Gravitational Waves Detected 100 Years After Einstein's Prediction

LIGO has opened a new window on the universe with the 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.

LIGO was originally proposed as a means of detecting these gravitational waves in the 1980s by Rainer Weiss, professor of physics, emeritus, from MIT; Kip Thorne, Caltech's Richard P. Feynman Professor of Theoretical Physics, emeritus; and Ronald Drever, professor of physics, emeritus, also from Caltech.

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LIGO's Beginnings

LIGO, the most ambitious project ever funded by the National Science Foundation, consists of two L-shaped interferometers with four-kilometer-long arms; at their ends hang mirrors whose motions are measured to within one-thousandth the diameter of a proton. Managed jointly by Caltech and MIT, Initial LIGO became operational in 2001; the second-generation Advanced LIGO was dedicated on May 19, 2015. On September 14 at 2:51 a.m. Pacific Daylight Time, both of the twin LIGO detectors, located in Livingston, Louisiana, and Hanford, Washington, nearly simultaneously detected the characteristic "chirp" of the black holes' fusion.

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The collision of two black holes—an event detected for the first time ever by the Laser Interferometer Gravitational-Wave Observatory, or LIGO—is seen in this still from a computer simulation. Read more


These plots show the signals of gravitational waves detected by the twin LIGO observatories at Livingston, Louisiana, and Hanford, Washington. The signals came from two merging black holes, each about 30 times the mass of our sun, lying 1.3 billion light-years away. Read more

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Assets for the Media


View the Press Conference

from the National Press Club in Washington, D.C., February 11, 2016

The Science

On September 14, 2015, LIGO observed ripples in the fabric of spacetime. This video narrative tells the story of the science behind that important detection.

The History

This video narrative tells the story of the history and legacy of LIGO from the genesis of the idea to the detection in September 2015.

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