The Laser Interferometer Gravitational-wave Observatory is back on the hunt for ripples in spacetime, months after reporting the first signature of a black hole collision in gravitational waves. After a series of upgrades, the LIGO detectors at Hanford in Washington state and near Livingston, La., made the transition from engineering test runs to science observations at 8 a.m. PT today. LIGO’s first detection of gravitational waves - a phenomenon that was predicted by Albert Einstein’s theory of general relativity back in 1915 - occurred during an engineering run in September 2015. But it took until February for the LIGO team to confirm the detection… Read More