Translations:Huygens’ principle/1/en

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A wavefront is a surface over which a wave disturbance has a constant phase. As an illustration, consider a small portion of a spherical wavefront emanating from a monochromatic point source S in a homogeneous medium. Clearly, if the radius of the wavefront at a given time is r, then at some later time t, the radius will simply be where v is the phase velocity of the wave. But suppose instead that the wave passes through a nonuniform sheet of material so that the wavefront itself is distorted. How can we determine its new form? Or for that matter, what will the waveform look like at some later time if it is allowed thereafter to continue unobstructed? The major step toward the solution of this problem appeared in print in 1690 in Traité de la Lumière (Huygens, 1690[1]), which had been written 12 years earlier by the Dutch physicist, Christiaan Huygens (Figures 8 and 9). In that work, Huygens enunciated what has become known as Huygens’ principle (Robinson and Clark, 2006b[2]).

  1. Huygens, C., 1690, Traité de la Lumière [Treatise on Light, in which are explained the causes of that which occurs in reflection and in refraction, and particularly in the strange refraction of Iceland Crystal]: The Hague. Republished by Macmillan and Company, London, 1912.
  2. Robinson, E. A., and R. D. Clark, 2006b, Huygens’ principle: The Leading Edge, 25, no. 10, 1252–1255.