 Quote by ABHoT
Does light only come from matter? The difference between a light bulb switched on and off is just temperature (or electricity?) If a star wasn't 'on fire' would it give off any light?
|
A star with no nuclear fuel left would give off light according to its temperature (same as a planet does).
Basically, everything gives off a range of light according to its temperature (google "black body radiation").
eg red stars are cooler than blue stars.
A light bulb gives off light because it is hot.
In
addition, some things give off light at certain
exact frequencies because their molecules are vibrating (eg sodium lamps).
|
I am wondering where the energy is going. Emitting light must cost the matter its energy(?), but being hit by light doesn't give you any so where is it going?
|
No, being hit by light
does give you both energy and momentum.
