Is Entropy dead?

Last month there was an outstanding article about entropy in Scientific American.

Entropy was mathematically flawed from the very beginning, it remains mathematically flawed, and it is only applicable in closed systems at equilibrium.

So whether it's dead or not, it's sure a quiet death.

We are to believe that models are not bound to be actual reflections of reality. If the model works its a physical success. If the graviton is discovered, the concept of space-time will still work, but will fail to be an accurate account of the underlying reality.

Aedes - Validity.

There seems to be a determination to unify the Quantum world with Gravity and yet the two models seem incompatible. Surely one or both models must give ground, after all, how weird would it be to have gravitons 'buzzing' about in curved space?
Unfortunately I have not been able to find the article on Entropy and Wikipedia gives two accounts of a Closed System, however, I'll take a guess.

The conventional view is that as work is done all energy eventually evens out and that seems fair enough locally, but when the principle is applied to the universe then things look a bit bleak. However, should the principle be applied in such a damning way? Can we be absolutely sure we don't live in a continuously recycling universe?
By a huge margin, visible mass exists in the universe as very energetic plasma contained by stars that spew enormous amounts of material and energy out into the cosmos to end up where and to end up as what? It can't be lost and Entropy suggests it might be added to some background level of energy (perhaps something already better than nil). Might this additional energy be enough to cause a continuous creation process, which would be more like 'Steady State' than 'Big Bang'? However, Entropy might indeed be dead.

In the syntax of infinity, wouldn't equilibrium be inevitable?

Not necessarily -- there is some evidence that matter is irretrievably lost in black holes.

But that's besides the point. Entropy has zilch to do with "the syntax of infinity". It has to do with finite, closed systems that in themselves are at equilibirum.

Bracewell, the article about entropy is in Scientific American from last month.

What would it mean if a model represented enough of reality, but it also represented more random factors then we could bunch together? Would this model express one possibility of actually existing in reality?

Where is the line for realizing these proofs? Or do they have to add up with the underlying beliefs?

thanks

Hi Joe

I apologise if I have misunderstood your question and this response is way off the mark.



I think that would depend on the nature of those random factors and why is it that we could not bunch them together. For example is it beyond our technological capabilites to test the predictions. If a model predicts contradictions, which are by their very nature beyond what we can bunch together, the only resolution here is to discount the model, as logical contradictions are signs of underlying poor or wrong assumptions.



It is entirely possible that a model could describe an actual reality, but how are we to draw this conclusion?



Proofs do not have to add up with underlying beliefs. Proof should correct beliefs.



I hope my interpretation of your comments are deserving of such.

... that's what science is all about, so you can count on it ...



... the laws of thermodynamics - which introduce the idea of entropy - currently only take into account closed systems (systems in which there is no inflow/outflow of matter/energy) ... however, we know of no naturally occurring closed systems (as Aedes remarks, black holes are a wild card that doesn't even allow us to confidently claim that the universe itself is a closed sysem) ... and so in that sense, entropy seems stillborn ... but the as-yet undiscovered laws of nonequilibrium thermodynamics are another story entirely ... within this set of laws, the idea of entropy may play a vital role ... consider the open system of the Earth, which continuously receives a huge influx of energy from the Sun ... much of this energy is reflected back out into space, but a lot isn't ... and you would think that a continous net inflow of energy would accumulate over time, eventually melting the Earth ... but it doesn't ... what is it, then, that offsets this net inflow of solar energy? ... is it entropy?

EDIT: I think I would be remiss if I weren't to mention a potentially competing hypothesis here - Daisyworld (Daisyworld - Wikipedia, the free encyclopedia) ... the hypothesis that life itself provides a variable energy reflector to achieve a net inflow of zero over a range of solar inflows ... (I say potentially competing because it could be the case that the Daisyworld effect merely regulates the net inflow to some constant level greater than zero that entropy then offsets.)

Hello Bracewell

I do not think either model will give ground, as they are both highly accurate in the predictions they make ie neither is, in a phyiscal sense, wrong. If QM and GR are both individual circles, the unify theory will be another circle that surrounds both "Circle QM" and "Circle GR". I see the resolution of reality a philosophical problem (if reality is such that it can be resolved)

[quote=Bracewell]The conventional view is that as work is done all energy eventually evens out and that seems fair enough locally, but when the principle is applied to the universe then things look a bit bleak. However, should the principle be applied in such a damning way? Can we be absolutely sure we don't live in a continuously recycling universe[/quote]We can be as sure as the accuracy of observations that the theory predicts. How do we observe the previous universe?

