2015Reputable sourceWell documented
Gravitational Waves Detected
On the timeline · around 2015 ·
What happened
A century after Einstein predicted them, gravitational waves — ripples in spacetime itself — were directly detected for the first time. On 14 September 2015 the twin LIGO observatories caught the faint signal of two black holes colliding more than a billion light-years away, stretching space by less than the width of a proton as the wave passed through Earth.
Why it matters
The detection confirmed the last major untested prediction of general relativity and opened an entirely new way of observing the universe — 'listening' to cataclysms invisible to ordinary telescopes. It earned the 2017 Nobel Prize and launched the era of gravitational-wave astronomy.
Sources
- LIGO Laboratory, Caltech. What are Gravitational Waves? · Reputable source
Related timelines
- The Universe → — A new way to observe the cosmos