Sensitive search fails to find ripples in space, but boosts hopes for future hunts.Supernovas, such as the one which created the Crab Nebula, should send out bursts of gravity waves.NASA The hunt for gravitational waves may not have found the elusive ripples in space-time predicted by Albert Einstein, but the latest results from the most sensitive survey to date are providing clear insight into the origins and fabric of the Universe.General relativity predicts that gravitational waves are generated by accelerating masses. Violent yet rare events, such as a supernova explosion or the collision of two black holes, should make the...