Fewer Than 10 ET Civilizations In Our Galaxy?

The Fermi Paradox focuses on the existence of advanced civilizations elsewhere in the galaxy. If these civilizations are out there — and many analyses suggest the galaxy should be teaming with life — why haven't we seen them? Carlos Cotta and Álvaro Morales from the University of Malaga in Spain investigate another angle by considering the speed at which a sufficiently advanced civilization could colonize the galaxy. Various analyses suggest that using spacecraft that travel at a tenth of the speed of light, the colonization wavefront could take some 50 million years to sweep the galaxy. Others have calculated that it may be closer to 13 billion years, which may explain ET's absence. Cotta and Morales study how automated probes sent ahead of the colonization could explore the galaxy. If these probes left evidence of a visit that lasts for 100 million years, then there can be no more than about 10 civilizations out there.

science.slashdot.org...

Interesting stuff indeed.
That there is even 1 ET civilization, let alone 10 in our galaxy should raise a few eyebrows.
My question is, how many of them are advanced beyond our tech level and have the ability to explore space? Are they already monitoring us?

reply to post by warrenb


These assumptions are based on our tech level and understanding of our place in the universe.

Its all about perspective. Our Universe is estimated to be 13 to 15 billion years old. That is a long time. Our existence in our galaxy isn't even a drop in a bucket. Its more like a grain of sand resting on a beach the size of Jupiter. Who knows how advanced civilzations would be?

Imagine what a caveman would think of our average person with iPods, cars, planes, watches, binoculars, etc. Caveman would think a modern person is a magician or even a God.

Our civilization is presumed to be 10,000 years old (I believe far older, but I digress). Imagine how we will be 100 years from now. How about 1,000 or even 1,000,000 years old? Could we even comprehend what our future selves would be like? Not even close.

Now imagine a civilization lasting even a 1,000,000 years old. That is a drop in a bucket. How advanced is their technology? Far advanced. Probably to the level of god-like. Do they even notice us? Would they even care like we care about ants scurrying around our picnic area?

What happens if we discover advanced civilization that is beyond our comprehension? What if these beings aren't even carbon-based? Do they rely on oxygen and water to live? The possibilities are endless. Assumping what ETs would be like based on our tech-level/mindset is egotistical. But at least it gets you thinking in the right direction.

reply to post by warrenb


I suppose you have to ask a few questions.

1) Would they want to explore the Universe?

2) Do they have a "Prime Directive" that forbids interference in our society?

3) As Guppy said, "Assuming what ETs would be like based on our tech - level/mindset is egotistical"

So it all depends on whether you believe they are already here or not, and if the present "Alien" presence on our planet isn't some sort of Psy Op of the American Government?

There could be one ET civilization in our galaxy. Could be 10. Could be trillion.
Even Fermi equation concerning the matter is nothing more then (very) educated guess with lot of variables. For some reason i do not get excited when new Earth-like planet is found or when guys, which are surely much much smarter then me, start guessing how many civilizations could be here based on OUR technology and OUR approach to space exploration.
Nobody knows what is inside Earth. Ocean floor is a Terra (or Mare?) incognita. So all the assumptions as to how many totally different life forms could be there or how they probes would work (if they would use probes at all) are pretty hollow.

I would like to believe we are not the only ones out there.I believe that if we aren't alone that they are just sitting back waiting to show up at the right time.Hard to imagine how big space is and we would be the only living things out there.

it's possible that the universe is teeming with life and that we are the most advanced civilisation, that would be interesting.

i've noticed how often the same discovery is sometimes made by two different people in different places at the same time, i wonder if this is a universal principle, maybe we're all advancing at the same rate.

I believe that there are other planets with life out there.

People might question why they haven't contacted us. Perhaps they just don't care about us yet.

Imagine that our civilization survives and continues to advance for the next 10,000 years. We have the ability to travel to distant worlds. Quite frankly I can't image what the technology would be like.

Anyway we come across a planet that has a civilization that is comparable to ours. What would our motivation be to interact with such a primitive society?

Perhaps the cultural anthropologist would enjoy studying that culture but I can't see a reason to land our space ship and announce our presence.

This is simply an exercise in dart board pseudo science. None of the given variables can be validated. It's just a thought experiment that reveals the limited nature of human intelligence.


