Royal Society Publishing

"Aether Drag" in a Transversely Moving Medium

R. V. Jones


A previous measurement of the Fresnel "aether drag" in a transversely moving medium (Jones 1972) has been repeated with improved accuracy to find whether the original Fresnel formula should be modified by a dispersion term as was shown by Lorentz and Zeeman for the longitudinal drag. A formula derived by M.A. Player and by G.L. Rogers gives the transverse displacement of a beam of light passing through a medium of thickness $t$ moving with transverse velocity $\upsilon $ as $\upsilon t(n_{\text{g}}$ - $n_{\phi}^{-1}$)/$c$ rather than $\upsilon t(n_{\text{g}}$ - $n_{\phi}^{-1}$)/$c$ as given by the original Fresnel formula, where $n_{\phi}$ is the phase refractive index and $n$$_{\text{g}}$ is the 'group refractive index.' The present experiment gives results in accordance with the Player-Rogers formula rather than with the Fresnel formula or one in which the group refractive index alone is involved; it parallels what Zeeman found for the longitudinal case. The main improvement in experimental accuracy has come from recognition of errors in the method of calibration by optical micrometry.

Royal Society Login

Log in through your institution