I asked my very aware grandson if he could tell me what polarization of light was. He answered with the same answer I've had all my life, all the explanations seem to be self-referential, and I can't make heads nor tails of them. So I'm starting this column talking about something I know nothing about. Let's see if I can learn anything in the process.
Google polarization and you get 22.6 million results. Let's start with a definition. I should have expected to get, among the "did you mean?" categories, politics, which probably accounts for about 21 million of those results, and psychology, another million, but Jazz Album? It turns out to be a 1977 Marine Intrusion album designed to "produce sounds that are mostly polarized between gentle Europeanized reflections and probes into the avant-garde." Well, that probably makes more sense than anything in the dictionary.
Anyway, getting back to the general definition, it is:
"The production or condition of polarity, as:
A process or state in which rays of light exhibit different properties in different directions, especially the state in which all the vibration takes place in one plane.
The partial or complete polar separation of positive and negative electric charge in a nuclear, atomic, molecular, or chemical system.
A concentration, as of groups, forces, or interests, about two conflicting or contrasting positions."
I don't even want to try to figure out what the "vibration" of "rays of light," let alone "rays of light" is, but at least the definition is specific as to it being a process or state, whatever they are, taking place in one plane. I know what a plane is. As this definition is of little help, lets go on to the physics definition:
"1. The act of polarizing; the state of being polarized, or of having polarity."
Okay, that's pretty clear in saying nothing.
"2. (Opt.) A peculiar affection or condition of the rays of light or heat, in consequence of which they exhibit different properties in different directions."
Well, that's meaningless, but now we get specific:
"Note: If a beam of light, which has been reflected from a plate of unsilvered glass at an angle of about 56°, be received upon a second plate of glass similar to the former, and at the same angle of incidence, the light will be readily reflected when the two planes of incidence are parallel to each other, but will not be reflected when the two planes of incidence are perpendicular to each other. The light has, therefore, acquired new properties by reflection from the first plate of glass, and is called polarized light, while the modification which the light has experienced by this reflection is called polarization. The plane in which the beam of light is reflected from the first mirror is called the plane of polarization. The angle of polarization is the angle at which a beam of light must be reflected, in order that the polarization may be the most complete."
Now this is a description of the effect. No one is going to argue there is an effect, the question is, what is causing the effect. There are suspicions that the Vikings might have used polarization in navigation as early as the 8th Century, but the recognition for its discovery goes to one Erasmus Bartholinus in 1669. At the time, Huygens was arguing light was a wave, Newton was arguing it was a particle, and no one was even asking, how does matter produce light, so here we see empirical science at it's best, monkey seeing, monkey naming, giving words to effects. But, wait, empirical science is always looking for ideas it can morph into facts.
"The term polarization was derived from the theory of emission, and it was conceived that each luminous molecule has two poles analogous to the poles of a magnet; but this view is not now held."
Well, this is invigorating. Empirical science rejected one of its own nonsensical explanations for an effect in reality. But, for what?
"According to the undulatory theory, ordinary light is produced by vibrations transverse or perpendicular to the direction of the ray, and distributed as to show no distinction as to any particular direction."
Why, for another one, of course, and frankly I liked the first bit of nonsense better. But guess what the second theory does (and what will make it permanent)? It allows empirical science to come up with a whole new bunch of names and a whole lot of measurements. Note this answers our earlier question, what the vibrations of rays of light are. The vibrations are the result of the undulatory theory of polarization that is basically the conclusion that Young's two-slit experiment demonstrates that light is like water waves. See column 09-04. The waves are apparently vibrations. Wonder what they are when they're particles, vibratory particles?
"But when, by any means, these vibrations are made to take place in one plane, the light is said to be plane polarized. If only a portion of the vibrations lie in one plane the ray is said to be partially polarized. Light may be polarized by several methods other than by reflection, as by refraction through most crystalline media, or by being transmitted obliquely through several plates of glass with parallel faces. If a beam of polarized light is transmitted through a crystal of quartz in the direction of its axis, the plane of polarization will be changed by an angle proportional to the thickness of the crystal. This phenomenon is called rotatory polarization. A beam of light reflected from a metallic surface, or from glass surfaces under certain peculiar conditions, acquires properties still more complex, its vibrations being no longer rectilinear, but circular, or elliptical. This phenomenon is called circular or elliptical polarization."
