3 ms·

Supermassive black holes are larger, so the characteristic timescale of their dynamics is longer, and the gravitational waves generated by their merger are corr

Supermassive black holes are larger, so the characteristic timescale of their dynamics is longer, and the gravitational waves generated by their merger are correspondingly of lower frequency. More specifically, supermassive black holes binary (SMBHB) mergers usually ring at 0.1-1 millihertz, whereas LIGO's sensitivity is concentrated around more like 0.1-1 kilohertz, a typical frequency of stellar-mass black holes binary mergers. The ~6 orders of magnitude difference comes directly from the fact that supermassive black holes typically weigh in at millions of stellar masses. See the plot here: http://www.tapir.caltech.edu/~teviet/Waves/gwave_spectrum.html http://www.tapir.caltech.edu/~teviet/Waves/gwave_spectrum.ht... (To convert from wavelength (meters) to frequency (hertz), take the speed of light and divide it by the wavelength.)

lugg 7y ago
So it's like how you can easily see a small swell from a small boat but a larger swell can be almost undetectable. Is this also why we don't just get ripped apart during one of these ripple events which are probably all around us as gravitational noise? I wonder if this is why seemingly tiny vessels can cross large oceans just as easily as larger ones.
- MrEldritch 7y ago
  The reason we don't get "ripped apart" during these ripple events is simply that spacetime is so stiff that even absolutely monstrous amounts of gravitational energy lead to only the tiniest distortions in spacetime geometry. A black-hole collision may put out more power in gravitational waves than the entire optical luminosity of the visible universe, and the result when it reaches us will result in a distortion of less than the diameter of a proton.