CERN's Large Hadron Collider is currently the biggest science experiment in operation, but it may have to pass that mantle on soon enough. A collaboration between NASA and the ESA plans to launch three spacecraft into orbit around the sun 3 million miles apart, then have them shoot lasers at each other, all in the name of proving the existence of gravitational waves, the last piece of Einstein's relativity theory that is as yet unproved.

Einstein's general relativity predicts several things, such as gravity's ability to bend time light and the constant speed at which gravity travels. But a means to prove the existence of gravitational waves -- huge ripples in time and space that flow outwards from the collision of huge celestial bodies like black holes -- has eluded scientists for years.