ALBERT EINSTEIN MADE MANY BOLD PREDICTIONS. One that even he thought would never be confirmed was the existence of gravitational waves. His general theory of relativity held that the movement of massive objects, such as black holes—another wild consequence of relativity—would create “ripples” in the fabric of space-time. Should any of these ripples, or gravitational waves, reach Earth, they would be so astonishingly tiny that directly measuring them looked hopeless.
Yet in the same spirit of curiosity that drove Einstein, scientists did not give up the hunt. In the 1970s, breakthroughs by physicists Ronald W.P. Drever, Kip S. Thorne and Rainer Weiss led to the development of an experiment that finally sensed gravitational waves. In 2015, the Laser Interferometer Gravitational-Wave Observatory, or LIGO, registered the slightest of jolts, just one-ten-thousandth the diameter of an atomic nucleus, as passing gravitational waves locally warped space-time. The distinctive signature of the waves showed they had emanated from the collision of a pair of monstrous black holes, 1.3 billion light-years away.
LIGO made this historic detection a century after Einstein unveiled general relativity. A second detection of merging black holes followed in December 2015. Never before had these sorts of events been discernible to science, demonstrating how LIGO has opened a whole new window on the exploration of the universe.
“For the direct detection of gravitational waves,” Drever, Thorne and Weiss will receive the 2016 Kavli Prize in Astrophysics.
Science writer Adam Hadhazy hosted a roundtable discussion with the laureates:
KIP S. THORNE – The Feynman Professor of Theoretical Physics at the California Institute of Technology.
RAINER WEISS – Emeritus Professor of Physics at the Massachusetts Institute of Technology (MIT) and a member of the MIT Kavli Institute for Astrophysics and Space Research.
Ronald W.P. Drever was not available to participate in the conversation, due to illness. The conversation has been amended and edited by the laureates.