Cosmologists are chasing invisible rainbows in the sky....

[webolife]

Slavek,
My utilization of "pressure" is a simple recognition that "tension" must be phenomenal at a finite, not infinitesimal area. Hence the elementary model of a light ray [which you may be describing as a twisted rope [you sound like a follower of Bill Gaede's Rope Theory, which Alton Hare [a former TB contributor] restructured into chains]] must be realized as a "beam" exerting pressure at the detector rather than as elementary vectoral "force". Light pressure is also exigent in the formations of inverse square mathematics. That said, it is easier to speak of force and rays in describing the "true"... er, observable nature of light. No waves have ever been seen, just theorized, and no particles either. What has been seen, and you were correct in noting its relevance, is that light action is quantized. This is again a recognition of the finite nature of light action which cannot be continuously detected by any means known to science. There must be a "smallest" and therefore discreet light action, and why not call that a "photon' for sake of discussion.
Now, to the spectrum: YOur use of "bulk" as a descriptor shows you don't get my concept yet. Try this:
"Look straight toward the light "source" or a reflection of it. Now you have identified the central line of sight [CLOS].
Anywhere you look there it is. Simple enough, you've been looking at it since you were born, and no longer even think about what's going on. But first let's talk about images -- a true image is always inverted so that image you saw through your pencil pinhole was no exception; remember the image was inverted in your eye, but your brain "corrected" and normalized it. An optical ray diagram describes virtually everything one can know about light action. (All waves and particles, yes strands also, are just hopeful culpabilities to satisfy our urge to make everything fit our little concrete box called modern physics; not mocking it, we all have our little box.) So what of the spectrum? Given the right size pinhole [your 1/32" works suffices], when you look toward your light "source" you will see along with a nice image of the surroundings a spectral array of colors, always in the same order, blue toward the CLOS, red toward the other direction then meeting right up again with blue and on through
reen, yellow, orange, red and ... violet sits right there between red and blue again. Newton's ROYGBIV is better understood as VBGYORVBGYORVBGYOR... which is seen in a simple rainbow, if the droplets are large enough to see the supernumeraries. Mie and Airy theories are mathematical models for this phenomenon, but the reality of it is that the rainbow colors are imaging the light field itself, symmetrically surrounding the CLOS. How do we know the spectrum is actually a field image? Well, if you haven't already, convert the pinhole to a slit, which eliminates the imaging capability in the long direction allowing you to see the exact shape of the light source imaged in the remaining symmetric spectra. If unconvinced simply look at a variety of lamp shapes. Include luminous letters such as a neon sign, and a CFL for comparisons to begin with. A monofilament is a great one to observe for this experiment as well. You will see discrete images in colored array. The image shapes remain in the double slit setup as well, "proving" that no distortion or interference is being caused to the light at the slit. In further investigation [you suggested in your post also], moving your eye closer and further from the slit and from left to right will demonstrate beyond any shadow of doubt that the optical rays are exactly straight LOS to each part of the spectral field. There is no bending at the slit, nor do the lines bend on the observer side of the slit as they should if Young's interference is happening [his moiré pattern "interference" nodes are hyperbolic, not linear like the actual observation]. My conclusion: The spectrum is a gradient of the light field about the CLOS, not a "bulk" pressure phenomenon, but an image of the field at your retina or whatever detector is eliciting the colors. Using color filters to render transparent parts of the spectrum doesn't change this basic fact. The extra dark lines near the center of the double slit image can be shown to be shadows of the beamsplitter rendered by the imaging of the source through two slit/pinholes. If a grating is used, the beamsplitter shadow will be arrayed multiply as the grating. Speaking of diffraction [were we?], the spectrum of the single slit and the double slit can be shown to originate in exactly the same way [contrary to wave interference], by creatively making a single slit that is divided only halfway by a hair beamsplitter... the only difference will be the redundant shadows near the center, once again defying the "evidence" for interference.
If it can be entertained that nothing is waving through the pinholes or slits, and further studies show that even a supposedly single photon creates the spectral pattern, defying the standard definition of "photon"; what is left is the overturning of Maxwell's equations [which were not actually Maxwell's; JC actually believed in action at a distance] and the opening of the mind to the possibility that nothing is being emitted from the source. The real mindbender then comes into play: The light force is directed/vectored toward the source, and the light action is instantaneous. The observer's locus is at the periphery of the light field, the source is at the center, which like gravitation and electricity is locally/centrally directed.. ie. centropy. Thus all forces may be unified.
By the way, all colors of the rainbow are invisible, not just the infra and ultra bands, it's just that our eye is designed to react to that little ROYGBIV band; or conversely, all colors including the infra and ultra bands are visible -- all that is needed is a resonant [pressure sensitive] detector.
And also, I like your "sideways" forces, as they remind me that magnetism is a "null" vector of the electric field [the electric, gravitational, and light fields all being manifestations of the one universal unified field], acting at 90o to the central vector. This will have to be a topic for another thread however.

