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Published Online: 27 December 2004
Review of Scientific Instruments 8, 239 (1937); https://doi.org/10.1063/1.1752300
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  • Research Laboratory of Physics, Harvard University, Cambridge, Massachusetts
A method is described for measuring the velocity of light with a relatively short base line. A Kerr cell modulates a light beam at very high frequencies and a photoelectric cell is used for detection of the modulations. The modulated light beam is divided into two portions by means of a half‐silvered mirror and the two parts sent over different optical paths. By noting the difference in path length required to produce a minimum of voltage in the tuned circuit of the photoelectric cell, and the frequency of modulation of the light, it is possible to measure the velocity of light with considerable precision. Modifications of this method are described and the theory developed. The mean result of a series of measurements involving 651 observations is given as 299,764 km/sec. ±15 km/sec. in vacuum.
  1. 1. Michelson, Astrophys. J. 60, 265 (1924); Google ScholarCrossref
    Michelson, 65, 1 (1927). , Astrophys. J. , Google ScholarCrossref
    Michelson, Pease, and Pearson, Astrophys. J. 82, 26 (1935). , Google ScholarCrossref
  2. 2. Karolus and Mittelstaedt, Physik. Zeits. 29, 698 (1928); Google Scholar
    Mittelstaedt, Physik. Zeits. 30, 165 (1929). Google Scholar
  3. 3. A. R. Frey, Phys. Rev. 49, 305 (1936). Google ScholarCrossref
  4. 4. Cf. Kingbury, R.S.I. 1, 22 (1930). Google Scholar
  5. 5. Cf. Chaffee, Theory of Thermionic Vacuum Tubes (McGraw‐Hill Book Company, 1933), pp. 480–534. Google Scholar
  6. 6. Cf. G. W. Pierce, Proc. Am. Acad. Arts. Sci. 10, 271 (1925); Google ScholarCrossref
    see also G. W. Pierce, Proc. I.R.E. 16, 1072 (1928). , Google ScholarCrossref
  7. 7. From unpublished thesis of Dr. H. H. Hall and notebooks of Professor G. W. Pierce, by courtesy of Professor Pierce and Dr. Hall. Google Scholar
  1. © 1937 American Institute of Physics.