IRM :shk:

Our galaxy is a big place,they may not even be aware of our existence(assuming they actually do exist).We also have to take into account technological advancement.It may have taken ET races thousands of years to achieve what we have in 30 years.We also have to take into account violence which i can bet is universal,they may have wiped themselves out through warfare.Their planet may have been destroyed via meteor,sun dying,gamma ray burst,super volcano etc before their technology advanced to such a level where they could colonize other planets or stop it from happening.

Too many variables,until we know for a fact intelligent civilizations exist we don't know if they do or not..we can play with numbers day in day out.Im not a believer they are or have ever visited earth if they do in fact exist though.And i personally dont care what type of alien life we find whether it be intelligent or not,i would be equally as excited if it was either because then we would know we are not alone in the universe.I don't think we will find alien life for atleast a few centuries though unless it's on a moon like europa etc until our technology can get us to the next closest star... lets hope we dont get wiped out before then.



[edit on 31-7-2009 by Solomons]

One of the biggest assumptions with the Fermi Paradox is that the universe and spacetime work the way they we perceive them to work from our own very limited perspective. That time and distances have consistent structures to them. That there are no odd irregularities in spacetime. Or that our own perception of spacetime has no effect on it, and we're passive observers.

If, however, spacetime has varying degrees of permeability and flexibility, all bets are off. We already know that time varies according to your speed. And observation of a quantum state defines it from all the virtual states it could be in. So we're not passive observers in the universe, and it probably wouldn't even exist if we weren't here to live in it. Richard Feynman figured that photon interaction is not time-dependent, and an action in the "future" can possibly have an effect in the "past."

So the Fermi Paradox doesn't account for all the potential ways things could exist in the universe. Fermi's reality was a very straightforward, horse and wagon, nuts-and-bolts kind of proposition. Actual reality might be (and probably is) a lot more complicated than that with virtual and parallel realities popping in and out of a flexible spacetime full of chutes and ladders.

our galaxy is an estimated what? 200,000 light years across? That is just the diameter, not including the width of it. And considering how many stars are within our own arm of the galaxy and how many millions more are near the center of the galaxy. It seems a bit arrogant to assume that we would be 1 of only 10 possible civilizations. Look at us. Our star is a child in comparison to most. Plant life on this planet depends on solar radiation to produce its energy. Who is to say that stars with much more energy output cannot be capable of sustaining even micro organisms on some planet thousands of light years away?

Originally posted by guppy


These assumptions are based on our tech level and understanding of our place in the universe.

Its all about perspective. Our Universe is estimated to be 13 to 15 billion years old. That is a long time. Our existence in our galaxy isn't even a drop in a bucket. Its more like a grain of sand resting on a beach the size of Jupiter. Who knows how advanced civilzations would be?

Well one way to look at it is that suns and planets as we know them really were not in full form until about 10 billion years ago, and using earth as a perfect example, that is just teeming with life, it took 5 billion years for us to come on the scene. So when you look at 10 billion years, if it takes let’s say 3 plus billion years for life to advance past simple stages then 10 billion is a lot smaller number comparatively to all this than one would think.

Now throw in the rarity of a planet to not only be in the right orbit but the right size with the right density. As we can see with Mars, a planet that is slightly off most likely would only support limited life forms if any at all. The cooling effect of Mars core that turned it from a liquid to a solid has shown that a planet needs a liquid core for 5 plus billion years to sustain life too.

There is also a growing theory that for solar system to form you need a giant planet like Jupiter as the catalyst, and this just continues to add to the rarity.

Our civilization is presumed to be 10,000 years old (I believe far older, but I digress). Imagine how we will be 100 years from now. How about 1,000 or even 1,000,000 years old? Could we even comprehend what our future selves would be like? Not even close.

This is true, but we are here mainly by an accidental occurrence that allowed us to advance and the dinosaurs to parish, or we could easily still be in the monkey stage or lower. Life is in abundance and inevitable, but we are a rather rare phenomena here on earth looking at the life it has created over billions of years.

Now imagine a civilization lasting even a 1,000,000 years old. That is a drop in a bucket. How advanced is their technology? Far advanced. Probably to the level of god-like. Do they even notice us? Would they even care like we care about ants scurrying around our picnic area?

So you assume that intelligence is actually a good evolutionary trait. Looking back in our history you will see one line of evolution, but looking from the beginning you will see an endless number of evolutionary off shoots that lead to dead ends. So far we have the capabilities of destroying all life any given day, and we are hunters not grazers and so we are very aggressive. Just maybe intelligence is a bad evolutionary trait that dies off since it would take not too big of an event to knock us back to the stoneage or worst. It really seems the chances of a fully functional spacefaring race needs an extreme number of varibles to make it happen and missing anyone of them it doesn't happen. BTW we are far from any proof that it can happen.

