flipmode said:
Hey, I have to disagree with the assumptions made by this person.
I wish I could take credit for disproving them, but others have beat me to it.
Each of the references I've listed below, if studied, will make obvious what you've posted as a reference is invalid in regards to the reflectivity of mirrors, as those that can be purchased commercially.
The reasons gave by this person are nonsensical and though they appear sound, are not. Major scientific discoveries concerning proven theories involving light, have been dissected down to the most finite equation as far back as the 1500's.
Do a Google on the below references of mine, and you'll discover that lighting and reflection are things that have been reduced to a known value.
By the way, I may not have made it clear, but your statement in your post is correct. Mirrors are crap for reflection. That's the bottom line. They do not, however, cause anything in real life that could be called a "hot spot", in reference to plant growth if ventilation is included in the equation. Hot spot's are ventilation issues, not reflectivity issues.
Enjoy the read, man, I get off on this stuff...check it out. It'll make your head hurt the first time. When you start understanding it, then you're really a mess.
I've always thought about writing a book on Algebra named "Understood while stoned" That's how I learned it. I've taught Algebra and Trig to a lot of people, and when you're stoned, it makes understanding it much easier during the basics. For the advanced work, being stoned is impossible. Way too much going on.
Well, anyway, these will keep you out of trouble for, like a decade. An understanding of each of these is necessary to fully understand how the reflectivity of mirrors and plant growth are surely not compatible.
Maxwell's equations
Snell's law
Fermat's principle
The Fresnel equations
Brewster's angle
refractive index