解析库 > Kaplan
According to Einstein's theory of general relativity, objects at different gravitational potentials or observers in motion experience variability in the speed of time. Where gravity is stronger, time moves more slowly; similarly, as an object's speed increases, its relative rate of time passage decreases. Atomic clocks moving at high velocities, such as on airplanes, or at high physical elevation have demonstrated these shifts in time. Even short distances, such as an upstairs bedroom or minor speeds, such as 10 meters per second, can demonstrate variance in the speed of time. This would appear to apply to normal biological processes: one's feet age more slowly than one's head as one's feet are more affected by Earth's gravitational pull. Living at higher altitudes, whether in mountains or in the penthouse of a skyscraper, also ages a body faster than spending more time closer to the ground. Objects in motion, even at a casual pace, would appear to a stationary observer to age more slowly as well. However, although the difference in perceived time is measurable, it is very small-about 100 nanoseconds over 100 years, so it's unlikely to entice anyone to give up their top floor corner office or mountaintop cabin to avoid a wrinkle or gray hair before its natural time.