After weeks of rumors and speculation, a new study funded by the National Science Foundation has revealed that scientists have observed gravitational waves for the first time, confirming one of the major predictions of Albert Einstein's 1915 Theory of Relativity, and opening up a whole new way of astronomy. The findings arrive on the 100th anniversary of Einstein's initial, previously unconfirmed predictions.
The gravitational waves, which carry information not only about their origins but the nature of gravity, were detected on Sept. 14, 2015 by both of the twin Laser Interferometer Gravitational Wave Observatory (LIGO) detectors. Physicists believe that these waves were the product of the merger of two black holes and created in the final seconds of this process, which led to the creation of a single, massive spinning black hole. Although this kind of collision has been predicted in the past, this is the first time that it has ever been observed.
"Our observation of gravitational waves accomplishes an ambitious goal set out over five decades ago to directly detect this elusive phenomenon and better understand the universe, and, fittingly, fulfills Einstein's legacy on the 100th anniversary of his general theory of relativity," David Reitze, executive director of the LIGO Laboratory, said in a press release.
Analysis of the observed signals led LIGO scientists to estimate that the black holes involved in this event were about 29 to 36 times more massive than the Sun, and collided 1.3 billion years ago. Approximately three times the mass of the Sun was transformed into gravitational waves in fractions of a second, creating a peak power output that reached almost 50 times that possessed by the entire universe.
Einstein's Theory of General Relativity predicted that a pair of black holes orbiting each other lose energy due to the emission of gravitational waves, causing them to move closer to each other over billions of years and finally, much faster in their final minutes. During the last fraction of a second, a collision takes place at around half the speed of light and creates a larger black hole. However, a portion of the combined black holes' mass is converted into energy, which is the final strong burst of gravitational waves, and in this case the waves that LIGO observed.
"With this discovery, we humans are embarking on a marvelous new quest: the quest to explore the warped side of the universe - objects and phenomena that are made from warped space-time," said Caltech's Kip Thorne. "Colliding black holes and gravitational waves are our first beautiful examples."
The findings were published in the Feb. 11 issue of Physical Review Letters.