[quote=Bracewell]By a huge margin, visible mass exists in the universe as very energetic plasma contained by stars that spew enormous amounts of material and energy out into the cosmos to end up where and to end up as what? It can't be lost and Entropy suggests it might be added to some background level of energy (perhaps something already better than nil). Might this additional energy be enough to cause a continuous creation process, which would be more like 'Steady State' than 'Big Bang'? However, Entropy might indeed be dead.[/quote] Does not the work needed to reconcentrate the radiant heat of a star, generate more heat, this continual generation of heat means the system can not be returned to an original state?

Validity - You are probably correct to predict there will be some circling-of-the-square if Gravitons are found but not before a knock down fight I suspect.

You are going to have to tease out the quoted sentence for me as at the moment I am distracted by my yearly hunt for that pesky Claus fella.

I changed the quoted sentence from a statement to a question, and may have lost some "what I wanted to say" in this transition.

[quote=Bracewell]By a huge margin, visible mass exists in the universe as very energetic plasma contained by stars that spew enormous amounts of material and energy out into the cosmos to end up where and to end up as what? It can't be lost and Entropy suggests it might be added to some background level of energy (perhaps something already better than nil). Might this additional energy be enough to cause a continuous creation process, which would be more like 'Steady State' than 'Big Bang'? However, Entropy might indeed be dead.[/quote] The star is losing matter/energy, the universe is not.

Validity - thanks for the edit but strangely I am not sure if you are agreeing with me or not. However, you might enjoy this -

It seems we know about galaxies that are 13.5 light years distant, which if we take the best possible rate for the transmission of information then it makes the big bang not less than 13.5 billion years old. So, can we assume that the cosmos is contained in a volume with a diameter of 27 billion light years? Well, maybe. However, if it is assumed that in that far away galaxy there is a telescope looking at us then is it reasonable to expect that the view thru that telescope would be the same as our view? And again, if we turned our telescope to look in the opposite direction might we not possibly see another similar situation? Hopefully, you are now ahead of me and you can see there is a potential at each distant telescope to increase the diameter of the cosmos by an infinite amount but in jumps of 13.5 billion light years. Now, is that not an awful lot of potential volume to be considered as closed?

I would agree that it's an awful lot of potential volume, but that does not mean that it is infinite. Given a finite space, a system must be closed at some point. It might not be at a point that we can easily conceive, but without a nullspace randomly generating energy/matter, the system is closed. The ocean is an awfully big place to a single amoeba floating around; it is so vast as to seem infinite, but it's not. I suggest that we're dealing with a finite space because a finite amount of matter would seem to suggest a finite space, although it's true that it would not prove it.

In terms of entropy, I don't see how it's dead. We still see the effects in a localized manner; if not to perfection (due to changes outside the given system affecting the system) then enough to see the truth of it. My basic thought runs like this:

Regardless of entropy tending to increase in systems, we are aware that there is no such thing as a perfect engine. Some energy is also lost to heat. Eventually, as long as there is motion, all energy will have been lost to heat. There are only two ways this scenario can be avoided.

One, an input of energy from an outside source. The difficulty with this scenario is that the heat is still there. Our heat never dissipates(as one thing gets hotter, another, necessarily, gets colder). Since Einsteinian physics relies on the idea that energy is never created or destroyed, it simply changes form, this solution would also invalidate what seems to be a very workable set of physics.

Two, we reverse the general theory of relativity. If E=MC2[I have no idea how to get superscript, my apologies] then necessarily M=E/C2. If you can turn matter into it's correspondant energy, then it should be possible, if the laws of mathematics are to be believed, to turn energy into matter. If, under certain circumstances, this useless heat can be transformed into matter, we've solved our problem. Entropy can exist and at the same time not be relevant in the grand scheme of things.

Of course, I'm not nearly as up to date on a lot of astronomy and physics as I ought to be, I'm just chipping my 2 cents in.

