Alien intelligence and civilizations

[Aethon]

One of my favorite subjects in all of science.

Op, Google search for the Fermi Paradox. Basically, Enrico and his buddies were at lunch talking about this very subject. The universe is so vast, why do we see among the stars, no evidence of an intelligent society other than our own. The Copernican revolution taught us that the earth is NOT the center of the universe, and in fact there is no reason to believe we are special at all. Therefore it would be highly unlikely that we were alone in the Universe and more unlikely yet that we could be the first species that is recognizable over interstellar distances. So where the heck are they?? He did some back of the envelope calcs. that went something like this.

The universe is 15 Billion years old. With near future technology, butt loads of money, and maybe a leeetle bit of unobtanium, we could build a spacecraft capable of attaining speeds of several percent the speed of light, decelerate at a nearby star and land on a suitable planet. It could be programmed then to use insitu resource utilization and additive manufacturing to create two copies of itself and send them off to do the same. Even if each ship took 500 years to create the copies of itself, and adding in the travel time, this method would allow us to explore the entire Galaxy in a few billion years, certainly in a fraction of the age of the universe.

Science also tells us that life started very early here on earth. Not long after the surface stopped being liquid lava, life on earth somehow began. Our sun is also a relatively young star. There are red dwarf stars that have been pouring forth reliable energy onto their orbiting planets for billions of years longer than the earth has even been habitable. So why haven't we been colonized or visited? Why don't we see a derelict Voyager or get to Rendezvous with Rama?

The op actually raises two "answers" to Fermi which both fall under what is called, DUN Dun dunnn The Great Filter. The idea that there are unknown obstacles facing species that may prevent them from attaining intelligence, or at least having enough technology to make them visible at interstellar distances. Perhaps other intelligent life forms are also predators (as the smartest animals on Earth are) and warlike as we are, and they destroyed themselves millions or billions of years ago, or maybe they don't have thumbs, or maybe they live under water and have no access to fire (and thus smelting metals etc. various other things our techno society relies on.) Perhaps their atmosphere is opaque and they don't know the stars are there.

You also have to remember that our sun (and probably all of the planets) did not form in isolation, alone in space, but in a HUGE cloud of gas and other stars of various masses. If you remember the Martian meteorite from a few years ago (no I'm not going there) but the very fact that we have rocks on earth that came from Mars is fascinating. Check out Litho- Panspermia. We have life here, so what about our thousands of cluster sister stars and their associated planets? Could some hardy spores have spread like wildfire throughout our birth cluster, safely sheltered from damaging radiation deep within chunks of crust, blasted from one star to the next, and then spread throughout the Galaxy as our cluster dispersed? http://www.space.com/25881-sun-sister-star-found-hd162826.html

(In my opinion litho panspermia is only feasible within star clusters, because the entry speed of meteoric life bearing rock will be slower than interstellar speeds, and those with Deadly Reentry know you really want to keep your speed down during reentry if you want to survive.)

My question is why would they want to talk to us? Check out this great short story "They're made of meat"

http://www.terrybisson.com/page6/page6.html

I could go on, and will at a later time but for now I'm going to turn it over to the user below me.

Edited June 20, 2014 by Aethon

[vger]

My question is why would they want to talk to us? Check out this great short story "They're made of meat"

Isn't curiosity sort of a prerequisite for developing a civilization? Without experimentation (let's see what happens when I bonk this skull with a femur), the development of technology can't happen.

Eventually they would wonder if there were other sentient life forms. Doesn't even matter if they 'want to talk to us.' Whether they're friendly, warlike, or indifferent, they'd still probably want to know if we were there at all.

Edited June 6, 2014 by vger

[Aethon]

Isn't curiosity sort of a prerequisite for developing a civilization? Without experimentation (let's see what happens when I bonk this skull with a femur), the development of technology can't happen.

Maybe, but there are things that a species simply may not discover. Heck we had ketchup for a hundred years before anyone thought to put it in a squeeze bottle.

