Around-the-World Atomic Clocks: Predicted Relativistic Time Gains

Area of Science:

• Physics
• Experimental Physics
• Relativity

Background:

• Einstein's theory of relativity predicts time dilation effects due to velocity and gravity.
• Testing relativity with macroscopic, high-precision instruments like atomic clocks provides empirical validation.
• Previous tests often involved astronomical observations or particle accelerators.

Purpose of the Study:

• To experimentally verify Einstein's theory of relativity using macroscopic cesium beam atomic clocks.
• To measure time differences experienced by clocks during global travel.
• To compare observed time discrepancies with theoretical predictions.

Main Methods:

• Four cesium beam atomic clocks were flown on commercial jet flights around the world.
• Flights were conducted twice: once eastward and once westward.
• Clock times were compared to reference clocks at the U.S. Naval Observatory.

Main Results:

• The eastward-flown clocks showed a time loss relative to the reference clocks.
• The westward-flown clocks showed a time gain relative to the reference clocks.
• Observed time differences align with predictions from Einstein's theory of relativity.

Conclusions:

• The experiment provides macroscopic evidence supporting the predictions of Einstein's theory of relativity.
• Velocity-dependent time dilation effects were observed in cesium beam atomic clocks.
• This study demonstrates the feasibility of using commercial flights for relativistic experiments.