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Life, The Universe, And Entropy

Forces of Darness, Forces of Light
  [vote for,

My apologies in advance for a somewhat theoretical post, happy to delete if it gets struck as theory, but would love thoughts/feedback on the following question:

We all know (an assumption, I know) that the Second Law Of Thermodynamics dictates the increase of entropy over time, some have even postulated it as the reason for the existence of time.

We also know that localized systems, can, in principle, go in the other direction e.g. a building or a living cell are more ordered than the matter around them despite going into a forward direction in time.

A common explanation has been that local entropy can decrease, with energy, by robbing an external system -- in other words, a cell does not violate the Second Law since it's not viewed as a closed system.

All good so far -- here is the question - assuming life continues to evolve, even without the magic of grey goo, wouldn't it be possible to make use of every available mass grain, thereby defeating entropy, as the entire universe would then be "ordered"?

theircompetitor, Nov 05 2011

Vacuum Photons http://www.chalmers...ht-from-vacuum.aspx
[theircompetitor, Nov 20 2011]

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       //make use of every available mass grain//   

       That was the corner where I fell off. Could you clarify the question?
pertinax, Nov 05 2011

       //wouldn't it be possible// I think the answer is "no."   

       For simplicity, let's postualte a single life form -- bacteria, or something, which eats the entire universe. This bacterium must not only eat [0], it must also excrete [1]. It's excreta must have higher entropy than its food source [2]. It cannot eat it's own excreta [3]. Eventually, the universe is partitioned into bacteria and excreta, and there it stops.   

       Now, complicate this a bit: two organisms, one plant, the other animal. The animal eats the plant, the plant consumes the animal's excreta. Does this evade the above problem? No, because the plant "eats" a third, low-entropy foodstuff (it's feeding off the free energy of a star) [4].   

       The plants cannot consume all the matter in a star: the star will end it's life in one of the ways that stars do, and all of them involve high-entropy stellar "excreta" [5] which the plants cannot consume [6].   

       And so on. Following this line of reasoning, how do you evade Thermodynamics?   

       Postulates numbered so you can indicate which you disagree with. You can also disagree with the logic, accuse me of petitio principii, whatever ....
mouseposture, Nov 05 2011

       but excretion could be used by a biosphere. I guess the genuine problem is the need for an external energy source. Even particle decay would end some day. But I don't know. Feels like this is one life will solve.
theircompetitor, Nov 05 2011

       This is like perpetual motion: there's a general principle which says it can't happen. You can ask a separate question, which is "what, specifically, gets in the way of this particular implementation," and, sometimes, it can be hard to work out what exactly. In fact, perpetual motion inventors may obscure that detail so effectively that people don't find it -- believing that they have, thereby, proven the possibility of perpetual motion. In fact, conservation of matter-energy is violated in an expanding universe, so decrease of entropy over time might be "more impossible" than perpetual motion.   

       I actually agree with "life will find a way," but more likely by escaping the "universe is a finite closed system" restriction.
mouseposture, Nov 05 2011

       //This is like perpetual motion: there's a general principle which says it can't happen// he said, standing on a planet spinning around its axis and around its star for the last five billion years and expected to go at least twice that :)   

       I agree in principle, of course. But life is strange, right? A chance occurrence -- the proverbial Shakespearean monkeys -- sure -- but entropy (and statistics) would say it should be much more likely to disintegrate than to become more complex.
theircompetitor, Nov 05 2011

       That's twice in 24 hours, in two unrelated internettyplaces, that I have seen the earth spiralling round the sun cited as evidence of perpetual motion.   

       By that logic, the completeness of the egg I just dropped, but which has not yet reached the floor, is also evidence of perpetual motion.
pocmloc, Nov 05 2011

       [pocmloc] I am a committed atheist, and not a physicist, of course. However, presumably you'd accept the big bang, which had created matter and eventually caused said motion either violated entropy or was initially "external" to the system. How else then was everything "set in motion"
theircompetitor, Nov 05 2011

       How else? There are at least a few dozen other theories on the subject, including a few postulating that 'it' was never set in motion because it's always _been_ in motion. Choose a card, any card...
Alterother, Nov 05 2011

       No way, [Alterother], I don't buy it. I'd more likely believe the quantized simulation idea.
theircompetitor, Nov 05 2011

       I'm not selling anything. Hell, these days they're giving Unified Theory proposals away for free.
Alterother, Nov 05 2011

       Isn't the big bank, extremely high entropy? i.e. everything in one place? And the whole universe thing is just everything spreading out as dullly and uniformly as it can?
pocmloc, Nov 05 2011

       If the Bing Bang followed a big crunch, then it seems to have achieved a higher entropy. How.   

       If the Big Bang is a bubble out of a different universe, or a crash of two 'branes, or whatever, then the entire entropy discussion is near meaningless -- in such a complex universe, what does "closed system" even mean.
theircompetitor, Nov 05 2011

       Well if we are talking about time, and how as time goes on entropy increases, then shirley the earlier you go the bigger is entropy, and at the very beginning it was either maximum or infinite i.e. the big bang.   

