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The Laser Interferometer Gravitational-Wave Observatory (LIGO) in the United States has detected gravitational waves for the first time. This is one of the most important astrophysical observations since the discovery of the Cosmic Microwave Background.

“We have detected gravitational waves. We did it!” said Daivd Reitze, Executive Director of the LIGO Laboratory at the California Institute of Technology, at a press conference announcing the discovery

Gravitational waves are a prediction of Einstein’s Theory of General Relativity. According to Einstein, gravity bends space-time, and the more massive an object is, the larger the effect. When massive objects move they create an oscillation in space-time, gravitational waves, a bit like the waves that form in front of a moving ship.

The gravitational waves were observed on September 14, 2015, and they were produced by a pair of merging black holes, one of the few events thought powerful enough to produce gravitational waves that we can detect. The two objects are about 150 kilometers (95 miles) across and merged 1.3 billion years ago. They had similar masses, one weighing 36 times the mass of the Sun and the other 29. The discovery has a statistical significance of 5.1 sigmas, meaning that there’s only 1 chance in almost 6 million that the result is a fluke. The results will be published in the journal Physical Review Letters.

The power released by the merging black holes was equivalent to 50 times the power of all the stars in the visible universe. In those 20 milliseconds, the energy of the waves was equivalent to annihilating the mass of three Suns...

Gravitational Waves Have Been Detected For The First Time | IFLScience

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