Gravitational waves as tiny ripples in time and space have been detected for the second time. Gravitational waves were formed as a result of the merger of two black holes. The latest discovery has come just four months after the same group of scientists detected the gravitational waves for the very first time.
The discovery in which more than 1,000 scientists and over 90 universities across the globe were involved has been confirmed after many months of analysis. The LIGO Scientific Collaboration has made the discovery.
For the first time, gravitational waves were detected by Albert Einstein in 1916 in his theory of relativity. As per Professor Susan Scott, both the detections have confirmed Einstein’s theory. With the detection, now scientists can test the theory in the extreme parts of the universe through black hole collisions.
“With this second event we can close the lid on his theories and now embark upon the era of gravitational wave astronomy … it really has opened up this window on to the universe and we can now map more of [it] than ever before”, said Scott.
On the Boxing Day Event in 2015, collision of two black holes that were eight and 14 times the size of the sun took place. The collision took place around 1.4 billion years ago in a farther galaxy. Dr. Robert Ward from the ANU Research School of Physics and Engineering (RSPE) was of the view that gravitational waves are a novel way for them to study the universe.
The detection of the gravitational waves for the second time was possible due to the analysis of specially developed software. The signal of the second event lasted for an entire second, 10 times longer than the first, which allowed researchers to have more information about the behavior of two black holes.
“Gravitational waves are the ripples in the pond of space-time. The gravity of large objects warps space and time, or “space-time” as physicists call it, the way a bowling ball changes the shape of a trampoline as it rolls around on it. Smaller objects will move differently as a result — like marbles spiraling toward a bowling-ball-size dent in a trampoline instead of sitting on a flat surface,” according to a news report published by Washington Post.
The second detection event, like the first, caught the gravitational waves produced when two black holes collided and merged. But this event was much smaller: The first event involved black holes that were 29 and 36 times as massive as the sun, while this new collision, which took place 1.4 billion years ago, brought together black holes of 8 and 14 solar masses. Although the resulting signal was weaker, scientists from LIGO and Virgo — a similar facility in Europe — have confirmed the signal’s validity with a confidence level of over 99.99 percent.
According to a story published on the topic by IB Times, “The discovery was made by the LIGO Scientific Collaboration. The ANU scientists helped in developing some of the crucial technologies used in the Advanced Laser Interferometer Gravitational-Wave Observatory (aLIGO) in the United States that made the first detection. The ANU scientists made significant other contributions including data analysis methods and techniques that squeeze laws of quantum mechanics and stabilising sensitivity systems.”
That “gravitational waves are our newest way to observe the universe.” University of Western Australia’s professor David Blair termed the discovery “fantastically significant.” “So you have to see more to get some idea of how many signals are out there and to get an idea of what we can expect in the future as we improve the detectors. This signal tells us that there’s going to be a flood of gravity wave signals coming in the next few years as the detectors are improved.”
A report published in CS Monitor revealed, “LIGO was developed with the hope of being an observatory, not just a one-time discovery of gravitational waves,” Lawrence Krauss, a theoretical physicist and cosmologist at Arizona State University, who wasn’t part of the LIGO team. And this second detection of gravitational waves means it will fulfill that goal. “It confirms what I have said before,” Dr. Krauss says, “That gravitational wave astronomy will be the astronomy of the 21st century.”
“We are learning a lot about the universe in a way we didn’t before.” “We didn’t have access to this dark universe because we don’t see it with electromagnetic radiation. Now we begin to see it with gravitational waves.” Until now, scientists have used telescopes to detect light, or electromagnetic waves, traveling through space in order to learn about our universe. But things like black holes don’t emit light. LIGO heralds the beginning of a new field of astronomy, says Krauss, offering “a new kind of telescope that sees part of the universe that is otherwise invisible.”
Scientists have been using Einstein’s predictions to create models of how gravitational waves should work for decades. And “it’s just jaw dropping” how accurate these models have proven to be, Natarajan says. “The fact that our measurements are at the level that we can exactly match, to such a high degree of accuracy, this theory that came out of Einstein’s pure thought … it’s just astounding.”