This year’s Nobel Prize for Physics has been awarded to three American-based scientists for their discoveries in gravitational waves.

Rainer Weiss of the Massachusetts Institute of Technology and Barry Barish and Kip Thorne of the California Institute of Technology are the men being honoured.

Gravitational waves are defined as are ‘ripples’ in the fabric of space-time caused by some of the most violent and energetic processes.  Thorne says they were predicted by Albert Einstein about 100 years ago and are easier to understand if you compare them with ripples in a pond after a rock is dropped in.

The three scientists were key to the first observation of gravitational waves in September 2015 and announced the discovery several months later.

Today’s winners make it six out of six so far for American scientists at this year’s Nobel prizes.  Yesterday, the medicine prize went to the all-US trio of Michael Rosbash, Michael Young and Jeffrey Hall for their research on circadian rhythms.