Rethinking the Process of Vision

(A NOTE: If it is not obvious, I do not consider these Comments  in any way  to be finished technical papers. The are meant only as updated thoughts  that occur to me that follow from the insight of my explanation for light interaction with the retina.. I would hope that they  might elicit reasoned discussion and/or argument. GCH)

The eye teaches that it is not photons that are detected but rather the wave nature of light.  Photoelectrons.generated within the absorbing mass are the product of this interaction. The nanostructural array formed by retinal outer segments absorbs light as the electromagnetic wave and transduces the absorbed energy at this point into quantized, i.e., particle, electrons..

I have proposed that the retina of the eye is an array (a nanostructure) of more than 130 million logically spaced light interactive devices that function to translate incident electromagnetic wave radiation into quantized electron particles that encode the visual image information. These devices function in the near field (oi.e., of d spatial imensions smaller than light wavelength) and in at least the femtosecond (10^-15 sec) time domain.

These small space and time dimensionalities define the regime of quantum physics. The initial (”first stage”) interaction of light with the retina involves quantum physics.

The individual light interactive sites (or devices) of the retina are each composed of two separate spaces: 1.) a variably dimensioned space that controls the wavelength of light absorption and, 2.) a space of smaller, fixed, material determined, dimension that “quantum confines” an electron (according roughly to the “electron-in-box” approximation of physics). The electron then constitutes the “absorbing mass”.

The generality of the devices of the retina is that they accept light as a wave and transfer the absorbed energy (laterally via an evanescent wave as I describe) to a “particle” electron that is used in subsequent electronic image formation processes.

Thus, it is a retinal nanostructure that is involved in light absorption.

This surface entails the same light absorption physics as the photoelectric surface studied by Einstein with the difference being that the particle electron is absorbed in the structure for subsequent use rather than being emitted into a vacuum.

Regarding Einstein’s interpretation of the photoelectric effect, a quote from Hunter and Alexandrescu “Photons in the Photo-Electric Effect”, p.2,:

“..of the conclusion of Einsteins’s ‘photo-electric’ paper of 1905 (ref) that the photo-electric effect is only understandable if the energy in a beam of light is concentrated in localized packets each having energy hv (now called photons) whereas it is not understandable in terms of the model of light as a plane wave having uniform intensity over the surface of the photo-emissive surface”.

Is it possible that light in the PE effect was absorbed as a wave and the “quantization” that Einstein correctly discerned occurred in the absorbing mass?

(One must note here that E. could not have had any notion of the specifics of a nanostructure being involved in the PE light interaction process. Even today the precise physics of photosurfaces are not well understood)

Did Einstein and subsequent physics make the mistake of “quantizing both sides” of the interaction (photon and electron) and therefore create the insoluble “wave/particle” dilemma?

Thus, from the teaching of the retina of the eye there are no such entities as light photons. The wave nature of light prevails in the universe with quantization occurring in the “detector” or the absorbing mass.

There is much more to support this claim I will refer to the writings of Richard Feynman:

F. after correctly noting that the “most fundamental interaction in nature was between the photon and the electron”, proceeded to make the same fatal error of “quantizing both sides” of this interaction.

I will begin by discussing of the characteristics of the light detection referenced by F. – the vacuum photomuliplier tube (PMT)  F. used this device and specifically its ability to detect “single photons” as the basis for his entire thought process.

I WILL EMPHASIZE HERE THAT I BELIEVE THE TERM “QUANTIZED INTERACTION” SHOULD BE USED INSTEAD OF “SINGLE PHOTON”. AND FURTHER, THE PMT DOES NOT DETECT EITHER –THE DETECTOR UNDER CERTAIN CIRCUMSTANCES IS ABLE TO DETECT SINGLE PHOTOELECTRONS.

From F’s treatise “QED The Strange Theory of Light and Matter”” (Princeton University Press, 1985):

(I must assume his statements in this book reflect and are not at variance with his deeper thinking).

From p.15:

“….where you were probably told something about light behaving as waves. I’m telling you the way it does behave – like particles” (the emphasis is F’s).

