Sources of lightWhat sources of light can you think of?Can you distinguish between “luminous” and

“non-luminous” objects? Which is the Sun? The Moon?

INCANDESCENCELight caused by heating up

a materiallightbulbsburning fuel

LUMINESCENCELight from unheated objectsThere are many different types …

fluorescenceLight is emitted by substances

when exposed to electromagnetic radiation

More complicated: gas particles emit UV light, which make a phosphor emit light

fluorescent lightbulbs

phosphorescenceThe ability to store energy from a source of light

and then emit it slowly over a long period Like florescence, but slowerglow-in-the-dark items

electric dischargeLight is produced by passing electricity through

the air or another gaslightningneon signs

chemiluminescenceLight produced from a chemical reaction without

a rise in temperatureglow sticksluminolBioluminescence is a natural form

nuclear fusionLight is released when hydrogen atoms are

pressed together to form heliumthe sun!