Do Scientist Doubt The Detection Of Gravitational Waves?

These questions originally appeared on Quorathe knowledge sharing network where compelling questions are answered by people with unique insights.

Answers by Leo C. Stein, Ph.D., researcher in gravitational waves, general relativity, and beyond, on Quora.

Q: Do you have any doubts about the detection of gravitational waves?

A: There is no doubt in my mind. The signal is exactly what you’d expect for gravitational waves from two black holes merging in general relativity. I mean this in more than one way.

First of all, the waveform is almost the same at both detectors (one in Hanford, WA and one in Livingston, LA). Actually’s it’s more than that. The two detectors are rotated almost 90° about the vertical relative to each other (see below). That means that the two waveforms should actually be the negatives of each other. That’s exactly what’s seen (from [1] ):

In the top right panel, you’ll notice that the Hanford signal has been inverted (flipped top-to-bottom). Again this is due to the relative orientations of the two detectors:

Furthermore, the diagnostics of the detectors show that they were performing very cleanly. LIGO has literally tens of thousands of auxiliary channels: acoustic sensors, seismic sensors, radio receivers, magnetometers, monitors for the electrical grid, you name it. All of these were clean at the time of the event. None of them “vetoed” the event.

Secondly, this gravitational wave signal is exactly the signal that everyone had been expecting to see in LIGO. Well, maybe they were expecting a binary neutron star before a binary black hole, but still, everyone was expecting to see the coalescence of a binary of compact objects. This is what theorists have been modeling for years now.

I expected the first detection to be kind of marginal, just at —> Read More