The Day the Universe Rang Like a Bell
On September 14, 2015, LIGO detected a ripple in spacetime from two black holes colliding 1.3 billion years ago. The story of how we learned...
Journal
Journal
Dead Stars That Tick Like Clocks and Outlast Civilizations
A collapsed star the size of a city, spinning hundreds of times per second, keeping time more precisely than atomic clocks. How pulsars work.