The other aspect is that our thumbs are just as important as our intelligence, and this continues to further requirements thus increasing rarity. The smartest creature in the universe might be a sponge that never moves and so we need the physical ability to complement our intelligence.

So with all that said I run with either we are very alone or there was an advance race a few billion years before us that was very alone and seeded us and other places. So far I need to run with there might be a few races out there but we are basically alone, until further data comes to light.



[edit on 31-7-2009 by Xtrozero]

Originally posted by Nohup
So the Fermi Paradox doesn't account for all the potential ways things could exist in the universe. Fermi's reality was a very straightforward, horse and wagon, nuts-and-bolts kind of proposition. Actual reality might be (and probably is) a lot more complicated than that with virtual and parallel realities popping in and out of a flexible spacetime full of chutes and ladders.

But then even if there are endless ways there are very limited ways we can interact. Most likely our greatest limitation is ourselves in whether we ever have contact with another intelligent race. We could easily go billions of years and never see anyone else out there even if life is as you suuggest could be.

reply to post by Xtrozero

Well one way to look at it is that suns and planets as we know them really were not in full form until about 10 billion years ago, and using earth as a perfect example, that is just teeming with life, it took 5 billion years for us to come on the scene. So when you look at 10 billion years, if it takes let’s say 3 plus billion years for life to advance past simple stages then 10 billion is a lot smaller number comparatively to all this than one would think.

That still leaves millions and millions of years of something to develop some intelligent life. How long is our known history? 10,000 years? You're assuming we're the only advanced civilization spawned on earth. How can we be sure a previous civilization existed like 250 million years ago when dinosaurs walked on earth? What if those people decided to move on, leave for the stars, and never to look back? Hell we could be the 6th human civilization that existed on this planet. We can't know for sure because our history is full of gaps.

Now throw in the rarity of a planet to not only be in the right orbit but the right size with the right density. As we can see with Mars, a planet that is slightly off most likely would only support limited life forms if any at all. The cooling effect of Mars core that turned it from a liquid to a solid has shown that a planet needs a liquid core for 5 plus billion years to sustain life too.

Again that's assuming. What if NASA finally discloses that life once existed (or still exists) on Mars? What if our probes do discover life teeming in the deep oceans of Europa? Just one discovery of life (living or fossilized) in another celestrial object within our solar system would drastically change the probability of life.

So you assume that intelligence is actually a good evolutionary trait. Looking back in our history you will see one line of evolution, but looking from the beginning you will see an endless number of evolutionary off shoots that lead to dead ends. So far we have the capabilities of destroying all life any given day, and we are hunters not grazers and so we are very aggressive. Just maybe intelligence is a bad evolutionary trait that dies off since it would take not too big of an event to knock us back to the stoneage or worst. It really seems the chances of a fully functional spacefaring race needs an extreme number of varibles to make it happen and missing anyone of them it doesn't happen. BTW we are far from any proof that it can happen.

Yes assuming intelligence is a good trait is bad. But I could care less if we first discover intelligent or non-intelligent life. Either way it proves life exists out there. And if life does exists then there is a good chance of intelligent life within our universe. How many? Too many factors, right?

Who knows how many times we have blasted ourselves back to the stone age? Archaeologists keep finding more older societies. But these societies already have the capability to build cities, buildings, farming, etc. When were humans nothing but a species learning how to build fire? And is that the actual time fire was discovered? Or was that when we previously bombed ourselves back to the stone age?

I don't discount the fact we might have been seeded on earth by another advanced civilization. Might have been done as a joke.

The other aspect is that our thumbs are just as important as our intelligence, and this continues to further requirements thus increasing rarity. The smartest creature in the universe might be a sponge that never moves and so we need the physical ability to complement our intelligence.

Thumbs? How about tentacles? Or articulated mandibles? Life finds a way. They evolve and adapt. But it doesn't have to follow our template. Insect hives, if allowed to live long enough, might evolve into a super-entity with intelligence. Tools might not be a requirement for life to move in space.

So with all that said I run with either we are very alone or there was an advance race a few billion years before us that was very alone and seeded us and other places. So far I need to run with there might be a few races out there but we are basically alone, until further data comes to light.

