0
$\begingroup$

As is said in the latest LIGO press realease, the detected gravitational waves vary with a frequency that is audible for us. The audio one can obtain from the detected data is actually plaied during the press realese: see https://www.youtube.com/watch?v=aEPIwEJmZyE&feature=youtu.be&t=2754 at 45:54.

I tried to reproduce this same sound, starting from the public data of the event: https://losc.ligo.org/events/GW150914/

What I do is to get the raw data from https://losc.ligo.org/s/events/GW150914/P150914/fig1-waveform-H.txt. This dataset contains only $3400$ rows, so I add new data by adding linearly interpolated data.

A sample of the python script (needs python3) is here: https://gist.github.com/anonymous/2f5f7d1824c11d2698b1

Unluckily I get something ways more noisy and "flat" than the one presented in the press release.

Do someone know which technique they used? maybe they have a sample with more datapoints in time?

$\endgroup$
  • 2
    $\begingroup$ She says "but it's so short it's just a thump, so ... we have shifted [the signal] a bit in frequency". So have you tried stretching the signal? $\endgroup$ – lemon Feb 12 '16 at 18:43
  • $\begingroup$ @lemon, yes. I see I was not clear: the whole part of the oversampling whit linear interpolation is to stretch the signal (more points at the same rate) $\endgroup$ – Antonio Ragagnin Feb 12 '16 at 18:53
  • 1
    $\begingroup$ As with most scientific "visualizations" one has to cheat to make it more interesting. I don't think that this one is of much use... the much more interesting piece of this phenomenon is the one that LIGO wasn't able to measure: it's the long, increasing rise of frequency as the two bodies are rotating ever closer. This sound is just the finale of a very long gravitational song (or scream of death, if you wish), that these two bodies are singing together. Future observatories will hear the singing of the gravitational universe. $\endgroup$ – CuriousOne Feb 12 '16 at 20:05
1
$\begingroup$

I finally found that the complete data (not undersampled) of this event is aviable in: https://losc.ligo.org/s/events/GW150914/GW150914_tutorial.html

It contains also a python tutorial on how to postprocess it in order to re-make plots and how to generate the sound!

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.