Without Einstein, GPS Would Fail in Hours

Your phone doesn't find you with a map. It finds you by listening to clocks falling around the Earth, and those clocks only work because engineers deliberately built them wrong on the ground. In this video: how a GPS signal turns time into distance, why it takes four satellites (not three), and the relativity correction hidden inside every GPS satellite: 10.22999999543 MHz instead of 10.23. Chapters 0:00 Satellites shouting the time 0:37 The signal 2:07 The geometry 3:53 Relativity 5:51 The hidden machine 7:22 What the blue dot is really doing Sources GPS interface specification IS-GPS-200N (clock frequency offset, relativistic correction): https://gps.gov/sites/default/files/2... Neil Ashby, "Relativity in the Global Positioning System," Living Reviews in Relativity (2003): https://doi.org/10.12942/lrr-2003-1 GPS.gov: space segment https://www.gps.gov/space-segment / accuracy https://www.gps.gov/gps-accuracy / Selective Availability https://www.gps.gov/selective-availab... / timing https://www.gps.gov/gps-and-telling-time U.S. Coast Guard Navigation Center, constellation status: https://www.navcen.uscg.gov/gps-const... NIST/RTI, Economic Benefits of GPS (2019): https://www.nist.gov/news-events/news... Music "Machinery of the Stars" by Scott Buckley - released under CC-BY 4.0. www.scottbuckley.com.au "Tears In Rain" by Scott Buckley - released under CC-BY 4.0. www.scottbuckley.com.au Image credits (public domain unless noted) Albert Einstein, 1921: Ferdinand Schmutzer Sputnik 1: NASA/NSSDC / Transit 1B: U.S. Navy / NTS-2: U.S. Navy/NRL Col. Bradford Parkinson: U.S. Air Force / Block I solar array test: U.S. Air Force KAL 007 flight path: U.S. Navy salvage report / Selective Availability data: NOAA NGS / gps.gov Schriever SFB / 2nd Space Operations Squadron: U.S. Space Force (Lekendrick Stallworth), U.S. Air Force (A1C Mike Meares, Staff Sgt. Robert Cloys) Earth textures: NASA Visible Earth (Blue Marble NG, Black Marble 2016) 3D satellite and graphics are computer-generated illustrations; the satellite is Block III-style, not an exact model. Narration: AI voice. #GPS #Einstein #Science