LIGO's Second Detection Of Gravitational Waves From 2nd Pair Of Black Holes

The Laser Interferometer Gravitational-wave Observatory (LIGO) announced on June 15, 2016, that the second pair of colliding black holes has been detected.

Gregory Harry, the associate professor of Physics at American University and a LIGO Scientific Collaboration Member stated that this second detection of gravitational waves implies that black holes are much more common in the universe than previously believed and clearly come together in pairs. With this, the researchers do not completely understand. He further said that the black holes in this second event have lower masses than in the first detection. He added that these lower masses allow for a stricter test of Einstein's theory of gravity.

LISTEN: @AmericanU's Gregory Harry on black holes and gravitational waves: https://t.co/pen8B6ouBp pic.twitter.com/f7gPdZmnVz

— WAMU 88.5 News (@wamu885news) June 16, 2016

LIGO detected the first gravitational waves earlier this year. The second detection has a rotation to one of the black holes. This can help with a greater understanding of the origin and evolution of black holes. The historic first detection of gravitational waves was announced on February 11, 2016. This has been called the beginning of the new field of science called gravitational wave astronomy, wherein the universe can be studied using gravity as well as light. The detection of gravitational waves was predicted by Einstein 100 years earlier.

LIGO uses lasers to measure accurately the position of mirrors separated from each other by 4 kilometers, which is about 2.5 miles. It detected the gravitational wave appeared at the two detectors the same time. This indicated that the source was located somewhere in a ring of sky about midway between the two detectors. They also observed that two merging black holes were less massive. They also noticed that one of the initial black holes was spinning like a top. This suggests that this object has a different history.