Three American physicists have won the Nobel prize in physics for the discovery of gravitational waves, ripples in the fabric of spacetime that were first anticipated by Albert Einstein a century ago.
Rainer Weiss was awarded one half of the 9m Swedish kronor (£825,000) prize, announced by the Royal Swedish Academy of Sciences in Stockholm today. Kip Thorne and Barry Barish will share the other half of the prize, reports The Guardian.
All three scientists have played a leading role in the Laser Interferometer Gravitational-Wave Observatory, or Ligo, experiment, which made the first historic observation of gravitational waves in September 2015.
Weiss, emeritus professor of physics at Massachusetts Institute of Technology, is an experimentalist and made a major contribution to the concept, design, funding and eventual construction of Ligo.
Kip Thorne, the Feynman professor of theoretical physics at California Institute of Technology, is a theorist and made crucial predictions of what the detection of a gravitational wave would actually look like and how to identify that signal within the data.
Barry Barish, a former particle physicist at California Institute of Technology (now emeritus professor) is widely credited for getting the experiment off the ground. When he took over as the second director of Ligo in 1994, the project was at risk of being cancelled. Barish turned things around and saw it through to construction in 1999, and its first measurements three years later.
In the end, detection required a peerless collaboration between experimentalists, who build one of the most sensitive detectors on Earth, and theorists, who figured out what a signal from two black holes colliding would actually look like.
Ronald Drever, a Scottish physicist, who alongside Weiss and Thorne played a leading role in developing Ligo, died in March from dementia less than 18 months after gravitational waves were first detected. The Nobel prize is not normally awarded posthumously.
Speaking at a press conference after the announcement, Weiss described receiving the phone call this morning as “really wonderful”. “I view this more as a thing that recognises the work of about 1,000 people. I hate to tell you but it’s as long as 40 years of people thinking about this, trying to make a detection … and slowly but surely getting the technology together to do it.”
Ahead of the announcement, the trio had been hotly tipped as potential winners and the choice of a discovery that captured the public imagination will be hugely popular. The detection of gravitational waves, announced in early 2016, marked the climax of a century of speculation and 25 years of developing a set of instruments so exquisitely sensitive that they could spot a distortion of a thousandth of the diameter of on atomic nucleus across a 4km length of laser beam.
The phenomenon detected was the collision of two black holes. Using the world’s most sophisticated detector, the scientists listened for 20 thousandths of a second as the two giant black holes, one 35 times the mass of the sun, the other slightly smaller, circled around each other.
At the beginning of the signal, their calculations told them how stars perish: the two objects had begun by circling each other 30 times a second. By the end of the 20 millisecond snatch of data, the two had accelerated to 250 times a second before the final collision and a dark, violent merger.
Last year’s prize went to three British physicists for their work on exotic states of matter that may pave the way for quantum computers and other revolutionary technologies.