We're certainly not the only intelligent species, not even here on Earth- but have you ever gone out to the driveway and tried to communicate with ants, or bees or termites or dolphins ( you shouldn't have dolphins in your driveway ). So why would aliens want to talk to us. I mean c'mon what do you say to sentient meat.

Further would we even recognize intelligent aliens looking directly at them. Those ants in your driveway see your car go down the lane every day. Do they suspect they're surrounded by a highly advanced, technological society, or do they see your car as a natural process of the world around them? Edit http://xkcd.com/638/

When we look into space we see some pretty hard to explain, hard to understand, highly powerful things. Alien societies could be quite visible, if you know what to look for. Occam's razor tells us to accept the simplest explanation that fits all the data, and unfortunately at our current level of understanding, advanced extraterrestrial civilization isn't an acceptable explanation for anything we may see.

What happens to our science and our theories about the universe if we are mistaking visible alien action for natural processes occurring in the Universe.

Edited June 9, 2014 by Aethon

[KerbMav]

Maybe their peasant revolts all failed and they still live in a monarchy, their religious leaders hold great influence over their royal leaders, their media is completely censored, all their public communication is filtered, every ounce of opposition smothered, the mere thought of other life in the universe a heresy punishable by exile, imprisonment or death?

[vger]

We're certainly not the only intelligent species, not even here on Earth- but have you ever gone out to the driveway and tried to communicate with ants, or bees or termites or dolphins ( you shouldn't have dolphins in your driveway ). So why would aliens want to talk to us. I mean c'mon what do you say to sentient meat.

Not sure if I have personally, but it's certainly in our nature (at least until "intelligent society tells us how stupid it is). Children try to directly talk animals all the time. That may be another sign of our inherent curiosity. Either way it's interesting that our younglings have an almost natural urge to try communicating with other species.

Granted, all I had to play with was ants, and mostly I just tried to blast them with magnified sunlight. If I'd had access to dolphins though? Things probably would have been pretty interesting.

[magnemoe]

Maybe their peasant revolts all failed and they still live in a monarchy, their religious leaders hold great influence over their royal leaders, their media is completely censored, all their public communication is filtered, every ounce of opposition smothered, the mere thought of other life in the universe a heresy punishable by exile, imprisonment or death?

This is a statistic society, they was very common, and they resist any change, pre-revolution China is a far better example than medieval Europe.

However they also handle change badly so if any external power pulls ahead they have a problem.

This was not a huge problem 1000 years ago, the last 200 it don't work well, add that the same groups don't relate well to other countries

[KerikBalm]

The universe is 15 Billion years old. With near future technology, butt loads of money, and maybe a leeetle bit of unobtanium, we could build a spacecraft capable of attaining speeds of several percent the speed of light, decelerate at a nearby star and land. It could be programmed then to use insitu resource utilization and additive manufacturing to create two copies of itself and send them off to do the same. Even if the first ship took 500 years to create the copies of itself, and adding in the travel time, this method would allow us to explore the entire Galaxy in a few billion years, certainly in a fraction of the age of the universe.

I think you are off by orders of magnitude.

A fusion powered vessel with the mass ratio of a saturn V could acheive 20% the speed of light. Lets also consider the possiblity of Bussard ramjets. The galaxy is 100,000 light years across.

At .2 C, you could cross it in a million years. With Ramjets, lets say accelerating to an average speed of .5 c, its only 200k years. Granted they won't be racing across, but stopping colonizing, and moving on.

We could estimate 10 million as a more reasonable time, or be generous and give them 100 million years.

Either way, it won't be billions... more like .1 billion years. 0.1/15 = 0.0066... ie, 2/3rds of one percent of the age of the universe/galaxy...

Our sun is also a relatively young star. There are red dwarf stars that have been pouring forth reliable energy onto their orbiting planets for billions of years longer than the earth has even been habitable.

