Peter Lott

Usually, black holes inch closer gradually, circling in a tightening spiral. This dance births a long ripple of gravitational waves — a tremor in the very fabric of spacetime. Detectors LIGO and Virgo routinely catch such mergers. But GW190521 is the exception.

The very first moment of the universe's existence is like a taut string suddenly struck. It vibrated, and those oscillations froze into galaxies and voids. But physicists suspect there were other vibrations — fast, local, almost like a drumroll against a slow melody.