Deep Dive
How GPS Actually Works
13:53
In 1977, engineers building the first cesium clock for orbit added a hidden switch — a hedge, in case Einstein was wrong. He wasn't. That clock became part of GPS, and the relativity correction it proved is running inside the phone in your pocket right now. Turn it off, and GPS drifts into uselessness in about two minutes.
This episode teaches how GPS actually works — and why almost everything…