Fate of the Universe

[foodchain]

If life on Earth, or intelligent life on Earth never goes extinct, and continues to grow on forever, would it be safe to assume that over a long enough period of time that it would basically consume the universe? Not to evoke some kind of psychological line of thinking but in a sci-fi tone I could actually see at some point the entire universe having to consist of nothing but life if growth continues forever.

 

What do you think?

[MM6]

No, that makes no sense at all. Life requires resources and all populations experience limited resources.

[Galindo]

I want to conduct an experiment where I share my ideas and see where it takes me

[foodchain]

No, that makes no sense at all. Life requires resources and all populations experience limited resources.

 

sorry, my bad. The question is basically me positing that unless extinction occurs, and giving of course resources like the universe in total, that continued growth would eventually eat up the universe. From what I know, or at least think I know, the universe has a finite amount of stuff in it currently. So I would think constant population growth would eventually consume it.

[Mr Skeptic]

We could in theory assimilate large portions of the universe into our bodies, but us intelligent creatures like to have a lot of material possessions, so most likely we would keep most of it as material goods. We can't really destroy the atoms; although we could significantly speed up the entropy of the universe. Still, the universe is doing just fine at increasing entropy without our help; the sun is wasting so much energy every second our puny little race could not compare throughout our entire history. Then there's all the other stars. Unless we start doing our own fusion, we really aren't going to make any difference overall. And then, there are enormous portions of the universe that are simply out of our reach, unless we invent faster than light travel which as far as we can tell is impossible.

[Sisyphus]

One has to consider entropy. A living thing decreases entropy within itself in exchange for increased entropy externally. This is a fundamental property, probably. So it doesn't seem like life could ever maintain itself if there was no nonlife, since entropy will have to increase somewhere.

[Mr Skeptic]

Not all life increases entropy externally. Apostrophes can intercept solar energy, which would have otherwise struck the ground and been lost as heat, and convert it into chemical energy. Absent the plant, there would have been more entropy. The rest of us parasites eat plants or things that eat plants. We do kill plants for their stored energy and release it, increasing entropy.

 

Even so, there is nothing we can do anytime soon that could compare with the immense wastes of energy and matter that are stars and black holes.

[Sisyphus]

Alright, but the point is that the plant uses energy to decrease entropy inside itself, and that energy was generated with a greater increase in entropy in the sun. So there is a net increase in the whole system, always.

[Mr Skeptic]

Yes, an increase in entropy but the plant didn't cause it. It just intercepted the energy for its own needs, postponing some of the entropy.

[Sisyphus]

The point being that it needs that entropy to exist. Life cannot be self-contained, and so couldn't ever absorb the entire universe (and thus become self-contained by definition).

[Mr Skeptic]

Life can be self-contained, just not forever. Imagine an organism that can do fusion; it could eat most of the universe and live quite a while on it. As you said though, in the end we all die. Much better than I could do holding my breath anyways

[Martin]

If life ... continues to grow ... forever, would it be safe to assume that over a long enough period of time that it would basically consume...

 

A good way to consume any kind of matter is to compress it into small black holes.

 

Small black holes are hot, the smaller the hotter. They evaporate, producing Hawking radiation.

 

It is more efficient to get heat that way than by fusion. If you start with hydrogen and do fusion you can only get up to iron. Only the fusion reactions up to iron nuclei release energy. There is always the iron left over.

 

so only a relatively small fraction of the mass is converted to energy.

 

With small black holes a large fraction is converted.

 

After all the stars die out, life forms could still get energy by gathering together any kind of matter and compressing it into small black holes.

 

Eventually all the extra matter that was lying around would be gathered and consumed.

 

A dilute soup of waste heat radiation. All the dead stars used up, and other junk.

 

There are several different ways to harvest gravitational energy, I left out a lot. But one way or another all the matter that they could get hold of that wasn't needed for life itself could, in principle, be used.

 

Your scenario seems reasonable to me. maybe I'm wrong and someone will correct me, but I think you are right.

 

From any given bunch of life, most of the universe escapes being eaten simply because it is expanding. Most of the galaxies that we can now see with telescopes are receding from us so fast that it is physically impossible to catch them. (Most galaxies recede faster than the speed of light.) There is something called the "cosmic event horizon" beyond which our local civilization can not, even in principle, exercise control.

 

So there is a limit to the amount of matter which any one bunch of life can gather and consume. But given whatever is available, your scenario of gradual complete consumption is plausible. (if it didn't go extinct earlier for some other reason)

[whap2005]

Life can be self-contained, just not forever. Imagine an organism that can do fusion; it could eat most of the universe and live quite a while on it. As you said though, in the end we all die. Much better than I could do holding my breath anyways

 

Well as soon as humans figure out a way to use fusion as a power source, that universe eating organisim may be you and I.

[Radical Edward]

Apostrophes can intercept solar energy, which would have otherwise struck the ground and been lost as heat, and convert it into chemical energy.

 

I guess you mean Autotrophs... An apostrophe is a punctuation mark... this one in fact --> '

[Mr Skeptic]

Wow.:doh:

[iPeppers]

I think humans and the material that we consume to survive can be related in this case to the classic wolves and caribou example (hopefully it's classic, at least I've heard of it a bunch).

 

Wolf population explodes as they eat the caribou population, but once the caribou population drops low enough, the wolf has to travel too far and expend too much energy to capture and eat enough caribou to survive (even though there is caribou left). The wolf population then plummets, caribou population explodes, and then the remaining wolves have food again, and the cycle persists.

 

In our case, ignoring possibilities of us wiping ourselves out, I hypothesize that the human population continues to expand and consume the universe (converting matter for our energy needs), but only to an extent. As was mentioned, because of expansion we can't ever reach most of the universe, so there is a point where even though there are resources out there, we may not be able to reach them, because it won't be energy efficient to do so. The human population then dies off from lack of resources, and their material is recycled as no longer living and considered part of the universe again. The remaining human population then begins to thrive again off of the new material (which is effectively matter that may once have been part of other humans), and the cycle persists.

 

I doubt an equilibrium will ever be realized, as humans are not very efficient, and tend to consume much more than the environment can continue to sustain (right now that environment really only includes earth, but one day may be considered as the known and accessible universe).

[Mr Skeptic]

No, if we go about converting matter into energy, it won't "get better" by us dying off and leaving it be. These resources are non-renewable, at all, ever. If we consume them all, we all die, forever. Unless the universe can recycle itself in a Big Crunch/Big Bang cycle, but there's no way we'd survive that anyhow.

[Law]

If life on Earth, or intelligent life on Earth never goes extinct, and continues to grow on forever, would it be safe to assume that over a long enough period of time that it would basically consume the universe? Not to evoke some kind of psychological line of thinking but in a sci-fi tone I could actually see at some point the entire universe having to consist of nothing but life if growth continues forever.

 

What do you think?

 

i personally think theres intelligent life with long lives but as for us...i dont see how humans make it too long...unless

 

we can program a computer to build a human on the next hospitable planet

 

or

 

we move brains into robot bodies (this would be my pick)

[StrontiDog]

The rest of us parasites eat plants or things that eat plants.

 

At the risk of being pendantic, we're mostly saprophytes, rather than parasites, with the exception of lawyers, of course.

 

Bill Wolfe