On Feb. 11, an international team of physicists at the Laser Interferometer Gravitational-Wave Observatory (LIGO) announced the discovery of gravitational waves. Dr. Josh Willis, an associate professor of physics at Abilene Christian University (ACU), as well as an ACU undergraduate student and two ACU graduates, contributed to the research.
In 1915, Albert Einstein proposed in his theory of general relativity that violent events in space (such as colliding stars and black holes) create ripples in the universe called gravitational waves. This prediction was the last one to be proved to confirm his theory, and provides a new way to view the universe.
“So, the big announcement is that it’s the first time we’ve seen gravitational waves, but we’re at least as excited about what else we’ll see — how many systems like this are out there, how far away they are, how massive they are, things like that,” said Dr. Willis said in a press release.
Since 2014, Dr. Willis has been one of the senior lead developers for an online database the detects and studies signals from gravitational waves. The database, PyCBC, was used for the discovery.
According to LIGO spokesperson Gabriella Gonzalez, the first signal detected from the waves was seen on Sept. 14 of last year, and it was the result of two black holes that collided and merged around 1.3 billion years ago.
“The gravitational waves that were first spotted originated from more than 1 billion light years away, when multicellular life here on Earth was just beginning to spread,” Gonzalez said in LIGO’s press conference in Washington, D.C.
According to Gonzalez, the LIGO team was able to measure the tiny gravitational wave by using two laboratories at the same time — one in Livingston, Louisiana, and one in Hanford, Washington.
“The waves are so small that if you only saw the tiny distortion in one lab, you wouldn’t be able to believe they were real,” Gonzalez said.
According to Murray, the fact that the signals were discovered in two different locations makes the discovery much more convincing.
Andrew Miller, a 2014 ACU graduate, also worked on the development of the PyCBC code. ACU graduate Marisa Walker is working towards her Ph.D. at Louisiana State University (LSU) while working for LIGO. Hannah Hamilton, a current senior and physics major at LSU, also was involved in data analysis.
“This first observation is important not only in and of itself, but because it represents the dawn of a new kind of astronomy,” Willis said in a press release.
Another significant part of this discovery is that this is the first time scientists ever actually detected a black hole.
“We have had evidence that black holes exist in the past, but they were indirect,” said Harding University physics professor Dr. Lambert Murray said.
According to Willis, the discovery of the gravitational waves has allowed for a new breakthrough in recording events in space.
“We have been able to see the universe, but not yet hear it, and now we can,” Willis said in a press release. “This will allow us to observe dramatic events in the universe that may not be visible to telescopes, and to learn directly properties of such events that can be hard to measure.”
Dr. Stephen Barber, a Harding University physics professor said the discovery of the waves might lead to new discoveries and observations as a result of the research conducted.