Physicists at the LIGO (Laser Interferometric Gravitational Observatory) first recorded gravitational waves - space-time perturbations predicted a hundred years ago by the creator of general relativity, Albert Einstein. Scientists of the Faculty of Physics, who are members of the LIGO international collaboration, announced the opening during a live broadcast organized by Lenta.ru and the Mikhail Lomonosov Moscow State University (MSU).
Gravitational waves were recorded on September 14, 2015 at 05:51 a.m. ET (13:51 p.m. ET) at two twin detectors of the LIGO laser interferometric gravitational wave observatory located in Livingston, Louisiana and Hanford, Washington) in the USA. The LIGO detectors detected relative fluctuations of ten to minus 19 meters (roughly equal to the ratio of the diameter of an atom to the diameter of an apple) of pairs of test masses spaced four kilometers apart.
Disturbances are generated by a pair of black holes (29 and 36 times heavier than the Sun) in the last fractions of a second before they merge into a more massive rotating gravitational object (62 times heavier than the Sun). In a fraction of a second, about three solar masses turned into gravitational waves, the maximum radiation power of which was about 50 times greater than that from the entire visible Universe. The merger of black holes happened 1.3 billion years ago (for so long the gravitational disturbance spread to the Earth).
Analyzing the moments of arrival of signals (the detector in Livingston recorded the event seven milliseconds earlier than the detector in Hanford), the scientists assumed that the signal source was located in the southern hemisphere. Scientists sent the research results for publication in the journal Physical Review Letters. The discovery was made jointly by the LIGO collaborations (which also includes the GEO collaboration with the Australian Consortium for Interferometric Gravitational Astronomy) and the Franco-Italian VIRGO, whose detector is located near Pisa.
The LIGO observatory is funded by the US National Science Foundation and built on the initiative of American physicists Kip Thorne and Ronald Driever, proposed in 1980. The installation cost is estimated at $ 370 million. Research at LIGO is carried out as part of a collaboration of the same name by more than a thousand scientists from the United States and 14 other countries, including Russia, represented by two groups from Moscow State University and the Institute of Applied Physics of the Russian Academy of Sciences (Nizhny Novgorod).
The Moscow group was created and until recently headed by Vladimir Braginsky, one of the pioneers of gravitational-wave research in the world. The scientific group, included in the number of co-authors of the scientific discovery, includes seven employees of the Department of Physics of Oscillations of Moscow State University, including the head of the team, Valery Mitrofanov. The group has been involved in the project since 1992 and is dedicated to improving the sensitivity of gravitational wave detectors and defining its fundamental quantum and thermodynamic limitations.
The theoretical and experimental studies of physicists from the Moscow State University were embodied in the creation of new-generation detectors that made it possible to directly observe gravitational waves from the merger of two black holes. In the course of the group's work on the LIGO project, results were obtained that are important not only for the search for gravitational waves, but also for physics in general. “The scientific significance of this discovery is enormous. As in the case of electromagnetic waves, we will become fully aware of it after a while,”said Mitrofanov.