Time dilation has been experimentally confirmed through various observations and measurements. Here are a few key experiments that provide evidence for the existence of time dilation:
The Hafele-Keating Experiment (1971): In this experiment, atomic clocks were flown on commercial airliners traveling eastward and westward around the Earth. The experiment aimed to test the predictions of time dilation due to differences in gravitational fields and relative velocities. The clocks that traveled at high speeds and experienced different gravitational forces were found to deviate from the reference clocks left on the ground, confirming the time dilation effect.
Muon Decay Experiment: Muons are elementary particles produced in the upper atmosphere by cosmic rays. Due to their short half-life, muons should decay before reaching the Earth's surface. However, in experiments conducted using particle accelerators and detectors, it was observed that muons created at high speeds in the Earth's atmosphere could reach the surface because of time dilation. The time dilation effect allowed the muons to survive longer than predicted by classical physics.
GPS Satellites: The Global Positioning System (GPS) relies on accurate time measurements to determine positions on Earth. The satellites in the GPS system have atomic clocks on board that are moving at high speeds relative to observers on the Earth's surface. Special and general relativity predictions are taken into account to correct for the time dilation experienced by the satellites. If this correction was not made, the GPS system would experience significant errors, leading to inaccurate position calculations.
These experiments and practical applications provide strong empirical evidence for the existence of time dilation. The effects of time dilation have been measured and confirmed with a high degree of precision, supporting the predictions made by Einstein's theory of relativity.