Need a good analogy of finding life in the universe

[uperkurk]

My friends who don't believe life elsewhere exists often use the argument of "Well if life exists then why haven't they found us yet?"

The only thing I can think of to explain it to them is it would be the same as a man in a fishing boat lost at sea somewhere in the pacific ocean, only the ocean is 100million times larger.

So you can see why it would be difficult to find someone?

I don't think it does enough justice though :/

 

[superearth]

IMO, using radio signals is not a requirement for life.

Even in this small solar system, we can still hope to have microbes on Mars, fishes on Europa and silicon-based life on Titan. But we can hardly hope they are smart enough to find us.

More on Fermi paradox.

 

[uperkurk]

The fact that the majority of humans believe that we are the be all and end all of the universe, the pinnacle of evolution is really quite ignroant, considering the size of the universe... It seems much much more likely that life as intelligent and more-so do exist.

We have only explored a glass of water out of the entire ocean in terms of how much of the universe we have explored.

 

[someGorilla]

If the fact they haven't found us proves they don't exist, then the fact we didn't find them proves we don't exist I guess.

 

[phyzguy]

My friends who don't believe life elsewhere exists often use the argument of "Well if life exists then why haven't they found us yet?"

You should consider the possibility that your friends are right. Enrico Fermi, a pretty smart guy, asked the same question (Fermi paradox). IMHO, the only reasonable explanation for the Fermi paradox is that intelligent life like us is very rare.

 

[uperkurk]

You should consider the possibility that your friends are right. Enrico Fermi, a pretty smart guy, asked the same question (Fermi paradox). IMHO, the only reasonable explanation for the Fermi paradox is that intelligent life like us is very rare.

So if I had a large net, threw it in the ocean and when I dragged it back to the ship and never caught a fish, we can assume that fish are very rare?

 

[phyzguy]

So if I had a large net, threw it in the ocean and when I dragged it back to the ship and never caught a fish, we can assume that fish are very rare?

You're missing the point. Your analogy describes you looking for the fish. The Fermi paradox question is not "Why haven't we found the aliens?" Admittedly we have only searched a small volume of the galaxy, and not very effectively. If we are looking for alien life at our level of development or less (analogous to you catching fish), then they are clearly hard to find. The Fermi Paradox question is "Why aren't they here?" We can imagine, with technology not much more advanced than we have now, spreading through the galaxy in a short time, on the order of millions of years. Since we can imagine doing it, other civilizations, if they exist, should have done it by now. Why haven't they? It's no good saying that they are inherently non-expansionist, since they don't all need to have spread through the galaxy, only one of them. Since they aren't here and we see no signs of them, the most logical answer is that they don't exist.

The Earth has been heavily modified by the presence of life - the atmosphere has been changed dramatically, the sea is filled with life, most of the landmass is covered with life. If intelligent life were ubiquitous, the galaxy should look like the Earth, filled with life almost everywhere you look.

 

[uperkurk]

The Fermi Paradox question is "Why aren't they here?" We can imagine, with technology not much more advanced than we have now, spreading through the galaxy in a short time, on the order of millions of years. Since we can imagine doing it, other civilizations, if they exist, should have done it by now. Why haven't they? Since they aren't here and we see no signs of them, the most logical answer is that they don't exist.

The answer is simple, the universe is a BIG BIG BIG place and let's use this as an example. nothing can travel faster than light, so if aliens found our planet using a sophisicated telescope or something, any method they choose to contact us must be limited by c (assuming wormholes ect remains a theory).

Now if they where even just 1000 light years, we've only had radio for 200 odd years... Our very own milky way is upto 120,000 lights years across so it could be upto 119,000 years before hearing any kind of contact.

I hope this properly illustrates the magnitute the problem involved with "contact".

 

[surajt88]

If the fact they haven't found us proves they don't exist, then the fact we didn't find them proves we don't exist I guess.

:D
T-shirt quote of the day.

