I believe that the universe is teeming with life. What say you?

[Grestarian]

@Sam_Stone

Single-celled life appears to have developed on Earth almost immediately after it cooled down enough for life to be possible. But it took billions of years from that point before the Eukarotes showed up.

Based on that, the best guess is that simple life forms are ubiquitous in the universe, but complex life forms are orders of magnitude rarer.

But that will remain a guess so long as we have only one data point.

Thank you, SAM! You’ve crystalized what I’ve been struggling to wrap my exceedingly verbose brain around.

And while I’m known around these parts for being digustingly verbose, I’ll apologize to you all in advance for lacking the proper terminology to convey these next thoughts:

In all of the discussion about suitable conditions and potential exoplanets, most of the responders seem to have forgotten a key factor: Ours may be a uniquely stable/unstable hunk of rock, having experienced earthquakes, ice ages, polar melts, the Late Heavy Bombardment mentioned in the LUCA article that Darren Garrison provided a link to, the increasing distance between the earth and its single moon, and another foreign-object strike that is (was?) blamed for the near-total extinction of the dinosaurs. And, in between the cataclysms, there were forms of life that lived, maybe thrived, and maybe even combined and/or recombined to achieve increasingly complex forms.

But it’s those conditions – in combination with those cataclysms that happened when they happened and which just-so happened to fail to completely destroy all of the life-bearing region(s) – which have somehow helped life on this planet to become as complex as it is (and I suggest humans, cetaceans, and cephalopods are some of the most complex examples) without utterly destroying everything.

Now contrast our familiar example with the thousands of possible equivalent planets across the universe. A more stable planet would tend to provide fewer benefits of evolution; a more violent planet could wipe out all life or counter-select against an important trait that would otherwise facilitate complexity. Two of three cases lead to extinction; the flame of life snuffed out. One case leads to stagnation – or stability, if you prefer that perspective – with the most abundant life-form becoming no more complex or sophisticated than, say, a Terran fiddler crab.

So what I’m suggesting is that it’s not just a planet or moon’s presence in a suitable zone around a star, but also a lot of unpredictable mechanisms that influence the evolution (or lack thereof) of any form of life that might get started. Therefore, out there in the universe, would we find…
[ul]
[li]Life? Yeah, probably (!) a good chance.[/li][li]Complex life? Possibly. Quite possibly even multicellular.[/li][li]Intelligent life? That’s one hell of a stretch.[/li][li]Technologically astute life? I seriously doubt it.[/li][li]Technologically advanced life? I definitely doubt it.[/li][li]Technologically superior life? I just don’t have enough faith.[/li][/ul]

G!
They’re not here, they’re not coming
Not in a million years
'Til we put away our hatred
'Til we lay aside our fears
You may see the heavens flashing
You may hear the cosmos humming
But I promise you, my sister
They’re not here, they’re not coming
[COLOR=White]…–Don Henley (solo)
…They’re Not Here, They’re not Coming
…Inside Job[/COLOR]

[Biffster]

@Grestarian

Thank you, SAM! You’ve crystalized what I’ve been struggling to wrap my exceedingly verbose brain around.

And while I’m known around these parts for being digustingly verbose, I’ll apologize to you all in advance for lacking the proper terminology to convey these next thoughts:

In all of the discussion about suitable conditions and potential exoplanets, most of the responders seem to have forgotten a key factor: Ours may be a uniquely stable/unstable hunk of rock, having experienced earthquakes, ice ages, polar melts, the Late Heavy Bombardment mentioned in the LUCA article that Darren Garrison provided a link to, the increasing distance between the earth and its single moon, and another foreign-object strike that is (was?) blamed for the near-total extinction of the dinosaurs. And, in between the cataclysms, there were forms of life that lived, maybe thrived, and maybe even combined and/or recombined to achieve increasingly complex forms.

But it’s those conditions – in combination with those cataclysms that happened when they happened and which just-so happened to fail to completely destroy all of the life-bearing region(s) – which have somehow helped life on this planet to become as complex as it is (and I suggest humans, cetaceans, and cephalopods are some of the most complex examples) without utterly destroying everything.

