time dilation

noun

Definition of time dilation

: a slowing of time in accordance with the theory of relativity that occurs in a system in motion relative to an outside observer and that becomes apparent especially as the speed of the system approaches that of light — called also time dilatation

Recent Examples of time dilation from the Web

There is a phenomenon of relativity known as time dilation, in which time appears to slow down almost to a stop for bodies that approach the speed of light.

— jerry adler, Newsweek, "Stephen Hawking, Master of the Universe: Our 1988 Cover Story on the Legendary Physicist," 14 Mar. 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'time dilation.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.