In a tour de force of technology and just plain stubbornness spanning half a century and costing more than $750 million, a team of experimenters from Stanford University reported on Wednesday that a set of orbiting gyroscopes had detected a slight sag and an even slighter twist in space-time.
The experiment was conceived in 1959, but the technology to make these esoteric measurements did not yet exist, which is why the experiment took so long and cost so much.