And a further quote from the same page:

“You might say that it’s just the photomultiplier that detects light as particles, but no, every instrument that has been designed to be sensitive enough to detect weak light has always ended up discovering the same thing: that light is made of particles” (this time the emphasis mine).

And yet another quote (pp.36, 37):

“…but the wave theory cannot explain how the detector makes equally loud clicks as the light gets dimmer”.

It is important to note that F. in his QED exposition does not generally differentiate between “weak light detection” and “single photon” detection and often uses these terms interchangeably.

Now….F’s use of the photomultiplier as a fundamental example of a “single photon” detector requires elaboration. A PMT is a vacuum tube device containing a photosurface (PS) applied to the inside light entrance surface of the glass envelope. Incident light releases photoelectrons into the vacuum where they are accelerated by a mechanical dynode or similar structure with the amplified signal reaching an anode output.

What has become to be termed the “single photon response” of the PMT was discovered only some years ago (in the 1960’s?) quite by surprise. What was really discovered, however, was that single electron events could be discerned (“counted”) at the output of the device. How this discovery was made is an interesting story and I believe that I might even have attended an IEEE Nuclear Science symposium in Washington, DC where this was first reported. I remember hearing this paper and sensing that it was truly important – single electrons could be detected at room temperature!

In essence, what was found was that in certain PMT’s an peak unexpectedly appeared on the low energy electronic “noise tail” at the electrical output of the detector. It could readily be deduced from the location of the peak that the events that it comprised: 1.)events that had undergone the highest amplification and, 2.) that this certainly would represent events that were initiated at the entrance photosurface, i.e., from one spatial location in the PMT structure. Importantly, events comprising the peak (broadened by the electronic noise of the PMT) would all have the same amplitude. All single photoelectron events had the same amplitude at the output of the device much as the output of a Geiger counter in nuclear particle detection. This becomes important in what follows.

In terming this output to be caused by single photons F. would have to assume that a 1:1 correspondence existed between the incidence of a single photon and the release of a single electron into the vacuum of the PMT. Einstein made the same assumption. Quoting from Eisberg and Resnick (Quantum Physics of Atoms, Molecules, Solids, Nuclei, and Particles” (John Wiley, 1974), p.35:

“He (E) also assumed that in the phbtoelectric process one photon is completely absorbed by one electron in the photocathode”

To my knowledge, and following the significant amount of study applied to the study of the physics of photosurfaces, such a 1:1 correspondence has never been demonstrated either theoretically or experimentally. Quite the contrary, there seemed to be an “anomalous” yield of single electrons released to the “number of incident photons”. As I remember (and I stand to be corrected) the best that could be discerned was that a statistical number of photons (30?) was required to release of a single photoelectron.

In the light of this teaching of the nanostructural aspects of light interaction, what is the physical situation here? All that is known is that this interaction occurs in an atomically thick chemical compound layer that had been vacuum deposited on the inside surface of the light entrance glass thickness of the PMT envelope. A primary requirement is that the compound/surface have a low work function, i.e., a propensity for releasing an electron. As I remember, cesium compounds are used but there are others. There was certainly no understanding of a mechanism or mechanisms involved in a 1:1 correspondence between a single incident photon and the release of a single electron!

I would add, and will discuss in more detail shortly, that the constant signal output from a PMT corresponding to single photoelectron events tends to explain one of Einstein’s conclusions about the PE effect.

I would propose that ALL detectors that reach the sensitivity level discerning single quantized events (SUCH AS THE RETINA) produce a “standard pulse height output”.

In the spirit of this communication, this means that this detector senses some minimum amount of light wave energy that is solely determined by the DETECTOR.

Quantization of electromagnetic energy occurs at the absorbing detector!

I will repeat a statement made earlier that we – at least through our organ of vision – proceed through a universal sea of electromagnetic energy using three geometrically-defined nanostructural “antennas” that are spatio-temporally tuned to the three wavelengths that we term “primary” with this absorption being quantized in the light detection process.

Questions…?????

GCH

11.22.08

Ojai,CA.

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