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How GPS actually knows where you are

It sounds like magic, but your phone or car's GPS works using a bunch of satellites orbiting way up in space. Basically, at least 24 satellites are constantly flying around the Earth, beaming down radio signals with exact timestamps.

When your phone picks up signals from multiple satellites at once, it calculates how long the signal took to reach you. Since radio waves travel at the speed of light, your phone can figure out your exact distance from each satellite.

By combining distance data from at least four different satellites, your device uses a geometric trick called triangulation to pinpoint your latitude, longitude, and altitude right down to the meter.