Entropy is Chaos?

Discussion in 'Physics & Math' started by TruthSeeker, Jun 26, 2015.

  1. TruthSeeker Fancy Virtual Reality Monkey Valued Senior Member

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    I have been reading about entropy and the second law of thermodynamics, particularly how gas in a chamber will always reach equilibrium in the same distribution. But then this equilibrium is equated to chaos. I find that very strange. If atoms will always reach equilibrium in a specific configuration, doesn't that mean that there is an underlying order that always organize the atoms in the same distribution? How is that chaos? Seems like order to me.
     
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  3. exchemist Valued Senior Member

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    Well it is probability really. The most probable arrangements are favoured. Liquid water has higher entropy than ice, because there are more ways to arrange the molecules in the liquid state than in the solid, since in the solid they have take up fixed orientations whereas in the liquid they can be oriented however they like.

    The distribution you mention, the Boltzmann distribution, is what you get as a result of random exchange of energy among molecules.

    But you have a point: one of the wonderful features of the physical world is how macroscopic order arises from randomness (I do not like the word chaos) at the molecular level. I think Statistical Thermodynamic is one of the most marvellous concepts in physical science.

    (N.B. Wellwisher alert: mentioning water and entropy in the same sentence risks the arrival of Wellwisher, with a screed of half-understood stuff, interspersed with attack on liberals and references to hydrogen bonding. If this happens please ignore it - he's a pleasant enough fellow but you won't learn any science from him.)
     
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  5. TruthSeeker Fancy Virtual Reality Monkey Valued Senior Member

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    I find it hard to "believe" that there is such a thing as "random" in the universe. A system might appear random to us, but I think the apparent randomness is caused by our ignorance of the rules of order that govern the system. It is no coincidence that smaller systems are more "random" then larger systems, they are harder to predict because we have less information about them... it's easier to predict what happens with the gas in an enclosed space than how quantum particles behave at higher speeds and over spooky distances.
     
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  7. sideshowbob Sorry, wrong number. Valued Senior Member

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    Matter and energy interact with matter and energy in ways that are determined by the laws of physics. Those interactions are random in the sense that we can only predict them statistically. However, it would be a mistake to conclude that they "must" be directed by anything beyond the laws of physics - e.g. by some "entity".
     
  8. exchemist Valued Senior Member

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    Well one has to concede that Statistical Thermodynamics, like any theory in science, is only a model of reality and hence we have to remain open to the possibility that it may not represent the whole picture. But the fact remains that, by assuming only random interactions among populations of molecules and energy levels, Stat.TD is able to predict pretty exactly what we observe. So we are entitled to conclude, albeit provisionally as always, that randomness is all that is required.

    However, as Sideshowbob perhaps implies, there is a high degree of order in what we call the "laws of physics" and it is this order, operating on the random populations of molecules and energy levels, that results in what we see at the macroscopic scale. That is why I do not use the term "chaos" to describe what is going on.
     
  9. wellwisher Banned Banned

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    Entropy is a state function, meaning entropy will have a specific measured value based on a specific state of matter. For example, water at 25 C has entropy of 6.6177 J mol-1 K-1 . This will be the same, no matter who measures it. This value is not random, or else this value would be different each time we measure. This is a standard.

    The reason entropy will increase in the universe; 2nd law, is because energy spontaneously moves from higher to lower potential. The release of energy, such as the release of heat, will be absorbed by matter. This can and will alter the state of matter, causing the entropy to rise. If I added heat to water at 25 C and it rose to 26 C, we have a new state with a higher measured entropy.

    The problem many people have with entropy is they use freshman level thermodynamics based on closed systems, which is more training wheels for the mind, that actual reality. Natural systems tend to be open with mass and heat transfer as well as changes in volume and changes in work. These can impact state changes.

    I believe that a random universe is more of simplifying assumption for math, than it is a statement of reality. This assumption is connected to statistical methods. These methods are based on the input and output from black boxes, where the mysteries in the black box do not have to be known to generate results. Inside can be squirrels or chip monks on tread mills or doing the stair master. Random is a working assumption of black box science. If you assume random, you don't have to think further, and explain what is inside the black box. We only need to know it went in and came out different.

    Random is not new, but was the way of alchemy before the age of enlightenment. Lead could turn into Gold in a random universe, since cause and effect is not in effect. There is magic in choosing the correct black box, which is why today coffee is good for you and tomorrow it is bad for you.

    The alchemy approach, which predated modern random, was predated by random assumption called the whims of the gods, who were fickle. One did not need bother and tire their little brain trying to explain reality, since the gods were very fickle and order could change on a dime. The polytheism of random changed to one god called chaos, who is a god but not a god due to randomness.

    Random may have evolved to make science more inclusive, since it allows a method that can take the place of thinking. By the book science is important to many people, with looking inside black boxes, scary and taboo.
     
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  10. exchemist Valued Senior Member

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    BINGO!

    (Good evening, wellwisher, nice to see you here as predicted. And caveat to other readers: do not rely on this poster for learning about science. You will get confused.)
     
    origin likes this.
  11. origin Heading towards oblivion Valued Senior Member

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    It isn't quite BINGO, there is no 'G' in the paragraph (goddamn liberals).
     
  12. cornel Registered Senior Member

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    Chaos/randomness usually means there are either too many values or we cannot measure/know each particular value,
    it's just a way of saying "we don't know"
     
  13. sideshowbob Sorry, wrong number. Valued Senior Member

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    That's like saying "we don't know" how tall a human being is. We do have a pretty good idea of the range and of the average, even if we don't have exact information on every individual.
     
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  14. JJM Registered Senior Member

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    Howdy....Hello....Entropy might be the dwindling force/energy reduction/style of the mechanical duration, which means there is a change in force/energy. which as it is flowing is read as entropy.
     
  15. exchemist Valued Senior Member

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    Meaningless gibberish, complete with illiterate punctuation. Can you do any better, or are we wasting our time reading what you post?

    P.S. I see the illiterate punctuation has subsequently been corrected by editing. So now we are just left with the meaningless gibberish. Any chance of some further editing, to clarify what is meant here?
     
    Last edited: Jun 29, 2015
  16. AlexG Like nailing Jello to a tree Valued Senior Member

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    JJM's writing style with the 'howdy' and use of the / reminds me of Undefined (aka Realitycheck). A sock?
     

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