Gravitational Redshift

Confirmation of gravitational redshift.

  • Test of Relativistic Gravitation with a Space-Borne Hydrogen Maser
    • Vessot, et al.
    • August 1980
    • https://doi.org/10.1103/PhysRevLett.45.2081
    • “We conclude from our results that the relativistic and gravitational factors affecting the frequency of the observed signals and governing the velocity of light are consistent with theory at the 70 x 10-5 level of accuracy.”
  • Gravitational Redshift Test Using Eccentric Galileo Satellites
    • Delva, et al.
    • May 2018
    • https://doi.org/10.1103/PhysRevLett.121.231101
    • “…we measure the fractional deviation of the gravitational redshift from the prediction by general relativity to be (0.19 ± 2.48) × 10-5 at 1 sigma…”
  • Atomic clock performance enabling geodesy below the centimetre level
    • McGrew et al
    • December 2018
    • https://doi.org/10.1038/s41586-018-0738-2
    • “We report systematic uncertainty of 1.4 × 10−18, measurement instability of 3.2×10−19 and reproducibility characterized by ten blinded frequency comparisons, yielding a frequency difference of [−7 ± (5)stat± (8)sys] × 10−19“
  • Resolving the gravitational redshift across a millimetre-scale atomic sample
    • Bothwell, et al.
    • February 2022
    • https://doi.org/10.1038/s41586-021-04349-7
    • “…we measure a linear frequency gradient consistent with the gravitational redshift within a single millimetre-scale sample of ultracold strontium. Our result is enabled by improving the fractional frequency measurement uncertainty by more than a factor of 10, now reaching 7.6 × 10-21.”
  • A lab-based test of the gravitational redshift with a miniature clock network
    • Xin Zheng, Jonathan Dolde, Matthew C. Cambria, Hong Ming Lim, Shimon Kolkowitz
    • August 2023
    • https://doi.org/10.1038/s41467-023-40629-8
    • “Here we perform a laboratory-based, blinded test of the gravitational redshift using differential clock comparisons within an evenly spaced array of 5 atomic ensembles spanning a height difference of 1 cm. We measure a fractional frequency gradient of [ −12.4 ± 0.7(stat) ± 2.5(sys)] × 10-19/cm, consistent with the expected redshift gradient of −10.9 × 10-19/cm.