When scientists with the LIGO experiment announced on Thursday that they had finally detected gravitational waves directly, it confirmed Albert Einstein’s general theory of relativity and gave researchers a completely new tool for studying the universe and its origins, two University at Buffalo physicists say.
“Being able to detect gravity waves opens an entirely new window in astronomy,” says Will Kinney, professor of physics in the UB College of Arts and Sciences. “It’s like being able to see a new kind of light. Gravity wave telescopes will allow us to observe directly entirely new phenomena that have been inaccessible to us previously.”
“We can now study black holes and other violent events in our universe — like mergers of very massive and dense stars — directly,” says Dejan Stojkovic, UB associate professor of physics, who has done theoretical research related to black holes. “In the past, we’ve had to rely on light that is coming from these events. Now we can study them directly through gravity waves, even if they do not emit any light.”
Perhaps even more importantly, gravitational waves could enable scientists to explore the very early stages of the universe, Stojkovic says.
These stages are impossible to study with light because the very early universe was “so hot and dense that it was opaque to light,” he says. But gravitational waves can freely propagate through the hot plasma of the very early universe, so scientists can use them to gain insight into what occurred during that otherwise invisible time.
“We have a completely new tool to study the universe and answer questions which were not answerable so far,” Stojkovic says.
A Triumph for Einstein’s Theory
In addition to opening new research avenues, the big discovery announced Thursday is also significant because it confirms Einstein’s general theory of relativity.
“Gravity waves are a basic prediction of Einstein’s theory of general relativity, which is the theory that describes gravity. So if they weren’t there, there would be something fundamentally wrong with our basic understanding of how gravity works,” Kinney says.
Though gravitational waves had been detected indirectly before, Thursday’s announcement marked the first direct observation.
The discovery was exciting news for physicists around the world, and the best science is yet to come, Kinney says: “This will allow us to directly study the physics of black holes, neutron stars and other astrophysical objects, and will almost certainly produce surprises — things that we had no idea were there.”
