For the second time, scientists have detected gravitational waves, or ripples in the fabric of spacetime.
The gravitational waves were detected by both of the twin Laser Interferometer Gravitational-Wave Observatory, or LIGO, detectors, located in Livingston Parish and in Hanford, Washington. Detection of the wave event was announced today.
The first detection of gravitational waves was announced on Feb. 11. Considered a milestone in the fields of physics and astronomy, the first detection confirmed Albert Einstein’s 1915 general theory of relativity.
The first detection also is significant because it marked the beginning of the new field of gravitational-wave astronomy.
Albert Lazzarini, deputy director of the LIGO Laboratory, says the second discovery “has truly put the ‘O’ for Observatory in LIGO.”
According to a news release, the second detection was made by the LIGO Scientific Collaboration, which includes the GEO Collaboration, the Australian Consortium for Interferometric Gravitational Astronomy, and the Virgo Collaboration using data from the two LIGO detectors.
Physicists have concluded that the waves were produced about 1.4 billion years ago during the final moments of the merger of two black holes that are 14 and 8 times the mass of the sun.
The black holes collided to produce a single, more massive spinning black hole that’s 21 times the mass of the sun.
“It is very significant that these black holes were much less massive than those observed in the first detection,” says Gabriela Gonzalez, LIGO Scientific Collaboration spokesperson and professor of physics and astronomy at LSU. “Because of their lighter masses compared to the first detection, they spent more time—about one second—in the sensitive band of the detectors. It is a promising start to mapping the populations of black holes in our universe.”
According to the news release, the LIGO Livingston observatory is located on LSU property. The university’s faculty, students and research staff are contributors to the 15-nation international LIGO Science Collaboration.
LIGO research is carried out by the LSC, a group of more than 1,000 scientists from universities across the U.S. and in 14 other countries.