Listening in on the ‘Black Hole Blues,’ the soundtrack of the universe

February saw one of the most important astronomical breakthroughs of the decade, as a team of scientists “heard” gravitational waves -- a key postulate of Einstein’s theory of relativity -- for the first time in human history. Now, astrophysicist Janna Levin recounts that incredible discovery, and the human drama behind it, in her new book “Black Hole Blues.” Levin joins Jeffrey Brown for more.