Thread: Extraterestrials

This question is a little more opinionated than scientific:

1) Do you scientifically think aliens exist?
2) Do you personally want aliens to exist?
3) Do you think they would be hostile?
4) Do you think that aliens are curently watching us (ooh I'm scared!)

Thanks

Okay. I don't want this thread to become a niche for talking about UFOs and similar delusions.

Regards,
Dishmaster (Moderator).

My answers:

1) yes
2) indifferent
3) some would, some wouldn't
4) no!

I want to believe! :P (this is an obvious X-files reference)

Originally Posted by Schemmy888

This question is a little more opinionated than scientific:

1) Do you scientifically think aliens exist?

If evolution has any real validity as a theory, then the odds of aliens not existing is incredibly poor. Doesn't mean they're near enough to make contact, however, unless a technology is possible that makes the distances easier to cross.

2) Do you personally want aliens to exist?

Not really. If aliens don't exist, then we've got the whole universe to ourselves. Once we have the technology, we can overpopulate to our hearts' content, and just ship the excess children out into space somewhere to colonize other worlds.

If they do exist, then there's a good chance that all the prime colonization real estate has already been claimed, at least all the potential colonies we would ever be able to reach.

3) Do you think they would be hostile?

I think they would dislike our expansionist tendencies. In that case, they probably wouldn't attack Earth, but we would not be welcome out in the stars.

4) Do you think that aliens are curently watching us (ooh I'm scared!)

Thanks

Yeah. I think it's likely. It might be just like Star Trek, only imagine that we're one of the primitive societies approaching the point of interstellar travel, and they're the ones on the star ship Enterprise. They might have a "Prime Directive" that dictates for them to limit their interaction to observation.

They probably want us to join them, but.... gotta give up that expansionism first, or no deal.

Originally Posted by Schemmy888

This question is a little more opinionated than scientific:

1) Do you scientifically think aliens exist?

Not sure what you mean--we've got no evidence for them.
Seems likely they do exist just based on the odds.

2) Do you personally want aliens to exist?

Other than thinking it might be cool, I don't have enough information.

3) Do you think they would be hostile?

I'd have to assume they have a completely difference set of values--perhaps hostile, perhaps not.

4) Do you think that aliens are curently watching us (ooh I'm scared!)

Depends what you mean. The distances make travel here unlikely so I don't think it's too likely their disguised as moths flitting outside my window at night. On the other hand, watching us like we're watching from afar in the Seti project--sure why not out of curiosity if nothing else.

I'll keep this short, good question though, I feel the are out there and there is indeed evidence of there visitation to earth in previous eras.

I feel some would be hostile for sure, and some not,

I would love them to exist, to expand our consciousness and learn about he universe is our ultimate purpose, what better way then to interact with a maybe ancient race of beings(hopefully peaceful) lol

Do i think they are watching us, I honestly don't know, my head says no, but my gut says yes!!!

oh well great topic!

Imagine how the discovery of the Americas would have worked out if Western Europe had had nuclear weapons. They wouldn't want to share any of their technology with a bunch of primitive hunter-gatherers for fear that they might learn how to build nuclear weapons, and then be too unsophisticated to know how to use them properly. (No easy way to prevent them from getting Uranium if they've got deposits of it on their own land.) In some ways, it's best just to set up a boundary around them and avoid direct contact.

I'm sure that whatever alien cultures have discovered us will face the same problem. Can't let us know about their technology until they're sure we'll be responsible with it. Can't even show it to us, or we'll know what's possible, and that will narrow our research avenues. If it looks like we're going to learn enough to be dangerous before we've evolved as a culture, the they'll probably wipe us out, but I don't think they really want to do that very badly.

High tech cultures prefer trade partners rather than slaves. They're probably more interested in our ideas than our resources, because we've experienced life differently than them, and it might avail them of a different perspective. I doubt Earth has any materials they couldn't get elsewhere, other than life.

Originally Posted by kojax

They're probably more interested in our ideas than our resources, because we've experienced life differently than them, and it might avail them of a different perspective. I doubt Earth has any materials they couldn't get elsewhere, other than life.

And ideas can move at the speed of light, much faster than materials.

1) There is possibly trillions of trillions of planets. The ingredients for life (including water) exists outside our solar system. Mars has probably got bacterial life on it and it may exist elsewhere in our solar system, so yes.

2) Yes. SF often relies on FTL craft but as yet we have no evidence that anything can travel faster than light. It is possible that nothing can, meaning that even though there may be trillions of races in the universe, few races ever make contact with each other because of the huge distances involved. Some might be rightly paranoid as contact may mean the destruction of a weaker race.

