An Undergraduate Test of Gravitational Time Dilation

TL;DR

This study experimentally verifies gravitational time dilation by comparing GPS-based and cesium clocks at different elevations, confirming Einstein's predictions with observable effects at high altitudes.

Contribution

First undergraduate-level experimental test of gravitational time dilation using accessible equipment and multiple elevation measurements.

Findings

Time dilation observed at high altitude matches general relativity predictions.

Clocks at 4302 m elevation tick 41 ns/day faster than sea-level clocks.

Results support the practical implications for GPS accuracy.

Abstract

Students at Colorado College and cadets at the US Air Force Academy have conducted an experimental test of gravitational time dilation. This relativistic effect, highlighted in the movie Interstellar, causes clocks to tick more slowly near massive objects. A measurement of gravitational time dilation was made by comparing signals generated by a GPS frequency standard, which is based on sea-level time, to a cesium-beam frequency standard located at three different elevations above sea level. The effect is small but observable; for the highest elevation studied (4302 m on the summit of Pikes Peak), a local clock ticks only 41 ns/day faster than a sea-level clock. Our results are consistent with the predictions of general relativity. We also discuss implications of gravitational time dilation on GPS operations.