QnAs with Steven A. Balbus.

In early 2016, Oxford University astrophysicist Steven Balbus was filling in for a colleague, teaching a course on general relativity. Although not an expert in relativity before the course, Balbus felt growing admiration for Albert Einstein’s century-old theory. In February, during the course, Balbus and others around the world heard news out of the Laser Interferometer Gravitational-Wave Observatory (LIGO) that a clear signal of gravitational waves, described theoretically by Einstein, had been detected. The waves were thought to emanate from the merging of two black holes, and the discovery opened exciting possibilities of using gravitational waves to observe astronomical phenomena, much as light waves are used to observe astronomical objects through telescopes. Balbus, elected to the National Academy of Sciences in 2015, thought that the textbook method for deriving gravitational wave equations contained a level of mathematics that could be daunting to some students. His Inaugural Article puts forth a streamlined derivation (1). Balbus recently spoke to PNAS about his work.