"Einstein's Pedometer" App Measures How Special Relativity Affects Your Daily Activity

Runners live longer, so they say, and a new iPhone app proves it through the theory of special relativity. Just in time for marathon season!  As your velocity increases, time as you experience it slows down relative to something moving slower than you.  A passenger on a spaceship traveling near the speed of light would appear to have aged less than his friends when he returned to Earth, for instance. Similarly, a fast runner appears to gain time compared to a slow runner.  

Einstein’s Pedometer brings special relativity to your daily activities, showing how much time you gain by moving. The faster you move, the more nanoseconds you gain relative to your stationary friends.    Get the full story from PopSci