Summary Thoughts of This Day
December 6th, 2006 | No Comments »As children we were taught that looking into the night sky was ‘looking back in time’. We were told that the light that enters our eye left these stars millions or billions of years ago and that we could never have any idea what was happening there ‘now’. A similar thought is translatable to shorter distances - I can only tell how my wife, standing a meter away, ‘looked’ some three nanoseconds (10-9 sec) ago. But these same considerations must continue into the eye itself. If one considers, as proposed in this work, that the function of the retina to detect a quantized ‘instantaneous’ image (defined again below) with this image coherently transferred along the finite length of the optic nerve to one of the visual cortex sites of the brain then the brain (our thought process!) is always ‘looking back’ in time relative to the retinal image! We can never comprehend the instantaneous image on the retina. Could this be the basis for the conundrum of the ‘arrow of time’ in physics? One is led in this thinking to quantum effects and the meaning of the ‘quantum instant’ that is detected by the retina. I will add more on this below.
But first, to be clear on how I believe the retina detects light. It is common knowledge that vision has evolved to the ‘quantum limit’, i.e, it is able to detect (or count) single or at most a few photons (that I refer to as ‘quantized interactions’). The mechanisms involved here must be explained. It becomes clear in this explanation that the retina must be considered as an array of 100 million plus individual light detection ‘devices’ each capable of, through isomerization of the retinal molecule, generating for transmission to the brain a usable (i.e., measurable) discrete signal. In electrical engineering terms this is akin to a ‘rectenna’. I have proposed that these devices, being of the necessary small spatial dimensions, must ’switch’ in very fast time to minimize ‘noise’ that would otherwise obscure the signal. It appears (ref) that the light interaction/ retinal isomerization action occurs in a very short time indeed - ~ 10-15 sec. One then has the picture of an image being formed on the retina by a vast array of elements each detecting quantized events in a very short time. This is a very unique situation.
One might think that the above describes light interaction with photographic film - single photons interact with individual silver grains in similar manner (and very probably by a similar mechanism). In the vision system, however, each of these devices (’pixels’) is connected to an individual fiber of the optic nerve (of which there are some 1.9 million) with this vast array of individual signals (’the image’) being coherently transported to the brain. I have proposed that the function of the optic nerve is to ’slow down’, using slow ionic mechanisms, the instantaneous (quantum) retinal signals to ‘human nerve compatability’. I believe that what has been termed the ‘reaction time of the eye’ should more properly be termed the reaction time of the human system. Two different time domains are involved in vision (see Comment on this subject).
The frontier of this line of thought is the ‘instant’ of time that I propose is present on the retina. This must involve the realm of quantum physics and is the most interesting aspect of this work. I feel that with these thoughts we are closing in on the ephemeral instant that has been the subject of so many thoughts - even into the realm of philosophy (Schopenhauer’s work comes to mind)
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GCH
12/06/06
