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What is the name of the physics law

  1. Jun 30, 2005 #1
    that says complex things tend to breakdown into simpler things over time?
  2. jcsd
  3. Jun 30, 2005 #2


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    Chaotical systems (the eqns of motion are nonlinear) could exhibit interesting behavior.I'm sure that the evolution of nonequilibrium statistical systems follows the second principle of thermodynamics.

    And your question is awfully vague.

  4. Jun 30, 2005 #3
    well I cant really remember much more about the law than what I asked, sorry

    I think creationists use it to disprove evolution
  5. Jun 30, 2005 #4
    Do you mean entropy?

    Yeah. :uhh:
    Last edited: Jun 30, 2005
  6. Jun 30, 2005 #5

    Claude Bile

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    I think he is referring to the second law of thermodynamics. Whether this law says that complex things tend to break down into simpler things over time is largely debatable.

    Maybe this susceptibility to misinterpretation is why creationists use it to disprove evolution?
  7. Jul 29, 2005 #6
    Sounds like the second law of thermodynamics to me too. To properly understand the second law one must be careful and rigorous--there's a LOT of misinformation out there. Pretty much all of statistical mechanics (a formal statistical framework from which the original "laws of thermodynamics" can be derived) is based around one postulate: A system in equilibrium has equal probability of existing in any of it's accessible states.
    (I am however still not too clear on the precise definition of equilibrium myself)

    Here's a little example to help you understand more about entropy and "complex things" becoming "simpler". First of all, you must understand that in (classical) physics the universe is a fundamentally reversible, deterministic system in which "information" is conserved. It is only when one invokes statistics that one can talk about "losing" or "gaining" information, and I think that's what you are getting at when you ask about complex systems becoming simpler.

    Imagine two chambers, connected by a tube with a valve in it. Say you close the valve and fill only the left chamber with gas. What do you know? Well, you know for instance that every particle of gas is in the left side of your system. Now say you open the valve. Equilibrium is eventually reached in which both chambers are filled with the same amount of gas. At this point, what do you know? Pretty much nothing! You really can't say what particle is where, can you? In this sense, one could say that information has been lost. Which would make it seem like the system is now "simpler".

    But again, you must realize that you are still talking in terms of probabilities, which are not fundamental, but rather an abstraction used to study macroscopic systems. At the heart of everything is Newton's laws, and actually, no information has been lost.
  8. Jul 30, 2005 #7
    Yep I think its the 2nd law of thermodynamics
  9. Jul 30, 2005 #8


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    Hah ! That's priceless...are creationists trying to use science to invalidate a scientific theory and replace it with an unscientific one ? :rolleyes:

    1. As Dexter mentioned, the Second Law does not apply to non-equilibrium systems like complex organisms,

    2. Even if it did (in some fantasy world), this is still a blatant misunderstanding (assuming there was even an attempt at understanding, in the first place) of the Second Law, which does NOT prohibit local reduction of entropy.

    Might as well go about denying the existence of snowflakes, while they're at it ! :grumpy:
    Last edited: Jul 30, 2005
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