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Gravity Waves and Superconductors (Raymond Chiao)

  1. Mar 24, 2009 #1
    Berkeley's Raymond Chiao has some interesting conjecture on gravity waves:

    http://www.technologyreview.com/blog/arxiv/23198/

    According to him, it should be possible for a superconductor to reflect gravity waves like a mirror.

    This then leads to all sorts of interesting possibilities, such as the idea of vibrating a superconducting element at a high enough frequency to produce a standing wave that could be of sufficient magnitude to offset gravity.

    It's just a theory of course, but Chiao claims to have found some interesting data from NASA's Gravity Probe B to corroborate his work.

    Since graphene is able to make electrons appear to behave as if they were massless, I wonder if it could be used in probing the nature of gravity?
     
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  3. Mar 24, 2009 #2
    Gravitational waves (gravity waves) are simply oscillations or fluctuations in the gravitational field or in the curvature of spacetime. These minor fluctuations are small in comparison to the magnitude of the field or curvature itself. And yet the implications of Chiao's conjecture, if true, are that you could use superconductive elements to act as efficient mirrors and optical elements for gravity waves. Consequently, by making use of such optics, you could build up the waves until you achieve sufficiently large effect.

    For example, we use lenses and mirrors to create lasers, which we use for all kinds of things.

    The question is, how to make gravity waves in the first place? What phenomenon generates gravity waves?
     
    Last edited: Mar 24, 2009
  4. Mar 24, 2009 #3

    wolram

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    May be the gravity probe B team missed some thing, but i doubt they did.
     
  5. Mar 24, 2009 #4
    Now that I think about it, I suppose just regular movements of mass must create gravitational waves. So the only way to create a large superposition of such waves would be to take something very light and oscillate it to and fro very fast. I suppose electrons are the lightest and most conveniently controllable objects we know of, so I guess they're what we would use to generate lots and lots of tiny manageable waves to build them up into something bigger, through superpositioning.

    That's why graphene seems like it might be more interesting to use than superconductors, since it's much more robust. A nice exotic form of matter that gives us as much control over the electrons as possible, should be the best thing.
     
  6. Mar 24, 2009 #5
    I honestly have no idea whatsoever what this means, but if "gravity has a fundamentally different affect on localised particles compared to delocalised ones" then wouldn't this have any sort of cumulative macroscale effect we could see in, for example, astronomical observations?
     
  7. Mar 24, 2009 #6
    Well, the problem is that delocalized particles are small, and not astronomically-sized objects.

    But I dunno -- dark matter, maybe? That's astronomically-sized, but not very concentrated or dense, and it has a cumulative effect that can be vaguely discerned. But it can't be seen, which is pretty anomalous and weird.
     
  8. Mar 24, 2009 #7
  9. Mar 24, 2009 #8
    Here, I meant to cite this latest new paper from Chiao, but somehow forgot to. It's quite interesting:

    http://arxiv.org/PS_cache/arxiv/pdf/0903/0903.0661v5.pdf [Broken]
     
    Last edited by a moderator: May 4, 2017
  10. Mar 25, 2009 #9
    Basically , Chaio is assuming that gravity acts differently upon a quantum condensate (superfluid) than upon 'normal' matter.....in other words, he is saying that the equivilance principle is violated with a superconducting condensate.....for which, BTW, there is no physical evidence. He is basically starting with Relativisitics and then jumps to Quantum indeterminancy as a reason to circumvent the equivalence principle.

    If condensates don't follow the geodesic then it seems gravity would not cause a laser beam to free fall either since it is also basically a single valued wavefunction (bosonic condensate).


    2ndly; his supposition (of GW detection in Superconducting condensate) hinges entirely upon the induced gravitomagnetic/gravitoelectric field being of the SAME order of magnitude as the electric field operating on cooper pairs in the superconductor.....In order to do this he tries to use concepts of 'plasma frequency' to justify a possible increase in the gravitoelectric field by 42 orders of magnitude ! (see page 4 here....
    http://arxiv.org/abs/0903.3280

    Someone more familiar with derivations of plasma frequency please tell me if this is justified.
    Everything looks OK up to equation #17; the problem is that it is well known that according to typical Maxwellian (low field/ low vel) GEM equations, E(g) is extremely miniscule and close to zero; he tries to increase E(g) by some sort of plasma freq. analysis....which I don't seem to fully comprehend. That last page seems loaded with assumptions.

    However, It is easily testable... I predict it will fail; just my opinion.

