The 2016 Kavli Prize in Astrophysics has been awarded to the three founders of the Laser Interferometer Gravitational-Wave Observatory (LIGO): Caltech's Ronald W. P. Drever, professor of physics, emeritus, and Kip S. Thorne (BS '62), the Richard P. Feynman Professor of Theoretical Physics, Emeritus; and MIT's Rainer Weiss, professor of physics, emeritus.
The $1 million prize, presented once every two years, honors the three for their instrumental role in establishing LIGO, an effort that led to the direct detection of gravitational waves—ripples in the fabric of space and time predicted a century earlier by Albert Einstein's general theory of relativity. On February 11, 2016, the international LIGO team announced the first observation of gravitational waves arriving at Earth.
The waves were generated 1.3 billion years ago when two black holes spiraled around each other and ultimately merged to form a single, more massive black hole. The twin LIGO instruments—one in Hanford, Washington, and the other in Livingston, Louisiana—detected the waves by measuring changes to the lengths of their 4-kilometer-long arms as small as one one-thousandth the width of a proton.
"The detection of tiny ripples in space and time, set up when two black holes merged more than a billion years ago, is one of the most amazing feats of the century," says Fiona Harrison, the Benjamin M. Rosen Professor of Physics and the Kent and Joyce Kresa Leadership Chair of the Division of Physics, Mathematics and Astronomy. "The LIGO project is a marvel of precision measurement, engineering, and technical ingenuity. Its founders, Kip, Rai, and Ron, and the entire LIGO team, deserve credit for this amazing discovery."
The existence of gravitational waves was predicted by Albert Einstein's 1915 general theory of relativity, but it was not until the 1960s that technological and theoretical advances made detection even possible to consider. In the 1970s, Thorne founded a research group at Caltech to study the theory of gravitational waves. Weiss had developed a design for a gravitational wave detector; he and Thorne recruited Drever, one of the leading creators of gravitational-wave interferometer prototypes, to lead what would become LIGO.
On September 14, 2015, during the first observations with the newly upgraded Advanced LIGO interferometers, LIGO detected the first signal of gravitational waves.
"The lion's share of the credit for LIGO's gravitational wave discovery belongs to the superb 1000-member LIGO team, who pulled it off," said Thorne. "They have made Weiss, Drever and me look good. And my deep thanks go out, also, to the succession of outstanding LIGO directors who provided the leadership required for success—Robbie Vogt, Stan Whitcomb, Jay Marx, David Reitze, and especially Barry Barish. Barry designed and led the transformation of LIGO from the small R&D project that Weiss, Drever and I created into the wonderfully successful big-science project that it is today."
According to the Kavli award citation, "the direct measurement of the tiny space-time ripples required the sustained vision and experimental ingenuity of Drever, Thorne and Weiss, spanning most of the last 50 years, as individual scientists and later as intellectual leaders of a team of hundreds of scientists and engineers."
The LIGO Observatories are funded by the National Science Foundation (NSF), and were conceived, built, and are operated by Caltech and MIT. The LIGO discovery team consists of the LIGO Scientific Collaboration (which includes the GEO Collaboration and the Australian Consortium for Interferometric Gravitational Astronomy) and the European Virgo Collaboration. The NSF leads in financial support for Advanced LIGO. Funding organizations in Germany (Max Planck Society), the U.K. (Science and Technology Facilities Council, STFC) and Australia (Australian Research Council) also have made significant commitments to the project.
The Kavli Prizes, established in 2008 and awarded every two years, recognize scientists for their seminal advances in three research areas: astrophysics, nanoscience, and neuroscience. Each prize consists of a scroll, a medal, and a cash award. The Kavli Prizes are presented in cooperation and partnership with the Norwegian Academy of Science and Letters and the Norwegian Ministry of Education and Research.
Past Caltech winners of the Kavli Prize in Astrophysics include Mike Brown, the Richard and Barbara Rosenberg Professor and Professor of Planetary Astronomy, who received the Kavli Prize in 2012 for work that led to a major advance in the understanding of the history of our planetary system, and Maarten Schmidt, the Frances L. Moseley Professor of Astronomy, Emeritus, who was awarded the prize in 2008 for his seminal contributions to our understanding of the nature of quasars. Other Kavli Prize recipients include alumni David C. Jewitt (MS '80, PhD '83), cowinner of the 2012 Kavli Prize for Astrophysics; James Roger Angel (MS '66), cowinner of the 2010 Kavli Prize in Astrophysics; and Caltech trustee Richard H. Scheller (PhD '80), cowinner of the 2010 Kavli Prize in Neuroscience.
Written by Whitney Clavin