Scientists said in an historic announcement, on Friday that they have for the first time directly detected the existence of gravitational waves. David Reitze,
Executive Director of the U.S.based Laser Interferometer Gravitational-wave Observatory (LIGO), said in Washington that the gravitational waves which were predicted 100 years, ago by Albert Einstein's theory of general relativity, was one of the two pillars of modern physics.
"We did it."This was truly a scientific moon-shot. I really believe that. And we did it. We landed on the moon." Reitze said 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.
The director explained that gravitational waves were the last piece of Einstein's theory of general relativity that has yet to be proven. Reitze said signals from gravitational waves are so weak that Einstein himself questioned whether a device sensitive enough could be developed to capture this phenomenon.
He noted that the collision of two black holes had been predicted but never observed. “The gravitational waves were detected on Sept. 14, 2015, at 5:51 a.m. EDT (0951 GMT) by both of the twin LIGO detectors, located in Livingston, Louisiana; and Hanford, Washington.
“Based on the observed signals, LIGO scientists estimated that the black holes for this event were about 29 and 36 times the mass of the Sun, and the event took place 1.3 billion years ago. “About three times the mass of the Sun was converted into gravitational waves in a fraction of a second, with a peak power output about 50 times that of the whole visible universe,’’ he said.
Reitze recalled that in 1916, German-born theoretical physicist Einstein, predicted the existence of gravitational waves, or ripples in the fabric of space-time resulting from the most violent phenomena in our distant universe such as supernovae explosions or colliding black holes. “In 1974, two American scientists discovered a binary pulsar, a pair of two dead stars emitting pulses of radio waves.
“They later realised that the orbit of the pulsar was slowly shrinking over time because of the release of energy in a way Einstein's theory predicted: gravitational waves,’’. He said for discovering the pulsar and indirectly confirming the existence of gravitational waves, the two were awarded the 1993 Nobel Prize in Physics. Rainer Weiss, Professor of Physics from the Massachusetts Institute of Technology, said the new LIGO discovery was the first observation of gravitational waves themselves.
He said they were made by measuring the tiny disturbances the waves made to space and time as they passed through the earth. "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.
"It would have been wonderful to watch Einstein's face had we been able to tell him," he said. Weiss said the new discovery, has been accepted for publication in the journal Physical Review Letters. The journal was made by the LIGO Scientific Collaboration (LSC), a group of more than 1,000 scientists from universities around the U.S. as well as in 14 other countries. Lawrence Krauss, a Theoretical physicist at the Arizona State University, described the finding as "a huge milestone."
He said the discovery would open a new window on the universe, like the invention of the telescope or discovery of radio waves from space. Krauss added that the gravitational wave astronomy would be the astronomy of the 21st century. Gabriela Gonzalez, LSC Spokesperson and Professor of Physics and Astronomy at the Louisiana State University, echoed the same view.
He said the detection was the beginning of a new era and the field of gravitational wave astronomy is now a reality. "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. "Colliding black holes and gravitational waves are our first beautiful examples," he said.