Red dwarfs have many problems:

They radiate primarily in the IR, which will make photosynthesis difficult due to the absorption spectra of most gasses (assuming water based life, and thus the compounds that are gaseous at those temperatures).

There is a high possibility of a planet being tidally locked if it is within the habitable zone. Tidall locking may result in atmosphere loss due to the atmosphere freezing on the cold side... unless there is sufficient convection, but this is a feedback mechanism, and there may be no stable state where the night side is warm enough, but not so warm that you get something like venus.

It also reenforces the absorption of the sun's energy before reaching the surface

They may be quite old ones, as you point out. This is a problem when it comes to heavier elements.

Granted the planets around Kepler 10 are a bit surprising, there is still likely to be a puacity of heavy elements for older stars. Heavier elements take time to form. Some particularly active areas with supergiants that burned very fast and when supernova very early may give some red dwarves a high metalicity number, but generally, they won't have heavier elements, the ones that do, still have to contend with the previous problems.

The suns luminosity increases over time... Earth is about 80% of the way through the suns usable lifespan for life, some models suggest far less than a billion years left for complex multicellular life. But lets just call it 4 billion years of life, 1 billion remaining.

Its on the inner edge of the habitable zone... it will get quite hot in the future (even without us pumping CO2 into the atmosphere, but... I'd rather have that unbearable heat be 100 million years in the future, rather than 1,000)

Mars on the other hand, will be in the habitable zone *soon* ... but long after it's lost its internal heat, and most of its atmosphere.

Its a runt of a planet, and new simulations of the solar system suggest that Jupiter stunted its growth, migrating inward and then outward.

If such a result often happens, we may have stars where the habitable planets are all along the inner edge of the habitable zone, and often billions of years pass without the life becoming spacefaring, and the life is snuffed out by its sun growing hotter.

Back to mars... it was habitable after formation... it had an ocean... it didn't take long for life to form on Earth... where is the evidence of life on mars...

Where are the fossil biofilms that should be covering the ancient seafloor and river beds...

the fossil stromatalites?

Where are the banded iron formations? photosynthesis evolved fast on Earh (causin O2 relase and preciptation of iron oxides, causing the banded iron formations) did it not evolve on mars due to less sunlight?

Not much geologic or subsequent biologic activity to get rid of them... why don't we see them?

Planets where life could exist are not neccessarily where life could form?

I won't get into the abiogenesis hypothesis, and how they would affect the chances of life on mars if they are correct... for now

Edited June 6, 2014 by KerikBalm

[Aethon]

Oh man Kerik. You're just the guy I'm looking for. :^) Pressed for time.. gotta work, so scrambling here.

I think you are off by orders of magnitude.

I'm glad somebody said this. I was being super conservative so as to not scare off the skeptics. You know these summer rabbits. You don't hardly have to set on them before they squeeeeeal.

Edit-"The total mass of probes needed to explore even the entire Galaxy is astonishingly small. If each self-replicating probe, mass fully-fueled about 10¹⁰ kg, makes 10 replicas during each of 11 generations, enough to span the entire Galaxy, that is 10¹¹x 10¹⁰ kg = 10²¹ kg or about the mass of Ceres, the largest known asteroid. If the Solar System carried the burden of manufacturing all 10¹¹ probes to explore the entire Galaxy, how could we know if one Ceres-size asteroid had ever been removed from the Asteroid Belt?

And take the argument one step further. Assume that one million extraterrestrial civilisations each pillage the Solar System for materials to build and launch their own million independent probe networks, each covering every star in the Galaxy. The total requirement is still only 10⁶ x 10²¹ kg = 10²⁷ kg, about the mass of Jupiter. It is doubtful we could say for certain if even this much matter had been stolen away sometime in the remote past." Robert A Frietas Jr.

Image of the asteroid Vesta showing an unusual series of concentric troughs: http://www.nasa.gov/images/content/595406main_pia14894-full_full.jpg

"Red dwarfs have many problems:"

Agreed, but so do we! And one of them is this:

"(assuming water based life, and thus the compounds that are gaseous at those temperatures)."

