Search for Time Variation of the Fine Structure Constant

Phys. Rev. Lett. 82, 884 – Published 1 February 1999
John K. Webb, Victor V. Flambaum, Christopher W. Churchill, Michael J. Drinkwater, and John D. Barrow


An order of magnitude sensitivity gain is described for using quasar spectra to investigate possible time or space variation in the fine structure constant α. Applied to a sample of 30 absorption systems, spanning redshifts 0.5<z<1.6, we derive limits on variations in α over a wide range of epochs. For the whole sample, Δα/α=(-1.1±0.4)×10-5. This deviation is dominated by measurements at z>1, where Δα/α=(-1.9±0.5)×10-5. For z<1, Δα/α=(-0.2±0.4)×10-5. While this is consistent with a time-varying α, further work is required to explore possible systematic errors in the data, although careful searches have so far revealed none.


  • Received 13 February 1998
  • Revised 9 July 1998
  • Published in the issue dated 1 February 1999

© 1999 The American Physical Society

Authors & Affiliations

John K. Webb1, Victor V. Flambaum1, Christopher W. Churchill2, Michael J. Drinkwater1, and John D. Barrow3

  • 1School of Physics, University of New South Wales, Sydney, New South Wales 2052, Australia
  • 2Department of Astronomy & Astrophysics, Pennsylvania State University, University Park, Pennsylvania 16802
  • 3Astronomy Centre, University of Sussex, Brighton, BN1 9QJ, United Kingdom

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