[jdmichal]

Right. One must remember that the target sink is going to be throwing radiation right back at the source emitter. Theoretically, they will exchange energy until they reach equilibrium between emission and absorption. Luckily for us, it will take a long time to heat space up enough to make a difference...

This also ties into why a magnifying glass cannot make something hotter than its source of light.

https://what-if.xkcd.com/145/

"Lenses and mirrors work for free; they don't take any energy to operate. If you could use lenses and mirrors to make heat flow from the Sun to a spot on the ground that's hotter than the Sun, you'd be making heat flow from a colder place to a hotter place without expending energy. The second law of thermodynamics says you can't do that. If you could, you could make a perpetual motion machine."

[ohyes]

Thanks for that, it really helped me understand the problem with my thinking.