Scientists at the LIGO (Laser Interferometer Gravitational-Wave Observatory) publicly announced the detection of gravitational waves on the 11th February. This is the last unproven prediction from Einstein’s theory of general relativity, which says that as a mass accelerates, energy in the form of gravitational radiation is emitted.
The proof comes from two black holes which collided 1.3 billion years ago and created a burst of gravitational waves, stretching and compressing the fabric of space time. The collision could be heard as a small ‘chirp’, and was detected at both of the LIGO sites.
This is also the first detection of a binary black hole. The results have told scientists how black holes combine: they orbit each other at up to 250 rotations per second before a final collision. The ripple created was about a billionth of the width of an atom when it reached Earth, so small that Einstein thought it would be too subtle to ever be detected.
The discovery could start to answer questions about the lives of stars, as well as the mysterious ‘dark matter’, which includes black holes and neutron stars, and could help scientists to unify the forces to link quantum theory with gravity. It could even tell us about events further back in time, possibly as far back as the Big Bang, since gravitational waves are virtually unaffected by the substances they pass through.
Photograph: NASA/Tod Strohmayer (GSFC)/Dana Berry (Chandra X-Ray Obervatory) via Wikimedia Commons