How was the Nobel-winning gravitational wave detection made?
For the first-ever gravitational wave detection, scientists used two US-based LIGO detectors separated by 3,000 kilometres, each being an L-shaped structure with 4-km-long arms. Gravitational waves distort space-time, and this distortion was measured using high-precision lasers as the change in length of the two arms, to an accuracy 10,000 times smaller than a proton's width.