STEVEN RADO :
POLARIZATION BY PHASE-INTERFERENCE

      INTRODUCTION

      Most scientists of the nineteenth century were convinced of the existence of an allpervading Aether which will eventually explain all remaining mysteries of the propagation of light and other 'action at a distance forces'of classical physics. However, all their attempts failed to produce a mechanically feasible model of this hypothetical medium. Then came Relativity and Quantum Mechanics and Aether was deliberately forgotten. Nevertheless, the latest, most sophisticated mathematical prediction of Quantum Electrodynamics has reopened the plausibility and necessity of the existence of an all-pervading medium, named the 'seething vacuum'or the 'zero point energy field'.Some of us who can still remember the gaseous Aether of the last century, could realize the identity of these two media. After a century of a totally futile fight against the denial of common sense and reality, it is now time to recognize that the problems of modern theories and their solutions neither can be found in their internal inconsistencies or in some vague misuse of the fashionable mathematical formalism, but they must be re-discovered in the fossilized body of classical physics itself.
      This study is based on the conviction of the nineteenth century, that an allpervading Aether would indeed reunite physics and proposes that the main stumbling block in the designing of a feasible model of the Aether was the simplistic theory of polarization of light which served as the conceptual foundation of the transverse electromagnetic wave theory of light. Further more an alternate theory of polarization will be suggested, based on Young's original undulatory theory of light and the empirically justified explanation of 'light interference'.Thereby, we attempt to liberate the Aether from the impossible requirements of transverse oscillation and reinstate the original gaseous model of Descartes and Huygens.

  Young's double-slit interference experiment and its mathematical proof of the wave nature of light.

       HISTORICAL REVIEW

       The first step toward the discovery of the polarization phenomenon of light was the recognition of double refraction which occurs when light passes through an iceland spar. A century later Malus discovered that when light was reflected from a window at a specific angle, there was no longer a double image through the iceland spar crystal. He concluded that the window pane reflected only certain components of the light waves. Based on Newton's hypothesis of the polarity of light corpuscles, Malus called the reflected beam 'polarized'and the phenomenon itself the 'polarization of light'.
      Later it was found that the light, passing through a thin tourmaline crystal, is also polarized in a certain direction. When this polarized light goes through a second plate, the intensity of light depends on the relative transverse orientation of the two crystals. When their optic axes turned into right angles, the transmitted light is reduced to zero. Thus, scientists concluded that the thin tourmaline crystal plate only transmits the components of light waves at a certain transmission angle and absorbs all the other components.
      Thomas Young suggested (1803) that within the mechanics of his undulatory theory, polarization might be explained as an effect of the crystal on the transverse components of the spherically expanding compression pulses. Since all effects of double refraction, specific reflection and polarization are proven to be wave-phenomena, Young felt that the task should be to search for a more complex version of Huygens' Principle and analyze how to describe the geometry and mechanics of polarization through the undulatory principles of the compression waves of light. - Eventually, however, this theory for the polarization of light has shifted into a much simpler direction.
      Based on Newtonian mechanics a general analysis of wave motion in an elastic media lead to a simple mathematical description. The generalization was based on the simplest possible form of wave-motion produced by the periodical up and down movements of a stretched string. (Figure-2)