       It didn't come from anywhere or anything because it was at the beginning.
pocmloc, Nov 05 2011

       I believe, [pocmloc] that's another way of saying I don't know. Which is fine, I don't either, but don't mask it as knowledge.
theircompetitor, Nov 05 2011

       //For simplicity, let's postualte a single life form -- bacteria, or something, which eats the entire universe. This bacterium must not only eat [0], it must also excrete [1]. It's excreta must have higher entropy than its food source [2]. It cannot eat it's own excreta [3]. Eventually, the universe is partitioned into bacteria and excreta, and there it stops.

I love this idea [mouseposture] ... we eat everything until the only thing left is a pile of shit. Then we eat each other until we all turn into shit. No matter what we do, whole universe will eventually be just a big pile of shit. This is a proof that my understanding of meaning of life is correct thus far. ... unless this conversion drives another factor that physics haven't taken into account yet. Maybe once everything used up it triggers a fresh start. What goes down, must come up?
ixnaum, Nov 07 2011

       //universe will eventually be just a big pile of shit//   

       //eventually// ?
mouseposture, Nov 07 2011

       //Maybe once everything [is] used up//

Nothing gets 'used up', it is just transformed into other stuff.
DrBob, Nov 07 2011

       1. If the big bang were to end up falling into a big crunch, it is entirely feasible that time itself will start to run backwards. In fact, there is no reason to say that we aren't experiencing this now, since there is no reference frame.   

       2. Entropy is specifically about heat. Life won't solve it, because life is dependent upon it. It's not solveable, it's a law. Once you've stirred the heat around enough, there's no more energy state difference to drive anything.
RayfordSteele, Nov 07 2011

       All matter dissipates into heat in time.
Voice, Nov 07 2011

       Entropy is infinite. That is to say, organization can always decrease. That being the case, given an infinite amount of time, would an observer notice any difference? Perhaps we exist in the long tail end of the heat death in the universe with time sufficiently slow that we experience it as dynamic and energetic. Will there ever be a final interaction?
Voice, Nov 07 2011

       Isn't the homogenization of matter and energy through entropy really just another form of organization?
Alterother, Nov 07 2011

       [Alterother] that's an excellent point. And consider this: Isn't heat expanding outwards from a homogeneous center the definition of a big bang?
Voice, Nov 07 2011

       I wouldn't rule it out.
Alterother, Nov 07 2011

       //Isn't the homogenization of matter and energy through entropy really just another form of organization?//   

       I like this idea, and it led me to postulate here, about a year ago, that "entropy prevents the big freeze". That is, there will come a point when the homogenization of the universe, as galaxies accelerate away from eachother and die, will reach an asymptotic entropy maximum where any further homogenization actually leads to less entropy. This will manifest as a variable gravitational constant (oxymoron) that forces the Big Crunch and hence a cyclic universal lifecycle (redundancy).
daseva, Nov 08 2011

       //It cannot eat it's own excreta [3]// I have seen dogs that have contradicted that law!
gnomethang, Nov 08 2011

       Good point. Rats too. Ought to have been "digest," or possibly "derive nourishment from."
mouseposture, Nov 08 2011

       //it is entirely feasible that time itself will start to run backwards//

As a lifelong administrator, I am pleased to see that others are finally realising what I, and others in my profession, have been vaguely aware of all along. To wit, "Didn't we do that yesterday?".
DrBob, Nov 08 2011

       Rabbits and guinea pigs derive energy and nutrition from their excreta; many other animals derive pro-biotics (elephants) and vitamins, particularly B-12 (dogs, rats, primates, and probably many others). Of course, these are all exceptions that prove the rule; in every case, there is no hint of perpetual motion.
spidermother, Nov 08 2011

       When new "space" is created between the galaxies as the universe is stretched -- that space is presumably like all other space.   

       So we just created a new "cubic foot" of space. This cube of space presumably attains a temperature above absolute zero (due to the fact that particles appear there).   

       Does this new cube automatically cool the rest of the universe 1/cube? Since the quarks have to cover more space? Would that be an instant cooling, or something that has to propagate 50B light years?   

       And if it's not cooling the rest of the universe, then whence is this heat coming from?   

       Seems to me that for all intents and purposes, explaining this entire phenomenon, whether in terms of "dark energy" or "dark matter", or "constant this or that" is effectively a way for physicists to say the universe is not really a closed system. In which case then, beating entropy is simply very hard, but not impossible.
theircompetitor, Nov 10 2011

       Sorry sir, but the books are balanced there also. The 'average temperature of space' is cooling as its stretching.   

       Beating entropy is impossible, and that's a good thing. Because if it wasn't, all sorts of weird things would happen.
RayfordSteele, Nov 10 2011

       Science tortures the universe for its secrets. Weird things have already happened, perhaps.
daseva, Nov 10 2011

       Mr. Steele -- would that imply there's an end to the expansion, corresponding to the average temperature hitting absolute zero?
theircompetitor, Nov 10 2011

       Yes, but only at absolute infinity.
MaxwellBuchanan, Nov 10 2011

       but would that imply that the energy of particles is required for expansion? Years ago I postulated that (extra, not counted on) pressure from light is what's accelerating the expansion.
theircompetitor, Nov 10 2011

       [marked-for-deletion] This needs to be rephrased as an idea instead of a question.
ldischler, Nov 20 2011

       [their] - the forces of darness have stolen your "k".
MaxwellBuchanan, Nov 20 2011

       //Science tortures the universe for its secrets// while plague victims tread lightly.
MaxwellBuchanan, Nov 20 2011


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