How The Laser Helped to Improve the Test of Special Theory of Relativity?

  • Satya Pal Singh


In this paper of I have reviewed the test done for validating the special theory of relativity using masers and lasers in last century. Michelson-Morley did the first experimental verification for the isotropy of space for the propagation of light in 1887. It has an accuracy of 1/100th of a fringe shift. The predicted fringe shift on the basis of propagation of light through ether was 0.4 but Michelson-Morley did not observe any fringe shift and came up with a negative result. Their experiment was repeated with modern and more sophisticated versions using highly monochromatic masers and lasers which have kept any ether drag to the limit of < 1/1000th of the earth’s orbital velocity and validated the isotropy of the space to the extraordinary limit of one part in1015. The necessary discussion on masers, lasers, its properties and applications with brief definition of beats is also given in this paper for the completeness of the discussion apart of the experimental method for validating the constant speed of light in different directions using masers and lasers.


Singh, S. P. (2012). Introduction to special relativity and space science (1st ed.). New Delhi: Wiley India Pvt. Limited.
Singh, S. P. (2009). An introduction to relativity: Space time and the principle of equivalence. Physics Essays 22(3), 304-317. DOI:
Singh, S. P., Singh, A. & Hareet, P. (2011). The redshifts in relativity, European Journal of Physics Education 2(2), 24-48.
Robert R. (2000). Introduction to special relativity, John Wiley and Sons: New Delhi.
Jaseja, T. S., Javan , A., Murray, J. & Townes, C. H. (1964). Test of special relativity or of the isotropy of space by use of infrared masers. Phys. Rev. 133(5), A1221-A1225.
Singh, S. P., Laser turns fifty (2010), Vigyan Pragati, August, CSIR, New Delhi.
Jenkins, W., E. (1981). Fundamental of optics. New Delhi: McGraw Hill.
Timothy, P. K., Maleki, L., Lutes, G. F., Primas, L. E., Logan, R. T. & Anderson , J. D. (1990). Test of isotropy of the one-way speed of light using hydrogen-maser frequency standards. Phys. Rev. D 42(2), 731-734.
Brillet, A., Hall , J. L. (1979). Improved laser test of the isotropy of space. Phys. Rev. Lett. 42(9), 549-552.
Hils, D., Hall , J. H. (1990). Improved Kennedy-Thorndike experiment to test special relativity. Phys. Rev. Lett. 64 (15), 1697-1700.
Antonini, P., Okhapkin , M., Göklü, E. & Schiller , S. (2005). Test of constancy of speed of light with rotating cryogenic optical resonators. Phys. Rev. A71, 050101.
Herrmann , S., Senger, A., Kovalchuk , E., Muller , H. & Peters, A. (15 August 1997). Test of the isotropy of the speed of light using a continuously rotating optical resonator. ArXiv:physics/0508097.
Coleman, S., Glashow, S. L. (1997). Cosmic ray and neutrino tests of special relativity. ArXiv:hep-ph/9703240.
How to Cite
SINGH, Satya Pal. How The Laser Helped to Improve the Test of Special Theory of Relativity?. European Journal of Physics Education, [S.l.], v. 4, n. 2, p. 25-38, feb. 2017. ISSN 1309-7202. Available at: <>. Date accessed: 22 feb. 2024.
Classroom Physics