3) Certainly some would be for various reasons. I believe some of the UFO abduction stories could be true and some have people operated on without anesthetic. Totally non-human aliens may regard us as little more than some kind of animals and not know or not care that such people are in agony.

4) It's possible. If a century from now with limited star travel we found pre-star travel life on a distant planet, we would study it but not like Star Trek interact with it. Aborigines, Eskimos, Red Indians, many African tribes, South Americans, etc, our contact with them has totally wrecked their civilisations. Hopefully our descendants will have learned by such mistakes and only watch them.

Originally Posted by Schemmy888

1) Do you scientifically think aliens exist?

Scientifically I have no idea, since science has so far failed to identify any aliens. Did you mean 'Based upon the scientific method how likely do you think it is that aliens exist?'
The objective, scientific answer to that question is - we don't know.
I suspect that aliens are quite common.
I suspect complex aliens are uncommon.
I suspect intelligent aliens are rare, or non-existent.

However, these supspicions are based upon interpretation of an inadequate data set.

From here I shall assume you meant to ask about intelligent aliens.

Originally Posted by Schemmy888

2) Do you personally want aliens to exist?

Only if they are not hostile and then most definitely.

Originally Posted by Schemmy888

3) Do you think they would be hostile?

What do you mean by hostile? Hostile implies a desire on their part to destroy us. If I burn some firewood tgus killing millions of microbes, was a I hostile to the microbes? No, I was indifferent to them. No hostility, but the microbes are still dead.

Originally Posted by Schemmy888

4) Do you think that aliens are curently watching us (ooh I'm scared!)

If intelligent aliens exist and some of them are older than humanity, then I should be amazed if some remote sensing system had not been set up to monitor events on the Earth. I would be more than amazed if it turned out that we have ever stumbled across evidence of such a system.

Originally Posted by kojax

High tech cultures prefer trade partners rather than slaves. They're probably more interested in our ideas than our resources, because we've experienced life differently than them, and it might avail them of a different perspective. I doubt Earth has any materials they couldn't get elsewhere, other than life.

I don't think you can really extrapolate how aliens would think/behave based on how humans would behave. It might seem like a good idea to us to set up trade deals, but there's no telling how the aliens would feel about such an idea (or if it would even occur to them). Consider how 1) a group of anthropology professors 2) a group of fundamentalist christian missionaries 3) a group of Viking warriors and 4) a group of corporate CEOs would treat a new primitive culture that they discovered. Now recall that all those groups are human. The differences between humans and alien psychology would probably be much greater than the differences between different groups of humans.

There are something like 500,000 galaxies within half a billion light years of us (approximately fifty quadrillion stars). If interstellar travel is possible at even a fraction of the speed of light by spaceships that are essentually enclosed microcosms, then a technologically advanced civilization that evolved over the first few billion years of the universe could have easily colonized that entire volume by now. (Galaxies were created after about 500 million years, allowing 10 billion years for one single, advanced, space-faring civilization to evolve anywhere and 3 billion years for them to colonize the 500,000 galaxies with simple, exponential growth cycles). When something grows exponentially, (doubles then doubles again) then after ten cycles of doubling it has grown a thousandfold (2-4-8-16-32-64-128-256-512-1024). So one star civilization colonizes another star, then their civilizations both colonize two more stars and so on. Thus, in less than forty cycles, they have colonized all the stars in a galaxy (a thousand colonies-a million-a billion-a trillion). Then all the colonies in one galaxy colonize another galaxy and they both colonize two galaxies, etc. Colonization would not mean looking for any specific type of planet. A star is a useful and practical source of energy and any material orbiting a star would be used to construct more microcosms around it (Bernal Spheres, etc.). Thus, every star would be colonized.
http://en.wikipedia.org/wiki/Bernal_sphere
http://en.wikipedia.org/wiki/Dyson_sphere
The Sun generates about a hundred trillion times the Earth's present energy requirement. So logically, six hundred sextillion humans could comfortably live in Bernal Spheres or Dyson rings around our Sun. This is a huge number, but far less than an unlimited number. Sooner or later, growth is limited if a species choose not to colonize. Besides, a Super Nova within several dozen light years or a GRB pointed at their home-world and it would be extremely hard for even an advanced civilization to survive. If the Earth's population doubled only every thousand years, then our power needs would max out the Sun's energy production in less than fifty thousand years. Our Sun will eventually become very inhospitable before settling down as a frigid White Dwarf. Alien civilizations would face this same reality. They must expand or die out.
I can't tell you how a culture a million years more advanced would travel through space. However, the physics we understand says that you cannot travel at 4/3 c, but that there is no scientific reason that you can't travel at 1/3 c. That's all that I am saying. Three billion years to expand one billion light years. They would have the energy of all the stars in their home galaxy at their disposal. We're talking googolplex-joules. Either there is some unknown reason that makes interstellar travel impossible, or I am quite cretain that they would figure it out. An interstellar ship that is a microcosm could travel anywhere. Stars are occassionally ejected from galaxies, so there would be stars between galaxies. These would form an archepelago of colonies linking the galactic hubs together. Also, traveling near the speed of light, the crew would not directly experience the passage of millions of years due to time dilation. When Dyson proposed that a civilization would find more living room in space habitats than on a planet's surface, it wasn't a human solution, it was the most intelligent solution. When Kardeshev proposed that an advanced civilization would use all the energy of their home world, then their star, galaxy and galaxy supercluster, this was also not just a human solution, but the most intelligent one as well. You might be able to argue that some species wouldn't necessarily do this, but not all of them. It only takes a minute percentage of explorers from one single Type III to settle all near-by galaxies and we would have neighbors.
http://en.wikipedia.org/wiki/Kardashev_scale
http://en.wikipedia.org/wiki/Time_dilation
When people ask if you believe in aliens, they usually mean the cute little grays that seem really interested in performing an anal probe before popping back to their home world. Except that what I have described is more likely what an alien culture would really do. Their Dyson sphere around the Sun would have been there for thousands or even millions of years and we would have only recently found out about it. Sextillions of their beings would not have to "interfere" in our civilization and they would not need to leave "our" solar system because we could finally see them. So where are they?
Life most likely exists for a scientific reason and thus would exist everywhere that these condtions exist, throughout the universe. However, intelligent life may be an exception. There have been something like 10^12 species on Earth and yet, the number of species that could build a campfire is less than ten. Or perhaps, the most intelligent members of any advanced civilization eventually discover technology that the most foolish members of their civilization use to destroy themselves.

