When a massive star reaches the end of its life, it collapses into a sphere of unimaginable density, creating a neutron star. If the conditions are right, this stellar corpse begins to spin rapidly and emit beams of radiation, becoming a pulsar. This episode explores how these objects form, what they are made of, and how they serve as some of the most precise natural instruments in the universe.

I wanted to understand how the violent death of a star gives rise to something so remarkably constant. Pulsars rotate with the reliability of atomic clocks, and their predictable signals allow astronomers to probe the deepest questions in physics. By examining the history of their discovery, from Jocelyn Bell’s initial observations to the modern use of pulsar timing arrays, we can see how these dead stars are used to detect gravitational waves and s ...