Great question, Skuncle Lenny. Something that I've always wondered as an outdoor grower. The reason the Full Moon does not affect plants is in the way the human eye perceives light and the way a plants photo-receptors perceive light. A plant can 'stare' at the Sun for 12 hours and not 'blink an eye'. We stare at the Sun for 12 seconds and may be blind for life. We often confuse lightness, brightness, luminoisity, etc., for the same thing. They are not. I will leave it to anyone interested to look it up.
A Full Moon is not bright at all but it appears to be very luminous to us. It 'seems' to light up our surroundings like daytime. A plants photo-receptors do not deal with luminosity very well and so the Full Moon does not 'light up the night' to a plant. The Full Moon is not at all bright. If you have an excellent light meter the Full Moon should measure about .0034 Lux or
.25 Lumens on your meter. Not bright enough to affect a plant.
The tiny little light bulb in your AC, or fan, etc, will generally produce at least 5 Lumens or more. That little light bulb is 20 times brighter than the Full Moon. It does not have much Luminosity due to it's small size. But it is bright. Plants don't care about luminosity but brightness does affect them. Also, different colored lights would affect plants differently as plants are affected by different color light spectrums. In street terms - this is why the Full Moon does not affect plants - it is not as bright as it seems.
5 Lumen AC Bulb
View attachment 89744
Longball