Originally Posted by Schemmy888

1) Do you scientifically think aliens exist?
2) Do you personally want aliens to exist?
3) Do you think they would be hostile?
4) Do you think that aliens are curently watching us (ooh I'm scared!)

1) As others said, statistically likely. I would add that, given an infinite universe (personal suspicion) it's a certainty and may be essential part of its workings. By "aliens" I mean "extraterrestrial life".

2) Honestly, yes I do want aliens to exist. But this has more to do with puzzling out the nature of the universe and existence, than hoping for a close encounter with UFOs.

3) Hostile depends on where one stands in relation, and I imagine most life - in the broadest possible sense - operates on entirely different scales than our own. Trees aren't exactly hostile to bats or clay. But where the niche is starlit water, yeah there's going to be competition and all parties must know that. This game has some universal rules, nothing personal.

4) I strongly doubt that aliens are watching us, because in the timeline of our galaxy this solar system and biosphere represents an early start. More will follow, but we're among the first up.

Yes
Yes
Yes
Yes

Wonder how will they react and how will we react wonder what will they bring to us

Originally Posted by Pong

4) I strongly doubt that aliens are watching us, because in the timeline of our galaxy this solar system and biosphere represents an early start. More will follow, but we're among the first up.

I believe life to be widespread, in the Galaxy, and the wider universe. However I feel that advanced technological civilisations are very rare. It is possible that we are the only one, or one of a very few, in our own Galaxy.
On the other hand, given the number of galaxies and the number of stars within each galaxy, this could still mean there are quite a number of alien civilisations.

Lastly, I do not agree with your 4th point. There are lots of stars older than the sun and presumably this means that many solar systems formed long before our system. An alien civilisation only 10,000 years older than ours (a moment on the astronomical scale) could be far more advanced than our own. If such civilisations do exist I do not believe they are "watching" us but they could well be aware of our existence.
I know much of this is speculative, but it is sometimes very hard not to believe there are a fair number of very advanced alien civilisations. I do not accept that, for a sufficiently advanced technological society, the vast distances of inter-stellar space will be anything more than a temporary barrier to exploration. So as the man (was it Fermi?) said "where are they?"

Originally Posted by Halliday

There are lots of stars older than the sun and presumably this means that many solar systems formed long before our system.

Not quite. Picture our galaxy as a newborn swirl of burning fuel, hydrogen and helium. As that burns, new elements are made. Eventually these interesting elements are ejected and condense to form next-generation systems, like our own. The developing make up of galaxies grows rich and so Earth-like planets become possible, then more common. Earth represents the cutting edge of this development.

I think it safe to assume first generation stars formed only of hydrogen and helium can't possibly spawn life. And I suppose intelligent life evolves only from a rich environment i.e. having many elements.

