📍 How does GPS know exactly where you are?

Your phone listens to signals from at least 4 satellites orbiting Earth. Each satellite carries an atomic clock and timestamps its signal.

Your receiver measures tiny differences in arrival time → calculates distances → uses trilateration to pinpoint your location.

And here’s the best part: Einstein’s relativity matters. Without correcting for relativistic time differences, GPS would drift by ~10 km per day.

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