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    Last edited: Mar 25, 2009
  11. Mar 25, 2009 #10

    MTd2

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    A long time ago, I wondered if the Meisner effect could really mean a change in the space time signature, lorentzian -> galilean, at least where the the effect microscopicaly happen. It would not affect almost not affect weight of the critaline structure, but, perhaps, the electrons of the cooper pair would either loose all the gravitational interaction, or weird stuff would happen accordingly to a galilean version of general relativity.

    The reason for thinking like this it is that since there is no variable magnetic variation, there is no photons, at least classicaly. So, MAYBE, there is no speed of light limit, involving the EM field, but causaility holds, so we have a galilean space time.

    Did anyone hear or think about that?
     
    Last edited: Mar 25, 2009
  12. Mar 25, 2009 #11
    Then test it they should.

    Last night, I emailed Dr Chiao to ask him about whether graphene could serve a similar role as the thin superconducting film, since its electrons also behave like Dirac particles, and across a wider range of temperatures including room temperature, even though it is not a superconductor. He replied back that it depends on whether graphene has the equivalent of a superconducting BCS energy gap, to prevent decoherence/localization. Does graphene have such an energy gap?
     
  13. Apr 7, 2009 #12
    I did read the article and came to the same analysis. Can I ask why should GTR no more apply inside a superconducting matter? Is there any good reason for that? For me, since GTR applies for black holes which are very dense "condensate" of matter, the assertion seams to be a non sense. But I am not a specialist. Can someone explain more precisely the hypothesis of Chiao?

    I know, personal research are not wellcome here but since one can develop (as I do it) a 3D model of classical string leading to the relation: pressure/c2 + volumetric density of matter = 0, why should we not propose that effective trajectories for such condensates are the result of an interaction between gravity and the local EM activity? Any comment would be appreciate. Once more time I am not a specialist and I fundamentaly study all these "things" with the viewpoint of a theorist.
     
  14. Apr 7, 2009 #13
    I'd always thought that suitably low mass is required for quantum indeterminacy, which means condensates don't qualify.

    In the case of a supercurrent, the mass of its Cooper pairs will be suitably low.
     
  15. Apr 8, 2009 #14
    Well an electron has a low mass(10-27kg), a proton also (10-30kg). But it does not avoid a realy important volumetric density of "matter" and a quantum behavior. How do you mix these two facts?
     
  16. Apr 8, 2009 #15
    But a condensate of matter is going to be a lot more massive than individual Cooper Pairs.
    Black holes were being mentioned, and any condensate attributed to them would not be a light mass capable of being delocalized by tiny quantum fluctuations. Cooper Pairs are indeed light enough to be kept in a delocalized indeterminate state.
     
  17. Apr 10, 2009 #16
    hello, BF .
    Thx for the question.
    Only recently has there been speculation that GTR may fail in condensed matter, specifically, in superconductors, under certain circumstances.

    In Chiao's case, he interprets the quantum "rigidity" of the single valued wavefunction to mean physical rigidity against Gravitational waves and tries to make a case for that. There is some reason to suspect this, but I am not totally convinced, especially since there are numerous terrestrial experiments revealing that quantum particles interact appropriately in g fields.

    Moreover, if it were true , then one could make the case that the non-geodetic effect would be quite evident in the orbits of neutron star binaries (since they are thought to be condensed matter)....


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  18. Apr 28, 2009 #17

    MTd2

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    A new article from Raymond Chiao was posted today on arxiv.org :

    http://arxiv.org/abs/0904.3956

    New directions for gravitational wave physics via "Millikan oil drops"

    Authors: Raymond Y. Chiao
    (Submitted on 25 Apr 2009)

    Abstract: "Millikan oil drops" are drops of superfluid helium coated with electrons, and levitated in a strong, inhomogeneous magnetic field. When the temperature of the system becomes very low compared to the cyclotron gap energy, the system remains in its quantum ground state. Two such levitated charged drops can have their charge-to-mass ratio critically adjusted so that the forces of gravity and electricity between the drops are in balance. Then it is predicted that the amount of scattered electromagnetic and gravitational radiation from the drops are equalized, along with these two kinds of forces. The cross sections for the scattering of the two kinds of radiation can become large, hard-sphere cross-sections at the first Mie resonance, due to the hard-wall boundary conditions on the surfaces of the spheres for both kinds of radiations. An efficient quantum transduction process between electromagnetic and gravitational radiation by such a pair of drops is predicted at microwave frequencies, and a Hertz-like experiment is proposed. A more practical implementation of these ideas to use pairs of levitated, charged superconducting spheres is briefly discussed.
     
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