I imagine that at some optimum distance the gravitational waves would create compression and rarefaction waves in air sufficiently loud to be heard by the human ear. What is that distance? The previous reference given came up with a change in length of 1% at 2000 miles distance. That IMHO would be a planet wrecker. I am looking for a distance where the sound could just be heard.
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5Possible duplicate of How close would you have to be to the merger of two black holes, for the effects of gravitational waves to be detected without instruments? – AccidentalFourierTransform Apr 09 '16 at 15:52
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They come up with a 1% change in length at 2000 miles, which sounds like a planet wrecker. – Apr 09 '16 at 16:07
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1@DirkBruere: A 1% change in your ear would be a very painful and possibly deafening sound level, though. The human ear is much more sensitive than that, which might put the detection threshold out much further, certainly when using proper "gravitational wave earbuds". One still wouldn't survive that because of the other radiation, but what the heck... :-) – CuriousOne Apr 09 '16 at 20:05
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I just made a very rough order-of-magnitude calculation for an answer to a similar question. It's hard to give concrete number because it would involve some 'relativistic biomechanics', but my estimate would be that the GW150914 event would have caused audible effects in your ear as far out as 1 billion kilometres (which might actually be a rather safe distance if there wasn't any accretion matter around). – Emil Jul 08 '17 at 14:51
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Sound is a longitudinal pressure wave in a fluid. A gravitational wave is something entirely different, it is a transversal wave of space-time geometry.
For all intents and purposes, you can't hear them (in much the same way you can't hear electromagnetic waves, no matter how strong they are; you can see EM waves, if their frequency is right).
Even if there is an ever so slight coupling between both types of waves, if you noticed the effect it would mean instant death since it implies a large changing quadrupole moment of mass in your vicinity.
Jens
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Something causing changes in length in a medium (air) will create sound. A trivial thought experiment suggests that the movement of the interferometer mirrors in LIGO towards and away from each other would generate sound if they were in air and not vacuum. Hence sufficiently intense gravitational waves will cause surfaces to radiate sound. – Apr 09 '16 at 17:02
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@DirkBruere But then you don't hear the GW. A 300Hz sound wave has a 1m wavelength. A 1m GW has a frequency of 300MHz. On the other hand, a 300Hz GW has a wavelength of 1000km and that's impossible to hear as a sound wave. – Jens Apr 09 '16 at 17:15
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@DirkBruere Does the "trivial thought experiment" take into account that the GW not only affects the mirrors, but also the volume of air? Don't think of the mirrors as a speaker membrane! The GW compresses all the space at nearly the same time. Where does the pressure differential come from? – Jens Apr 09 '16 at 17:31
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@DirkBruere I would not assume moving mirrors. What was measured was a phase shift in an electromagnetic wave traveling along perpendicular paths. The GW modified the space-time along that path; that's not the same as moving mirrors in an otherwise constant space-time metric. – Jens Apr 09 '16 at 19:03
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So a 1% change would have absolutely no planetary effects at all? is that what you are claiming? – Apr 09 '16 at 19:40
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2Gravitational waves cause elastic deformations and they can very well be "heard" with the correct type of "microphone" called a Weber bar: https://en.wikipedia.org/wiki/Weber_bar. The only problem with this device is the sensitivity, which is too low to achieve successful detection, the event rates are simply too low. The frequencies of the LIGO event are within the audio spectrum. LIGO's peak sensitivity is at approx. 150Hz. – CuriousOne Apr 09 '16 at 20:02