I'm not challenging your suggestion of 10,000 year old alien civilizations, or how rapidly they spread. I'm just saying that 4 billion year old Earth life represents an improbably early start in this 13.7 billion year old, developing universe.

Gravity from dark matter causes a cloud of hydrogen gas to collapse into stars. This large cloud of gas is known as a stellar nursery. Due to the abundance of hydrogen, several huge stars rapidly form. These huge, first generation stars rapidly fuse their cores so that after only a few million years they go super nova. Nearly every element is created in the explosion and many solar masses of these elements spread throughout the remaining cloud of hydrogen gas. The super nova shockwave may actually promote the creation of further stars. So when stars like our Sun form, the elements of life, and everything else, are already present. Just because it took 13.7 billion years to get the Sun and the Earth, doesn't mean that the process that creates stars like the Sun with planets like the Earth takes that long. Statistically, there would have been stars like the Sun and planets like the primordial Earth with the elements of life within the first billion years of the universe.

Thanks Arch2008. I didn't know about that early wave of huge stars.

I think we differ over how subjectively "young" the universe is. In your view, other Earths formed a long time ago, so we enter relatively late. In mine, the universe isn't yet mature in terms of elements, so we're early.

But my view's wrong if the universe does not continue to diversify its elements.

Any idea how long this will go on, and when the "golden age" of Earthlike planets will be?

Originally Posted by Arch2008

Just because it took 13.7 billion years to get the Sun and the Earth, doesn't mean that the process that creates stars like the Sun with planets like the Earth takes that long. Statistically, there would have been stars like the Sun and planets like the primordial Earth with the elements of life within the first billion years of the universe.

In other words, you are saying that conditions existed which made it, at least, possible for technological civilisations to exist, in the universe, which are or were millions, if not billions, of years older than our own.

The universe is about 13.7 billion years old and the first huge stars formed after the first few million years. These were stars a hundred or more times the mass of the Sun. They rapidly fused their cores to iron and exploded. So many solar masses of the elements on the periodic table were created relatively quickly in the early universe. The "Golden Age" of star and planet formation certainly started then as well. Our Earth is over 4 billion years old, so planets like today's Earth should have been around by 5 billion years after the Big Bang. Within the next billion years, the Sun will become very inhospitable and life on Erath will certainly end. Also, if the inflationary force that currently drives the expansion of the universe continues to grow, then the "Big Rip" will overcome the nuclear force and destroy everything in about 50 billion years. In this scenario the universe is more than 21% as old as it will get before atoms fly apart.

Halliday-Yes.
http://www.biocab.org/Exobiology.html#anchor_51

P.S. I found this which states that the Big Rip is in 22 billion years, so the universe is over 38% as old as it will get before doomsday.
http://en.wikipedia.org/wiki/Big_Rip

I hate to argue from personal incredulity, but mere billions of years seems suspiciously tailored to the human experience, and too short for galaxy lifespans. How could discrete galaxies of different types evolve so rapidly? It's too brief a window even for the evolution of many stars, e.g. ours won't have time to bow out as black dwarf because the universal curtain drops before then.

It's another discussion.

If true, it means the universe is incompatible with enduring interstellar life, because the medium is unsettled, won't stabilize, and will cut short. A forest can't evolve in three seasons.

1) There is no other way
2)It doesn't matter my oppinion.
3)Depends ....
4)Could be a big probability

Pong-If a discussion about aliens is based on belief and incredulity, then we might as well discuss the Easter Bunny. Galaxies evolved well within the first billion years after the Big Bang.
http://www.jwst.nasa.gov/firstlight.html
Science is about figuring out how the universe really works and not about imagining how we really want it to work. Life has endured on Earth for billions of years, from simple replicating molecules all the way up to the plants and animals that exist today. A billion years is an unimaginably long epoch in which plate techtonic forces build mountain ranges that then are ground down to dust. Continents grow, merge and then vanish. All multicellular life evolved in less than half a billion years. Atoms have done an amazing job in 13.7 billion years, but they won't last forever.

Originally Posted by Arch2008

Pong-If a discussion about aliens is based on belief and incredulity, then we might as well discuss the Easter Bunny.

I know that. I make a point of confessing personal incredulity so we all know where I'm coming from. "This doesn't feel right" is a reasonable statement.

Originally Posted by Arch2008

A billion years is an unimaginably long epoch in which plate techtonic forces build mountain ranges that then are ground down to dust. Continents grow, merge and then vanish.

It isn't unimaginable. You imagine plates of different buoyancy drifting against each other, and crumpling, grinding to dust and welling up again recycled, until you get a sense of tectonic equilibriums... the "steady state", if you will, of Earth's crust.

