The Time Domain Again!
July 27th, 2005 | No Comments »At the risk of entirely losing the attention of any biologically-oriented reader (if any such read this?)… and following the thoughts of July 25th below …searching for an effect in the time domain that would “complete” the inverse Fourier transform necessary to form an image… might this be accomplished by the curvature of the retina and particularly the accentuated curvature of the fovea centralis? A feature of curvature is that it has the correct property of synchronizing refracted light rays arriving at such a surface.
Refracted rays must always take a longer path length than direct, i.e., undiffracted, rays (Pythagorean theorem). Curvature, however, mitigates this effect. Magnitude… I have guessed that the time difference between primary color foci lies in the picosecond domain (10^-12 sec.). The depth of the fovea centralis I estimate (Yamada, 1969) to be ~150 microns (?). Light travels ~250 microns per picosecond. Thus at least the distances and times are in the same ballpark.
(I would note that the function generally (universally?) attributed to the fovea centralis is the enhancement of visual accuity. For the life of me I cannot reason out optically why this should be so.)
I would state again that these picosecond times represent “differentiated starting times” and have nothing to do with any, subsequent, “biological signal processing times”. These short picosecond times, however, represent real (physics) numbers and would seem to have to be accounted for in the process of light interaction with the retina and the formation of the visual image.
I find myself continually refining definitions as this evolves…the term “zero time” that I have used to describe the Fourier focal points of the initial spatial transform might more properly be termed just “instants” as, within quantum limits, they “negate time”. It is as if time disappears in the first transform and reappears as a spatial image in the second inverse transform.
