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B GW-detector proposal: MAGA

  1. Apr 15, 2017 #1
    Ivette Fuentes and her group are attempting to use phonon excitations in BECs to detect gravitational waves. Their GW-detector is called MAGA, which stands for Micrometre Antenna for Gravitational-wave Astronomy. Here's a video of her explaining it:

    More from their blog:
  2. jcsd
  3. Apr 21, 2017 #2
    Thanks for the thread! This is an automated courtesy bump. Sorry you aren't generating responses at the moment. Do you have any further information, come to any new conclusions or is it possible to reword the post? The more details the better.
  4. Apr 22, 2017 #3

    Paul Colby

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    One question I have because I have 0 details of the proposed detector physics is why is this a good approach? My naive thought is that very cold systems are dominated by few quantum states. If the energy required for the excitation to the first excited state is too great the probability of transition might tank (formal term for go to zero). Just asking.
  5. May 1, 2017 #4
    Maybe this page on their blog can help with some of the detector physics. Else you could try reading a few of their papers, linked in this post.

    In any case, I think the fact that it's an attempt to approach an experimental regime of general relativistic effects by using QT at relatively large scales (instead of GR at small scales), plays a big role. Optimistically, this might even kill two birds with one stone, namely detect Gravitational Waves and more importantly lead to experimental data in the ongoing quest to probe quantum gravity.
    Challenging no doubt, but I can't help but still be somewhat excited though. It's not everyday you hear of a possibly doable experiment on the interface of QM and GR which isn't pretty much centuries or even millennia away, let alone already being undertaken. Unforeseen experimentally based directives pointing the way on the road towards quantum gravity are much needed and more than welcome.

    Can you by the way give any estimates from experience how much you figure the cost of one of these detectors would end up being? I presume (naively) after a dozen or so replicated prototypes, scaling up to large amounts would be much more cost-efficient. And how challenging do you figure it, say compared to the prospects of building a larger collider (bigger than SSC) within the coming century?
  6. May 1, 2017 #5


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    I don't know how expensive such a detector would be.

    How much would we learn from it? Let's say future improvements make it feasible, and such a detector is built. It picks up gravitational waves at the same time as LIGO/VIRGO or the Einstein telescope. And now? How does this improve the attempts to make a consistent theory of quantum gravity?
    The experiment would test the weak field limit, where nonlinear effects are negligible. We know how to make quantum gravity in that regime. You can write down the Lagrangian, and it works perfectly well in first order - until you realize that the integrals in higher orders diverge for large energies.

    We have experiments using a gravitational potential to get quantized energy levels already - neutrons bouncing above a surface for example.
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