The galactic timespans feel wrong to me because they're far too brief to admit that kind of equilibrium. To my eyes, the galaxies don't appear freshly spilled into those arrangements. They look like they've developed out of countless generations.

Yeah that's my personal opinion, and I think it's worth reflection.

Originally Posted by kojax

High tech cultures prefer trade partners rather than slaves. They're probably more interested in our ideas than our resources, because we've experienced life differently than them, and it might avail them of a different perspective.

I do wish this were right, but we have way too little experimental data to confirm it as a general principle. Most of the time on this planet, when more advanced technology met a lower one (iron over stone, firearms over spears, planes over rifles), those who wielded the deadlier weapon were out for slaves, resources, or both (quite often seing slaves as a resource/commodity like many others).

Any idealists or philosophers who wanted to learn the "inferior" people's ways of thinking were so few and far between that they hardly made any difference.

Originally Posted by Leszek Luchowski

Originally Posted by kojax

High tech cultures prefer trade partners rather than slaves. They're probably more interested in our ideas than our resources, because we've experienced life differently than them, and it might avail them of a different perspective.

I do wish this were right, but we have way too little experimental data to confirm it as a general principle. Most of the time on this planet, when more advanced technology met a lower one (iron over stone, firearms over spears, planes over rifles), those who wielded the deadlier weapon were out for slaves, resources, or both (quite often seing slaves as a resource/commodity like many others).

Yeah. In the modern world, we're seeing that it's becoming more about resources and less about slaves, since a slave usually can't be trusted to operate complicated machinery without an excessive amount of supervision. Unskilled human labor is never under-abundant for us.

I'm optimistically predicting that the next jump will be for natural resources to become over abundant. A space faring culture would have so many places available to mine, that the whole concept of real estate, or scarcity might be meaningless to them.

.... but.... admittedly that's only optimism. Maybe it all comes full circle at some point, and slaves become practical again.

Any idealists or philosophers who wanted to learn the "inferior" people's ways of thinking were so few and far between that they hardly made any difference.

Good point. We have to assume their decisions will be dictated primarily by economics, unless they've learned the notion of "population control", or have otherwise permanently solved their scarcity problems.

I used to think there were other civilizations. Now I think we are IT.

Originally Posted by Arch2008

Or perhaps, the most intelligent members of any advanced civilization eventually discover technology that the most foolish members of their civilization use to destroy themselves.

Heh funny that sounds like the exact path we tend to follow.

A belief in aliens is basically a modern myth. Something had to take the place of the previous (before science) belief that the sun, moon and stars were deities. Carl Jung produced a lot stuff regarding this. Of course, nobody can prove that aliens do or do not exist, and probably never will unless space probes find extraterrestrial life. I think Arthur C Clarke gave the best quote on this subject:
"Sometimes I think we're alone in the universe, and sometimes I think we're not.
In either case the idea is quite staggering".

This discussion appears to be about the Fermi Paradox.
http://en.wikipedia.org/wiki/Fermi_paradox

The great physicist Fermi asked the simple question of aliens : "Where are they?"
As Arch pointed out, population growth and travel at even a fraction of light speed would lead to a civilised species populating the entire galaxy within a short time (a few million years). Fermi realised this.

Even if another species visited Earth a billion years ago, they should have left traces. After all, if soft jellyfish leave mudstone impressions (we have 500 million year old jellyfish fossils), the alien equivalent of a coke bottle should be very clear cut.

So the question : Where are they, is very pertinent. In addition, we have the failed efforts of SETI to consider. With almost the entire Milky Way galaxy scanned (though not thoroughly) without finding traces of aliens, it further suggests that civilised aliens may not be terribly common.

I am personally convinced that, with perhaps a trillion galaxies in the universe, there must be intelligent alien life somewhere. Within one galaxy, an advanced species should eventually colonise the entire galaxy. However, travelling between galaxies at less than light speed is probably not feasible. Which explains why they have not visited Earth, as far as we know.

Why would travelling between galaxies at less than light speed probably not be feasible? As I posted, there are star formations between the galaxies, so its not like they must make a trek of several million light years at one leap, not that they couldn't. Traveling near the speed of light, the crew would not experience the passage of millions of years due to time dilation. The population would already live in huge microcosm type space habitats. Add a propulsion system and they could weather a journey of any length. Smart materials held together by synthesized strong force with computers the size of molecules embedded in them may last until the Big Rip. Also, intergalactic travel may be a problem not of technology, but of biology. We are only beginning to explore the Human Genome. Perhaps they have perfected theirs so that death from old age is no longer a natural occurance. This would be a civilization millions of years more advanced than our own. Anything that can be organized, can be done.

