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 and dust that fill the universe. This means that by measuring gravitational waves, astrophysicists like me can peek directly into the heart of some of these most spectacular phenomena in the universe.
