The Refraction of Light in Stationary and Moving Refractive Media

A new theory of the refraction of light is presented, using the mathematical fact that the equations of acoustics and optics are identical and that light may therefore be treated as waves in a fluid ether. Light waves are penetrated by the more slowly moving constituents of a refractive medium and so the rays behind them are perturbed and made wavy as they are diracted around material particles. The arc-length along a wavy ray is thus increased by a factor µ(> 1). This simple observation permits the quasi-propagation of waves, in a refractive medium moving in any direction, to be handled mathematically. It is shown to conform to true wave-propagation in a fluid medium, with true wave-speed c/µ, but moving in the same direction with a velocity reduced by a factor (1 1/µ 2 ). Using this result the relation between the angles of incidence and refraction of an oblique wave-front, when the refractive medium is moving, is derived, so giving a relation more general than Snell’s ‘law’. Light is nothing but an agitation or disturbance caused in the particles of the ether. The parallel between light and sound is, in this respect, so well established that we can boldly maintain that, if the air became as subtle and at the same time as elastic as the ether, the velocity of sound would also become as rapid as that of light.