Now contrast our familiar example with the thousands of possible equivalent planets across the universe. A more stable planet would tend to provide fewer benefits of evolution; a more violent planet could wipe out all life or counter-select against an important trait that would otherwise facilitate complexity. Two of three cases lead to extinction; the flame of life snuffed out. One case leads to stagnation – or stability, if you prefer that perspective – with the most abundant life-form becoming no more complex or sophisticated than, say, a Terran fiddler crab.

So what I’m suggesting is that it’s not just a planet or moon’s presence in a suitable zone around a star, but also a lot of unpredictable mechanisms that influence the evolution (or lack thereof) of any form of life that might get started. Therefore, out there in the universe, would we find…
[ul]
[li]Life? Yeah, probably (!) a good chance.[/li][li]Complex life? Possibly. Quite possibly even multicellular.[/li][li]Intelligent life? That’s one hell of a stretch.[/li][li]Technologically astute life? I seriously doubt it.[/li][li]Technologically advanced life? I definitely doubt it.[/li][li]Technologically superior life? I just don’t have enough faith.[/li][/ul]

G!
They’re not here, they’re not coming
Not in a million years
'Til we put away our hatred
'Til we lay aside our fears
You may see the heavens flashing
You may hear the cosmos humming
But I promise you, my sister
They’re not here, they’re not coming
[COLOR=White]…–Don Henley (solo)
…They’re Not Here, They’re not Coming
…Inside Job[/COLOR]

They’ll come screamin’ cross the universe
Just to find McNuggets?

[eburacum45]

@dtilque

Furthermore, a trillion years from now, the only stars left burning will be the lowest mass red dwarfs.
.

Good news, everyone! There are far more red dwarfs than any other kind of star, and in a trillion years time they’ll be shining a lot more brightly thanks to helium build-up. The universe a trillion years from now doesn’t look so bad. You need to travel a few more trillion years into the future to reach the true dark ages.

[GreysonCarlisle]

There is an idea (I don’t call it a hypothesis and certainly not a theory) that there are several exact copies of this world out there. (No, this doesn’t invoke Many Worlds or any form of alternate realities.)

The idea is that there’s near infinite matter and energy in the universe, but only so many ways it can arrange itself. So there are bound to be repeats, giving multiple versions of you, multiple versions of me, almost down to the molecule.

I don’t buy that, but something kind of close? Maybe. Something like “copies” where the prerequisites for life as we know it are all met on an Earth-sized planet that’s mostly stable for long periods of time, as our world has been.

I guess it depends on how much matter there really is in the universe and on whether there really are a finite number of ways it could arrange itself.

If the math works out, that would satisfy the teeming requirement for me.

[k9bfriender]

@GreysonCarlisle

There is an idea (I don’t call it a hypothesis and certainly not a theory) that there are several exact copies of this world out there. (No, this doesn’t invoke Many Worlds or any form of alternate realities.)

The idea is that there’s near infinite matter and energy in the universe, but only so many ways it can arrange itself. So there are bound to be repeats, giving multiple versions of you, multiple versions of me, almost down to the molecule.

I don’t buy that, but something kind of close? Maybe. Something like “copies” where the prerequisites for life as we know it are all met on an Earth-sized planet that’s mostly stable for long periods of time, as our world has been.

I guess it depends on how much matter there really is in the universe and on whether there really are a finite number of ways it could arrange itself.

If the math works out, that would satisfy the teeming requirement for me.

Either it is infinite or it is finite. There is no really such thing as “near infinite”.

In the case that it is finite, the many copies idea is possible, if it is big enough, but it would be really big, making our bubble that we call the observable universe a microscopic speck of the overall universe.

If it is infinite (and also assuming that the laws of physics stay the same in all locations), then it is more or less guaranteed that there are copies out there, but they are so far away that it really doesn’t count.

[Biffster]

@GreysonCarlisle

There is an idea (I don’t call it a hypothesis and certainly not a theory) that there are several exact copies of this world out there. (No, this doesn’t invoke Many Worlds or any form of alternate realities.)

The idea is that there’s near infinite matter and energy in the universe, but only so many ways it can arrange itself. So there are bound to be repeats, giving multiple versions of you, multiple versions of me, almost down to the molecule.