Arch

Time dilation effects become significant only at very high fractions of light speed. It is highly doubtful that it will ever be possible to achieve those high fractions. A Scientific American article I read about a decade back, by two NASA space scientists, suggested that humanity may one day learn to travel between the stars at between 0.1c and 0.2 c, but no more.

Now, of course, they may prove wrong with more scientific and technological progress, but by today's physics, it appears unfeasible to think we might get anywhere near light speed.

If we were able to achieve 0.2c - the suggested maximum - it would take 10,000,000 years to reach Andromeda, which is the nearest non-satellite galaxy to our own. I doubt this is ever likely to happen. And further off galaxies are essentially impossible.

So none of the 10^30 immortal beings in a pan-galactic civilization several million years more advanced than ours would ever expand out of their galaxy to interim star formations on their way to the next galaxy because 20th century technology says it just ain't possible?
Got it.

Arch

If you stretch your imagination, you can come up with ways. For example : there is no theoretical reason why we could not send frozen embryos on a 10 million year voyage, with robots and computers of futuistic design to thaw them, incubate them, and feed and teach the resulting children.

Even better, if the technology advances sufficiently, is to send the children to Andromeda as information, which will be translated via robotic action into DNA, chromosomes, and ultimately, people. I am assuming that a future technology will be able to make computers and robots capable of surviving that long.

However, will it be done?

Originally Posted by skeptic

This discussion appears to be about the Fermi Paradox.
http://en.wikipedia.org/wiki/Fermi_paradox

The great physicist Fermi asked the simple question of aliens : "Where are they?"
As Arch pointed out, population growth and travel at even a fraction of light speed would lead to a civilised species populating the entire galaxy within a short time (a few million years). Fermi realised this.

Unless they philosophically arrived at the conclusion that population expansion isn't the goal of existence. If they're fully immortal, then they might not care about having kids, nor see any benefit in it.

Even if another species visited Earth a billion years ago, they should have left traces. After all, if soft jellyfish leave mudstone impressions (we have 500 million year old jellyfish fossils), the alien equivalent of a coke bottle should be very clear cut.

The statistical odds of us finding a trace of something are proportional to how widespread the thing we're looking for is. If a few pockets of aliens inhabited a few regions of the world for a brief time, we'd be very lucky to find even one example of a piece of evidence for it today.

And ... even if we did find something, archaeologists would classify it as an Oopart, or fluke, unless they continued finding more objects like it.

One Van Daniken theory (not that I think anyone should take him seriously, just giving him credit for his idea) is that visiting aliens might have carved out caves for them to live in, which they could then seal in order to isolate themselves from the Earth's biosphere. In which case, we'd have to hope they didn't collapse the caves before they left.

So the question : Where are they, is very pertinent. In addition, we have the failed efforts of SETI to consider. With almost the entire Milky Way galaxy scanned (though not thoroughly) without finding traces of aliens, it further suggests that civilised aliens may not be terribly common.

Partly, that's because we're expecting them to use radio waves, which might be a very primitive technology from their perspective (if they have something better). It would be the metaphorical equivalent of an indigenous tribe concluding that America doesn't exist because they haven't seen any of our carrier pigeons.

The advanced species may become immortal, but the stars in their galaxy won’t be. Sooner or later, huge populations will have to find new homes as their stars become white dwarfs or worse. They would have to expand to other stars and other galaxies. We can postulate how they might do it, but there really wouldn’t be much beyond their abilities. They wouldn’t need to actually visit the Earth either. Sextillions of these beings would be living in their space habitats orbiting the Sun and collecting sunlight. Of course, they would have other energy sources too, but the immense free energy of a star would not be ignored. They would have everything they need to expand without limit and their expansion really wouldn’t interfere with any local planetary life forms. So where are they?

Responding to kojax.

Why would an intelligent immortal species want to keep its population expanding?

We have only one sample to judge by, which is Earth life. One universal quality of Earth life is some form of impetus to grow each population. The power of evolution. For bacteria, it is the inevitable growth that happens when the wee fellars split in the presense of adequate food. It is totally automatic. For higher life forms, the impetus may be more complex, and involve behavioural adaptations.

For example : female chimps come into heat and become receptive to the randy alpha male, and reproduction follows.

What of humans? How may evolution drive us to over-populate in the future? We now have fertility control. So reproduction comes as a result of our desire to have kids. A woman stops popping the pill when she wants a baby. So the tendency to increase the population is a result of the desire for children. At the moment this can result in population decrease, since the desire for children is currently insufficiently strong to drive a population explosion.

