How GPS Knows Exactly Where You Are (and Why Einstein Matters)

Your phone finds you to within a few yards, using signals from satellites more than 12,000 miles away. Those satellites never hear from you, and their clocks run fast because of Einstein. Here's how GPS actually works, in plain English. Plus: the US used to blur civilian GPS on purpose. Chapters 0:00 Your phone is listening to clocks in space 0:18 How does GPS find you? 0:33 The satellites (and why they never hear you) 1:12 The one message every satellite sends 1:24 Time is distance: the lightning trick 1:55 Trilateration: Chicago, Atlanta, New York… Nashville 2:26 Why you need four satellites, not three 3:03 Einstein's correction: 38 microseconds a day 3:47 Why your blue dot jumps in Manhattan 4:21 GPS used to be blurred on purpose 4:47 Recap Sources GPS.gov, Space Segment: https://www.gps.gov/space-segment GPS.gov, GPS Accuracy: https://www.gps.gov/gps-accuracy GPS.gov, Selective Availability: https://www.gps.gov/selective-availab... GPS.gov, Civilian Benefits of Discontinuing Selective Availability: https://www.gps.gov/news/civilian-ben... GPS.gov, What Is GPS?: https://www.gps.gov/what-gps US Coast Guard Navigation Center, GPS overview: https://navcen.uscg.gov/global-positi... NIST, How do you measure your location using GPS?: https://www.nist.gov/how-do-you-measu... National Weather Service, Understanding Lightning: Thunder: https://www.weather.gov/safety/lightn... GPS World, GPS and relativity: https://www.gpsworld.com/inside-the-b... Everyday Circuits explains the tech you use every day, in a few minutes. New explainer every week. Music and sound: original tracks made for Everyday Circuits. Narration voice: AI text-to-speech (Kokoro). Thumbnail and all visuals: original flat-vector animation drawn in code for Everyday Circuits. #GPS #HowItWorks #EverydayCircuits