Spinning black holes

ScienceNow: Hurricane Katrina had nothing on GRS1915. This black hole seems to be rotating at least 950 times per second, hundreds of thousands of times faster than Katrina. The measurement marks the first time astronomers have been able to quantify the spin of a black hole so directly, and the findings could bring physicists closer to verifying the source of elusive cosmic phenomena known as gamma-ray bursts.