time dilation

time dilation

In the theory of special relativity, the “slowing down” of a clock as perceived by an observer in relative motion with respect to that clock. Time dilation becomes noticeable only at speeds approaching that of light and has been accurately confirmed by the apparent increased lifetime of unstable subatomic particles traveling at nearly the speed of light and by the precise timing of atomic clocks carried on airplanes. See also Lorentz-FitzGerald contraction.

This entry comes from Encyclopædia Britannica Concise.
For the full entry on time dilation, visit Britannica.com.

Seen & Heard

What made you look up time dilation? Please tell us what you were reading, watching or discussing that led you here.

Get Our Free Apps
Voice Search, Favorites,
Word of the Day, and More
Join Us on FB & Twitter
Get the Word of the Day and More