizes but its becoming clear that Earth is somewhat smaller than average. So it should take less time in principle for things to happen on those planets (more surface area = more statistically independent attempt sites), however since we don't know where life started on Earth its hard to estimate how much an increase in surface area actually increases the attempt rate. Things that are restricted to a limited width equatorial band on land, for example, wouldn't scale the same as things in ocean volumes. So this can push the numbers around by a bit. Since those planets are larger, however, the deflections are in the direction of life occurring earlier than on Earth rather than later, at least once the appropriate geological conditions and chemical conditions have been met.

[CombatOwl]

Sure you can, we orbit an average star and live on an average planet and are made of average elements. By all accounts we're normal and average and it's not unreasonable to assume others will be like us.

The Sun is within normal limits for a star of its type, but yellow dwarves aren't the most populous type of star. The large majority of stars are red dwarves, however. We know nothing at all about the conditions around them, other than what can be inferred from our knowledge of physics. There is also relatively little data about the surfaces of small rocky planets; we basically have the inner planets of our own solar system and that's it. The planets we've been detecting so far are usually far more massive than our own.

Assuming Earth is "average" is probably not a good baseline assumption for this. "Unremarkable" may be a better term, though as we have no other evidence of life on any other planet that too fails to sufficiently describe it. There is insufficient evidence to do more than make educated conjectures about the probability of life elsewhere.

Honestly, until we find life elsewhere, it's going to continue to be speculation.

[Lord Torath]

Other problems, space is ridiculously big, our own radio transmission haven't spread all that far even on a galactic scale. Anything farther than 110 light years away isn't being reached yet. Our galaxy alone is 1200 000 light years accross.Just had to point this out: You're off by an order of magnitude. The Milky Way is about 100,000 light years across (http://www.universetoday.com/75691/how-big-is-the-milky-way/), not 1.2 million light years across.

[Ravens_cry]

Just had to point this out: You're off by an order of magnitude. The Milky Way is about 100,000 light years across (http://www.universetoday.com/75691/how-big-is-the-milky-way/), not 1.2 million light years across.
True, but the point still very much stands.

[NichG]

Reminds me of the joke about how the error bars in astrophysics are best placed on the exponents.

[Talya]

Just had to point this out: You're off by an order of magnitude. The Milky Way is about 100,000 light years across (http://www.universetoday.com/75691/how-big-is-the-milky-way/), not 1.2 million light years across.

Looks like a typo of an extra 0.

The milky way is generally described as between 100,000 and 120,000 light years across. (exact measurements are rather hard -- we can't actually see across it, nor can we see the entire galaxy... ever.)

[Segev]

Looks like a typo of an extra 0.

The milky way is generally described as between 100,000 and 120,000 light years across. (exact measurements are rather hard -- we can't actually see across it, nor can we see the entire galaxy... ever.)

Well, just let me set up this tachyon-emitter to scan...

[Ravens_cry]

Looks like a typo of an extra 0.

The milky way is generally described as between 100,000 and 120,000 light years across. (exact measurements are rather hard -- we can't actually see across it, nor can we see the entire galaxy... ever.)
Heck, only in the 2000's did we find out that the Milky Way is a barred spiral galaxy, as opposed to looking more like, say, the Andromeda galaxy.

[Mr. Mask]

Nich: You need the first proteins to be formed, before you can even get to the stage of the nucleotides, now that I think about it. I can't think of a case of observed proteins forming on their own, so the event which caused it must be fairly rare.

[NichG]

Nich: You need the first proteins to be formed, before you can even get to the stage of the nucleotides, now that I think about it. I can't think of a case of observed proteins forming on their own, so the event which caused it must be fairly rare.

This isn't necessarily true. For the reverse citric acid cycle we don't know how to make it happen without catalysts (which I should point out doesn't mean that it can't happen without catalysts, just that we haven't found a workable way yet - new steps in the chain get published every couple of years), but the formose reaction is much less picky and it creates ribose. Anyhow, this gets into the whole metabolism-first versus RNA-world versus lipid world versus self-replicating clays versus who knows what argument space, which isn't actually necessary to descend into for this particular question. The point of using more abstract math is to cut the Gordian knot - we don't have a specific pathway for how life emerged on Earth, but we do have data about the environmental conditions on Earth when it did as well as how long it took. So we can figure out some things (lower bounds) about how common or uncommon those conditions are elsewhere in the universe without actually needing the full chemical detail.

