Gravitational waves detected
Two black holes collide, and LIGO measures a distortion smaller than a proton.
- When
- Era
- Contemporary, Holocene
On 14 September 2015 LIGO detects the merger of two black holes 1.3 billion light years away, measuring a change in a four-kilometre arm length of about a thousandth the width of a proton. Einstein predicted the waves in 1916 and doubted they could ever be measured. It opens an entirely new channel of astronomy, and a 2017 neutron star merger was observed in both gravitational waves and light simultaneously.