How many plants can you put under one UFO LED grow light?

2-3 plants depending on how big your space is.

For 90 watt UFO grow light (like this one: bestlightingbuy.com/90-watt-ufo-led-gro ), Both red and blue light are part of the visible spectrum, this is the portion of the electromagnetic spectrum that is visible to (can be detected by) the human eye. Red light has a wavelength of 620-750nm and a frequency of 400-484THz. Blue light has a wavelength of 450-495nm and a frequency of 606-668THz.

And the red region has a utilization peak around 660-670 nm for Chlorophyll A and around 635-645 nm for Chlorophyll B, depending on the source of information. Plants generally make good use of all red wavelengths except for ones much longer than 670 nm.

I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.