Did you see the cartoon in my above post. Much like the ants there, we are stuck in the 'life as we know it box'. Can we see the forest through the trees? I suppose that convergent evolution and inter-cluster litho-panspermia could allow similar organisms to employ similar mechanisms to solve some universal problems confronting intelligent life in the universe, but I see no reason to confine our thinking to life as we know it.

"This is a problem when it comes to heavier elements."

Another fine example of a possible- DUN Dun dun- Great filter. We don't see alien evidence because until very recently (cosmically speaking) and for many reasons the universe may have been incapable of supporting, and even hostile to, life in any form. Which begs the terrifying question. Is the Great Filter behind us... or is it yet to come? Supernovae, Gamma ray bursts. Perhaps life has begun uncountable times in the past only to be coldly obliterated- vaporized by light, or torn apart by magical forces in a more chaotic young universe. Will our precocious selves, all our knowledge, triumphs, loves and hopes, everyone we've ever known or heard of, be obliterated by an unknown disaster somewhere in the future, before we can leave a lasting mark?? To paraphrase a famous quote : ..what rude beast lurches toward Bethlehem, yet to be born. ( Another reason for those in the US to jump down your representatives throat about the poor state of funding given the space program. We've got to get some of our eggs out of this basket. Remember, the dinosaurs went extinct because they failed to appropriately fund a capable space program).

"where is the evidence of life on mars"

K really running short on time. sorry about lack of editing.

How well have we looked? Sure, we can see Mars pretty well from space and have fine orbital maps, but you can't find evidence of past life like that. Mars is indeed smaller than Earth. I've probably looked at Mars surface more than 99 percent of all the humans that have ever lived, ( I take a short stroll there every day, and you can too. http://mars.jpl.nasa.gov/msl/multimedia/raw/ ) but I've only seen a fraction of a millionth percent of it's surface. Until we get a geologist and a biologist on the surface we won't know.

Manned spaceflight plug : All of the amazing things accomplished by the fabulous MSL (Curiosity) in it's almost two years on the surface, could have been done by a human geologist in less than a Martian day.

More later.

Edited June 10, 2014 by Aethon

[Idobox]

On that subject, I'm actually worried one of the most recent xkcd might be right

http://xkcd.com/1377/

Our own species and civilisation is a little bit like a plague, extending as much as possible, using all the resources and destroying the species on our way. The reasonable thing for an advanced species, either because they use resources in the galaxy, or because they don't like the idea of humans running wild and destroying everything, would be to either wipe us out or contain us as soon as they notice us. If the average civilisation is similar to ours, the oldest one would probably spend a big part of its resources weeding the galaxy from new aggressive species before they can be a real issue.

The resolution of Fermi's paradox might be that civilisations either hide or get eaten by the big bad intergalactic wolf.

And we're actively trying to find aliens, and to get them to notice us. Maybe not such a great plan.

[KerikBalm]

Much like the ants there, we are stuck in the 'life as we know it box'. Can we see the forest through the trees? I suppose that convergent evolution and inter-cluster litho-panspermia could allow similar organisms to employ similar mechanisms to solve some universal problems confronting intelligent life in the universe, but I see no reason to confine our thinking to life as we know it.

Yes, I know, water based life may not be the only type...

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

but, they all have some problems that may or may not be insurmountable. H20 is pretty common throughout the universe.

Maybe we are looking too narrowly, maybe we're not.

If we're not, we may have a solution to the Fermi paradox.

If these other biochemistries were viable, we'd expect there to be a whole lot more life out there.

We have no evidence to support these other biochemistries being viable.

I can't prove they aren't viable, but I also can't prove that there isn't a teapot orbiting pluto.

I'm not saying other life isn't out there, but I am saying its likely it rarely makes it to our level of technology/spaceflight, and probably (within our galaxy) has not mastered fusion power (or even more advanced... bussard ramjets and antimatter production/storage)

Great filter. We don't see alien evidence because until very recently (cosmically speaking) and for many reasons the universe may have been incapable of supporting, and even hostile to, life in any form. Which begs the terrifying question. Is the Great Filter behind us... or is it yet to come?