This is just a bunch of naming until we get to the last part dealing with the vibrations no longer being rectilinear, but can be circular or elliptical. If the vibrations are analogous to the rise and fall of water waves, how can they then be anything but rectilinear, which is defined as moving in a straight line? And as Young's two-slit experiment analogized light to circular water waves, how can they primarily be rectilinear? Do these nut cases ever read what they write? In any event, we're right back to where we started, polarization is the result of the wave theory of light, with waves becoming undulations, then vibrations, then anything else anyone can think up to make a buck, maintain a reputation, or keep a job. Let's continue:
"3. (Elec.) An effect produced upon the plates of a voltaic battery, or the electrodes in an electrolytic cell, by the deposition upon them of the gases liberated by the action of the current. It is chiefly due to the hydrogen, and results in an increase of the resistance, and the setting up of an opposing electromotive force, both of which tend materially to weaken the current of the battery, or that passing through the cell."
Polarization? Why not just call it resistance, or feedback effect, or bird dropping?
So I'm just as unenlightened as I was when I began. I have no understanding of what's happening with polarization. So let's use my own views on light. Light is made up of the same thing matter is made up of, electrons, and light is produced when matter gives off electrons in sufficient numbers that they cannot all be emitted from the surface at the same time. How matter gives up electrons is explained in the 08-05 column on field replacement.
If there are more electrons freed from the matter than can be emitted from the matter, they have to line up in order to be emitted as discussed in column 04-06. Matter can emit electrons without light in the form of heat, but light is structured. It has to be structured because it not only expands in a manner that permits it to diminish inversely with the square of its distance from its source, it expands, and this is probably one of the most important, and most overlooked facts in realty, uniformly. If it expands uniformly, then it has to have something regulating its expansion. If it didn't, it would overexpand, with some light crowding out other light, and when we lit a cigarette, we'd get a match like the collecting screen in Young's experiment, with areas of light and no light, although it wouldn't be as uniform as the light on the collection screen.
Light expands uniformly, and its regulator is not hard to find. We know that a flow of electrons produces an inductive flow and we know that inductive flows combine electric flows in proportion to the strength of the flows. As light is a flow of electrons, it has inductances. These inductances are easily measurable on the surface of light bulb filaments where electrons are lining up waiting to be emitted that's how the electric company makes its bucks, it charges for delivering these electrons to your house).
The reason that light has no charge is these inductances balance the charge of the flows of light to result in a neutral measurement. As light expands, it overexpands. As inductances are proportional to the flows, the overexpanded flows of light, just as in Young's experiment, are recombined. The movement of light is a continuous interplay between overexpanding flows and inductances recombining the overexpanding flows. The result is, at any point in the expansion of light, the light is being recombined. As the strength of the light decreases by the square of its distance, the strength of the mechanisms that recombine the light do also, and it is these mechanisms that grab the units in the nuclei of atoms and moves them back toward the source of the light, in other words, gravity. See column 02-05.
Getting back to the electrons on the surface of combusting matter lining up to be emitted, they are emitted in pulses, with a group emitted, then another group, then another group, continuing as long as the object is undergoing combustion at a rate that will allow it to produce light. These pulses produce the frequency of the emissions. The hotter something burns, the higher frequency light it emits. We don't go around saying, hey, that's blue hot, we say it's red hot. See columns 11-05 and 04-06.
Electromagnetic frequencies can be produced in any numbers of ways, and stretch from the extremely long to the extremely short, but light occupies a small band of frequencies we can see with our eyes. The notion that the frequencies we can see are bundled together into a single frequency, that white light is made up of all colored light, is a Newtonian fantasy that is blindly repeated by mindless empirical science. Light frequencies are the same as any other frequencies except we can see them, and how they interact with matter might tell us what is happening with the phenomena of polarization.