[LimSindull]

Mr. Mask

I've been thinking of a way to incorporate the problem with star travel from the book The Forever Wars with the Fermi Paradox. I came up with a few options that might be helpful to your setting.

The overall idea would be that aliens aren't uncommon in the universe (or galaxy maybe) but there are plenty of savage slave driving species that want to dominate newer or weaker species. So, all civilizations keep their communications off while they travel, because this will draw attention from the predator species.

Traveling takes time though, lots of time. This is where the fun starts, if one (or more) species sent ambassadors or slavers to us(lets say) five hundred years before your campaign takes place. This ship would know that it would take five hundred years and decided that we were worth saving/enslaving. The people who left would not be the people who arrive. Five or so generations would have passed (unless they have very successful cryosleep) with the only purpose of telling us (random aliens that they are going to interact with for the first time) about their planets history up to the point that they left on -Five hundred Years Ago- and that we should watch out for (predator races).

However, we continued to evolve and spread out throughout our solar system. ( BTW, have we expanded to more than just our system?) So when they get here, they may want to stop and study us before making their appearance known (especially if we are attacking each other). So you can have a group of aliens with only slightly better technology trying to hide/ decide when to approach humanity and let us in on basic space fare knowledge. You can also have the first race being integrated into human civilization through a large political campaign (or not, depending on your players).

Let that be timetable one.

Now on to the next bit, within (really however long you want it to be) a few months after first discovering the first aliens, another ship arrives. This ship would have left a predator planet (lets say) three hundred years before the campaign. However, with advances technology from the two hundred years before they left, they arrive only months after the first aliens arrive. Thinking us an easy target, they sent their troops to eradicate/ enslave us, but humanity (yay) may move faster with technology than these other aliens and that gives us a chance to fight them. (or maybe we just got lucky and skipped a step somewhere) So, we either invite these new aliens in (thinking that they are like the others) or we fight them (possibly like the first group) but either way the second act is a lot of space battles between three factions (joined up any way).

And this cycle can repeat, each ship having left with more technology than the last one. The most important tech for this is simply propulsion. Each ship gets to have around a hundred or so years of tech on the last voyage.
This is also what keeps older species home worlds safe. There is no way to attack a planet that will know how to defeat you with better weapons before you leave. You would be fighting an enemy with hundreds of years of technology on you when you arrived. But a baby civilization that is already a thousand years behind you, would still be under powered when you arrived.

And then you can introduce FTL and everyone will be everywhere.

A few things to keep in mind are:
1. Space is brutal,even tiny particles can rip any ship to shreds if the path is not planned perfectly.
2. Asteroids can blindside planets as well as ships. (maybe the destruction of a human colony on Ceres wasn't nuked, but hit my an asteroid)
3. Aliens can (and probably will) look like everything that we know (including us). Meaning that their could be aliens already here backing one of the main human factions.
4. Aliens may communicate/ perceive reality differently than we do. Different vocal octaves, light frequencies, all that stuff.
5. Aliens do not have to all be rational, the one thing that we will probably share with them is emotion (not all, just a lot).
6. Aliens probably have a multitude of religions, philosophies, and ideas about aliens (relative to themselves).

Anyways, I hope that this helps you. Mr. Mask

[weckar]

The FP overlooks the fact that alien creatures, even sentient and techologically developing ones (assuming they are developing in the same timeframe as us, relativistically speaking), are even interested in radio technology at all. Their particular biology may not be suited to take advantage of it, after all, or it may even be superfluous. Let's not forget that we are already working with information transfer methods beyond radiowaves, and if that is at all indicative of a general development the relative timespan during which any civilized race will emit notable radio waves is slim.

#repeatingthethread

[Mr. Mask]

Nich: Just, I consider that aspect important to the estimate. If you can't get the first stage going, it won't matter how suitable the environment is in other respects.