       The conceptual result of the analysis was that the waves travel along the horizontal length of the string by the varying transverse displacements, y,of the individual particles. It is the elastic cohesional restoring force in the body of the string which tends to re-establish its initial density equilibrium and straight shape and it is the inertial mass and momentum of the particles that tends to overshoot into the opposite displacement.
       Because this mechanical tendency is analogous with the motion of a pendulum, scientists concluded that the particles in the string perform 'simple harmonic oscillation' transverse to the direction of propagation. The geometrical result is a sinusoidal curve and by this the general mechanical and mathematical properties of wave-motion seems to be established.
       Figure-3 shows that, while the wave is travelling to the right, the vertical displacement, y, of any particle of the elastic medium is a function of x, that is, y = f(x vt).        This became the general equation of wave motion, describing a wave of any form traveling on a string. Based on this conceptual and mathematical generalizations it was possible to define and classify different waves in various elastic media. - Most generally, wave-motion is defined as the transport of energy by the advancement of a local density disturbance in space without any corresponding bulk motion of the material substance itself.
       Based on the above definition, waves moving along a string are classified one dimensional,surface waves on water two dimensionaland sound or light waves are three dimensional. A further classification was made according to the direction of the oscillation of the individual particles relative to the direction of the propagation: Waves on a string propagate by the transverse oscillationof the particles and classified as transverse waves. Sound waves in fluids propagate by the back and forth oscillationof the particles in the direction of propagation, thus called longitudinal waves.It has also been found that the mathematical expression for describing the transverse displacements, y,of the particles in the string can also be applied for the longitudinal 3-D pressure waves of sound, where yrepresents pressure fluctuation. - In the application of these principles to the polarization of light, scientist used the simple analogy of the waves produced on a string as they move through mechanical wooden grids representing the structure of tourmaline crystals.
Woodtope.jpg
       As Figure-4 (a) shows, when wooden grids, P (polarizer) and A (analyzer) are vertical and parallel, the vertical transverse waves on the string are passing through freely. - Turning the second grid at right angles with the first, as illustrated in (b), the vertical transverse momentum of the string particles are absor- bed by grid A and the wave-motion immediately dies down.
       It is possible to imagine that when the hand describes a circular motion, the particles of the string will move in a 3D spiral. However, the vertical and horizontal wooden 'filters'in will absorb both horizontal and vertical components and destroy all waves. Thus, the simple mechanical analogy became the foundation of the electromagnetic wave theory of light and polarization. As a result of this analogy the y component of the displacement of the string was extended into three-dimensions and became the general concept and equation of the theory of the transverse oscillation of light and electromagnetic waves and their polarization by crystals or optical grids.
       In the eighteenth century Oersted established a physical connection between electricity and magnetism by showing that an electric current carrying conductor creates a circular magnetic field in its vicinity rectangular to the conductor. Later Faraday discovered that a changing magnetic field creates an electric current in a conductor. Since the magnetic fields are perpendicular to the electric current, scientist arrived to this conclusion:
       "....when either an electric or a magnetic field is changing with time, a field of the other kind is induced in adjacent regions of space. We are led to consider the possibility of an electromagnetic disturbance, consisting of time varying electric and magnetic fields that can propagate through space from one region to another, even when there is no matter in the intervening region. Such a disturbance, if it exists, will have the properties of a wave, and the appropriate term is electromagnetic wave." (Hugh D. Young, Physics 1992, [919]).
       Figure-5 shows the final visualization of the propagation of electromagnetic waves in empty space, where both electric/magnetic vectors oscillate transversally. This is an obviously artificial attempt to extend the mechanical transverse wave image of the string into the three dimensions of light-wave phenomena.

         With this visualization of electro-magnetic waves Maxwell succeeded to replace Huygens and Young compression waves by the intangible self induction of electric and magnetic fields in empty space, which could be mathematically integrated with the wave equation of the original transverse waves on a string.
       Accordingly Figure-6 (a) shows that in natural, unpolarized light, the rotating electric and magnetic vectors are erected equally and randomly in every transverse direction. The tourmaline crystals, or the modern polarizing sheets (molecular grids) are equivalent with the wooden grids,
Polariz.jpg
       As (b) illustrates, when the transmission angles of Polarizer-1 and the Analyzer are vertical and parallel, 50% of the light still passes through. When Polarizer-1 remains vertical and the Analyzer is turned horizontal (90) all electric and magnetic vectors are absorbed, and no light passes through.
       Nevertheless, there is a mysterious phenomenon that cannot be explained by this theory; the re-appearance of light upon inserting an extra Polarizer-2 at 45, between Polarizer-1 and the Analyzer, as illustrated in (c). This modern enigma comes from the assumption that the filters must absorb all components of light other than the ones parallel with their transmission angle. If that is the case, Polarizer-1 must absorbed all horizontal components of light. Thus, Polarizer-2 could only effect the remaining vertical components by absorbing half of them for its 45 grid. Therefore, the analyzer would still absorb all the remaining vertical components.
       Think about the string and the wooden grids. Would a third grid, inserted between the two, be able to reinstate some of the waves on the string? - Evidently not.
       The absorption theory leads to the conclusion that the polarizer annihilate certain components of the transverse oscillations of light. But experiment shows that they were not really annihilated. Theoretical physics obviously cannot accept both results. There must be something wrong with the wooden grid analogy.
       Nevertheless, there has been no alternative theory on the scientific horizon for over a century.