However, a predictable outcome is that more and more of the world's population over many generations will be descended from those women who have a stronger desire for offspring. Evolution will increase the love of offspring. Sexual desire no longer being enough.

Now back to aliens.
Any single alien species might be happy to stay small in number, even though this flies against what we know of evolution. However, the process of evolution creates mechanisms to increase the population. If there are more than just one or two alien intelligent species out there, it is predictable that some will have evolved powerful behavioural adaptations to drive population increase.

The human population has increased 6-fold in 100 years. A simple calculation shows that a species that simply doubles each 100 years will rapidly increase, over a very few thousand years, to the point where it can over-populate their home star systems more quickly than they can actually get to other stars. A few million years for such a species would be MORE than enough to over-populate the entire galaxy, even restricted to travel at 0.1c to 0.2c.

And about 10% of the stars in our galaxy ( 10 billion of the beggars!) are up to 2 billion years older than our sun. If they have planets, life, and end up evolving intelligent life, they will have a 2 billion year head start on humans. Where are they?

Originally Posted by skeptic

And about 10% of the stars in our galaxy ( 10 billion of the beggars!) are up to 2 billion years older than our sun. If they have planets, life, and end up evolving intelligent life, they will have a 2 billion year head start on humans. Where are they?

Well, there might be an answer to this. About 7K years ago a reptilian race (aliens) interbred with homo sapiens and created a line of shapeshifting rulers which prevail even today. The British Royal Family are one such example. I know all this because I have read it in David Icke's book 'The Biggest Secret', although if you were to ask me if I believe it then I would say no (however I am convinced that the Royals do have their secrets!). However I do believe something might have happened about then to accelerate the progress of our ancestors. And anyway Icke once described himself as the 'Son of God'. You pay your money and you take your choice.

The problem with time dilation as in humans travelling very fast is that while the bodily processes slow down, the speed of light remains the same. Effectively, the electricity as in the electrochemical processes in the body becomes more energetic till the body literally burns up.

Originally Posted by Cyberia

The problem with time dilation as in humans travelling very fast is that while the bodily processes slow down, the speed of light remains the same. Effectively, the electricity as in the electrochemical processes in the body becomes more energetic till the body literally burns up.

Uhmm... No. That's not even wrong.

Originally Posted by skeptic

Responding to kojax.

Why would an intelligent immortal species want to keep its population expanding?

I presume you meant to ask why would it "not" want to?

What of humans? How may evolution drive us to over-populate in the future? We now have fertility control. So reproduction comes as a result of our desire to have kids. A woman stops popping the pill when she wants a baby. So the tendency to increase the population is a result of the desire for children. At the moment this can result in population decrease, since the desire for children is currently insufficiently strong to drive a population explosion.

However, a predictable outcome is that more and more of the world's population over many generations will be descended from those women who have a stronger desire for offspring. Evolution will increase the love of offspring. Sexual desire no longer being enough.

Now back to aliens.
Any single alien species might be happy to stay small in number, even though this flies against what we know of evolution. However, the process of evolution creates mechanisms to increase the population. If there are more than just one or two alien intelligent species out there, it is predictable that some will have evolved powerful behavioural adaptations to drive population increase.

If they're fully immortal, then one sociological reason would be that it's such a massive hassle to bring the newborns up to speed with their 10,000 + year old peers. Also, it may be that they've learned a certain wisdom in all that time, and they know newborns wouldn't be possessed of that wisdom, which could make them dangerous, if they were given access to the full range of technology.

(The nuclear bomb may not be the only dangerous tech we ever discover. In fact, it could turn out to be just the tip of the ice berg.)

The human population has increased 6-fold in 100 years. A simple calculation shows that a species that simply doubles each 100 years will rapidly increase, over a very few thousand years, to the point where it can over-populate their home star systems more quickly than they can actually get to other stars. A few million years for such a species would be MORE than enough to over-populate the entire galaxy, even restricted to travel at 0.1c to 0.2c.

And about 10% of the stars in our galaxy ( 10 billion of the beggars!) are up to 2 billion years older than our sun. If they have planets, life, and end up evolving intelligent life, they will have a 2 billion year head start on humans. Where are they?

This is exactly why they would have to take measures to control their population. An intelligent species understands exponents, that 10 doublings is the same as multiplying by 1024, 20 doublings is a factor of over a million, 30 doublings puts you over a billion, etc.... There's simply no amount of territorial expansion that would keep them ahead of that, even if they invented faster than light travel.

