Yesterday, over a hundred years after Albert Einstein first predicted the existence of gravitational waves, three American physicists won the 2017 Nobel Prize for Physics for their “decisive contribution to the LIGO detector and the observation of gravitational waves.”
Half of this year’s prize went to Rainer Weiss from MIT for his work conceptualizing and constructing the Laser Interferometer Gravitational-wave Observatory (LIGO), while the other half of the prize was split between Kip Thorne and Barry Barish from Caltech, both co-founders of the LIGO/VIRGO Collaboration.
As Einstein laid out in his general theory of relativity, gravity is a result of space and time being warped by the presence of mass, much like an electric field is warped by the presence of a charge. When a mass accelerates, it changes the curvature of space-time, producing a gravitational wave. This wave then ripples out through the cosmos at the speed of light, slightly distorting the fabric of space-time as it goes.
LIGO, a sophisticated pair of laser interferometers separated by a distance of nearly 2,000 miles, is designed to detect the largest of these faint cosmic ripples. And on September 14, 2015, it did. After traveling over 1.3 billion light-years, gravitational waves generated by the merger of two closely orbiting black holes finally reached Earth, producing an iconic “chirp” from LIGO, proving Einstein was right.
In a press release responding to the announcement, Professor Paul Hardaker, CEO of the Institute of Physics, explained why the discovery of gravitational waves is so groundbreaking:
“We are delighted that the discovery of gravitational waves has won this year’s Nobel Prize for Physics. For as long as we have had astronomy we have used light in some form or another to understand how our universe works. This significant result marked the beginning of another way of viewing the universe, using gravity, which is what makes it such a major step forward, and so deserving of the Nobel Prize.”
In addition to the iconic gold medal featuring an image of Alfred Nobel, each of the three laureates will also receive a diploma from the King of Sweden and split over $1 million in prize money.