European satellite confirms general relativity with unprecedented precision

A space mission to test how objects fall in a vacuum has released its first results, providing an improved foundation for Einstein's famous theory. The first results of the 'Microscope' satellite mission were announced today by a group of researchers led by the French space agency CNES and including Imperial scientists. The findings are published in the journal Physical Review Letters . Launched in April 2016, the mission set out to test the 'equivalence principle', the founding assumption of Einstein's theory of general relativity. The theory poses that gravity is not a 'pulling' force, but is the result of large bodies, like the Earth, bending spacetime. As a result, when two objects are dropped in a vacuum under the same force of gravity, they fall at the same rate, no matter what their difference in weight or composition. This principle was demonstrated by Apollo 15 astronaut David Scott, who dropped a hammer and a feather on the Moon and showed them both reaching the ground at the same time.