An explosion that briefly released 50 times the power of all the stars in the observable universe traveled for 1.3 billion years and, on arrival at Earth, shifted a detector by a fraction of the width of a proton. This episode follows the century-long story of gravitational waves, beginning with Einstein's 1916 prediction from general relativity, Arthur Eddington's jab that they travel at the speed of thought, and Einstein's own 1936 attempt with Nathan Rosen to disprove them, which collapsed after an anonymous referee, Howard Percy Robertson, found the flaw in the math.

We cover Richard Feynman's sticky bead argument at the 1957 Chapel Hill conference that settled whether the waves carry real energy, the quadrupole asymmetry rule illustrated by a tumbling dumbbell, and the 1974 Hulse-Taylor binary pulsar whose orbital decay matched Einstei ...