 

[boisebrats]

The number of stars and possible planets is incredibly huge,and the space that separates them is very emense.(look these numbers up) . . If life happened by chance on this planet by evolution (if you choose to go that route), . then the probability of it happening elsewhere due to mathmatical probabilty is very good simply concerning the number of planets in the universe alone,. . also consider life is tenacious, . it thrives to exist. even beyond itself as a single organism, such as the death of a parent which has ensured the existence of its protege, life "wants" to exist and to live on with desperation, . also consider the extremophiles. not only is life tenacious it is also lives in diverse environments, . . lastly, for those of your friends who oppose the life by chance happening and evolution scenario, the religious souls may consider that with the abundance of distant planets in the universe, God could have not only spread the breath of life across the universe, but also had the wisdom to put the galaxies at such a great distance so that mankind could never come in close contact with them, If a Creator God created all this, . why not?, . I'm just looking at both sides of the equation, . . either way you look at it, With the vast number of planets out there,and the tenacity of life itself to thrive and live, . the probabilities for life outside our own planet, are very good

 

[phyzguy]

The answer is simple, the universe is a BIG BIG BIG place and let's use this as an example. nothing can travel faster than light, so if aliens found our planet using a sophisicated telescope or something, any method they choose to contact us must be limited by c (assuming wormholes ect remains a theory).

Now if they where even just 1000 light years, we've only had radio for 200 odd years... Our very own milky way is upto 120,000 lights years across so it could be upto 119,000 years before hearing any kind of contact.

I hope this properly illustrates the magnitute the problem involved with "contact".

Read the Fermi paradox again. The question is not "Why haven't they contacted us?" The question is "Why aren't they already here?" Again, if intelligent life is ubiquitous, it should have already spread throughout the galaxy.

 

[phyzguy]

The number of stars and possible planets is incredibly huge, . If life happened by chance on this planet (if you choose to go that route), . then the probability of it happening elsewhere is good simply concerning the number of planets,. . also life is tenacious, . it thrives to exist. even beyond itself, such as the death of a parent which has ensured the existence of its protege, also consider extremophiles. not only is life tenacious it is also diverse in its environments, . . lastly, for those who oppose the life by chance happening scenario, the religious may consider that with the abundance of planets in the universe, God could have not only spread the breath of life across the universe, but also had the wisdom to put the galaxies at such a great distance so that mankind could never come in close contact with them, just looking at both sides, depending on who you are . . either way you look at it,with the vast number of planets out there,and the tenacity of life itself to thrive the probabilities for life outside our own planet, are very good

I agree that the number of stars and planets is huge. I also agree that life is tenacious and tends to spread to diverse environments. This is the basis of the Fermi paradox - if intelligent life is common, it should already have spread throughout the galaxy. However, you can't argue that the probability of intelligent life existing elsewhere is good because the number of planets is large, because you have no idea how small the probability of intelligent life developing is.

 

[uperkurk]

Read the Fermi paradox again. The question is not "Why haven't they contacted us?" The question is "Why aren't they already here?" Again, if intelligent life is ubiquitous, it should have already spread throughout the galaxy.

The rate of said "expansion" can only occur at the speed of light maximum! Sinse we are the new kids on the block compared to the age of the other galaxies. We too will be visited, and once we develop our own more advanced technology, we can go seeking ourselves.

The amazing thing about Earth is it isn't just home to people, there are millions of species here and bacteria all thriving. So life in itself isn't special, just intelligent life.

But so special to be at a minimum of 1 in 10²⁴ are really really amazing odds.

 

[phyzguy]

The rate of said "expansion" can only occur at the speed of light maximum! Sinse we are the new kids on the block compared to the age of the other galaxies. We too will be visited, and once we develop our or more advanced technology, we can go seeking outselves.

The amazing thing about Earth is it isn't just home to people, there are millions of species here and bacteria all thriving. So life in itself isn't special, just intelligent life.

But so special to be at a minimum of 1 in 10²⁴ are really really amazing odds.

