Our universe — or at least what scientists know about it — seemed to get a little larger earlier this month.

That’s when the Laser Interferometer Gravitational Wave Observatory, or LIGO, spotted two black holes merging 3 billion light years away from Earth.

How significant is this and what can we learn?

We turn to Brendan Mullan to find out. He is an astrophysicist and assistant professor of physics at Point Park University.