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Langevin Twins Paradox

  1. Aug 21, 2005 #1
    Does someone have any opinion regarding the following paper attending to prove that Hafele & Keating experiment (that actually verified the time distorsion caused by speed & gravitation in General relativity) to be highly unreliable?

    Hafele & Keating Tests; Did They Prove Anything?
    A. G. Kelly PhD*
    http://www.dipmat.unipg.it/~bartocci/H&KPaper.htm
     
  2. jcsd
  3. Aug 21, 2005 #2

    russ_watters

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    The paper is an allegation of academic fraud - such things do not belong in a scientific paper, and I'm loathe to accept the allegation without any real evidence.

    Regardless, better experiments have been performed since then, so if you're looking for a way to disprove Relativity, you haven't found it.
     
  4. Aug 22, 2005 #3
    I aggree with you that this article looks quite suspicious but this is more a feeling than actual data. I would like to ask some expert.
    I will move this dicussion to the "special Relativity Forum".
    Thanks
     
  5. Aug 23, 2005 #4
    I forget the other papers, but there are other sources that discredit the HK.
    Here's one By Louis Essen (the inventor of the atomic clock) that said the experiment was not nearly accurate enough...
    L Essen, Electron. Wireless World 94 (1988) 238.

    HK isn't really a concern anymore with the advent of GPS. GPS is far more accurate. If you're just looking into finding controversy, begin examining the GPS calculation adjustments made in jet airplanes. Accuracy there requires c+/-v calculations but I believe the mainstream explanation for this is simply the one-way sagnac effect.

    Basically, the dissenter opinion is that to be accurate, jet airplanes must calculate the distance toward a sattellite they have traversed from the time the signal was transmitted to when it was received. They then subtract this distance. (this is actually true) By doing this, the end calculation of c is c+v.

    On the other hand, this same apparent c+v happens in a sagnac device and the GPS satellites have proven to act in the same way as a sagnac ring such that the travel time of C in one direction around the earth is faster than the other (simply a shorter distance) So the apparent problem with GPS on airplanes is just another example of the Sagnac effect already described by GR.

    Either way, it makes for fun discussion. (and regardless of my beliefs, devil's advocate can be loads of fun)

    Could someone correct me on the two opinions if I'm wrong...
     
    Last edited: Aug 23, 2005
  6. Aug 23, 2005 #5

    jtbell

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    Here's a paper about observations of relativistic time effects on a clock in an airplane flying around in circles:

    http://tycho.usno.navy.mil/ptti/ptti2002/paper20.pdf
     
  7. Aug 23, 2005 #6

    pervect

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    There is a giant tempest in a teapot going on about relativity in rotating frames - both on the net and in the professional physics community.

    One can, for instance, spend about $200 to get the following book devoted exclusively to this topic an this topic alone.

    http://www.amazon.com/exec/obidos/t...102-9843228-9685732?v=glance&s=books&n=507846

    But there isn't really any serious difference in the results of the calculations, it appears to be mainly a giant philosophical muddle. When push comes to shove, one can (for instance) simply adopt a non-rotating frame of reference (such as the Earth-centered inertial frame used for GPS) and do one's calculations in this non-rotating reference frame. General covariance insures that the choice of the frame of reference is irrelevant. Everyone agrees that this gives the right results, but there appears to be an unnecessary amount of controversy over how to go about formulating the problem in an inertial frame.

    My personal favorite paper on the topic is by Tartaglia, I'll cut and paste a link to the paper I like when I get back to my other computer.

    [add]
    Tartaglia et al
     
    Last edited: Aug 24, 2005
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