# Introduction ow the idea of ? and µ-dispersion appeared and evolved is illustrated vividly in the monograph of well-known specialists in physics of plasma [1]: while working at the equations of electrodynamics of material, media, G. Maxwell looked upon electric and magnetic inductivities as constants (that is why this approach was so lasting). Much later, at the beginning of the XX century, G. Heavisidr and R.Wull put forward their explanation for phenomena of optical dispersion (in particular rainbow) in which electric and magnetic inductivities came as functions of frequency. Quite recently, in the mid-50ies of the last century, physicists arrived at the conclusion that these parameters were dependent not only on the frequency but on the wave vector as well. That was a revolutionary breakaway from the current concepts. The importance of the problem is clearly illustrated by what happened at a seminar held by L. D. Landau in 1954, where he interrupted A. L. Akhiezer reporting on the subject: "Nonsense, the refractive index cannot be a function of the refractive index". Note, this was said by L. D. Landau, an outstanding physicist of our time. What is the actual situation? Running ahead, I can admit that Maxwell was right: both ? and µ are frequency -independent constants characterizing one or another material medium. Since dispersion of electric and magnetic inductivities of material media is one of the basic problems of the present -day physics and electrodynamics, the system of views on these questions has to be radically altered again. # II. # Plasma Media It is noted in the introduction that dispersion of electric and magnetic inductivities of material media is a commonly accepted idea [1][2][3][4][5]. The idea is however not correct. To explain this statement and to gain a better understanding of the physical essence of the problem, we start with a simple example showing how electric lumped-parameter circuits can be described [6]. As we can see below, this example is directly concerned with the problem of our interest and will give us a better insight into the physical picture of the electro dynamic processes in material media. In a parallel resonance circuit including a capacitor ? and an inductance coil L, the applied voltage U and the total current I ? through the circuit are related as ? + = + = ? t d U L t d U d C I I I L C 1 , where t d U d C I C = is the current through the capacitor, ? = t d U L I L 1 is the current through the inductance coil. For the harmonic voltage U = U 0 sin ?t t U L C I ? ? ? cos 1 0 ? ? ? ? ? ? ? ? ? = ? . (2.1) The term in brackets is the total susceptance ? ? of the circuit, which consists of the capacitive ? ? and inductive ? L components From the mathematical (i.e. other than physical) standpoint, we may assume a circuit that has only a capacitor and no inductance coil. Its frequencydependent capacitance is L C L c x ? ? ? ? ? 1 ? = + = . H © 2014 Global Journals Inc. (US) # Global Journal of Researches in Engineering ? ? ? ? ? ? ? ? ? = ? ? ? 1 ) ( * C C . (2.2) Another approach is possible, which is correct too. Eq. (2.1) can be re-written as t U L I ? ? ? ? cos 1 0 2 0 2 ? ? ? ? ? ? ? ? ? ? = ? . In this case the circuit is assumed to include only an inductance coil and no capacitor. Its frequencydependent inductance is ? ? ? ? ? ? ? ? ? = 1 ) ( * 2 0 2 ? ? ? L L . (2) ( * ? L . We shall not consider here any other cases, e.g., series or more complex circuits. It is however important to note that applying the above method, any circuit consisting of the reactive components C and L can be described either through frequency -dependent inductance or frequency -dependent capacitance. But this is only a mathematical description of real circuits with constant -value reactive elements. It is well known that the energy stored in the capacitor and inductance coil can be found as 2 2 1 U C W C = , (2.6) 2 2 1 I L W L = . (2.7) But what can be done if we have ) ( * ? C and # ) ( * ? L ? There is no way of substituting them into Eqs. (2.6) and (2.7) because they can be both positive and negative. It can be shown readily that the energy stored in the circuit analyzed is 2 2 1 U d d W X ? ? ? = ? ,(2.8) or [ ] 2 ) ( * 2 1 U d C d W ? ? ? ? = ? , (2) ( * 1 2 1 U d L d W ? ? ? ? ? ? ? ? ? ? ? ? = ? . (3.10) Having written Eqs. (2.8), (2.9) or (2.10) in greater detail, we arrive at the same result: , 2 1 2 1 2 2 I L U C W + = ? Where U is the voltage at the capacitor and I is the current through the inductance coil. Below we consider the physical meaning jog the magnitudes ?