It would seem there is already a system of destruction and construction. Stars scrunch up 'solid things,' reducing them to particles (partially condensed things) which are then spewed out to be absorbed by 'solid things'. But just to add 'Tonic' to the conundrum, we like to think of our condensed world as solid but this is not entirely true as it seems our solid things retain a small vestige of the behaviour of their wave-like beginnings, i.e. at times it is really uncertain what is contained in the 'test tube'.
A good example in the wild (as it were) is ball lightning. The eye witness reports of the phenomena are fascinating. Out of nowhere appears a bright round structure often emitting a buzzing sound that seems to 'dance' to the electro-magnetic 'tune' but it often carries a huge energy load. If ever we needed a reminder of how close we are to the world of waves then this potentially dangerous phenomena is it.
As I pointed out, a Big Bang may indeed have happened but it might be that what we know of it is being revealed day-by-day as light reaches us. Is it then reasonable to assume that what we see can be considered as a 'closed system?
I think it spoils the 'fun' somewhat to consider a Big Bang as the final answer as surely what happened once could just as easily be happening continuously.

As a scientist come Engineer I really can not agree that entropy can die. Indeed it is because of entropy we die.

On the huge Marco scale of the universe, entropy must win in the end. If the universe is an open system then in the unimaginable far future it must die a cold bleak death.

If the universe is a closed system then it will die a heat death of equilibrium.

If the universe is cyclic, big bang and back to big crunch then entropy must win again.

An analogy to this would be a bouncing rubber ball. Throw it hard against the ground and the first bounce would be high and the next lower and lower until it comes to rest

If the universe is infinite and eternal, well that is an enormous subject and the latest physics are nearly all in agreement that the universe had a definite beginning

Of course there is the vast subject of zero point energy

Alan

I guess what I'm faililng to see here is how it's possible for the universe to be an open system. Even if the amount of space in the universe is infinite, the amount of matter remains finite. As long as no more matter is entering the universe, it's a closed system. A vast closed system, but a closed system nonetheless. If additional matter (or energy, to be fair) is entering the universe from some other space outside of the universe, then we could encompass that space in our "system" and again see a closed system. The only possible solution for an open system is for matter or energy to appear in the space of our system from nowhere. Otherwise, we can simply expand our system to encompass whatever space the matter/energy comes from. The universe, and possibly the extension of whatever other spaces might dump into ours, is/are by necessity a closed system.

I think this is the correct link.

www.sciam.com/article.cfm?id=second-law-of-thermodynam - 62k

So, entropy is not dead, well, not as a subject it seems. Thanks 'O', I finally found the article in Sci Am, Oct 08 - Does Nature Break the Second Law of Thermodynamics. If our population growth rates are to be believed then it surely does (only kidding).
I was inspired by one of the bloggs on the article, which stated that all heat is electro/magnetic in nature. This is interesting because if this is correct then the cause has quite different characteristics from the effect. Let me explain using the microwave oven analogously.
If our sun were a microwave oven working in multi frequencies then everything sensitive to these frequencies would be heated. Heated objects would of course cool, shedding particles along the way as would the sun and eventually the sun would lose the ability to heat anything, which is so far so good. However, the microwave oven cannot heat anything if there is nothing in it that is sensitive to the radiation, which bodes bleak for the transfer of heat energy to the outer limits of the cosmos by electro/magnetic radiation. You might be ahead of me here but if this blogger is correct then there is even worse to come.
Consider the singularity that is the source of the Big Bang. This object (if that is an acceptable word for it) must then be at absolute zero temperature (because there could be no electro/magnetic radiation). So, what should happen next? The worst case scenario is that at some trigger point there would be in an instant change of temperature to an infinite value occurring in an infinitely short time. Now, is this reasonable because I can't think of a better case scenario, can you? Of course the blogger could be entirely wrong.

To make our understanding of each other crystal clear. Are you saying the universe should not be considered as closed?

I disagree with the consideration that the universe is not closed. The universe, no matter how large, can be considered a closed system. It is through the definition of universe that allows it to be considered as such, not because it is isolated from something outside the universe, rather than by definition if there is anything outside the universe that contains it, then this outside enclosure is by defintion a part of the universe. The universe is all there is and as such can be considered closed to any "outside"