Chemistry
Visible Light and Spectroscopy Basics
Quick fact
The entire visible spectrum (from red to violet) spans less than one 'octave' of frequency, yet our eyes can distinguish millions of colors by combining just three types of receptors.
Why this is interesting
You see colors everywhere, but did you know that every color is a tiny slice of an invisible 'rainbow' that fills the universe? How can we use that slice to know what stars are made of?