The Guardian reports: Physicists have detected ripples in the fabric of spacetime that were set in motion by the collision of two black holes far across the universe more than a billion years ago.

The event marks only the second time that scientists have spotted gravitational waves, the tenuous stretching and squeezing of spacetime predicted by Einstein more a century ago.

The faint signal received by the twin instruments of the Laser Interferometer Gravitational Wave Observatory (LIGO) in the US revealed two black holes circling one another 27 times before finally smashing together at half the speed of light. [Continue reading…]