Year in review: Gravitational waves offer new cosmic views
Soon astronomers might detect black hole collisions as often as once a day
MAKING WAVES The first gravitational wave signal detected by LIGO came from the merger of two black holes spiraling inward, as depicted in this numerical simulation.
© S. Ossokine, A. Buonanno (Max Planck Institute for Gravitational Physics), Simulating eXtreme Spacetime project, D. Steinhauser (Airborne Hydro Mapping GmbH)
The secrets gleaned from the universe’s most mysterious giants are incongruously subtle when witnessed at Earth: Detectors budge by a tiny fraction of a proton’s breadth, outputting a feeble, birdlike chirp.
For centuries, astronomers have peered out into the universe almost exclusively by observing its light. But 2016’s announcement of the first detection of gravitational waves, produced 1.3 billion years ago in the collision of two monstrous black holes, has given scientists a whole new way of observing the heavens.
The waves tore through the cosmos at the speed of light and arrived at Earth just in time for the start-up of the Advanced Laser Interferometer Gravitational-Wave Observatory, LIGO, which measured the minute stretching and squeezing of space. With a second