Thermal radiation
All bodies, regardless of their material or temperature, emit thermal radiation. The higher the body temperature, the more thermal radiation the body emits per unit of time.
Light as energy
Valguse kätte jäetud esemed soojenevad. Pikaks ajaks päikese kätte jäetud esemed pleekuvad. Päikesepatareisid kasutatakse elektrienergia saamiseks. Millise energia arvel need protsessid toimuvad?
What simple experiments can be used to prove that light has energy?
What bodies emit infrared light?
Why is ultraviolet light dangerous for humans?