(?) and µ(?) for material media. A superconductor is a perfect plasma medium in which charge carriers (electrons) can move without friction. In this case the equation of motion is E e t d V d m ? ? = , (2.11) Where m and e are the electron mass and charge, respectively; E ? is the electric field strength, V ? is the velocity. Taking into account the current density , V e n j ? ? = (2.12) we can obtain from Eq. (2.11) ? = t d E m e n j L ? ? 2 . ( In Eqs. (2.12) and (2. ? = t d E L j k L ? ? 1 . (2.14) Here L k is the kinetic inductivity of the medium [7][8][9][10][11]. Its existence is based on the fact that a charge carrier has a mass and hence it possesses inertia properties. For harmonic fields we have is the current through the inductance coil. t E E ? sin 0 ? ? = and Eq. (2.14) becomes t E L j k L ? ? cos 1 0 ? = ? . (2 In this case the Maxwell equations take the following form , 1 , 0 0 ? + = + = ? = t d E L t E j j H rot t H E rot k L C ? ? ? ? ? ? ? ? ? ? ? ? µ (2.16) Where ? 0 and µ 0 are the electric and magnetic inductivities in vacuum, = + + H L t H H rot rot k ? ? ? µ ? ? ? µ . (2.17) For time-independent fields, Eq. (2.17) transforms into the London equation [12] 0 0 = + H L H rot rot k ? ? µ , where 0 2 µ ? k L L = is the London depth of penetration. As Eq. (2.16) shows, the inductivities of plasma (both electric and magnetic) are frequencyindependent and equal to the corresponding parameters for vacuum. Besides, such plasma has another fundamental material characteristic -kinetic inductivity. Eqs. (2.16) hold for both constant and variable fields. For harmonic fields t E E ? sin 0 ? ? = , Eq.(2.16) gives t E L H rot k ? ? ? ? cos 1 0 0 ? ? ? ? ? ? ? ? ? ? ? = . (2.18) Taking the bracketed value as the specific susceptance ? x of plasma, we can write t E H rot X ? ? cos 0 ? ? = , (2) ( * 1 1 2 2 0 0 ? ? ? ? ? ? ? ? ? ? ? ? = ? ? ? ? ? ? ? ? ? = ? = k X L , (2.20) and ? ? ? ? ? ? ? ? ? = ? ? ? ? ? ? 2 0 1 ) ( * , where k L 0 2 1 ? ? ? = is the plasma frequency. Now Eq. (2.19) can be re-written as t E H rot ? ? ? ? ? ? cos 1 0 2 2 0 ? ? ? ? ? ? ? ? ? ? ? = , or t E H rot ? ? ? ? cos ) ( * 0 ? ? = . The ?*(?) -parameter is conventionally called the frequency-dependent electric inductivity of plasma. In reality however this magnitude includes simultaneously the electric inductivity of vacuum aid the kinetic inductivity of plasma. It can be found as ? ? ? ? X = ) ( * . It is evident that there is another way of writing ? ? , * 1 1 1 1 2 2 0 k k k X L L L ? ? ? ? ? ? ? ? ? = ? ? ? ? ? ? ? ? ? = ? = (2.21) where ? ? ? ? ? ? X k k L L 1 1 ) ( * 2 2 = ? ? ? ? ? ? ? ? ? = . L k *(?) written this way includes both ? 0 and L k . Eqs. (2.20) and (2.21) are equivalent, and it is safe to say that plasma is characterized by the frequency-dependent kinetic inductance L k *(?) rather than by the frequency-dependent electric inductivity ?*(?). Eq. (2.18) can be re-written using the parameters ?*(?) and L k *(?) Thus, the parameter ?*(?) is not an electric inductivity though it has its dimensions. The same can be said about L k *(?). t E H rot ? ? ? ? cos ) ( * 0 ? ? = , (2.22) or t E L H rot k ? ? ? cos ) ( * 1 0 ? ? = . (2 We can see readily that ? ? ? ? X = ) ( * , ? ? ? X k L 1 ) ( * = . These relations describe the physical meaning of ?*(?) and L k *(?). Of course, the parameters ?