Remember how hard it was to stay awake in high school physics lectures? Well, it’s time to wake up and listen–you’re about to get woke.
One hundred years ago, Albert Einstein proposed a groundbreaking theory, the general theory of relativity. Recently, the LIGO Scientific Collaboration (LSC), a group of scientists researching gravitational waves and their use in astronomy, confirmed Einstein’s theory: on Sep. 14, 2015, at approximately 5:51 a.m., the Laser Interferometer Gravitational-Wave Observatory, located partly in both Louisiana and Washington states, detected gravitational waves resulting from the collision of two black holes 1.3 billion years ago.
The theory of relativity itself describes gravity in a way where presence of matter can change the shape of space. Instead of thinking of a straight line between two points, the line is a curved path with the presence of matter.
LIGO was able to capture the sound of two colliding black holes a billion light-years away that proves the theory of Einstein. The captured tone is direct proof of gravitational waves. Gravitational waves, as explained by the California Institute of Technology, “are ‘ripples’ in the fabric of spacetime caused by some of the most violent and energetic processes in the Universe.” The strongest gravitational waves are made by large-scale events, like the collision of two black holes or the death of a stellar body.
Shana Tribiano, a professor of physics and astronomy and a Hayden Associate at the Museum of Natural History, explains how this recording is evidence of gravitational waves. “There is nothing else that could shift the interference pattern of light that is used to detect these waves by the amount and in the way that two merging black holes can.”
“The shift is tiny. The gravitational waves changed the distance that light traveled in the detector between two mirrors by merely 10-18 meters,” Tribiano explains. “And yet, this was a strong signal in the instrument corresponding to two stars that total over 60 times the sun’s mass, spiraling into each other at nearly the speed of light.”
To bring it down to earth, the two black holes orbiting around each other will lose energy through the gravitational waves, causing them slowly to move toward each other over billions of years. Over the last few minutes, this approach speeds up significantly. During the final second, the black holes collide into each other at a super speed and form a single, more massive black hole, converting a portion of the combined black holes’ mass to energy, according to Einstein’s formula E=mc2. This energy is emitted as a final strong burst of gravitational waves, which LIGO was able to capture.
This discovery leads to finally having a solid proven theory in physics, where some research can now be discarded and some can be further explored. Tribiano jokes that those who contested the theory might not be so employable now.
“Gravitational waves is a part of the prediction that many did not take seriously as being possible to measure for decades. Now it’s accomplished,” she triumphs along with LIGO. “And so now funding for making the instrument even more sensitive will bring a wave of further discoveries. The physics community worldwide can celebrate this discovery. It will probably win a Nobel Prize.”
David H. Reitze, executive director of the LIGO Laboratory, said in their press release after the recording was confirmed, “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.”
With this discovery, scientists can now move on into deeper research of warped spacetime. Now with the added ability to “listen” to the universe, instead of just observing it visually, there is a window for new discoveries. However, there are rarely–if any–flawless theories, and Einstein’s general theory of relativity still has not let the physicists down, which will only push new ways to test the theory.
In a Q&A for Columbia News, Michael Tuts, chair of Columbia’s Department of Physics, said, “the discovery of gravitational waves is on a par with the major discoveries of the last decade, like the Higgs Boson. It’s something that we’ve known–Einstein predicted it 100 years ago–but it’s taken us this long to finally be able to confirm it. Like the Higgs, I think this is Nobel-quality work.”
These new discoveries of gravitational waves will also help research black holes. As NASA explains, a black hole is a place in space where the gravitational pull is so intense that even light particles cannot get out. People cannot see black holes with a bare eye, only special telescopes that show how stars close to the black holes react and change their behavior due to the immense gravity.
Now that these ripples in space and time can help explore black holes, Imres Bartos, a Physics lecturer at Columbia, also joined the conversation and expanded on how this research impacts astronomical discoveries.
“Up to this point, we’ve only had indirect evidence that black holes exist at all,” Bartos says. “We want to use black holes as gigantic cosmic laboratories where we can test physics that was untestable before. Gravitational waves will help us put together all the puzzle pieces that we have about objects in the universe to get a more complete picture of what’s out there and increase our understanding of how the cosmos evolved.”
With a new chapter in astrophysical history just opened, science will just keep getting cooler. Maybe time travel isn’t that far away after all.