       AN ALTERNATE HYPOTHESIS FOR THE POLARIZATION OF LIGHT

       The theory of Aethro-kinematics reinstates the all-pervading gaseous Aether of Descartes, Huygens, Young, Faraday, Maxwell and Lorentz and proposes an alternate explanation for the phenomenon of polarization of light based on Young's suggestion of extending the original longitudinal compression wave theory of light.

Wavesphere.jpg
       Figure-7 illustrates the vector components of the propagation of compression waves. It seems to be obvious, that compression waves must possess both longitudinal and transversal components, otherwise there would be no spherical expansion.
       Recalling from Figure-6 the vectorial illustration of the 'natural unpolarized' light, it can be seen, that the two vectorial interpretations of the phenomenon are identical and the only difference is that allegedly the electro-magnetic version doesn't require a substantial medium.
       The laws of reflection, refraction, diffraction, dispersion and interference are all explained and predicted by a geometrical construction, called the Huygens Principle:
       All points on a wave front can be considered as point sources for the production of spherical secondary wavelets. After a given time the new position of the wave front will be the surface tangency of the secondary wavelets.
       Figure-8 (below) shows some plane wave fronts falling on an interface between air and glass at an oblique angle (q1). The speed of light is marked by C in vacuum, C1 in air and C2 in glass. Light is slower in air than in vacuum and still slower in glass: C> C1 > C2. The frequency always remains the same but the wave lengths (g) are decreasing in the different media: they are shorter in air than in vacuum and still; shorter in glass.
WPOL_INT-A.jpg
       As a result of the different speeds, the light beam bends toward the Normal (q2) when it enters the glass and bends back again into the angle of its incidence, (q1) when it re-enters into air. This phenomenon is called refraction and explained by the Huygens Principle, based on the mechanics of the compression wave theory of light, directly analogous to sound.        Figure-9 illustrates the fact that when light is incident on a glass perpendicular to the interface, - parallel to Normal - there is no change in the direction of the beam. Nevertheless, even in the case of Normal incidence the speed of light decreases in the glass, thus the wavelengths get shorter, while the frequency remains the same.
WPOL_INT-B.jpg
       As it is illustrated, when the wave train returns to air, it regains its initial velocity and wavelength and keeps the initial direction. Everything else happens exactly the way as it happens in the case of refraction except since the angle of incidence equals to Normal, there is no refraction change in the initial direction of the beam.
       Also keep it in mind, that the change in the wavelength has nothing to do with the color of light. If you would be able to see a monochromatic red light inside the glass it would be the same color as in the air or vacuum. The color only depends on the number of pulses reaching the receiver per unit time, that is, the color only depends on the frequency, which remains the same in all media.
       There are a number of simplifications in these illustrations and descriptions which should be noted :        Although the Huygens Principle is a macroscopic geometrical construction, the mechanical causes that make it work is in a lower order of magnitude than the wave itself. In the case of sound waves this lower order mechanism is the kinetic interaction between the atoms and molecules of air. Applying Huygens' Construction to light waves, the mechanism must be in a supermundane order of a gaseous medium, the constituents of which are in constant random motion. This is the gaseous Aether and its units of mass and motion are the Aethrons. When we talk about the new wave front produced by the surface tangency of Huygens' secondary wavelets, we are in the order of magnitude of the wavelengths of visible light, which is in the vicinity of 2 x 10^-5 cm or approximately. one hundred thousandth of a cm. This is the distance between the wave fronts represented by the straight dotted lines on the drawing. It follows that Huygens' secondary wavelets are still one order of magnitude lower than the wavelength.
       Furthermore, the five arches in one row represent the secondary wavelets that form the tangential envelope. There are, of course, a great number of them, side by side originate on the previous wave front and each must also be imagined as a great number of stages of spherical expansions through the distance of a wave-length. Thus, all this must happen in an even lower order of magnitude of the supermundane gaseous Aether. Accordingly, Huygens' Principle can be taken as a 'kinematic interference'of the fluctuating density of the Aether which is conveyed through the medium by the individual collisions of the Aethrons. The result is that the excess kinetic energy density, imparted to the medium by an oscillating source, propagates away in the form of spherically expanding compression layers .
       In Chapter-14 of Aethro-kinematics this kinematic procedure was given to explain the inner mechanism of the Huygens Principle and through that showing that the cause of the phenomenon of polarization could be the blocking of some components of this kinematic interference by the polarizing grids. Therefore, the original longitudinal wave theory could be reinstated and the light conveying medium is emancipated from the extreme restoring force requirements of 'transverse oscillations'.- The present theory is also based on the same kinematic causality, but describing the phenomenon at a higher order of magnitude. It interprets the mechanics of polarization through the macroscopic causality of the compression wave theory of light in the order of magnitude of wave-optics and 'wave interference'. WPOL-GRID.jpg
       Figure-10 is the simplified schematics of polarization.
       It illustrates a grid made out of long narrow slabs of glass spaced out evenly to form a vertical grid alternating the two transparent media, glass and air. The modern polarizing grids are made by placing complex molecular strand into clear plastic alternately. The illustration shows that some portion of the light beam passes through the glass, some others through the air gaps.