Lim Sindull: Just Mask is fine.

Thank you for taking the time for such a thorough analysis on my account.

Your idea that fear of other aliens, and reason to have that fear is quite reasonable. Notably with the Fermi Paradox, I found out that our radio signals quickly atrophy so that they're barely detectable noise before they're outside our solar system, so the detection of our signals isn't much of an issue (or the aliens unless they develop something very strong and focused pointing out into space, but your idea would work against that evolution).

In the setting, there might be a mission planned for Alpha Centauri, but the technology is similar enough that it's more a one way probe than any serious travel. People would still be excited about it.

Your idea of studying before making an appearance is what I was thinking as well. The decision has to be made of whether they want to ally, avoid, or destroy or enslave humanity. It may even be the subject of a quest, convincing them that humanity is worth siding with.

The waves with a hundred years difference in tech is pretty interesting. Having some sort of allied war against aggressor aliens could be fun.

Plenty of good points. Thank you for sharing them with me Lim.

[NichG]

Nich: Just, I consider that aspect important to the estimate. If you can't get the first stage going, it won't matter how suitable the environment is in other respects.

You don't generally need every single detail in order to analyze things accurately. To give an example, you can model the growth of populations of humans without understanding the detailed neurochemistry of attraction. That's because you can abstract those details away with observation - you know from data that people get together and have kids. Even if you can't calculate whether two people will get together and have kids in an ab-initio way, you can measure it and use that data in an empirical model that abstracts away those details.

Similarly, if I measure the time until a particular event occurs after it becomes possible, then I can extract information from that empirically even if I don't fully understand what went in to determining that number from first principles.

[Mr. Mask]

The first stage in the process of evolution can make the difference between any planet where proteins and cells can survive will be thriving with life, and life being exceptionally rare. It is a crucial data point. Neuro chemistry of attraction, we know it will be there if you have humans, unless these are very different humans from our understanding of humans.

[NichG]

The first stage in the process of evolution can make the difference between any planet where proteins and cells can survive will be thriving with life, and life being exceptionally rare. It is a crucial data point. Neuro chemistry of attraction, we know it will be there if you have humans, unless these are very different humans from our understanding of humans.

My point is that the fact that once the conditions were in place, life emerged very quickly indicates that this is not actually such a turning point. Given the conditions, if you don't get life in the first 100 million years then you get to try again in the next 100 million, and the next, and the next, and the next. These 'attempts' are not statistically dependent on eachother. Therefore, even if there's variance in how long it takes you to get that initial life, given the right starting conditions the next steps are basically guaranteed. All of the stuff you only 'get one shot at' is in whether or not the planet has the right composition, position relative to the star, etc to produce those conditions. Everything else basically gets retried until it happens, because if life fails to occur in a particular time period that means the situation doesn't change, but if life does emerge and thrive then the situation locks into that state.

So the question is not 'whether it will happen' but 'how long will it take?'. We have data on how long it did take in one trial, which is not a huge amount of information, but it does establish things like order of magnitude pretty well since we know the type of distribution that the single data point is drawn from (Poisson).

Now, all this could go out the window if the distribution is wrong - e.g. if life was seeded rather than spontaneously emerging. But rather than saying 'okay, so we can't say anything', its better to say 'lets make a prediction as best we can given what we think is true, and if our observations are inconsistent with these predictions, it points to something wrong with our information and its telling us something new'.

[Mr. Mask]

Sure, but it's going to make the difference in your speculation from unique lifeforms being a dime a dozen, rare, or non-existent. With that much variance possible in a speculation... take your pick.

[NichG]

Sure, but it's going to make the difference in your speculation from unique lifeforms being a dime a dozen, rare, or non-existent. With that much variance possible in a speculation... take your pick.

Even the lower bounds suggest that we should find some form of life in at least one other place in a 50 lightyear radius, so I think 'rare' and 'non-existent' are right out.

[Mr. Mask]

That is the suggestion, for lack of evidence.

[veti]

So the question is not 'whether it will happen' but 'how long will it take?'. We have data on how long it did take in one trial, which is not a huge amount of information, but it does establish things like order of magnitude pretty well since we know the type of distribution that the single data point is drawn from (Poisson).


