Physical concepts electromagnetism

NANOPHOTONICS A TRANSFER OF CONCEPTS AND IDEAS FROM QUANTUM PHYSICS TO ELECTROMAGNETISM... 

The penetration depth is physically defined as the depth for an electromagnetic wave penetrating into a conductor when the wave hits the conductor surface. The physical concept of the penetration depth is very useful to explain the behavior of a current and a voltage on a conductor and also to derive impedance and admittance formulas of various conductor shapes and geometrical configuration. However, it should be reminded that the concept is based on TEM wave propagation and thus is not applicable to non-TEM propagation. Also, remind that it is just an approximation. 

You can appreciate why scientists were puzzled The results of some experiments (the photoelectric effect) compelled them to the view that electromagnetic radiation is particlelike. The results of other experiments (diffraction) compelled them equally firmly to the view that electromagnetic radiation is wavelike. Thus we are brought to the heart of modern physics. Experiments oblige us to accept the wave-particle duality of electromagnetic radiation, in which the concepts of waves and particles blend together. In the wave model, the intensity of the radiation is proportional to the square of the amplitude of the wave. In the particle model, intensity is proportional to the number of photons present at each instant. 

The concept of quantization enabled physicists to solve problems that nineteenth-century physics could not. One of these involved the thermal properties of solids when they are heated to incandescence. The other involved the induction of electrical current in metals when they are exposed to only specific frequencies of electromagnetic radiation. 

The present chapter is devoted mainly to one of these new theories, in particular to its possible applications to photon physics and optics. This theory is based on the hypothesis of a nonzero divergence of the electric field in vacuo, in combination with the condition of Lorentz invariance. The nonzero electric field divergence, with an associated space-charge current density, introduces an extra degree of freedom that leads to new possible states of the electromagnetic field. This concept originated from some ideas by the author in the late 1960s, the first of which was published in a series of separate papers [10,12], and later in more complete forms and in reviews [13-20]. 

A general form of the electromagnetic field can be obtained from a superposition of various EM, S, and EMS modes. Thereby it should be observed that the EMS modes can have different velocity field vectors C. These wave concepts provide new possibilities in the study of problems in optics and photon physics, both when considering plane waves and axisymetric modes with associated wavepackets. 

Finally, in this section, we develop the concept of electromagnetic phase from U(l) to 0(3). This is a nontrivial development [4] that has foundational consequences for interferometry and physical optics for example. In U(l) electrodynamics, the electromagnetic phase is defined up to an arbitrary factor... 

Electromagnetic radiation is an oscillating electric field E in space which is propagated with the velocity of light. The idea of field is wholly derived from its measurable physical effects the additional concept of aether is valueless and unnecessary. 

It is noted that the derivation of this equation involves the phenomenological concept of the nonlinear response of the atoms. This equation is derived on the basis of the standard Abelian theory of electromagnetism, which is linear, and where the nonlinearity obtains by imposing nonlinear material responses. The physical underpinnings of these nonlinearities are not completely described. This soliton wave corresponds to diphotons, or photon bunches. 

The various fields that make up a science tend naturally to integrate, and with time such a process can lead to a true synthesis. Physics was the first science to achieve a synthesis of its disciplines, and it may be useful to compare that experience with its biological counterpart. The first unification occurred between mechanics and thermodynamics, in the first half of the nineteenth century, and the second came shortly afterwards, with the integration of electromagnetism. The result was the imposing edifice of classical physics, a conceptual system that described all reality in terms of particles and waves, with equations that seemed perfect because they were perfectly deterministic. The common denominator of all branches of classical physics was in fact the concept of determinism, and nodoby doubted, in the nineteenth century, that that was the true logic of the universe. 

Radiation heat transfer involves a different physical mechanism—that of propagation of electromagnetic energy. To study this type of energy transfer we introduce the concept of an ideal radiator, or blackbody, which radiates energy at a rate proportional to its absolute temperature to the fourth power. 

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