Foundations of Physics Letters

, Volume 16, Issue 6, pp 593–604 | Cite as

Universal One-Way Light Speed from a Universal Light Speed Over Closed Paths

  • Ettore Minguzzi
  • Alan Macdonald


This paper gives two complete and elementary proofs that if the speed of light over closed paths has a universal value c, then it is possible to synchronize clocks in such a way that the one-way speed of light is c. The first proof is an elementary version of a recent proof. The second provides high precision experimental evidence that it is possible to synchronize clocks in such a way that the one-way speed of light has a universal value. We also discuss an old incomplete proof by Weyl which is important from an historical perspective.

special relativity simultaneity clock synchronization one-way light speed round-trip axiom 


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  1. 1.
    R. Resnik, Introduction to Special Relativity (Wiley, New York, 1968).Google Scholar
  2. 2.
    G. F. R. Ellis and R. M. Williams, Flat and Curved Space-Times 2nd edn. (Oxford University Press, Oxford, 2000)Google Scholar
  3. 3.
    A. P. French, Special Relativity (Chapman & Hall, London, 1968).Google Scholar
  4. 4.
    R. W. Brehme, Am. J. Phys. 56, 811(1988).ADSCrossRefGoogle Scholar
  5. 5.
    A. L. Macdonald, Am. J. Phys. 51, 795(1983).ADSCrossRefGoogle Scholar
  6. 6.
    E. Minguzzi, Found. Phys. Lett. 15, 153(2002).MathSciNetCrossRefGoogle Scholar
  7. 7.
    H. Weyl, Raum, Zeit, Materie 7th edn. (Springer, New York, 1988), based on the 5th German edn. of 1923.CrossRefzbMATHGoogle Scholar
  8. 8.
    R. Anderson, I. Vetharaniam, and G. E. Stedman, Phys. Rep. 295, 93(1998).ADSMathSciNetCrossRefGoogle Scholar
  9. 9.
    A. Janis, Conventionality of Simultaneity, The Stanford Encyclopedia of Philosophy, fall 2002 edn., E. N. Zalta, ed.; Scholar
  10. 10.
    P. Wolf, S. Bize, A. Clairon, A. N. Luiten, G. Santarelli, and M. E. Tobar, Phys. Rev. Lett. 90, 060402(2003).ADSCrossRefGoogle Scholar
  11. 11.
    W. M. Macek and D. T. M. Davis, Jr., Appl. Phys. Lett. 2, 67(1963).ADSCrossRefGoogle Scholar
  12. 12.
    H. Erlichson, Am. J. Phys. 41, 1298(1973).ADSCrossRefGoogle Scholar
  13. 13.
    G. E. Stedman, Am. J. Phys. 41, 1300(1973).ADSCrossRefGoogle Scholar
  14. 14.
    H. Weyl, Space, Time, Matter (Dover, New York, 1952), based on the 4th German edn. (1921), translation by H. L. Brose.Google Scholar
  15. 15.
    C. Møller, The Theory of Relativity 2nd edn., (Clarendon Press, Oxford, 1972), Sec. 2.2.Google Scholar

Copyright information

© Plenum Publishing Corporation 2003

Authors and Affiliations

  • Ettore Minguzzi
    • 1
  • Alan Macdonald
    • 2
  1. 1.Dipartimento di FisicaUniversità di Milano-BicoccaMilanoItaly
  2. 2.Department of MathematicsLuther CollegeDecorah

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