Of course the rate of expansion is much less than the speed of light. That is why it would take many millions of years to spread through the galaxy, even though the galaxy is only ~100,000 light years across. But if intelligent life is ubiquitous, there should be intelligent species that started the expansion process billions of years ago, and even at an expansion speed of .001*c, it would only take 100 million years to fill the galaxy, and they should have arrived long ago.

 

[uperkurk]

You're basing that off our galaxy, there's a chance that we are infact the only life in our entire galaxy, still another 500billion - 1trillion galaxies to explore. Even if 0.1% of all the galaxies in the universe has life that's still 1,000,000,000 extraterrestrial life forms.

Even if 0.0001% of those 1billion extraterrestrial life forms is what we would call intelligent, that's still 1000 intelligent life forms in the universe.<sup>1

1</sup>All figures taken from quick google searching. (No yahoo answers though)

 

[boisebrats]

I agree that the number of stars and planets is huge. I also agree that life is tenacious and tends to spread to diverse environments. This is the basis of the Fermi paradox - if intelligent life is common, it should already have spread throughout the galaxy. However, you can't argue that the probability of intelligent life existing elsewhere is good because the number of planets is large, because you have no idea how small the probability of intelligent life developing is.

First the post said "life" and not "intelligent life", and the possibility of just that is greater anyway ( depending on definition of intellegent, and one could make that point moot anyway), . . second of all concerning the paradox, for life to migrate it would need to adapt and change to its environment drastically and suddenly, In space there are very few elements for survival, slowing the timeline for expansion greatly, . or the so called life would have to be intelligent to do so, (as we would travel to distant planets), . . the first scenario would be for a simple organism to either adapt a way to leave its own planet and travel on its own through space somehow, or to be ejected from such an event as meteor impact and be put into frozen suspension, . a theory which is already being explored, . the second possibility is for a complex organism which would require it sustaining itself long enough with its own biological energy needs or to hibernate while traversing these great distances,(and these are very great distances) . not only do these organisms require time to evolve to the state of a complex organism with sentient capabilities to do so, but also there is more historical timeline needed to travel these great distances, I think we as universal life are to young for that,(give it time) .not only that, but if we look at extremophile we must understand that other complex sentient liveforms may not even perceive or live in the universe as we do with our limited understanding and five senses, and communication to them may be even as of now be undetectable or completely unknown to us ..so looking at all these evolution theories and how young our universe really is, . i see no paradox, just simply an underdeveloped universe. personally "myself", . i believe the universe is teaming with "life" literally, and the universe may even be able to be classified as a living organism itself, if one can grasp the definition, ., . .as for the probability of life, (yes i was stretcing it here, good call) and that is an interesting and good question, i wonder of we could answer that probability to some extent knowing the number of elements in the universe with also the known number of planets, etc., the hypothetical probability of of anyone single life form none or unknown, being created, , .. . but like i also said, . i think man and his ego, tends to think in restricted terms anyway in thinking what a life form is made up of: molecular, carbon based, whatever, . . . as i said, . life is tenacious, just to exist in and of itself, .

 

[boisebrats]

rather messy it think, . ergo, . . the universe is teaming with life, .. the universe is to young and distances are to great for lifeforms to have become so prolific as to reach a total saturation point among lifeforms,it takes time to overcome obstacles such as meeting biological energy needs (food etc), propulsion research ,political sidetraking, stopping universal expansion to terraform mine etc. (not enough time in the life of the universe yet, not a paradox). . and lastly, the universe itself may be a symbiotic eclectic life form of its own designation with its own sentience

 

[uperkurk]

i think man and his ego

Exactly, us humans are the be all and end all, if we can't do it, it simply can't be done. We can't live without oxygen, so neither can anything else. We need to drink water, and sinse there are no planets with water, life can't possibly exist.

People need to stop being so arrogant and awaken to the possibility that we are not the kings of the universe. The thought that humans are not at the top of the chain really makes us feel vulnerable, so we simply deny it.

