The frequency response of the retina and visual cortex ranges from sensitivity to approximately 420 nanometers (4200 angstroms) to sensitivity to approximately 700 nanometers (7000 angstroms). The frequency response follows a bell curve with peak response at approximately 560 nanometers (5600 angstroms). Thus the bell curve covers a sensitivity range of twice 140 nanometers or 280 nanometers total. This is the “octave” of human visual sensitivity. The obvious question is why is this less than a full octave? One might expect that the range would be from 420 to 840. Or to correlate more closely with the auditory spectrum, perhaps even from 440 – the musical note of A below middle C – to 880. One would expect something close to a doubling of wavelengths (halving of frequencies), perhaps the other example of 350 to 700. The most plausible could be the range of 385 nanometers to 770. First, the musical analogy is impertinent here because the 440 number is purely a coincidence. The fact is that the region of 600 to 700 nanometers is the region of longer wavelength and thus red (bordering on infrared), and the region of 420 to 500 nanometers is the violet (bordering on ultraviolet) region. Second, we must remember that these numbers follow curves of doubling to represent octaves! This is a key to understanding, something that neither the esotericists nor the physicists have yet seemed to fully grasp. In other words, we cannot think in terms of linear numbers alone. From 770 nanometers down to 560 is 210, then from 560 down to 385 is 175! This leaves a discrepancy of 35 nanometers over an octave range. An analogous problem is encountered in music and in all other fields of knowledge and endeavour that use octaves. Light and Electricity Light and Electricity: Notes of Two Courses of Lectures Before the Royal ... By John Tyndall 1871 Lectures on Light Lectures on Light: Delivered in the United States in 1872-'73 By John Tyndall
Planck's Quantum hypothesis was dormant for over a decade until a new mystery emerged in the form of the photo-electric effect. If high frequency light falls on certain metals electrons are ejected from it which are moving much faster than predicted by the classical wave theory of light. Again, Classical Physics was faced with unexplainable experimental facts. |
lab of Nikola Tesla, spring of 1894.
T.C. Martin called "Tesla's Oscillator and Other Inventions"
that appeared in the Century Magazine (April 1895).

Nevertheless, amidst this seemingly hopeless situation Einstein suggested that Planck's mysterious Quanta, when applied to light energy, would explain the high velocities of the 'photo electrons'.