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Extra dimensions

  1. Apr 19, 2006 #1
    I heard from a professor at my deparmant that there are some "simple" experiments in searching for extra dimensions. after a research, the only thing that I've found is this:

    http://www.stanford.edu/group/kgb/Research/gravity.html [Broken]

    after checking the experimental procedure, now, i am almost sure that he was just teasing me... are there really such experiments that you can conduct at an average physics dept. laboratory?
    Last edited by a moderator: May 2, 2017
  2. jcsd
  3. Apr 20, 2006 #2
    I think there really are people who are trying to do this, and the link you provide shows that some of them are trying to apply a kind of nanotechnology to the problem. But the research is prospective....that is, they are trying to find an effect, but if they do not find one, it does not mean that the idea is dead. There may just be an effect present at very slightly smaller distances, and they would not know. So if they find something, great, but if not, it does not prove it isn't there. 'Absense of evidence is not evidence of absense', someone said.

    If I had access to an ordinary university physics lab, I would like to try to test for extra dimensions by checking the inverse square law at small distances by opposing gravity (a constant, presumably) against electromagnetism (a variable of considerable sensitivity). One might suspend a small mass at known variable distance from an EM field generator (electromagnet) and vary the em field until the force of gravity just overcomes the em force.

    My attempts to do this at home have been laughably crude, but I should think some student with modern technology could at least verify the inverse square law to distances such as are suggested in your link.

    It would be good to keep in contact with you if you are in a position to try this. Maybe I could provide some suggestive assistance. Best luck to you.

  4. Apr 20, 2006 #3
    Hi there,

    indeed, there are several people doing the sub-mm measurements, also in
    Stanford. See eg.

    "[URL[/URL] Gravity on Small Length Scales
    S. J. Smullin, A. A. Geraci, D. M. Weld, J. Chiaverini, A. Kapitulnik[/URL]

    here are some results:

    [PLAIN]"[URL[/URL] Experimental Constraints on Non-Newtonian Forces below 100 microns
    J. Chiaverini, S. J. Smullin, A. A. Geraci, D. M. Weld, A. Kapitulnik[/URL]

    There are some other groups around the world doing similar stuff. Some interesting links



    [PLAIN]"[URL[/URL] of the inverse square law of gravitation.
    Contact C. Speake[/URL]


    Last edited by a moderator: May 2, 2017
  5. Apr 21, 2006 #4
    See also:

    Submillimeter tests of the gravitational inverse-square law, by Hoyle et al., Physical Review D, vol. 70, Issue 4, id. 042004 (2004).

    Best wishes,
  6. Apr 27, 2006 #5
    Interesting, can they actualy detect or measure the presence of extra dimensions? That would make things alot cooler.
  7. Apr 28, 2006 #6


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    Others better informed than I can correct me on this, but my impression is that so far, results are negative for this particular manifestation of higher dimensions. Work is continuting though.
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