 

[phyzguy]

You're basing that off our galaxy, there's a chance that we are infact the only life in our entire galaxy, still another 500billion - 1trillion galaxies to explore. Even if 0.1% of all the galaxies in the universe has life that's still 1,000,000,000 extraterrestrial life forms.

Even if 0.0001% of those 1billion extraterrestrial life forms is what we would call intelligent, that's still 1000 intelligent life forms in the universe.<sup>1

1</sup>All figures taken from quick google searching. (No yahoo answers though)

But you just made up those numbers. You have no idea whether those numbers are 0.1% and .0001% or 10^-20 and 10^-50.

 

[phyzguy]

First the post said "life" and not "intelligent life", and the possibility of just that is greater anyway ( depending on definition of intellegent, and one could make that point moot anyway), . . second of all concerning the paradox, for life to migrate it would need to adapt and change to its environment drastically and suddenly, In space there are very few elements for survival, slowing the timeline for expansion greatly, . or the so called life would have to be intelligent to do so, (as we would travel to distant planets), . . the first scenario would be for a simple organism to either adapt a way to leave its own planet and travel on its own through space somehow, or to be ejected from such an event as meteor impact and be put into frozen suspension, . a theory which is already being explored, . the second possibility is for a complex organism which would require it sustaining itself long enough with its own biological energy needs or to hibernate while traversing these great distances,(and these are very great distances) . not only do these organisms require time to evolve to the state of a complex organism with sentient capabilities to do so, but also there is more historical timeline needed to travel these great distances, I think we as universal life are to young for that,(give it time) .not only that, but if we look at extremophile we must understand that other complex sentient liveforms may not even perceive or live in the universe as we do with our limited understanding and five senses, and communication to them may be even as of now be undetectable or completely unknown to us ..so looking at all these evolution theories and how young our universe really is, . i see no paradox, just simply an underdeveloped universe. personally "myself", . i believe the universe is teaming with "life" literally, and the universe may even be able to be classified as a living organism itself, if one can grasp the definition, ., . .as for the probability of life, (yes i was stretcing it here, good call) and that is an interesting and good question, i wonder of we could answer that probability to some extent knowing the number of elements in the universe with also the known number of planets, etc., the hypothetical probability of of anyone single life form none or unknown, being created, , .. . but like i also said, . i think man and his ego, tends to think in restricted terms anyway in thinking what a life form is made up of: molecular, carbon based, whatever, . . . as i said, . life is tenacious, just to exist in and of itself, .

I agree that the Fermi paradox only applies to intelligent life. Lower life forms would appear to be unable to spread beyond a single star.

 

[and7barton]

We shouldn't so much worry whether we are "Top of the chain", but more whether we are "Top of the food chain".
I'm not too sure meeting aliens would be beneficial to us. We are made of protein after all.

 

[boisebrats]

we may be made of protein, . . . but are we tasty?

 

[davenn]

we may be made of protein, . . . but are we tasty?

a lot of cannibal societies seemed to think so ;)

Dave

 

[bahamagreen]

The point is that on Earth it appears that it takes about 3 billion years to go from the emergence of self replicating molecules to a worm, then only another billion years to go from the worm to modern man. So four billion years from scratch to man.

The local conditions for life on Earth were four billion years ago, but in a universe 13+ billion years old, if life generally pops up, one would expect similar conditions to have been present in some places long before the solar system began to form; places that had a considerable head start on us... other life could have billions of years of head start.

If you just review the technical progress we have made in the last 10K, 1000, and 100 years, it seems that an intelligent life that has been at it for billions of years will have had plenty of time to expand and utilize technologies well advanced over our own.

Any way you look at it, a few billion years head start is going to mean they have been here, may have been here billions of years ago, have been everywhere, should still be all over the place. That was the sense of Fermi's question - where are they, why don't we have any clear sense of their present and past activities? Only one single instance of an intelligent life gaining a billion year head start anywhere within a good portion of the observable universe would be pretty obvious - see Kardashev scale for why...

But of course, this a human question asked from a human perspective in human terms of understanding... none of that may apply after a few billion years of development.

