This document discusses several laws governing radiation, including reflection, refraction, absorption, and the inverse square law. Reflection occurs when rays encounter a medium they cannot pass through, refracting at the same angle. Refraction causes rays to bend when passing between media at different angles depending on density. Absorption involves rays being absorbed by media, with the amount depending on factors like wavelength and incidence angle. The inverse square law states that intensity decreases with the square of the distance from the radiation source.