Without Einstein, your Google Maps would be wrong by 10 kilometers every single day. 🗺️ It turns out, GPS doesn't actually measure distance. It measures time. Your phone figures out where you are by calculating exactly how long the signal took to arrive from space. But here is where the physics gets messy…. The universe is constantly trying to break that calculation. Since GPS satellites are launching through space at 14,000 km/h, Special Relativity says their clocks should tick slower. But because they are floating 20,000 km above Earth in weaker gravity, General Relativity says they should tick faster. It’s a cosmic tug-of-war, and gravity actually wins. The net result is that time in space runs 38 microseconds faster than time here on Earth. That sounds like absolutely nothing, but light travels 300 meters in a single microsecond. If we didn’t code a correction for that drift, the entire global navigation system would be useless in 24 hours. Einstein isn't just a theory in a textbo...