Casimir Effect and Gravity Question

  1. gps

    gps 1

    Could Gravity be related to the Casimir Effect? Could atoms somehow interfere with the creation of virtual particle pairs such that in the space between any two atoms, there is less "pressure" and the atoms are forced together?

    Thanks to anyone who takes the time to read my question.
  2. jcsd
  3. taylaron

    taylaron 388
    Gold Member

    Hello gps, welcome to Physics Forums.
    Your inquiry on the Casimir Effect is (to my limited understanding) in fact, very complex. There are many scholarly articles out on Google or other science journals which can give you a decent description of this unusual phenomenon. I would suggest starting there. I can not answer your question, but i'm confident there is an answer to your question based on current theory proposals. The root mechanics behind this phenomenon are still largely unknown, so tread lightly in your assumptions.

  4. Vanadium 50

    Vanadium 50 18,478
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    With all due respect, Taylarin has no idea what he is talking about. The answer to your question is straightforward: "no". These are totally different phenomena.
  5. taylaron

    taylaron 388
    Gold Member

    Respect taken. May I clarify that I did not claim to fully understand the phenomenon or answer his question, but to suggest more outside research.

    Vanadium, do you deny that gravity has no integral part whatsoever in the various documented observations? Does the theory of universal gravitation F = GMM/r^2 not have any effect on all 'Casimir effect’ experiments? I would say it does, to a very small degree. I don’t need a PhD in physics to say that.

    Vanadium, I would appreciate it if you would supply scholarly references in support of your "no" statement. I would very much like to know exactly what 'vacuum energy' is exactly and whether or not ‘dark matter’ or the acclaimed ‘zero point energy’ has any part in the phenomenon (let alone what they are). My research into it has been inconclusive and it would appear that you have the answers.

  6. Vanadium 50

    Vanadium 50 18,478
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    No you don't. But it would still be wrong.

    Now you are arguing "You don't know everything so you don't know anything." Piffle.

    First, the Casimir effect has nothing to do with gravitation. Second, the Casimir effect can be explained without recourse to virtual particle creation at all. It's not a very nice derivation, but it can be done. But finally and most importantly, the idea of gravity as some sort of shielding of an outside pressure was completely discredited a hundred years ago. About once a month someone posts their "new theory", unaware that it was first proposed in 1690.

    Any such theory makes the following (unobserved) predictions:

    • Violation of the equivalence principle.
    • Deviations from the inverse square law - i.e. reduced range of gravity.
    • A non-central gravitational force.
    • Rapid increase (> 1020 degrees/second) m in temperature of any object producing a gravitational field.
    • A drag on any moving body.
  7. taylaron

    taylaron 388
    Gold Member

    Very well Vanadium, I can not successfully argue something I do not understand. We all make mistakes. I apologize for any hostilities.
  8. turbo

    turbo 7,063
    Gold Member

    With all due respect to Vanadium 50, Sakharov thought in the 1960s, and Padmanabahn currently writes of the vacuum as if it were an elastic solid, and as if it had a vital role in the emergence of gravitational forces. Padmanabahn's papers are highly cited, and if you search the forum using his name, you'll see a recent (very!) paper of his at the top of the list in a poll asking which paper is the most influential in quantum gravity.

    The Casimir effect is generally regarded as macroscopic evidence of the reality of a sea of virtual particle pairs. This is a very weak effect, though it has been detected between conductors with a wide variety of shapes, such as flat plates, plates and spheres, spheres and spheres, etc. The effect is there. It is weak, but so is gravitation.

    Can the virtual particle "sea" have a role in gravitation between objects made of sensible matter? It is possible. It is wrong-headed and very premature to claim otherwise without relevant research and thought. We do not yet have any viable mechanism whereby gravitational effects between sensible masses can arise. We can talk about space being curved, etc, but that model begs the question. We could speak of gravitation as an attractive force, but that brings us back to Mach and deeper questions about the range and speed of propagation of such forces. We can speak of Higgs bosons, gravitons, etc, but that type of speculation seems increasingly like a plausibility argument that was fashionable in the hey-day of particle physics. It might not be true. Let's remember that.
  9. vanesch

    vanesch 6,189
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    The point is that the Casimir effect is an effect that comes out of QED - which you can calculate and everything, and in QED, people didn't put any gravity.

    It's a more sophisticated version of a question like: "does magnetic induction have a relationship with gravity" ?

    The simple answer is no, because magnetic induction is described by Maxwell's equations, in agreement with observation. Engineers wanting to apply magnetic induction (in, say, a transformer) use Maxwell's equations, and don't use anything related to gravity, and the stuff they make, works.

    Of course, then you can come up with "yes, but there might be a relationship between the Maxwell equations and Gravity, Klein recently published something about that".

    True. But it doesn't change the fact that magnetic induction is well described by a theory that hasn't gravity in it.

    Same with the Casimir effect. It comes out of QED, and QED doesn't contain gravity in any way.
  10. I work in the field of the Casimir effect. I struggle every day to demystified this effect which is, for me, nothing more than basic van der Waals interactions :smile: (with a twist, granted… :biggrin:)
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