1972/07/14 by J. C. Hafele, Richard E. Keating · 2 citations
Physics and Astronomy · #Advanced Frequency and Time Standards #Atomic and Subatomic Physics Research #Cold Atom Physics and Bose-Einstein Condensates
paper · doi:10.1126/science.177.4044.168
openalex publication_date 1972/07/14 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/23
Four cesium beam clocks flown around the world on commercial jet flights during October 1971, once eastward and once westward, recorded directionally dependent time differences which are in good agreement with predictions of conventional relativity theory. Relative to the atomic time scale of the U.S. Naval Observatory, the flying clocks lost 59 +/- 10 nanoseconds during the eastward trip and gained 273 +/- 7 nanoseconds during the westward trip, where the errors are the corresponding standard deviations. These results provide an unambiguous empirical resolution of the famous clock "paradox" with macroscopic clocks.