Yep, I think we're on the same page here. As I said, life on Earth is already 80% of the way through the usable lifespan of our star. If we blow it, there probably won't be time for another civilization to arise. And we sure look like we've got a good chance to blow it.

Of course, if there were billions of planets with life out there in our galaxy, and they all blow it at about our stage... then it seems likely that we are doomed too. I hope the 99.99% filter isn't occuring at about our level, but rather its spread out across multiple stages (such that there aren't billions and billions of earthlike planets), and the mere fact that we're multicellular animals means that we are past most of the filters, and that we are sentient means we are on the cusp of being past all the filters and to interplanetary(or whatever you call colonizng moons and asteroids) colonization and eventually interstellar travel

How well have we looked? Sure, we can see Mars pretty well from space and have fine orbital maps, but you can't find evidence of past life like that.

Well, the biofilms should be very widespread. Microbial matts once covered almost all of earth's seafloor, even with much more active weather and geologic processes, much of it has survived. Other evicence, like banded iron formations, is very abundant. The evidence should be all over the place on mars without an active hydrological cycle, or subduction and active geological processes...

There are inverted relief formations... which basically form when old riverbeds are more resistant to wind erosion that the stuff surrounding the riverbead.

One explanation is simply cementing due to water... but I wonder if inverted relief formations on mars are really massive biofilm fossiles from old riverbeads choked with microbial mats...

But on the other hand... we have sent rovers into the old seafloor, to places that had standing water... no rocks displaying banded iron formations (so no oxygenic photosynthesis evolved?), no fossil biofilms mats....

I'm pretty sceptical

[Aethon]

Granted, all I had to play with was ants, and mostly I just tried to blast them with magnified sunlight. If I'd had access to dolphins though? Things probably would have been pretty interesting.

LoLd. The same could be said if you'd had bees.

[Aethon]

Well, the op asked for an argument.

Apparently there are no skeptics here. K I'll take it.

I hope the 99.99% filter isn't occuring at about our level, but rather its spread out across multiple stages

This. Yes. Many filters. The leap from unicellular to multi-cellular life was a big one, oppose able thumbs were big- but a filter could be something 'simple' that we take for granted every day, like the invention of glass. Glass is pretty amazing ( thanks to NPR science Friday). A durable material that light passes through?? Amazing! We know of very few elements in nature like this.

Most of an atom is empty space, and you would think that light would just pass through most things and they would be transparent. What happens is that a photon of light approaches most surfaces and electromagnetically interacts with an electron in the substance, usually the photon is absorbed- changing the energy state of an electron and creating some heat- but not our friend glass. Light goes right through it.

Imagine what our society would be like without glass. It's a durable storage device. It brought religion and thus science out of the dank caves in which it used to dwell before the stained glass windows of the middle ages ( "The night is far spent- the day is at hand. Let us therefore cast off the works of darkness, and put on the armor of light."). In fact it's almost impossible to imagine that the car would have taken off without glass, and for that matter, aircraft or even spacecraft. AND if you take a piece of glass, you can grind it and polish it and make a lens, and now you've got eye glasses... and telescopes... and you can take a smaller piece of that same glass- grind and polish it and you've got a microscope.

The enormity of it all. It boggles the mind.

Edited June 18, 2014 by Aethon

[SelectHalfling0]

Alien Consciousnesses/Extraterrestrial Civilizations could be beyond our own comprehension. Read the book "Sphere" by Micheal Crichton and it will give you an idea about how messed up our ideas of extraterrestrials may be.

[Aethon]

Not to bash the folks at SETI but I wish they had a more modern approach to their search. Bean counting our way through individual stars in our tiny (relatively speaking) Milky Way Galaxy, straining to hear a weak whisper from someone like us may indeed meet with success, but we should devote some time to searching for evidence of massive technological erections (tee hee) in other galaxies. If a super society (Kardeshev type II or III) exists in a distant galaxy their actions could be visible to us (If we know what to look for) over intergalactic distances, and by looking at other galaxies we dramatically increase our sample size.