[Roshi]

How does a photon maintain it's direction if it has no mass, so no inertia? Why does it travel (with no mass) in the first place? How can it be moved?

[webolife]

How does a massless photon move and maintain direction?

Here's my answer to that:
Simple put, the photon is not really a "thing"... so it doesn't have inertia, and doesn't have to move, ie. not from source to peripheral observer or vice versa. In the Centropic Pressure Field Theory, when the centroid/source's atomic/electronic configuration "normalizes", usually described as an electron returning or jumping to a lower energy level, its field "contracts" with it. Not over time, as though the field were a separate entity, needing some form of delayed communication from the electron, but because the field is a property of the electron, this is an instantaneous change. Here's the clincher: my retina is at a peripheral point in the electron field, so when the electron jumps "down", my retinal photoreceptors "jump" with it. That action is translated electrochemically to my brain as a light action.

[webolife]

Oh, and Slavek, I forgot to respond to your assertion that the thickness of the pinhole material was consequential.
It is not. The slit "tunnel" itself is not affecting the light rays transmitted through it, contrary to suggestions in some articles I've read. Construct your slit device from various thicknesses of and types of materials, and you'll see this for yourself.

Here's another one for you: creatively replace the beamsplitter in a double slit device with a card held perpendicular to [and on the observer side of] the slit plane, and the image will not be damaged, nor will the spectral pattern associated with "interference" be dismembered in any way. This latter fact is for me absolute proof that interference simply does not happen -- light is not waves.

[webolife]

Since no-one has bit on that hook yet, let me add an additional bit about making slits and pinholes:
When I first started making and having students make slit devices [spectroscopes], I followed instructions in a project manual which recommended the use of a pair of opposing razor blades as slit edges, the inference being that the straightness of the slit was somehow phenomenal in producing the spectrum. It didn't take me long to realize this was not a particularly handy set of materials to put in the hands of teenagers -- So I started using more easily obtained and readily transformed materials such as folded construction paper, cardboard, etc. Students were of course not all of as meticulous mind or steady hand as I might like, so designs and structures varied greatly. I also found students had fun making a camera obscura from a shoebox, oatmeal container, watermelon, hole in the shade of a dark closet window... and guess what... it doesn't matter. There is an optimal diameter/width for the pinholes or slits, that is best found through experimentation, but the type of materials, precision and thickness of the edges are of little consequence to obtaining the light field spectrum. The tube spectroscope requires a chunk of diffraction grating at the other end, which you can pick up for not much at your local science supply store. But if you happen to have a CD/DVD sitting around you can creatively use that for a spectroscope as well. Reflect the light from a CFL for starters to see why I say the spectrum is an image of the source.
Light focused through a pinhole, slit, lens or prism will produce the spectral patterns. Later when I graduated to studying so-called interference patterns, I discovered again that the actual design of the slits can vary greatly, and by doing so, one can learn a great deal about optics, and inferentially about the nature of light. These days, when I want to construct a double slit device, I fold a card, cut a narrow slit along the fold with a sharp pair of scissors or an Exacto, tape a hair right into the groove of the card, and I'm ready to begin. Three mechanical pencil leads stuck into an eraser at a judicious small distance of separation will produce the same results. I believe that the truth about light is plain to see, quite unlike alleged "particles" and "waves".
While we're chasing rainbows, here's another seminal experiment to try with your new slit device:
1. Get a monofilament lamp [if they still carry those at your grocery store, typically 25 watts, but a 40W is fine].
2. Set it into a socket so that you can observe it through a slit [single or double, it doesn't matter] that is roughly parallel to the filament.
3. Notice that the spectral array is nicely in the exact shape of the filament, with all its curves and kinks exactly in place. Every color images the source perfectly.
4. Now for the surprise that if recognized will convince you forever that light is not diffracting or interfering as it transmits through the slit[s]: See those perpendicular shadows blocking the filament light at intervals, and carried throughout the spectral pattern? Yep, those are in fact the shadows of the wee support wires that keep the monofilament in place. Now, we "know" that light waves should diffract right around those tiny wires so that they wash out of the spectrum by the time the wavefronts hit your slit device... but hey, they don't. There they are as sharp as ever, imaged as shadows along with the filament image, the bulb image, the background images... If light is actually waving, as Young and "every" physicist for the last century have supposed, you should NOT be seeing those shadows! Step back a few paces and look again! The shadows are still there, sharp as ever. This proves that the projection of the spectrum is a straight line phenomenon from the source to the screen of your retina, imaged in simple optical ray fashion though whatever focusing device you choose.

