Re: Curious how they eliminate one potential source of error
The mirrors are suspended to avoid vibrations of similar frequencies. So if it came from the Earth crust, it must have been pretty strong to shake two facilities 2000 km apart. So why it was not recorded by seismometers? And with a frequency of up to 75 Hz, we would actually hear this continent-wide chirp. Finally, seismic waves of acoustic frequencies don't travel far. That's why we do not actually hear them.