One year ago, scientists with the Laser Interferometer Gravitational-Wave Observatory, known as LIGO, told the world about their revolutionary discovery of gravitational waves. The dramatic find confirmed a century-old prediction of Einstein’s theory of general relativity and promised to revolutionize how we explore the cosmos.
More than 1,000 researchers from 90 institutions worldwide were involved in the project, and UWM scientists played a critical role. They helped design and build LIGO’s computers, databases and programs, while also analyzing data that confirmed the gravitational wave discovery. Now, they’re turning their attention to what the discoveries reveal.
“It’s a fabulous feeling to know that we don’t have to worry about finding gravitational waves, so we can now focus on the science,” says Patrick Brady, a member of the LIGO team and director of UWM’s Leonard E. Parker Center for Gravitation, Cosmology and Astrophysics.
Just as light waves and radio waves offer distinct ways to observe the universe, gravitational waves give scientists a fresh way to see what’s out there. Observing the waves will produce data about celestial objects and cataclysmic events billions of light years away, opening doors to projects previously impossible with conventional telescopes.
“There’s lots of potential for just being surprised,” says Jolien Creighton, another Parker Center researcher and LIGO team member. “Like seeing something that violates the theory of general relativity or some other cherished principal of physics – just because we’re looking at the universe in a completely new way.”
During the next five years, the LIGO team expects to find hundreds of gravitational wave sources as LIGO’s instruments improve, and new techniques and observatories join the gravitational astronomy field. More sources of gravitational waves give scientists more data to examine and more envelopes to push.
“If we find that what we observe is not exactly as predicted by Einstein’s equations, that would be dramatic,” Brady says, noting that scientists might have to tweak the theory of general relativity.
Among the gravitational wave sources most want to observe are events involving neutron stars, the ultra-dense remnants left over when large stars go supernova. They’ve been studied with conventional telescopes, but there’s much more to learn. “We have no idea how matter behaves at that density,” Creighton says. “Neutron stars provide the only physical laboratory we have to study matter of this sort.”
In addition to Brady and Creighton, UWM’s LIGO efforts have been spearheaded by Parker Center researchers and LIGO members Alan Wiseman and Xavier Siemens. Overall, UWM’s involvement in the LIGO project has generated some $25 million in federal grants.