Huygens’ theory

Huygens theory of light hI-gonz- n This theory states that light is a disturbance... 

Dutch mathematician Christiaan Huygens first states his wave theory of light, published in Traite de la lumiere in 1690. 

The possibility that the propagation of fight could have a dual nature arose in the seventeenth century as a controversy between Newton and Huygens corpuscular versus undulatory descriptions, respectively. When Maxwell s electromagnetic theory was developed in the nineteenth century, the matter seemed settled in favor of the proponents of wave-like electromagnetic phenomena. 

The characteristic function W plays the same role as the eikonal cf> and a/2m(E — V) serves as the index of refraction. It becomes clear why Huygens wave theory and Newton s formulation were able to account equally well for the phenomena of reflection and refraction. 

The ray model of light is of limited usefulness. If we are to understand the fundamental processes involved in the formation of an image by a lens, we must consider the wave nature of light. The simplest form of the wave theory of light is based on a geometrical construction known as Huygens principle, which is usually stated as follows ... 

Visible light is diffracted by small holes and slits in a manner that can be described by Huygens wave theory in terms of interference between scattered light. In a similar way X-ray diffraction is the interference between X-ray beams scattered by the electrons surrounding atomic nuclei. 

Multiple Scattering Theory was first formulated by Lord Rayleigh [17] in a paper published in 1892 dealing with the propagation of heat or electricity through an inhomogeneous media. However, for most people the application to optics known as Huygens principle [36], is probably better known. It states that ... 

Also in Alhazen s writings we find reports of very detailed early dissection of the human eye. We also find speculations on the method of propagation of light that anticipates the seventeenth-century theory of Huygens. And we find the hints or rather the suggestion, demonstrated only in the nineteenth century, that light travels less easily (i.e., at lower velocity) when it enters a dense medium, and that this causes the ray to be bent toward the normal. ... 

Huygens discovered the laws of circular motion. At the same time he furnished the method of determining to what circle each element of any curve ought to belong. By combining these two theories Newton discovered the theory of curvilinear motion and applied it to those laws which Kepler had found to be followed by the planets in their elliptical orbits. 

---