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Would an Eternal Universe Violate the Second Law of Thermo?

  1. Dec 11, 2015 #1
    http://phys.org/news/2015-02-big-quantum-equation-universe.html

    Some people claim that universe has existed for eternity to get around the Big Bang theory. However wouldn't this violate either the 1st of 2nd laws of Thermodynamics which forbid perpetual motion of the 1st and 2nd kind respectively? In other words, doesn't the impossibility of perpetual motion as stated by Thermodynamics make the notion of infinite or eternal amount of time absurd?

    Cheers,

    Gabriele
     
  2. jcsd
  3. Dec 11, 2015 #2
    There's no violation if the entropy asymptotically approaches some value towards the infinite past.
     
  4. Dec 11, 2015 #3
  5. Dec 11, 2015 #4
    Do you know what asymptote means?
     
  6. Dec 11, 2015 #5

    Ye of course I've posted an example in the link above.... maybe you meant that the asymptotycal value doe not have to be infinity?
     
  7. Dec 11, 2015 #6
    Yes, asymptotic value does not have to be infinity.
     
  8. Dec 11, 2015 #7

    But isn't what you're saying equivalent to the law of increase of entropy, that the entropy of an isolated system (e.g. universe) can only increase until it reaches max at equilibrium? This is basically a re-statement of the 2nd law.....

    G
     
  9. Dec 11, 2015 #8
    I was only answering your initial question "However wouldn't this violate either the 1st of 2nd laws of Thermodynamics which forbid perpetual motion of the 1st and 2nd kind respectively?"
    I don't know if the universe indeed is infinite in time or if entropy indeed asymptotes to a value. I am simply answering your question in the negative.
     
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