LIGO Detection of Gravitational Waves

Twin four-kilometre interferometers measuring spacetime strain from black holes merging far away.

Core Principles & Analysis

• GW150914, recorded on 14 September 2015, came from two roughly 30-solar-mass black holes coalescing.
• The strain of about 10⁻²¹ changed each 4-km arm by a fraction of a proton’s width.
• Weiss, Barish, and Thorne received the 2017 Nobel Prize; the instrument is a descendant of Michelson’s interferometer.

Specifications & Metrics

• YEAR: 2015