The discovery was a long time in the making, in human terms as well as astronomical ones. Dr. Weiss, Dr. Thorne, Dr. Barish and several of their colleagues labored on LIGO for decades. The landmark discovery in 2015 involved more than 1,000 collaborators dotted across five continents. The project exemplifies a long-term vision among scientists 和 policy makers that is almost unimaginable today, as distant as those colliding black holes.
The idea was audacious, to say the least. To detect gravitational waves of the expected amplitude using the interference method, physicists would need to be able to distinguish distance shifts of about one part in a thousand billion billion. That’s like measuring the distance between the earth and the sun to within the size of a single atom, while controlling all other sources of vibration 和 error that could swamp such a minuscule signal.