Effect of the 1999 solar eclipse on atomic clocks

Article metrics


Solar eclipses have been reported to have a strange influence on the behaviour of atomic clocks1 and pendulums2,3, which has been attributed to some unknown feature of gravity4. Here we correct this idea after being unable to detect any anomalous changes in the relative rates of three types of atomic clock, based on the ground-state hyperfine transitions of hydrogen, rubidium and caesium, during the solar eclipse of 11 August 1999 over central Europe.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Figure 1: Time differences in four atomic clocks during the solar eclipse.


  1. 1

    Zhou, S. W., Huang, B. J. & Ren, Z. M. Nuove Cimento C 18, 223–236 (1995).

  2. 2

    Allais, M. Aero/Space Eng. 9, 46–55 (1959).

  3. 3

    Saxl, E. J. & Allen, M. Phys. Rev. D 3, 823–825 (1971).

  4. 4

    Eckhard, D. H. Phys. Rev. D 42, 2144–2145 (1990).

  5. 5

    Jun, L. et al. Phys. Rev. D 44, 2611–2613 (1991).

  6. 6

    Kuusela, T. Phys. Rev. D 43, 2041–2043 (1991).

  7. 7

    Kuusela, T. Gen. Relativ. Grav. 24, 543–551 (1992).

  8. 8

    Mishra, D. C. & Rao, M. B. S. Curr. Sci. 72, 782–783 (1997).

  9. 9

    Turneaure, J. P., Will, C. M., Farrell, B. F., Mattison, E. M. & Vessot, R. F. C. Phys. Rev. D 27, 1705–1714 (1983).

  10. 10

    Prestage, J. D., Tjoelker, R. L. & Maleki, L. Phys. Rev. Lett. 74, 3511–3514 (1995).

Download references

Author information

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Udem, T., Reichert, J., Holzwarth, R. et al. Effect of the 1999 solar eclipse on atomic clocks. Nature 402, 749–750 (1999) doi:10.1038/45442

Download citation


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.