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Will LHC measure gravitational waves?

  1. Jun 14, 2010 #1
    Considering they will eventually be colliding gold or lead ions, will they measure or be able to measure the gravitational impact of the collisions?

    Just curious since the velocity will be so extreme. I would think Tevatron would already have something to say about this, but I'm unsure of the interest in testing it due to the fact that I've not seen anything at all down this avenue.

    I'd like to think such powerful collisions would create extremely minute, possibly measurable, vibrations. However, lacking the effort to run the numbers, I'm simply curious if anyone knows of any plan to test such.

  2. jcsd
  3. Jun 14, 2010 #2
    The kinematic effects of gravitational waves(or gravitons) on the colliding ions will be negligible. My guess is that gravitational effects will be smaller by about 10^-40(~the ratio of gravitational force to EM force between electrons ). So LHC alone will not detect effects due to gravity on particle collisions.

    However it might be LHC collisions will also produce weak gravitational waves. It will be interesting to compute if experiments like LIGO can measure these waves. Maybe a gravitational detector can be placed near the LHC.
  4. Jun 15, 2010 #3
    AFAIK there is no way that LIGO will be able to detect anything of the sort from the LHC. There are better sources out there, orders of magnitude stronger that will be detected first.
  5. Jun 15, 2010 #4


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    This paper by Schutz and Ricci, recently published in the arXiv is a review of grav. wave theory and contains much of interest. It's called " Gravitational Waves, Sources, and Detectors".

    http://arxiv4.library.cornell.edu/abs/1005.4735 [Broken]
    Last edited by a moderator: May 4, 2017
  6. Jun 15, 2010 #5
    How does one roughly make an estimate of the magnitude?
  7. Jun 16, 2010 #6
    Distance and mass, such as in simulations of merging black holes, stellar collapse or merging neutron stars. All of this, and the distance from the detector.
  8. Jun 17, 2010 #7
    I was just wondering if it was possible to execute a simple stochastic test much like the way the Cosmic Microwave Background was discovered. Perhaps there could be noise plateaus while collisions were in progress slightly above the inherent noise level of several high Q bar detectors which would be somewhat subtracted out. (laser interferometers probably don't have adequate precision if shrunk to a size that will fit close enough to any LHC collision point. That doesn't include having to assume the frequency and possible resonance thereof to get a signal.)

    Thanks for that paper by the way. It was a great read, the data to confirm it is highly anticipated.

    The thing that probably would make this impossible is quantum noise which is likely more powerful than any perturbation produced in the collisions.

    Still it leaves one to wonder if it were possible to compare different collision points and subtract out the common noise. Would that leave some sort of noise plateau when the machine is in collision mode, different from one with the machine out of collision mode.

    But then again, there is the whole premise of detector being within the same space-time perturbations, therefore making it impossible to produce any signal that didn't change the measurable with respect to the detector. The quantization (slice) of time required to make such a test would probably have to be unimaginably small.

    Again, untrained enthusiast spewing of the mind.
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