Electromagnetic radiation, Maxwell

Theory The initial understanding of the refraction of light dates back to Maxwell s study of electromagnetic radiation. Ernst Abbe invented the first commercial refractometer in 1889 and many refractometers still use essentially the same design. 

In this final section, it is shown that the three magnetic field components of electromagnetic radiation in 0(3) electrodynamics are Beltrami vector fields, illustrating the fact that conventional Maxwell-Heaviside electrodynamics are incomplete. Therefore Beltrami electrodynamics can be regarded as foundational, structuring the vacuum fields of nature, and extending the point of view of Heaviside, who reduced the original Maxwell equations to their presently accepted textbook form. In this section, transverse plane waves are shown to be solenoidal, complex lamellar, and Beltrami, and to obey the Beltrami equation, of which B is an identically nonzero solution. In the Beltrami electrodynamics, therefore, the existence of the transverse 1 = implies that of , as in 0(3) electrodynamics. 

So far as the classification of the type of spectroscopy performed is concerned, the characterisation of the dynamical motions of the nuclei and electrons within a molecule is more important than the region of the electromagnetic spectrum in which the corresponding transitions occur. However, before we come to this in more detail, a brief discussion of the nature of electromagnetic radiation is necessary. This is actually a huge subject which, if tackled properly, takes us deeply into the details of classical and semiclassical electromagnetism, and even further into quantum electrodynamics. The basic foundations of the subject are Maxwell s equations, which we describe in appendix 1.1. We will make use of the results of these equations in the next section, referring the reader to the appendix if more detail is required. 

The most significant subsequent modification of Maxwell s nineteenth-century picture of electromagnetic radiation is our awareness that wave motion may have particulate properties associated with it. Planck developed his the-... 

Einstein s work extended German physicist Maxwell Planck s (1858-1947) concept of enei y quantization to electromagnetic radiation. 

In preparation for the thermodynamic analysis of radiation effects we study the pressure exerted by electromagnetic radiation, based on Maxwell s equations for electromagnetic fields. Readers not wishing to wade through the rather lengthy derivation may note the final result, Eq. (5.5.11), and proceed to the next section. 

Max Planck in 1900 derived the correct form of the blackbody radiation law by introducing a bold postulate. He proposed that energies involved in absorption and emission of electromagnetic radiation did not belong to a continuum, as implied by Maxwell s theory, but were actually made up of discrete bundles—which he called quanta. Planck s idea is traditionally regarded as the birth of quantum theory. A quantum associated with radiation of frequency v has the energy... 

After holding posts at the universities of Munich and Kiel, Planck succeeded Kirchhoff at the University of Berlin in 1888 after the latter s death. Planck continued his research in thermodynamics, including attempts to connect heat with the Scottish physicist James Clerk Maxwell s theory of electromagnetic radiation. He also addressed a problem suggested by Kirchhoff, who had earlier established that the energy of radiation emitted by a blackbody depends on temperature and the frequency of the radiation. 

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