Not really. The anthropic principle tells us, it's unsafe to extrapolate anything from the history of life on earth to apply to planets other than earth.

We're stuck in our own laboratory. Anything we attempt to deduce from that about conditions in other laboratories, elsewhere - is never going to be better than "pure speculation".

[NichG]

Not really. The anthropic principle tells us, it's unsafe to extrapolate anything from the history of life on earth to apply to planets other than earth.

We're stuck in our own laboratory. Anything we attempt to deduce from that about conditions in other laboratories, elsewhere - is never going to be better than "pure speculation".

This is really overly pessimistic. We have no reason to believe that e.g. relativity just works on Earth, and once you get away from Earth its replaced with something new. We have no reason to believe that quantum mechanics will change in a similar vein. Between the two, that means that chemistry will be the same - a given reaction in given concentrations and in the same conditions will still happen at the same rate.

And if all the underlying building blocks are the same, there's no reason to believe that suddenly when you're talking about 'life' instead of 'stellar nucleosynthesis', everything becomes different.

Now I'm not saying that every Earth-like planet we go to will have bipedal, hairless mammals as the dominant intelligent species, or that something like 'mammal' will even be a meaningful concept. Once you get things like heredity going, there's such a huge search space that you expect ergodicity breaking to occur and individual instantiations will be different. But before you have a form of heredity, you just don't have that many degrees of freedom to load contingent information into the system with - you've got the chemical composition of the environment, the temperature, the pressure, and any sort of periodic forcing (electric discharge, thermal gradients from hydrothermal vents, chemical potential gradients, mineral surfaces, etc). Its still quite a few degrees of freedom, but they're highly conditioned on what sorts of things are geologically and physically possible.

Add to that that the general motifs needed to get basic life-like behaviors are incredibly common. Autocatalysis gives you a basic self-replication, and it can happen in dozens of different known systems (there are theorems that autocatalysis is inevitable in any sufficiently large fully-connected catalytic chemical network; for non-catalytic networks, I don't know that there's a theorem of that sort but observationally you can find autocatalytic sets all over the place). Heredity is potentially the harder thing to obtain, though that may just be because we don't really have a good theory for counting the total number of bits you can store in a particular dynamical system. But the fact is that there's a simple heredity mechanism that's basically right next to a simple and fairly general autocatalytic set in carbon chemistry (e.g. formose reaction producing ribose and giving you the stuff you need to make nucleotides). And that's baked into chemistry - it'll be the same here or on another planet.

[nedz]

Well, here is the most damning evidence to sya fermi's paradox isn't worth the paper it's printed on. Probability.

Go on, I dare you to give me the probability for the following.

Probability of life appearing on another planet
Probability that said life becomes complex
Probability that said complex life get sapience
Probability that said sapient life develop technology
Probability that said sapient life with technology survives
Probability that said surviving sapient life with technology actually wants to make it to the stars

You can't give it any probability, you might say it's probable given how vast the universe is and you'd be right, but you can't give any actual numbers anywhere along the line because we don't have enough data points.

Therefore the end result can be 10 billions spacefaring species per galaxy or 1 per 10 billion galaxies.

All fermi's paradox needs to be worthwhile is for 1 spacefaring specie per galaxy, that's true, but we have absolutely no way to be sure the odds are even that high.

Fermi's paradox makes for an interesting thought experiment but nothing else, it can't be scientificly discussed because there isn't enough data.

You seem to be hinting at the Drake equation (http://en.wikipedia.org/wiki/Drake_equation), which I'm surprised no one has mentioned yet since it's a formal analysis of the Fermi Paradox.


It does answer it, if all life was seeded around the same time. It could be very Master of Orionesque.
Panspermia is neither necessary nor sufficient to explain the origin of life.
I should explain:

The Theory of Evolution is incomplete in that it only describes part of an inductive process.

Inductive processes require two things: An initiator and an iterator. Evolution describes an iterator perfectly well but it tells us nothing about the initiator. This initiator is the origin of life which as far as we know happen exactly once about 3.5 billion years ago. Whilst rocks from that time have been found they are quite rare and haven't provided an answer to this question — so far.

