How black holes happen

How do black holes form?

Astronomers using supercomputers at the Max Planck Institute for Gravitational Physics in Germany recently simulated one, the New York Times reports.

The simulation, led by Luciano Rezzolla of the Institute of Theoretical Physics in Frankfurt, took six weeks to complete, with two neutron stars 11 miles apart orbiting each other and eventually colliding.

According to Dennis Overbye, the Times' cosmic affairs correspondent, it took just seven milliseconds "for the larger star’s gravity to rip apart the smaller star and unwind it into a spiral resembling flaming toothpaste writhing with magnetic fields and begin munching up the gas."

The neutron stars, believed to be the universe's densest stable form of matter, then collapse into a black hole, and the resulting gamma ray burst is "the final step in the series of transformations by which stars shrink and slump from blazing glory to oblivion, winding up as bottomless deadly dimples in the fabric of space-time."

Overbye described the supernova, which he says was witnessed by the inhabitants of New Mexico's Chaco Canyon in 1054, as "one of the great catastrophes in the history of our galaxy."

Astronomers believe such gamma-ray bursts happen once a day, with the closest ever measured at a distance of 119 million light-years from Earth. Which is good, Overbye writes: "If one happened nearby, in our own galaxy, we could be swathed with radiation."