We might feel alone because no one is listening to us. Our primitive technology may only sound like background noise. Which is why I believe SETI is useless using radio waves to find life. ET might be using some phased communication device that we won't discover for another century.

I think human ego is preventing us from progressing to where we can be. We have unlimited potential. Perhaps that's why ET refuses to contact us. Maybe they see us as a threat, like a cancer in the universe. Maybe they're trying to keep us "contained" on earth.

and many analyses suggest the galaxy should be teaming with life — why haven't we seen them?

The government doesn't want you to know ET exists... I would love to see their list of reasons for why they aren't coughing it up, or erm... Should I say, excuses? Deep down, our masters enjoy the power that comes with witholding this knowledge. And that's the only reason aliens are being covered-up. That's the reason we haven't "seen them" in the flesh.



[edit on 31-7-2009 by sliceNodice]

Originally posted by Xtrozero
But then even if there are endless ways there are very limited ways we can interact. Most likely our greatest limitation is ourselves in whether we ever have contact with another intelligent race. We could easily go billions of years and never see anyone else out there even if life is as you suuggest could be.

I agree completely. And I'm in no way saying that it's guaranteed there's other intelligent life out there. As far as anyone knows, life starting is such a weird, fluky event, we could be the only game in town.

On the other hand, because of how slippery time and space are, it might be more likely to encounter different versions of ourselves in different aspects of reality, than with intelligent creatures who evolved all on their own around some distant star.

Our limitation is that we, as a planet with life on it, took over 4 billion years to even figure out that stars were other suns, and our own cleverness with genetics and artificial intelligence will likely wipe out our species in less than 5,000 years. At least in this version of reality.

The most plausible explanation I can muster about why we haven't come across that advanced star faring civilization is that we may just be an early intelligent Civ to appear.

It took 4 billion years for us to appear after the earth formed. We have rapidly rose to a civilization in less than 10 thousand years.

Intelligence seems very difficult for evolution to develop and it seems a very very precise series of circumstances is required to pressure and organism into sentience.

Plus someone has to be first and who ever it is/was is going to say "Where the hell are all the others?!"

Originally posted by Welfhard


It took 4 billion years for us to appear after the earth formed. We have rapidly rose to a civilization in less than 10 thousand years.

Intelligence seems very difficult for evolution to develop and it seems a very very precise series of circumstances is required to pressure and organism into sentience.

You're basing your assessment on the history of Earth and it's creatures. One planet from one solar system out of billions. Have you stopped to wonder that perhaps the conditions we arose in aren't as conducive to intelligence/sentience than other parts of the universe?

We live in our own bubble and our intelligence appears to be marred by that. I highly doubt that we took the only road available in this universe to sentience.

IRM

reply to post by InfaRedMan

We live in our own bubble and our intelligence appears to be marred by that. I highly doubt that we took the only road available in this universe to sentience.

I didn't say that this planet is the only one to develop sentience. My point is that for us it took a vastly long time, long after life began. Life doesn't strictly lead directly to intelligence, yet once it begins to appear, it takes a short time for it to mature to a civilization like our own.

I feel that life is abundant in the galaxy - maybe in our own solar system even. But intelligence is something much more than life, a bizarre product of nature that is bound to be dishearteningly rare.

If we go looking for it, we may not even recognise it. I image that in great irony, we would stumble across a species on their way to world domination but since we do not find cities and artificial satellites, we would move on.

I also think that even rarer than finding intelligence would be finding intelligence that is a similar level to us. Therefore it's unreasonable to think that we'd find civ's less advance than us - our best shot is that we, ourselves are discovered by something more advanced.

Edit to add:
Another thought that occurs is that given that it's a rather specific series of events/pressures that lead to our own cognitive maturity, it makes one wonder what would have happened if things went down slightly differently.
Common crediting for our development go to rudimentary tool use and a fish-rich diet, that gave us the opportunity to develop language on which we could now form humanistic though lines of reasoning and logic.

It may be that the first steps towards intelligence are actually rather common but something interferes. I would imagine that it may take many successive occurrences of those early stages before it really took off with us.

We may need to take what species we find in nature and ourselves pressure intelligence out of them. Maybe it's not so much find-intelligence as it is make-intelligence.

[edit on 1-8-2009 by Welfhard]

reply to post by guppy


Did you know time speeds up the further away you are from gravity, which means that what people think are billions of years old are infact only thousands.