Chad Hanna Professor of Physics Penn State

Gravitational wave detector LIGO is back online after 3 years of upgrades – how the world’s most sensitive yardstick reveals secrets of the universe

After a three-year hiatus, scientists in the U.S. have just turned on detectors capable of measuring gravitational waves – tiny ripples in space itself that travel through the universe. Unlike light waves, gravitational waves are nearly unimpeded by the galaxies, stars, gas…