h a l f b a k e r yOn the one hand, true. On the other hand, bollocks.
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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"?
Vacuum Photons
http://www.chalmers...ht-from-vacuum.aspx
[theircompetitor, Nov 20 2011]
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//make use of every available mass grain// |
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That was the corner where I fell off. Could you clarify the question? |
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//wouldn't it be possible// I think the answer is
"no." |
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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. |
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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]. |
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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]. |
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And so on. Following this line of reasoning, how
do you evade
Thermodynamics? |
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Postulates numbered so you can indicate which
you disagree with. You can also disagree with the
logic, accuse me of petitio principii, whatever
.... |
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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. |
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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. |
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I actually agree with "life will find a way," but
more likely by escaping the "universe is a finite
closed system" restriction. |
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//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 :) |
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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. |
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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. |
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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. |
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[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" |
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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... |
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No way, [Alterother], I don't buy it. I'd more likely
believe the quantized simulation idea. |
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I'm not selling anything. Hell, these days they're giving
Unified Theory proposals away for free. |
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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? |
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If the Bing Bang followed a big crunch, then it seems
to have achieved a higher entropy. How. |
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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. |
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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. |
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It didn't come from anywhere or anything because it was at the beginning. |
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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. |
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//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? |
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//universe will eventually be just a big pile of shit// |
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//Maybe once everything [is] used up//
Nothing gets 'used up', it is just transformed into other stuff. |
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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. |
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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. |
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All matter dissipates into heat in time. |
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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? |
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Isn't the homogenization of matter and energy through
entropy really just another form of organization? |
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[Alterother] that's an excellent point. And consider
this: Isn't heat expanding outwards from a homogeneous center the definition of a big bang? |
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//Isn't the homogenization of matter and energy through entropy really just another form of organization?// |
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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). |
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//It cannot eat it's own excreta [3]// I have seen dogs that have contradicted that law! |
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Good point. Rats too. Ought to have been "digest,"
or
possibly "derive nourishment from." |
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//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?". |
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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. |
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When new "space" is created between the galaxies
as the universe is stretched -- that space is
presumably like all other space. |
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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). |
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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? |
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And if it's not cooling the rest of the universe,
then whence is this heat coming from? |
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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. |
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Sorry sir, but the books are balanced there also. The 'average temperature of space' is cooling as its stretching. |
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Beating entropy is impossible, and that's a good thing. Because if it wasn't, all sorts of weird things would happen. |
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Science tortures the universe for its secrets. Weird things have already happened, perhaps. |
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Mr. Steele -- would that imply there's an end to the
expansion, corresponding to the average
temperature hitting absolute zero? |
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Yes, but only at absolute infinity. |
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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. |
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[marked-for-deletion] This needs to be rephrased as an idea instead of a question. |
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[their] - the forces of darness have stolen your "k". |
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//Science tortures the universe for its secrets//
while plague victims tread lightly. |
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