According to Einstein's theory of special relativity, the speed of light, denoted by "c," is a fundamental constant in the universe that remains constant in all inertial frames of reference. The theory introduces the concept of time dilation, which means that time can appear to pass differently for observers moving relative to each other at different speeds.
When an object or observer is in motion relative to another, time dilation occurs. As an object's velocity approaches the speed of light, time for that object slows down relative to a stationary observer. This effect is known as "time dilation."
Specifically, as an object's velocity increases, its time dilation factor, or "time dilation factor," increases. The time dilation factor, denoted by γ (gamma), is a function of the relative velocity between two observers or frames of reference. The equation for time dilation is:
t' = t / γ
Where: t' is the time interval observed by the moving observer. t is the time interval observed by the stationary observer. γ (gamma) is the Lorentz factor, given by γ = 1 / √(1 - (v^2/c^2)), where v is the relative velocity between the frames of reference.
This equation shows that as the relative velocity (v) approaches the speed of light (c), the denominator of the Lorentz factor approaches zero, leading to a larger value of γ. As a result, time dilation becomes more significant, and time appears to slow down for the moving observer relative to the stationary observer.
This phenomenon has been experimentally verified in various experiments, such as the famous Hafele-Keating experiment, which involved atomic clocks flown around the Earth. The experiment demonstrated that moving clocks experience a slight time dilation compared to stationary clocks.
It's important to note that time dilation is a relative effect, meaning that observers in different frames of reference will perceive time passing at different rates. From their own perspective, time would appear normal. Time dilation has practical consequences, such as the time differences experienced by astronauts in space travel compared to people on Earth, but it does not lead to any sort of time travel or arbitrary manipulation of time.