I don’t buy that, but something kind of close? Maybe. Something like “copies” where the prerequisites for life as we know it are all met on an Earth-sized planet that’s mostly stable for long periods of time, as our world has been.

I guess it depends on how much matter there really is in the universe and on whether there really are a finite number of ways it could arrange itself.

If the math works out, that would satisfy the teeming requirement for me.

I believe this sounds like the million chimpanzees and a million typewriters typing out the complete works of Shakespeare, given enough time. I believe you could double the number of chimps and typewriters and they will never even type out the first 14 lines of Romeo and Juliet. The mathematical possibility is simply not enough; life is a pretty rare and precious thing, and it doesn’t happen just anywhere. Especially not all at once. A million years in the past or future and there’s a greater possibility, I’d say. It’s just that we’ll never see it.

[GreysonCarlisle]

@Biffster

I believe this sounds like the million chimpanzees and a million typewriters typing out the complete works of Shakespeare, given enough time. I believe you could double the number of chimps and typewriters and they will never even type out the first 14 lines of Romeo and Juliet. The mathematical possibility is simply not enough; life is a pretty rare and precious thing, and it doesn’t happen just anywhere. Especially not all at once. A million years in the past or future and there’s a greater possibility, I’d say. It’s just that we’ll never see it.

But if you doubled the million chimps and typewriters, then added 198 million more, then multiplied that number by a few hundred trillion…?

[Biffster]

@GreysonCarlisle

But if you doubled the million chimps and typewriters, then added 198 million more, then multiplied that number by a few hundred trillion…?

Ha ha! If one chimp can’t do it, it doesn’t really matter how many other chimps also can’t do it. I wonder if the belief in life elsewhere in the universe corresponds at all with religious belief? I’d like to believe could exist elsewhere, but I also believe it doesn’t really make much difference if it doesn’t. The existence of life on this planet is nothing short of a miracle in my opinion.

[snowthx]

"Two possibilities exist: either we are alone in the Universe or we are not. Both are equally terrifying.” -Arthur C. Clarke

[Novelty_Bobble]

@Biffster

I believe this sounds like the million chimpanzees and a million typewriters typing out the complete works of Shakespeare, given enough time. I believe you could double the number of chimps and typewriters and they will never even type out the first 14 lines of Romeo and Juliet. The mathematical possibility is simply not enough; life is a pretty rare and precious thing, and it doesn’t happen just anywhere. Especially not all at once. A million years in the past or future and there’s a greater possibility, I’d say. It’s just that we’ll never see it.

The analogy doesn’t *quite *work because the whereas the typing is completely random, the combinations of elements into complex molecules and even more complex chemicals, is not.

e.g. there is an affinity for oxygen or carbon to bond with a lot of stuff, there is no equivalent affinity on a random typewriter for a “u” to follow a “q”

[GreysonCarlisle]

@Biffster

Ha ha! If one chimp can’t do it, it doesn’t really matter how many other chimps also can’t do it. I wonder if the belief in life elsewhere in the universe corresponds at all with religious belief? I’d like to believe could exist elsewhere, but I also believe it doesn’t really make much difference if it doesn’t. The existence of life on this planet is nothing short of a miracle in my opinion.

One chimp did do it.

[Biffster]

@GreysonCarlisle

One chimp did do it.

Really? Which chimp was that?

[Biffster]

@Novelty_Bobble

The analogy doesn’t *quite *work because the whereas the typing is completely random, the combinations of elements into complex molecules and even more complex chemicals, is not.

e.g. there is an affinity for oxygen or carbon to bond with a lot of stuff, there is no equivalent affinity on a random typewriter for a “u” to follow a “q”

Good point. Not an equivalent example, but that’s what it reminds me of. Expecting us to find life elsewhere is a pretty far-fetched proposal at this time.

[GreysonCarlisle]

@Biffster

Really? Which chimp was that?

That’d be you and me.

Unless god is Shakespeare in this analogy, and we’re here by divine fiat. But there’s no evidence for that outside of creation myths.

[Biffster]

@GreysonCarlisle

That’d be you and me.

Unless god is Shakespeare in this analogy, and we’re here by divine fiat. But there’s no evidence for that outside of creation myths.

Hmm. Never thought of myself as a chimp before. You may be on to something. Or you may just be on something.