Edited June 18, 2014 by Aethon

[ZetaX]

Our sample size is already much too big if we just look at this galaxy. And it is significantly less likely that a sufficiently advanced civilisation already existed a (or some) billion years ago, i.e. at the time the light from that galaxy would have originated.

[Aethon]

On that subject, I'm actually worried one of the most recent xkcd might be right

http://xkcd.com/1377/

Our own species and civilisation is a little bit like a plague, extending as much as possible, using all the resources and destroying the species on our way. The reasonable thing for an advanced species, either because they use resources in the galaxy, or because they don't like the idea of humans running wild and destroying everything, would be to either wipe us out or contain us as soon as they notice us. If the average civilisation is similar to ours, the oldest one would probably spend a big part of its resources weeding the galaxy from new aggressive species before they can be a real issue.

The resolution of Fermi's paradox might be that civilisations either hide or get eaten by the big bad intergalactic wolf.

And we're actively trying to find aliens, and to get them to notice us. Maybe not such a great plan.

Well said, however if the universe is truly infinite we could never "destroy" its ecology or even make a noticeable mark on it, and no matter how many billions of animals Earth pumps into it, the population of an infinite universe will always remain zero.

Rather than spend the time nipping aggressive, potentially competitive species in the bud, better to just build a giant holographic "planetarium" ( although this would be a universe-atarium, ) around their system, essentially hanging a mobile over a baby's crib. I can see the infomercial on intergalactic CCTV now...

" It dices. It slices. Guaranteed not to rust, crumble or smell bad in water. Watch as the amazing Universe Replacer slices through this Baelezian Mega freighter, and is still able to nip potentially competitive species in your quadrant right in the bud. Keeping them occupied and confused about the nature of reality for 20 galactic rotations or your money back! "

... "big bad wolf intergalactic wolf." Yes this.

We may not hear alien chatter from space simply because those that chatter carelessly are promptly (cosmically speaking) tracked down and eliminated. Our military early warning radars (much more powerful than our tv signals) have been screeching obviously non natural signals out into space like a hungry baby bird for fifty years.

I agree. It is not wise to shout into the jungle.

Edited June 8, 2014 by Aethon

[78stonewobble]

Or maybe they're only opposable thumbs. Imagine that!

I am... Now I'm wondering how they'd respond to a thumbs up...

[rtxoff]

Nice, the people on Mu Arae have pretty much fun with the Twillight right now

[PrivateFlip]

Intelligence alone is not enough to create an technological advanced civilization. I can imagine countless reasons why a highly intelligent being could or would not end up having a advanced civilization. Thats said, I could also imagine and intelligent enough species which has everything stacked against it, no way to directly use tools, a restrictive environment, not a naturally cooperative species, immobile, to find a way to overcome all those obstacles anyway.

[78stonewobble]

Completely guesstimating and in my humble interpretation...

I'd say that it is reasonable to think there is life elsewhere in the universe and that some of it will be intelligent.

I even think it's reasonable to think there is life elsewhere in this galaxy and that some of it may be intelligent.

Guesstimating again, my bet is on maybe 10 intelligent species and life in maybe a few thousand places in the milkyway. Obviously more if we include the entire universe.

As to why we haven't seen or heard from them. I think that intelligent life will be comparatively rare and that interstellar communication and travel will turn out to be exceedingly hard and to become even a limited interstellar species (just enough to survive some sort of homeplanet cataclysm) will require the will to pour an incredible amount of ressources into it. Not all civilisations will want to do that and offcourse not all will survive long enough to do so. It would also render interplanetary conquest an exercise in futility.

I might offcourse be completely mistaken, but it doesn't seem an unreasonable position, without any evidence to the contrary. They might be out there, they might not be out there... It's mostly a philosophical question...

