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Confused about ZPE

  1. Jun 11, 2003 #1

    wolram

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    i am a bit confused about ZPE, it seems to imply that there is still energy in a system even at absolute zero temperature ,if that is correct then the absolute must be less than that quoted, because there is still a possibility to extract energy, somone put me back on the rails.
     
    Last edited by a moderator: Feb 5, 2013
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  3. Jun 11, 2003 #2

    chroot

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    ZPE essentially means "the vacuum is not empty."

    - Warren
     
  4. Jun 11, 2003 #3
    Re: Zpe

    That is exactly what it means.

    You appear to be making the assumption that the zero point energy originates from kinetic energy of real particles (temperature), which it doesn't. It comes from the vacuum. However there is still the possibility to extract energy ... if you are clever enough.

    Creator
     
    Last edited: Jun 11, 2003
  5. Jun 11, 2003 #4

    wolram

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    energy "is" energy it is inconsiquential to say if you are clever enough to extract it, if energy exists in a system then the system must be ENERGETIC therfor energy is availiable, with respect your replyies are nonsence.
     
    Last edited: Jun 11, 2003
  6. Jun 11, 2003 #5

    chroot

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    wolram, sorry, but that is incorrect. Creater was making a joke. While the vacuum is certainly not really empty, you cannot extract energy from it -- despite what many loonies will tell you.

    - Warren
     
  7. Jun 11, 2003 #6

    marcus

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    if you go back to the greek, energy means "the ability to do work"

    ergon is work-----energon is a kind of "inner work content" that a thing or place might have.

    but in reality energy is not quite that simple because
    energy can vary as to how available it is. some energy you just
    cannot get at to make do work.


    this can seem paradoxical to anyone who happens not to have taken a one-week course in thermodynamics (in freshman year they spend a week or so on saying why you cant get work out of heat unless you have reservoirs at two different temperatures)

    Room temp is 300 kelvin (absolute is the only scale that works for this)

    You cant make the heat in a room turn wheels unless you have a colder place-----like maybe outdoors is 280 kelvin, where you can put the cooling coils and dump the waste heat. If you do have a colder place, then you can run some kind of power device, some engine, on the difference.
    You take in heat from the room at 300, extract some of it to turn the wheel, and dump the rest outside.


    Or like, maybe the air on Mars is 230. That is very cold but it still has energy in it. However you wouldnt be able to run an engine with that energy unless you had an even colder place to put the cooling coils and dump the waste heat.

    So yes the vacuum has energy in it, but how can you run an engine if there is no place colder?

    that is not just a rhetorical question. maybe thermodynamics is wrong and loonies are right!!! anything can happen!!!
    Maybe you can find a machine that will run on the vacuum energy. The idea causes peals of insane laughter but really
    the theories we all believe do not have to be right forever.
    However I personally choose to believe in thermodynamics.
     
    Last edited: Jun 11, 2003
  8. Jun 11, 2003 #7

    drag

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    Or, to make things much easier with the logical
    reasoning involved in the most basic foundations
    of modern science - the vacuum does not exist.
    (No action at a distance, no total emptiness and
    "nothingness" - that sort of things.)

    Live long and prosper.
     
  9. Jun 11, 2003 #8

    russ_watters

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    But WHY? Because the very thing that predicts that ZPE exists (Heisenberg Uncertainty) also predicts that if you collect enough of it, it'll average out to zero total energy (hence the name, ZERO point energy).
     
  10. Jun 12, 2003 #9
    That's not at all why it's called ZPE. It's called ZPE cause it represents the lowest energy state virtual particles can inhabit, which iz not zero energy. Marcus is right, and there's no way to move it around without using up energy.
     
  11. Jun 12, 2003 #10

    russ_watters

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    I guess i'll have to go back and read up on it, but I thought it was due to the spontaneous creation and destruction of matter/anti-matter pairs. Add enough up and the sum of the energy is zero.
     
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