Charting the Cosmos at RIT's CCRG
by Kristin Grant | published Dec. 20th, 2017
Lately, exciting announcements seem to pour out regularly from RIT’s Center for Computational Relativity and Gravity (CCRG). Just this past semester on Oct. 17, the team discovered that their contributions helped confirm the first detection of gravitational waves produced by dual neutron stars.
“This is the beginning of the new scientific era: multi-messenger astronomy. It’s here,” said fourth year Physics major Monica Rizzo, who has been working with the CCRG since her first year at RIT.
Now, if you’re anything like me — a third year Industrial Design student — you might be excited for Rizzo, but have absolutely no idea what any of that means.
In order to start answering some of those questions, it’s helpful to have a baseline understanding of what the CCRG studies in the first place.
The Gravity of the Matter
“What we do here at the CCRG has everything to do with gravity, and strong gravity in particular — which you will find near black holes and neutron stars,” explained CCRG Director Dr. Manuela Campanelli. “It has to do with violent phenomenon, a lot of matter condensed in small places, moving really fast.”
Over the past couple years, the CCRG has been an essential member of the LIGO-VIRGO Collaboration, a global team of engineers and scientists looking to investigate and detect gravitational waves.
While that already sounds impressive, it is even more so considering that Einstein — the very man who theorized the existence of gravitational waves — believed that the human race would never be able to detect them.
These waves (ripples in the very fabric of the universe) are caused by masses in space. Some, like black holes and neutron stars, generate larger waves than others. Yet even the largest disturbances were long thought impossible to detect, as such phenomenon only cause the universe to expand and contract at just a fraction of an atom.
Nevertheless in 1992, the National Science Foundation decided to take a huge risk and fund the Laser Interferometer Gravitational-Wave Observatory (LIGO), hoping the experiment would be able to detect these waves.
Quite unlike a traditional observatory, LIGO's methods are very much its own. Hyper-precision lasers are sent out in perpendicular directions. At the end of a 2.5-mile-long tube, powerful optical mirrors reflect these beams back to the source. If there were no gravitational waves, the two laser beams should return to the source with their wavelengths perfectly out of sync, resulting in a perfect cancellation. There would be no detectable light. If the lasers beams were effected by gravitational waves, however, their waves would not be perfectly misaligned and light would be detected.
In 2016, after years of inconclusive data, LIGO was able to detect a gravitational wave and pinpointed its source — a black hole some 1.3 billion light years away. Since then, LIGO has detected three more gravitational waves generated by black hole mergers. Now, with its European counterpart VIRGO, LIGO conclusively pinpointed the first detection generated by the collision of two neutron stars.
Neutron stars — collapsed cores of former stars, are incredibly dense bodies composed entirely out of neutrons. It was theorized for years that the collision of two such bodies would generate an intense gamma ray burst as well heavy elements such as gold and platinum. Now, thanks to the work done by the LIGO-VIRGO collaboration, these theories have been confirmed.
Current & Future Contributions by the CCRG
Even though RIT was not directly working at the observatory itself, the CCRG still contributed to these discoveries in a variety of fashions.
"We were one of the first teams that did the modeling for the black hole detection.”
“We have a team working on the actual analysis of the data itself and we have a team that works on modeling these phenomenon by solving Einstein's equations numerically,” said Campanelli.
The research conducted by the CCRG and their peers is not just limited to the realm of physics, however. These recent findings provide crucial information about the very elements we interact with everyday.
“We are all made of things that are a little bit heavier than hydrogen and helium. And these heavier elements are all generated within stars, and supernova, and now, thanks to this morning’s announcement, we now know neutron stars,” explained Campanelli. “A lot of people don’t realize that these elements are generated through this process.”
Campanelli also insisted that the technological innovation that went into producing these discoveries will have an effect on other industries.
“We’re measuring things that change at an amount smaller than the size of a proton,” Campanelli said. “The technology used for measuring these gravitational waves is just amazing. You need to invent very stable lasers, very sophisticated suspension systems, very pure optics and keep track of time very precisely.”
Rizzo and Campanelli are excited for what these breakthroughs could mean for the future of astrophysics as well.
“I’m honestly hoping for more binary neutron star detections — the more we have, the more we can say,” said Rizzo. “Right now, we can only say in very loose constraints what they’re made out of, or how they were formed.”
Campanelli is also eager to get RIT more involved in the LIGO development process.
"If you’re able to construct the third generation detectors, maybe a thousand times more sensitive than the current one, you can see all the black holes in the universe.”
“We want to participate more in the design of the next generation LIGO detectors,” said Campanelli. “We can already do a lot of things [with the current detectors], and then the next time we can do even more. Suddenly, if you’re able to construct the third generation detectors, maybe a thousand times more sensitive than the current one, you can see all the black holes in the universe.”
While the CCRG’s contributions to science are invaluable, Rizzo and Campanelli agreed that the lessons imparted to the RIT students working on these projects are also priceless.
“It’s an experience I don’t think I would have had anywhere else,” said Rizzo. “I feel ready to be a grad student. It’s a great learning experience because you learn how to problem solve, which is great skill to have no matter what field you’re going in.”
Campanelli concurred. “We’re doing cool stuff at the frontiers of science,” she said. “It’s absolutely motivating for a student, to be there and see something you would have never heard before, and didn’t understand before. That’s what the CCRG is doing.”