 

[Chronos]

The Fermi paradox raises another, more ominous thought, IMO. Perhaps interstellar travel is prohibitively expensive, or, so demanding we would appear about as interesting as an ant colony to any who had mastered it.

 

[DHF]

The Fermi paradox raises another, more ominous thought, IMO. Perhaps interstellar travel is prohibitively expensive, or, so demanding we would appear about as interesting as an ant colony to any who had mastered it.

an Excellent point. overcoming the physics needed to casually travel the stars would denote a extremely advanced society. Your Ant Analog is a good one. Assume you have an ant colony in the middle of an empty field. you walk past that ant hill. you might look down and think "hmm, look at those busy ants" then go about your way. meanwhile the ants are asking themselves "there is lift outside this anthill why hasn't it visited us and introduced itself?"


Don

 

[phyzguy]

an Excellent point. overcoming the physics needed to casually travel the stars would denote a extremely advanced society. Your Ant Analog is a good one. Assume you have an ant colony in the middle of an empty field. you walk past that ant hill. you might look down and think "hmm, look at those busy ants" then go about your way. meanwhile the ants are asking themselves "there is lift outside this anthill why hasn't it visited us and introduced itself?"
Don

I don't think this is a good analogy at all. The ants are surrounded by evidence of more advanced life (us), they are simply incapable of noticing it. For your analogy to work, we would need to be surrounded by more advanced intelligences who have modified the galaxy extensively, but in ways that we are incapable of noticing. The fact is that we have a good inventory of the universe around us in ways that ants do not.

 

[DHF]

I don't think this is a good analogy at all. The ants are surrounded by evidence of more advanced life (us), they are simply incapable of noticing it. For your analogy to work, we would need to be surrounded by more advanced intelligences who have modified the galaxy extensively, but in ways that we are incapable of noticing. The fact is that we have a good inventory of the universe around us in ways that ants do not.

I don't agree that we have a good inventory of the universe. I feel our understanding of the universe is still in its infancy. we have glimpses of other stars and hard confirmation of planets in a few hundred systems but there are literally trillions of stars out there.

you feel that if the universe was populated then there would be obvious evidence but I feel that the ant analogy is fitting because just as we have modified our world extensively to fit us, the ants in that single ant colony in the middle of a field are unaware of our presence. unless we made direct contact with them they wouldn't know we existed or frankly even be capable of comprehending us. if you placed a cell phone next to that ant hill they would be incapable of fathoming what it was much less its function.

In this same way I feel that any race that has figured out how to traverse the stars as casually as we traverse our globe then that race will have evolved beyond what we are currently capable of understanding. Another thing to consider is that that a highly advanced race that is aware of our presence might take pains to go unnoticed just as scientists take pains not to contaminate a sub glacial lake or an uncontacted tribe in the wilderness.

I am not saying the universe is swimming with Galactic empires, I am just saying its possible for another race to be out there and us not know it.

Don

 

[Naty1]

... Perhaps... we would appear about as interesting as an ant colony to any who had mastered it.

more likely the constituents of our planet will be of value to them...??

Anyway, I do not want to be a slave laborer!

 

[phyzguy]

I don't agree that we have a good inventory of the universe. I feel our understanding of the universe is still in its infancy. we have glimpses of other stars and hard confirmation of planets in a few hundred systems but there are literally trillions of stars out there.

you feel that if the universe was populated then there would be obvious evidence but I feel that the ant analogy is fitting because just as we have modified our world extensively to fit us, the ants in that single ant colony in the middle of a field are unaware of our presence. unless we made direct contact with them they wouldn't know we existed or frankly even be capable of comprehending us. if you placed a cell phone next to that ant hill they would be incapable of fathoming what it was much less its function.

In this same way I feel that any race that has figured out how to traverse the stars as casually as we traverse our globe then that race will have evolved beyond what we are currently capable of understanding. Another thing to consider is that that a highly advanced race that is aware of our presence might take pains to go unnoticed just as scientists take pains not to contaminate a sub glacial lake or an uncontacted tribe in the wilderness.

