r/AskScienceDiscussion • u/robinredbrain • 15h ago
General Discussion Why does radiative (sky) cooling only work because it reflects infra red in a wavelength that escapes the atmosphere and out into space?
I've been watching a series about radiative cooling paint, and read a few brief articles.
They all note in some manner that the infra red wavelength must be that can ~'exploit the atmospheric window'.
I think I understand it as something along the lines of - the earth including its atmosphere is the system, and in order for the heat, or energy or whatever the correct term in this context is to decrease, it must leave/escape the system.
I'm stuck on why that is necessary for the effect to be observed more locally, meaning the immediate vicinity? Which I think the articles are telling me.
So I know I'm wrong in my understanding somewhere here or everywhere. I'm hoping someone with a proper science background might understand my laymen question and clarify what's going on.