One of the first things discarding Newton's absurd notions about white light containing all colors also discards is the corresponding notion that materials absorb all the colored light except the color they display. No one, at anytime prior to Newton, ever doubted that color was the result of light reflecting off the surface, and in doing so, changing characteristic, (hey, that sounds a little like light changing its properties, like, uh, polarization). Newton "proved" light contained all colors by taking light broken down in a prism and recombining it into white light. The fact that color adding light increases its frequency in no way proves that white light contains all colors, and it definitely doesn't do away with the obvious conclusion that it is the surface that changes the nature of light rather than the surface absorbing billions of shades of colors to emit the one particular mauve that it's emitting.
What happens in a prism is, as the light passes through the glass of the prism, it is having its frequency reduced. Thus, Newton's other conclusion, that the light is lined up the way it emerges from the prism is also absurd, with it lining up the distance it passes through the glass of the prism, with blue going the longest distance, and thus having the longest frequency, and yellow the shortest, having the least diminished frequency. See again column 11-05. Anyone can see the effect of adding colors on the computer with a color wheel. Each color increases the frequency of the overall color until white is reached. They start with the lowest frequency, blue, then reach the highest frequency through two paths, either green or red, both ending up with yellow (white is not considered a color). The reason for the two paths is explained in detail in Light, the 6th volume of The Copernican Series.
So what's happening when light strikes a glass pane at an angle. Some of the light is passing through the pane, but that's not what polarization is measuring, it is measuring reflected light. Light from any point is expanding over a sphere uniformly, and the inverse square measurement comes from the fact that as light moves, it expands, and the sphere over which it expands is defined by the square of its radius. Before the light strikes the plane, it is expanding in 3-dimensional space. That's why light contains information, it diminishes uniformly.
When it hits the pane of glass, however, the light that is reflecting off the glass has been altered in what I refer to as re-expanding spheres of light. This is how we can locate objects in reality, because every hard angle within our vision has had expanding light bounce off it. When the light begins to re-expand, it diminishes, and therefore, our eyes are collecting the information about the comparative locality of all those hard edges of reality. That's the information the optic never transfers to the gray matter in the skull, and while I won't get into how here, that gray matter uses the information to reconstruct the picture of reality we see with our eyes. This is the content of The Model Mind and How the Body Really Works, the 4th and 9th volumes of The Copernican Series respectively.
However, when the light bouncing off an unsilvered glass plane is reflected onto another plane, the angle the other glass plane receives the light has a lot to do with what happens to the light. If the angle the light is reflected off hits a plane of glass at the same angle, none of the light will be distorted. At each point the light reflected, it is expanding in a new expanding sphere. This is what happens in Young's experiment, a portion of the expanding sphere is passed through a slit and it begins to once again expand, only, with more space, it overexpands.
What happens if the angles aren't similar? Remember, not all the light is being reflected. When the angle of incidence is equal, then the expanding spheres hit the plane of glass, some pass through, others are accurately reflected in new expanding spheres. However, if the angle is not identical, then the light bounces off at an angle, and the re-expanding spheres start to interfere with one another, and just as happens in Young's experiment, where the inductances recombine the overexpanded light leaving the lines of light and no light on the collection screen, the overexpanding angled spheres interfere, and their inductances recombine the light, eliminating some of it. Thus, when the second plane of glass is parallel, there'll be no interference, but when it's perpendicular, there will be interference, and therefore polarization.
So polarization is misnamed and poorly analyzed, but it's empirical science at its best, measure, measure, measure, then make up a bunch of gibberish to fake knowledge and I learned something.
Peter Bros is the author of the 9 volume Copernican Series and is President of The Far Museum of Dallas, an actual history museum, which will house its collection of 50,000 rare Eastern Mediterranean manuscripts and artifacts together with actual history displays and tours in a full-sized replica of the Egyptian Temple at Dendera to be built in the Dallas Ft. Worth area. Email:peterbros@therealskeptic.com