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Absolute zero

  1. Oct 7, 2007 #1
    Hello all

    This question is probably a bit ridiculous, but here goes:

    Hypothetically, If any given closed system has obtained absolute zero temp, does any media (time, gravity, events)occur within? Thermodynamically, Wouldn't this be a state of infinite entropy? Can anyone describe such a system?


    BTW feel free to enlighten me on the laws of absolute zero, for all I know, I could have just asked, does 1 + 1 = an orange peel
  2. jcsd
  3. Oct 8, 2007 #2


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    Absolute zero is limit which is impossible to reach for a real system.
    Also, note that absolute zero does not imply zero energy since you still have the zero point energy.
    In many cases we can model real systems quite well without taking the temperature into consideration (i.e. we assume zero temperature) and nothing dramatic happens. This is a valid approximation assuming the temperature (or to be more precise, kB*T)is much smaller than the typical energies of the problem (e.g. much smaller than the bandgap of a semiconductor, or the gap in a superconductor). Hence, in most cases it won't matter if the system is at zero K or just very small. There is nothing "mysterious" about zero temperature.

    If am not qute sure why you think the entropy would go to infinty; entropy is essentially a measure of disorder and is only indirectly connected to temperature (there are measures of entropy that are not related to temperature at all, e.g. the von Neumann entropy).
  4. Oct 8, 2007 #3

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    Thermodynamically, it would be a state of zero entropy (or a constant entropy for non-degenerate systems).

    The system will have a minimum energy, which is called the zero point energy. This is a quantum-mechanical effect. Classically, it should have had zero energy.
  5. Oct 8, 2007 #4

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  6. Oct 8, 2007 #5
    I guess I was thinking along these lines.

    Thanks for the help.
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