How Time Flies; Scientific American Time; Special Editions; by John Matson; 2 Page(s)

If you have ever found yourself cursing a noisy upstairs neighbor, take solace in the fact that he or she is aging faster than you are.

Einstein’s general theory of relativity predicts that clocks at different gravitational potentials will tick at different rates—a clock at higher elevation will tick faster than will a clock closer to Earth’s center. In other words, time passes more quickly in your neighbor’s upstairs apartment than it does in your apartment.