Defensive vs iRelativity

Official Defensive Driving School mobile app. View upcoming lessons and schedule your next behind the wheel, observation or classroom session.

Every time you move, time passes slightly slower for you than for someone standing still. That's not science fiction — it's special relativity, and it's happening to you right now. iRelativity uses your real GPS speed to calculate exactly how much time dilation you're experiencing. Every trip, every commute, every flight adds a tiny slice of time to your lifetime total. The faster you travel, the more you save. Features • Live time dilation — your phone's GPS feeds real velocity into the Lorentz equation in real time • Lifetime total — watch your accumulated time saved grow across every journey, displayed in the most readable unit from femtoseconds up to seconds • Daily history — a chart of how much time you've saved each day • Global leaderboard — compare your lifetime total with other travellers via Game Center • What-if simulator — drag a slider toward the speed of light and see what time dilation would feel like at 0.9 c • Learn tab — interactive animations of the light clock and Einstein's train thought experiment, with a Lorentz factor calculator The numbers are real. At highway speeds you save about a nanosecond per hour. Board a plane and that climbs to microseconds. The physics is identical to the corrections that keep GPS satellites accurate every day.