February 11, 2016

Gravitational Waves Detected 100 Years After Einstein’s Prediction

The plots show signals of gravitational waves detected by the twin LIGO observatories.
The signals came from two merging black holes 1.3 billion light-years away.
The top two plots show data received at each detector, along with waveforms predicted
by general relativity. The X-axis plots time, the Y-axis strain—the fractional amount by
which distances are distorted. The LIGO data match the predictions very closely.
The final plot compares data from both facilities, confirming the detection. Credit: LIGO

(February 11, 2016)  LIGO opens new window on the universe with observation of gravitational waves from colliding black holes

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 September 14, 2015 at 5:51 a.m. Eastern Daylight Time (09:51 UTC) by both of the twin Laser Interferometer Gravitational-wave Observatory (LIGO) detectors, located in Livingston, Louisiana, and Hanford, Washington, USA. The LIGO Observatories are funded by the National Science Foundation (NSF), 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.

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