And if they expand far enough, they run the risk of running into the territorial borders of another advanced intergalactic civilization. Even if space were infinite in size, the random odds of encountering another intelligent species when you move in a given direction are based on the random odds of that species emerging. This places an upward limit on how much territory you can expand into, before you've encountered another species in every spatial direction.

kojax

What you say is totally correct, as far as it goes.
However, it fails to take into account the non rational components of behaviour, which get built into any thinking species by the forces of evolution.

As I pointed out before, every species on Earth has some means of expanding its population. With abundant food, and no attacks by predators or disease, any population will grow exponentially. Intelligent species evolve behaviour to drive this exponential growth.

I doubt that aliens will be free of this evolutionary drive. Some may be able to rise above it, but some will not. Thus, it there are a number of intelligent alien species in our galaxy, we would expect at least one to explode in numbers, and expand to colonise the entire galaxy.

My own view is that the reason no such species has done this (or else Earth would have been colonised long since) is simply because intelligent alien species are a rarity. We may be the only one in our galaxy.

Originally Posted by skeptic

kojax

What you say is totally correct, as far as it goes.
However, it fails to take into account the non rational components of behaviour, which get built into any thinking species by the forces of evolution.

Part of the reason for that is that, going off of what self proclaimed abductees and and others who claim to have interacted with them say, apparently the aliens, even the ones that look human, are very emotionally detached.

There might not be any non-rational component to their behavior.

As I pointed out before, every species on Earth has some means of expanding its population. With abundant food, and no attacks by predators or disease, any population will grow exponentially. Intelligent species evolve behaviour to drive this exponential growth.

That works as long as some entity more powerful than you is able to override you when your population gets too large. In an evolving species case, it's the environment that does that half of the thinking for them. Once the environment is no longer powerful enough to enforce its side of the balance, one of two things has to happen:

A) - The species has to consciously choose to take over and carry out that function on itself.

-or-

B) - Keep on going until a sudden shortage drives them into a cataclysm of some kind, probably nuclear.

I doubt that aliens will be free of this evolutionary drive. Some may be able to rise above it, but some will not. Thus, it there are a number of intelligent alien species in our galaxy, we would expect at least one to explode in numbers, and expand to colonise the entire galaxy.

My own view is that the reason no such species has done this (or else Earth would have been colonised long since) is simply because intelligent alien species are a rarity. We may be the only one in our galaxy.

My view is that it's because any species that doesn't overcome this evolutionary drive inevitably nukes itself to extinction before it's able to become a significant force in the universe. Those rare few that manage to escape their home world before overpopulation chokes them to death are probably seen as a nuisance by the other, less expansionist species in space. So, the less expansionist species probably collaborate to put them in check (or wipe them out, if need be). That's what I would do.

Suppose it were statistically determined that, on average, every 200 millionth star harbors intelligent life, that would put an upward limit of 200 million stars that any one intelligent species could rightly claim as their own. An exponentially expanding species would inevitably exceed that number. Even if the number were 200 trillion stars, they would still exceed it at some point. So, wiping out an expansionist culture is simple self defense.

Originally Posted by Enrico Fermi

So where are they?

Originally Posted by skeptic

The forces of evolution.. The power of evolution... it is predictable that some will have evolved powerful behavioural adaptations to drive population increase.

There you've answered your own question, maybe? Let me put it another way: Effective interstellar colonisation requires such radical adaptations of the "alien species" that it rarely bears any resemblence to the original. So the little green men can't remain as little green men to succeed in this environment. No, better be little green plankton - and win the game of life hands down... counting diversity, total population or biomass, catastrophy survival, whatever.

Even colonists who do not see the wisdom of a soft approach, would evolve en route. It's a long trip. And then become jellyfish or brains-in-jars unable to endure gravity, or return home feral to cannibalize their makers? No, better send basic seed only, and let it naturalize & adapt to the new homes.

It may occur to advanced civilisations that any life given evolution must eventually become them. So why bother pickling their little green bodies in capsules and making planets hospitable to this one snapshot of species?

Originally Posted by Enrico Fermi

So where are they?

The reason why aliens are not visiting earth is because they are here already. In fact the visa department of the earth embassy at planets in the cosmos closed about 7000 years ago. A sign outside reads 'No more visa applications for Earth. Please try another planet'. In English of course.

Maybe they've stopped having kids of their own, and now they like to go around adopting other cultures as their "children".

If you don't what you are talking about, anything is possible!

What I'm really operating off of is Tolkein's theory of the immortal elves. Apparently their birth rate was getting just abysmally small at the point of the Lord of the Rings series. He probably articulates the problem better.

Originally Posted by fizzlooney

If you don't what you are talking about, anything is possible!

Indeed.

I hope this lasts a little bit longer before it becomes pseudo science, though. It's good to refine our approach to looking for aliens, before we draw any conclusions about their existence.