At a press conference at LIGO today Thursday 11 February 2016 scientists have announced that they have definitely detected gravitational waves.
The signal was detected on 12 September 2015 and was caused by two colliding black holes. The signal is said to exactly match the predictions made by Einstein’s General Theory of Relativity. The Black Holes concerned are about 30 solar masses each with a diameter of 150 kms and are located at a distance of 1.3 billion light years. As well as confirming gravitational waves the discovery is proof that binary black hole systems can exist.
At the time of collision the black holes had a velocity of about half the speed of light. 60 solar masses of material crashing at this speed are certainly gong to release plenty of energy.
These gravitational waves have been travelling for 1.3 billion years before they reached Earth. The effect of the fantastic release of energy all that time and distance ago was to move the LIGO machinery by 1/1000 of the width of a proton particle.
The detection of gravitational waves is being likened to the Apollo moon landings of the 1960’s. As a result of the detection it is being predicted that we will now go on to see things that we never knew existed.
The team feel confident that they have definitely seen gravitational waves because the signal turned up in two detectors 7 milliseconds apart which matches the delay expected since the detectors are located in different places.
We will update this report at our March meeting.