time dilation

American  

[tahym-dahy-lay-shuhn] / ˈtaɪm daɪˈleɪ ʃən /

noun

1. Physics. a difference in the rate at which time passes for one observer compared with another, depending on their relative motion or locations, especially where differing gravitational influences are present.

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time dilation British  

noun

1. the principle predicted by relativity that time intervals between events in a system have larger values measured by an observer moving with respect to the system than those measured by an observer at rest with respect to it

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time dilation Scientific  

1. The relativistic effect of the slowing of a clock with respect to an observer. In Special Relativity, a clock moving with respect to an observer appears to run more slowly than to an observer moving with the clock. In General Relativity, time dilation is also caused by gravity; clocks on the earth's surface, for example, run more slowly than clocks at high altitudes, where gravitational forces are weaker.

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time dilation Cultural  

1. In physics, the apparent slowing down of moving clocks that is predicted by the special theory of relativity. Time dilation is well verified experimentally.

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Example Sentences

Time itself passes differently at such distances -- a phenomenon known as cosmological time dilation.

From Science Daily • Nov. 7, 2025

Caffeine has a time dilation on it so it could be hours that I’m in there or 30 minutes.

From Los Angeles Times • Aug. 21, 2025

High-energy muons traveling at near–light-speed endure longer, for milliseconds, because of the time dilation predicted by Einstein’s theory of relativity.

From Science Magazine • Mar. 27, 2024

Quasars found in faraway galaxies ticked slower than ones born in the later, nearby universe, with time dilation making those most distant appear to run at a glacial one fifth of the standard speed.

From Scientific American • Jul. 19, 2023

You become compressed in the direction of motion, your mass increases, and time, as you experience it, slows down, a breathtaking consequence of traveling close to the speed of light called time dilation.

From "Cosmos" by Carl Sagan