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Extracting zero-point energy using the Casimir effect?

  1. Aug 24, 2010 #1

    People have hypothesized that one could extract energy from the zero-point field using the Casimir effect by letting the two conducting plates move together and do some useful work.

    But surely to reset the system one needs to supply the same amount of work to separate the plates again so no net work is done by such a system?

    Is that correct?

  2. jcsd
  3. Aug 28, 2010 #2


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    I had subscribed to this thread, hoping that someone with some useful contribution would respond. But since I am somewhat curious myself, let me try to get this discussion started...
    Your argument makes sense. This sounds a bit like a perpetuum mobile (which would make this impossible a priori), but I'm not sure it technically is one... after all, AFAIK it is a commonly accepted theory that virtual particles can become "real", for example if they are created near a black hole and one is sucked in.

    So can you get a little more specific who "people" are and how they visualise this extraction of energy?
  4. Aug 28, 2010 #3


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    Sakharov, Haisch, Rueda, and Puthoff all have thought that energy might be extracted from the zero-point field. The latter three had some research financed by NASA's Breakthrough Propulsion program. Sakharov urged his government to ban zero-point experimentation, thinking it was too dangerous (the destroy-the-universe kind of dangerous). So far, no practical extraction of energy, only theoretical "what-ifs".
  5. Aug 28, 2010 #4


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    No, energy can't be extracted using the Casimir effect. Puthoff & Co are infamous crackpots. (From what i understand, Puthoff hasn't done a single serious thing in physics since he got his PhD. But he's done quite a lot of non-serious stuff, such as vouching for Scientology and Uri Geller)

    Neither QED in general, or the Casimir effect in particular, or virtual particles allow for the violation of conservation of energy (despite some popular-scientific descriptions to that effect). That's really all there is to it as far as I'm concerned.
  6. Aug 29, 2010 #5
    Hi John;
    Some years ago Robert Forward sent me some stuff he was working on at Hughes Labs for the Air Force.
    I found this one to be interesting with regards to your Casimir energy question:


    Also I found your thread on Zitterbewegung and spin to be astute enough to warrant a reply but haven't found the time to give it the attention it deserves.
    Maybe I can get to it later.
  7. Sep 1, 2010 #6

    Thanks for link to Robert Forward's paper.

    How about this for a Casimir energy machine cycle?

    1/ Start with two conducting plates placed opposite each other at separation d.
    2/ Let the Casimir force pull the plates together and use the resulting energy to do some useful work.
    3/ Now slide the plates apart - hopefully this shouldn't require much energy.
    4/ Separate the plates by distance d again. This shouldn't take much energy as long as they are *not* opposite each other while you separate them.
    5/ Now slide them so that they are back opposite each other at separation d.
    6/ Repeat

  8. Sep 1, 2010 #7


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    It takes at least as much energy as you got in work. It's a conservative force.
    You might as well suggest the same only using gravity, or London forces. (Incidentally, London forces are related to the Casimir effect.)
  9. Sep 1, 2010 #8
    I once saw an article which basically relayed calculations which suggesged plates the size of a city could generate useful power.

    If I recall correctly, it was exploiting the fact that the plates are not pulled together uniformly by the Casimir vacuum thus there would be miniscule waves in each plate, the energy of which could be extracted.
  10. Sep 6, 2010 #9
    I don't know whether the Casimir Force is conservative of not.

    Maybe the situation is analogous to that of extracting energy from a water fall.

    1/ We slide a plate into the flowing water.
    2/ The pressure of the water pushes the plate down and does useful work.
    3/ We slide the plate out of the stream of water.
    4/ We move the plate up to its original position.
    5/ Repeat

    Number 2/ is like the Casimir force in that it is induced by a pressure difference.
  11. Sep 6, 2010 #10


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    Except that the maximum amount of work done, is mgh, where m is the mass of the plate and h is the difference in height. And once the plate has been slid out from under the water fall, you will need at least that same amount of energy to push it back up. The trick being, of course, that gravity is definitely conservative.
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