Question: In a room where everything is black, and the only light source is a light bulb would you be able to see anything- would there be any light?

Sam Geen answered on 17 Jun 2013:

Well, you’d see the lightbulb and yourself. Plus if the room is genuinely black – i.e. it absorbed all light that hit it – then it would still make light! Things emit light according to their temperature, which is why really hot metal glows. This is called a “blackbody”. The Sun is almost a blackbody, because it makes a lot of light inside it but most of it gets absorbed before it gets out, so what we’re seeing is the light that’s been absorbed and reemitted so many times. It’s weird calling the brightest thing in the solar system “black”, but there you go.