*(?) and L k *(?) are hardly usable for calculating energy by the following equations 2 0 2 1 E W E ? = and 2 0 2 1 j L W k j = . For this purpose the Eq. (2.9)-type fotmula was devised in [2]: [ ] 2 0 ) ( * 2 1 E d d W ? ? ? ? ? = . (2.24) Using Eq. (2.24), we can obtain 2 0 2 0 0 2 0 2 2 0 0 2 1 2 1 1 2 1 2 1 j L E E L E W k k + = ? + = ? ? ? ? The same result is obtainable from We have found that ?(?) is not dielectric inductivity permittivity. Instead, it includes two frequency-independent parameters ? 0 and L k . What is the reason for the physical misunderstanding of the parameter ?(?)? This occurs first of all because for the case of plasma the 2 0 ) ( * 1 2 1 E d L d W k ? ? ? ? ? ? ? ? ? ? ? ? = .? t d E L k ? 1 -type term is not explicitly present in the second Maxwell equation. There is however another reason for this serious mistake in the present-day physics [2] as an example. This study states that there is no difference between dielectrics and conductors at very high frequencies. On this basis the authors suggest the existence of a polarization vector in conducting media and this vector is introduced from the relation m m r e n r e P ? ? ? = ? = , (2.25) Where n is the charge carrier density, m r ? is the current charge displacement. This approach is physically erroneous because only bound charges can polarize and form electric dipoles when the external field overcoming the attraction force of the bound charges accumulates extra electrostatic energy in the dipoles. In conductors the charges are not bound and their displacement would not produce any extra electrostatic energy. This is especially obvious if we employ the induction technique to induce current (i.e. to displace charges) in a ring conductor. In this case there is no restoring force to act upon the charges, hence, no electric polarization is possible. In [2] the polarization vector found from Eq. (2.25) is introduced into the electric induction of conducting media E P E D p ? ? ? ? ? ? ? ? ? ? ? ? ? = + = 2 2 0 0 1 ) ( * ) ( * ? ? ? ? ? ? . Thus, the total accumulated energy is 2 2 2 0 1 2 1 2 1 E L E W k ? ? ? + = ? . (2.26) However, the second term in the right-hand side of Eq. (2.26) is the kinetic energy (in contrast to dielectrics for which this term is the potential energy). Hence, the electric induction vector D*(?) does not correspond to the physical definition of the electric induction vector. The physical meaning of the introduced vector ) ( * ? P ? is clear from E L E P k L ? ? ? 2 1 ) ( * ? ? ? ? = = . The interpretation of ?(?) as frequencydependent inductivity has been harmful for correct understanding of the real physical picture (especially in the educational processes). Besides, it has drawn away the researchers attention from some physical phenomena in plasma, which first of all include the transverse plasma resonance and three energy components of the magneto electro kinetic wave propagating in plasma [13][14]. # III. # Dielectric Media Applied fields cause polarization of bound charges in dielectrics. The polarization takes some energy from the field source, and the dielectric accumulates extra electrostatic energy. The extent of displacement of the polarized charges from the equilibrium is dependent on the electric field and the coefficient of elasticity ?, characterizing the elasticity of the charge bonds. These parameters are related as ). 1 ( ) ( * 2 0 2 2 0 ? ? ? ? ? ? ? ? ? ? = p It is appropriate to examine two limiting cases: ?>>? 0 and?<>? 0 , ) 1 ( ) ( * 2 2 0 ? ? ? ? ? ? ? p ? = , and the dielectric behaves just like plasma. This case has prompted the idea that at high frequencies there is no difference between dielectrics and plasma. The idea served as a basis for introducing the polarization vector in conductors [2]. The difference however exists and it is of fundamental importance. In dielectrics, because of inertia, the amplitude of charge vibrations is very small at high frequencies and so is the polarization vector. The polarization vector is always zero in conductors. For ?<>? t H E rot y ? ? ? µ µ ? ? ? ? ? ? ? ? ? ? ? =? ? ? + = t d H t H E rot y y ? ? ? ) 1 ( 2 0 0 µ µ ? ? µ , or ? + = t d H C t H E rot y k y ? ? ? 1 0 ? ? µ . For ?<