I am not saying the universe is swimming with Galactic empires, I am just saying its possible for another race to be out there and us not know it.

Don

I understand what you are saying, but I just don't buy it. You say, "if you placed a cell phone next to that ant hill they would be incapable of fathoming what it was much less its function." Notice that you don't say that they wouldn't know it was there (because they would). To continue the analogy further, do we see anything lying around that we are incapable of fathoming? Do we see any mysterious structures that we have no idea what they are? The answer is no, everything that we see is quite explainable.

I think it must be the case that an alien race, no matter how advanced, would still be composed of matter and energy, and we would be able to perceive them and their constructs, even if we couldn't understand them. The only alternative I can see would be if this hypothetical alien race existed on a "higher plane" that we are incapable of perceiving, but this takes us out of the realm of science and into mysticism.

 

[DHF]

I understand what you are saying, but I just don't buy it. You say, "if you placed a cell phone next to that ant hill they would be incapable of fathoming what it was much less its function." Notice that you don't say that they wouldn't know it was there (because they would). To continue the analogy further, do we see anything lying around that we are incapable of fathoming? Do we see any mysterious structures that we have no idea what they are? The answer is no, everything that we see is quite explainable.

I think it must be the case that an alien race, no matter how advanced, would still be composed of matter and energy, and we would be able to perceive them and their constructs, even if we couldn't understand them. The only alternative I can see would be if this hypothetical alien race existed on a "higher plane" that we are incapable of perceiving, but this takes us out of the realm of science and into mysticism.

Even leaving the Ant Analogy off the table I feel that we would be hard pressed to notice another civilization if that race didn't knock on our front door. There are thousands of asteroids in our solar system that are unaccounted for, highlighting that fact was the rock that exploded over Russia. Until it hit our sky we had no idea it was there. On the larger scale we recently discovered a planet in Alpha Centuri. We have been watching the skies for a very long time and cosmically speaking it was right next door but we completely missed it until a few years ago, just confirming it in 2012.

If our astronomy was a lot more advanced or if NASA had the budget of a pharmaceutics company then I would be more inclined to agree with you that we would notice if life was out there. Unfortunately I think we have a long way to come before we can look at our sky and say with confidence that we have it all figured out.

Don

 

[Naty1]

A meteorite with amino acids was only recently discovered...
and they are still having issues deciding if life [as we know it] exists or existed on Mars...

And who sayseven if we found life we'd even recognize it if different from our carbon based life forms??

 

[nitsuj]

A meteorite with amino acids was only recently discovered...
and they are still having issues deciding if life [as we know it] exists or existed on Mars...

And who sayseven if we found life we'd even recognize it if different from our carbon based life forms??

If it's to become as complicated as us, I can't see how anything else would do.

Reading the wiki article it looks like carbon has some pretty unique characteristics with respect to electrons.


That said I hear you with respect to "even recognizing it". Just saw a "deep sea" type show that featured an Octopus. My Land those things are strange, and apparently as smart as my dog...in the realm of mimicry . Thought I was looking at a rock, then all of the sudden it turn into some weired animal and "swam" away.

 

[AKOHana]

I agree that the number of stars and planets is huge. I also agree that life is tenacious and tends to spread to diverse environments. This is the basis of the Fermi paradox - if intelligent life is common, it should already have spread throughout the galaxy. However, you can't argue that the probability of intelligent life existing elsewhere is good because the number of planets is large, because you have no idea how small the probability of intelligent life developing is.

The fact that we (life) exist here on this planet Earth tells me that the probability of similar life existing elsewhere in this galaxy is very high. Seems like the more we know, the more we know how little we know, and I think we need to accept this in our thought process.

 

[Chronos]

I think it is a lot like the copernican principle. Our existence is statistically meaningless. A sample of one proves nothing. I suspect the fact we are here is highly significant and strongly suggests we are not alone. I do not, however, believe we have any realistic chance of 'communicating' with our fellow confused beings.