Rays, vectors... force. This further infers that the spectrum is an image of the light field, as a pressure gradient about the CLOS.

[Webbman]

how do you reflect pressure?

[+EyeOn-W-ANeed2Know]

how do you reflect pressure?

Using an Adamantium Vibranium alloy.

(Sorry, couldn't resist the joke.)

[webolife]

how do you reflect pressure?

As is the case with any reflection, this is easily modeled with vectors. But to physically picture it, think of a pendulum in mid-upswing; freeze that picture. Look at the forces; there is a force against the bob along the direction of "string" and a vector "down" with gravitation (ignore for now vectors from air resistance, friction at the pivot, etc.) -- because there is an upward force counteracting gravitation involved in the building of PE, you can say that the gravitational vector is not in full effect. It's not that gravitation isn't in full effect, but that the "weight" of the bob is less than it would be if weighed in the "straight down" position. Likewise, If you were to "weigh" the bob at the top of it's swing [make it swing to a horizontal position] the bob would be "weightless". If you haven't done so already, switch your perspective from outside observer to the bob's perspective. Depending upon the angle of "hang" the bob experiences less than the full effect of gravitation but as it reaches the bottom of its swing it experiences the full effect, and this force gradient is symmetric on the second half of its trajectory. Of course momentum vectors play a part in this, but once set in motion, the momentum vectors can be seen as integral, causative or resultant... the perception of gravity is the relevant phenomenon for our purposes. Another way of looking at the gravitation gradient is to consider the vectors of a plank being lifted up from one end until it is standing vertically. Or consider the angles involved in a pile of sand, rocks, or say a cinder cone volcano... at some point the gravitational vectors are overcome by normal vectors, and the pile stays intact, but bring that angle closer to vertical and the gravitation vectors prevail. The gradient I'm referring to is that set of "continuous" angular relationships relative to the perpendicular, or think of it as the central line of gravity.
Now look at a light reflection. Let's start with the case of a diffraction grating, where multiple reflections at very small angle increments can be considered. The vectors in the direction of the light source are of course greatest at the CLOS, but less looking toward and depending on the reflection angle. There is a vector gradient between the reflection angle and CLOS that is analogous to the gravitational vector gradient of the pendulum. This a pressure gradient because it is experienced at a photosensitive surface, and in fact a geometrically defined "ray" is dimensionless and therefore non-phenomenal. Viewing light reflected by/through a prism or raindrops [or think of it in terms of the refractive index of a prism or raindrops] elicits this same pressure gradient with respect to the CLOS. Remember that blue colors are angularly closer to the CLOS than reds, so when you see a rainbow it is the culmination of two optical phenomena; first the reflection within a single droplet switches the blue-red order, but then the droplets spread across the angular region required for a rainbow sighting redirects the "correctly'" angled rays back toward our eye in the expected order of blue to red. A simple ray diagram explains this better than these words.

For the case of reflections against a surface, let's take the special case of a mirror, then apply that generally to any dyed or "rough" surface. The fact that the optical ordering of light vectors images a source is important to keep in mind here. Since the mirrored surface is finely smooth and its atoms are electronically configured via the aluminum and glass [silica] or similar atoms to resonate* with all white light, or all parts of the field gradient, the reflection of the light rays makes this mirrored object a proxy of the central source. [*Resonate...hmm, perhaps an imprecise term. Stimulate, quickly respond, "jump" ...?] By jumping out of their level then immediately back in, very little entropy occurs at the surface allowing us to see the surface as a proxy to the light source. I'm guessing this will be very hard to comprehend if the analogy of bouncing objects is being used to imagine the reflection of light, rather than a ray or vector.
Dyed surfaces "absorb" certain colors, which is to say the return of the "jumped" electrons after light stimulation takes more energy than the energy of the initial "jump" as the electrons encounter the light rays. No one really [certainly not I] knows how this happens, but the electronic configuration of the molecules dictates which electrons will be stimulated more, etc. This energy draw depends on the precise configuration of a particular dye so electrons lifted a certain angles with respect to the source don't jump out of their energy levels, resulting in no "return" effect. Remember again that in the Centropic Pressure Field Theory, it is electrons that "drop" to a lower energy level that cause the field "contraction" that our retina observes as "light". The short of all that is that absorption results in less action transmitted to the observer. Since our eye [normally] responds to all aspects of the colored pressure gradient, whatever colors that are absorbed are not detected by our eye. In this view, vision, and therefore reflection, is all about vectors... directed towards the source [as a sink], not particles or wave energy emanating or emitted from the source.