Panspermia is not sufficient because it just describes a pre-step in the iterator and does not provide an initiator.

Panspermia is not necessary because of a corollary to the principle that earth is not special — no where else is either; so if life could have been initiated elsewhere, it could just as easily have originated here.

Theories which are neither necessary nor sufficient are not necessarily wrong, but they are rarely worth pursuing.

[Segev]

Yeah, unless the point of your story is to get into religion and "the meaning of life" and the like, I would avoid panspermia. The problem of panspermia is that it really doesn't answer the question it purports to. It just pushes the question back to, "okay, where did THEY come from?" (Heck, one could construct an argument to claim that belief in God is a belief in panspermia: God is a Being that created the universe AND seeded it with life. Panspermia doesn't forbid the seeding entity from being Divine.

In truth, even belief in God doesn't answer the root question of "where did He come from?" Most monotheistic religions simply acknowledge this and explain that this isn't something to which we need to know the answer.)

I wouldn't focus your game on HOW things got to be as they are, not from a "root cause" scenario. In truth, I'd put aliens where you want them and just say "hey, it happened to be this way." The best our science can give us, right now, is "Earth happened to be this way" to have us show up. From a statistical standpoint, it doesn't really matter anymore what the odds of us being in the particular circumstances we find ourselves WERE. We are now in those circumstances. They're therefore givens. We've gone from "if A, then B," to "Given A..."

[Mr. Mask]

In a finite material universe, things have beginning and endings. This doesn't always apply to divine entities.

Life seeding is certainly a way of avoiding the question of the origin of life, imposing an origin for humans and some other planets' life instead. It was sort of cool in Chrono Trigger, but without making the aliens all powerful creators who humanity are toys to, or having them harvest humanity in some way, it's not likely to fit into a story aside from an aside (that's often how it feels in stories).

Sentient life being around within 50 light years of Earth since the distant past would be a problem, since it'd imply that either distant space travel wasn't possible/economical or that there ought to be an outpost in our solar system from a few billion years back.

[Ravens_cry]

Well, we don't even know if the universe is finite or not. All we know is there is only so far we can see.

[Mr. Mask]

Doubt it. Would need an infinite power source.

[NichG]

In a finite material universe, things have beginning and endings. This doesn't always apply to divine entities.

Life seeding is certainly a way of avoiding the question of the origin of life, imposing an origin for humans and some other planets' life instead. It was sort of cool in Chrono Trigger, but without making the aliens all powerful creators who humanity are toys to, or having them harvest humanity in some way, it's not likely to fit into a story aside from an aside (that's often how it feels in stories).

Sentient life being around within 50 light years of Earth since the distant past would be a problem, since it'd imply that either distant space travel wasn't possible/economical or that there ought to be an outpost in our solar system from a few billion years back.

One thing to keep in mind is that Earth goes around the galaxy once every 300 million years or so. Over that time, stars that end up within 50ly were previously scattered across about 40000ly. So even with first-generation life (that is to say, life that emerged before metal-rich stars were born), its not necessarily the case that they'd have billion-year-old monitoring stations or whatever.

[Mr. Mask]

Depends how common life forming is. If life is bound to form on a planet less radiation battered than Mars, and sentient life will eventually form on planets similar to Earth, then the earlier planets ought to have had some sentient life form. Even if some are wiped out by disasters before they become advanced enough, in the first billion years of the first planets with the necessary qualities you should have an extensive space network, if such is possible.While it is true this solar system shifts about so that we may be conveniently far away from alien home-worlds, under the stated conditions aliens ought to have been expanding since billions of years ago, so our solar system should have come near to some interstellar group who could probably afford and want to place outposts around nearby stars and worthwhile planets. You could try and say they wouldn't be interested in a dwarf star like the sun or that their travel is so advanced they don't need outposts as frequently, but as an organization expands its rate of expansion also kicks up, so you ought to be getting people setting up in all directions from all directions, creating a universe bursting at the seams with life. Working from the theory of a universe where life is common and guaranteed to occur, I can see where the Fermi Paradox gains strength.