Time dilation is not something that is directly experienced in everyday life. It is a phenomenon that is inferred through its effects on various observations and experiments. The effects of time dilation can be observed and measured in experiments conducted with precise clocks and high-velocity particles.
One of the most famous experiments that confirmed time dilation was the Hafele-Keating experiment in 1971. In this experiment, atomic clocks were placed on airplanes that traveled in opposite directions around the Earth. The clocks on the airplanes, which were moving at high speeds, were found to run at slightly different rates compared to synchronized clocks that remained at rest on the ground. This confirmed the predictions of time dilation based on the theory of relativity.
Additionally, time dilation is also inferred through its effects on light from distant celestial objects such as galaxies and stars. When light from these objects reaches us, it carries information about the time it took to travel from the source to our location. The immense distances involved and the effects of gravity can cause significant time dilation for these light signals. Scientists study the redshift or blueshift of light from distant objects, which indicates the relative motion and gravitational fields, allowing them to infer the presence of time dilation.
While we do not directly perceive time dilation in our daily lives, its effects have been observed and measured through experiments and the study of distant astronomical objects. These observations support the validity of the theory of relativity and our understanding of the nature of time.