Neutron stars — the incredibly dense, weird remnants of stars more massive than the Sun — are like nothing on Earth. They occupy a corner of physics where strong gravity, high temperature, and intense nuclear forces combine. And when two neutron stars collide, they create some of the most powerful explosions in the cosmos, prosaically known as short-duration gamma ray bursts. My latest story in Nautilus explores the nature of these collisions, the history of our understanding of what they are, and why they’re important to the chemistry of the cosmos.

Collisions between neutron stars, by contrast, happen quite quickly, since each star’s mass is packed into a sphere roughly the diameter of an Earth city. (I speculate not on alien city sizes.) Instead of being made of atoms, they are a form of nuclear matter: neutrons and other particles jammed into a hot compact sphere. If supernovas are hydrogen bombs, then neutron-star collisions are particle colliders fit for gods. The amount of energy compressed and released in such short time is unrivaled in the cosmos. [Read more…]