On 14 September 2015, after 50 years of searching, gravitational waves
were detected for the first time and astronomy changed for ever.
Until then, investigation of the universe had depended on
electromagnetic radiation: visible light, radio, X-rays and the rest.
But gravitational waves- ripples in the fabric of space and time- are
unrelenting, passing through barriers that stop light dead.
At the two 2.5 mile long LIGO observatories in the US, scientists
developed incredibly sensitive detectors, capable of spotting a movement
100 times smaller than the nucleus of an atom. In 2015 they spotted the
ripples produced by two black holes spiralling into each other, setting
spacetime quivering.
This was the first time black holes had ever been directly detected- and
it promises far more for the future of astronomy. Brian Clegg presents a
compelling story of human technical endeavour and a new, powerful path
to understand the workings of the universe.