[Aethon]

We may want to ask ourselves what kind of "life" can we expect to find out there. Our intelligence allows us to make predictions about the future, based on an initial set of conditions. Futurists like Ray Kurzweil theorize that we may be approaching a technological singularity beyond which the future of human life on Earth is difficult to predict. Moore's law observes that the number of processors in a dense integrated circuit, doubles every two years. What happens when machine intelligence approaches, or surpasses that of humanity?

Kurzweil postulates that about the year 2045 a man will invent a machine, that can invent machines, that far surpass all the intellectual activities of any human, no matter how clever. This will be the last invention that humanity will ever make, and the end of our culture as it is today. These machines, with their super intelligence will extrapolate sets of initial conditions further and more accurately into the future than humans ever could ( unless we begin to 'augment' own brains with implants ). We will then join the chimpanzee JV team on the bench of also rans.

If we can imagine this happening to us, perhaps we can imagine this happening to biologic life on a universal scale. Maybe we should look for 'post biologic' entities- but where (in what way) would super intelligent, highly powerful machines choose to live. Certainly not in the gravity well of an Earth like planet around a hot sun. My intelligence tells me that heat is the enemy of computation so I imagine they would migrate to the outer galactic reaches and perhaps bury themselves in cold dark molecular clouds, storing, crunching, processing, and sharing information with their peers through sophisticated, efficient (non leaky) comm links, but completely invisible to us.

It's easy (but fruitless) to speculate about infinity, but if intelligent life quickly evolves to a post biologic form, we're certainly not looking in the right places for it now. The discovery of 'other' intelligent life would be the greatest, most important discovery in human history, and while the search for intelligent life in the universe may seem silly to some, if we don't search, the chances of success are exactly zero.

Edited June 12, 2014 by Aethon

[78stonewobble]

Yeah, I'm not really gonna jump on the whole "technological singularity" bandwaggon.

There are certain physical hard limits that even AI cannot surpass.

Ie. if you make anything too dense it will collapse gravitationally (or just stop working due to heat).

If you spread it out too far you'll be wasting energy in transmitting information back and forth and light speed and travel distance.

Sure, an AI might end up vastly more intelligent than humans, but so what? There's room enough... Heck, it might like having pets around and I like having my belly scratched.

[Aethon]

I'm actually pleasantly surprised we haven't had anyone post about 'UFO's' and modern visitation. While I won't discount the possibility that the Earth has been visited over it's history, we certainly see no evidence of it today. Probably the most famous 'visitation' was the crash at Roswell, New Mexico, USA 60 years ago. I don't know if you've ever been to the Roswell museum, but if you went to the village where Columbus landed in the Americas 60 years after the fact, the people there would be able to produce some pretty convincing evidence that the Spaniards were real.

Edited June 9, 2014 by Aethon

[phoenix_ca]

I'm actually pleasantly surprised we haven't had anyone post about 'UFO's' and modern visitation. While I won't discount the possibility that the Earth has been visited over it's history, we certainly see no evidence of it today. Probably the most famous 'visitation' was the crash at Roswell, New Mexico, USA 60 years ago. I don't know if you've ever been to the Roswell museum, but if you went to the village where Columbus landed in the America's 60 years after the fact, the people there would be able to produce some pretty convincing evidence that the Spaniards were real.

I...you...they...

...what?

[Aethon]

I...you...they...

...what?

The arrival of Cristobol Columbus in the Americas can be used as an analogy of a landing by extraterrestrials. In fact the native Americans hadn't seen a man on horseback, and didn't think the Spaniard were even human. I'm saying that if you went to the place where Columbus first landed in 1560 (60ish years after the arrival) the natives would show you Spanish weapons, and armor, and horses and other hundreds of conquistadors that were waging a genocidal campaign against the populace. You would be convinced by the evidence that the Spaniards were indeed real. Visiting Roswell however will give no such assurance about the existence of extraterrestrials.