Re:Sigh (Score 2, Insightful)

Mirrors reflect (typically) 60-70% of the light that hits them, turning the rest into heat.

Have you ever looked in a mirror? Seriously!

The next time you go to the barber, and he shows you the back of your head by holding up an extra mirror, check if the reflection looks even detectably darker than the real thing. If you check out one of those places where you can stand between two mirrors and get "infinitely" many reflections, how do you think you can see so many reflections?

(Assuming we are speaking about visible light, of course)