Daniel Kasen

In August 2017, the LIGO gravitational antennas, built with the decisive involvement of Rainer Weiss, caught a shudder in spacetime from gravitational waves — the merger of two neutron stars.

When two neutron stars, the ultra-dense cores of dead stars, collide, a kilonova is born: an explosion a thousand times brighter than a typical nova. This is the universe's true smelting works. In the scorching cloud racing outward at near-light speeds, a furious flux of neutrons transmutes atomic nuclei into gold, platinum, osmium.