       Consider now the filter illustrated in a top view below.
       Long narrow slabs of glass are spaced out evenly to form a vertical grid (going into the page). The light beam travels in a horizontal plane and is incident at Normal. The arriving beam is propagated according to the Huygens Construction, thus the spherical secondary wavelets and their resulting tangential surface envelopes continuously reproduce the wave front.
WPOL_INT-C.jpg
       Nevertheless, it follows from all foregoing, that during the transmission, those sections of the beam that pass through the glass slow down, and their wavelengths decrease compared to the sections that pass through the air. Consequently, the emerging beam is broken up into sections which are out of phase with one another and therefore no tangential Huygens envelope can form to tie the wavelets together into a wave front. Since the filter is a vertical grid, the resulting phase-shift affects all the horizontal transverse components of the wave trains.
       Of course the vertical components of the wave train also suffer retardation through the glass. However, the Huygens wavelets could still be combined to vertical surface envelopes which still reproduce the vertical wave fronts through each gaps and the propagation can remain continuous. Thus, a grid of alternate transparent materials, like alternating glass and air, or a grid of alternating extruded molecular strands and clear plastic, that is, a 'polaroid sheet' - produce a 'phase-shift-interference' in the transverse components of the light. This interference does not absorb any part of the light but similarly to Young's multiple slit experiments, a destructive interference developes beyond the grid in the phase-shifted horizontal components.
      
       Due to this phase-shift-interference the total loss in visual intensity ranges from 50-100% depending on the relative transmission angles of the polarizer and analyzer. As an aid for visualizing this procedure, consider the fact that diffraction is also explained by the interference of Huygens secondary wavelets in the same order of magnitude as the above.
       Further more, it should also be realized that interference is not a static phenomenon but it is constantly recreated by a specific obstruction in the reproduction of the light-waves between the continuously radiating source and the continuously absorbing receiver. Thus, it can also be realized that the interference fringes are constantly reproduced in every point of space regardless whether or not there is a screen to visually demonstrate them. The same way you can imagine that once a beam of light passes through a polarizing filter which produces a phase-shift in some of its transverse components of the wave-train, the emerging light beam must carry this imprint and produce the same interference fringes at every point of space as long and as far as it propagates. Nevertheless, this effect is not the result of a change in the character of the waves or an annihilation of part of the energy, but it is a result of destructive and constructive interference. This means that the energy is still propagating in space, but the receiver only records the local sum or outcome of the interference. This also means, that with the intervention of Polarizer-2 the interference pattern can be altered in space which could result of the reappearance of light.
       The Aethro-kinematic alternative is based on the existence of the ideal gas of Aether and on Youngs compression wave theory of light in agreement with Newtonian Mechanics, the laws of Optics, the Huygens Principle and the geometrical Huygens Construction of wave propagation. Of course, this heuristic theory is very far from sufficient experimental and theoretical development. One of the important and sofar neglected aspect of the phase interference hypothesis is intimately connected to the phenomenon of diffraction which, however is too complicated to the goal of this introductory paper. The main purpose of publicizing it, as is, is to demonstrate the possibility that:
       a) In general the problems and unacceptable results of modern physics originate from the problems of classical physics and must be solved by classical logic, common sense and by the Principles of Causality.
       b) In particular, it demonstrates that an alternate explanation of polarization can eliminate the century old barricade that so fatally obstructed the reinstatement of the allpervading gaseous model of Aether and therefore the possible unification of all physics and cosmology.
       c) This paper is merely meant to be a wedge to open up the tightly closed file of polarization and give a chance to other independent minds to re-think this fatal stumbling block of classical physics.
 

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