For the first time, scientists have observed ripples in the fabric of spacetime called gravitational waves, arriving at the earth from a cataclysmic event in the distant universe. This confirms a major prediction of Albert Einstein’s 1915 general theory of relativity and opens an unprecedented new window onto the cosmos.
Gravitational waves carry information about their dramatic origins and about the nature of gravity that cannot otherwise be obtained. Physicists have concluded that the detected gravitational waves were produced during the final fraction of a second of the merger of two black holes to produce a single, more massive spinning black hole. This collision of two black holes had been predicted but never observed.
The gravitational waves were detected on Sept. 14, 2015 at 5:51 a.m. EDT by both of the twin Laser Interferometer Gravitational-wave Observatory (LIGO) detectors, located in Livingston, La., and Hanford, Wash. The LIGO Observatories are funded by the National Science Foundation and were conceived, built and are operated by Caltech and MIT. The discovery, accepted for publication in the journal Physical Review Letters, was made by the LIGO Scientific Collaboration (which includes the GEO Collaboration and the Australian Consortium for Interferometric Gravitational Astronomy) and the Virgo Collaboration using data from the two LIGO detectors.
‘Dreaming about this for a long time’
University of Chicago physicists played an important role in determining that the LIGO detectors had detected gravitational waves from the merger of two black holes. Three UChicago physicists are among the many co-authors of the study detailing the discovery.
For scientists at UChicago, the finding speaks powerfully to their field’s past and its exciting future.
“We’ve been dreaming about this for a long time,” said LIGO collaborator Daniel Holz, associate professor in physics at UChicago. “It’s our first time ever seeing something like this, and it truly opens up a new chapter in physics. You don’t get to do that very often.”