so red just, vroom, skates right out by and only interacts here and there. guess which color should get through fastest? red. you see it's red? and a term we're gonna learn later on that when the different speeds will bend different amounts. and that's why this and rainbows you see above you, display the colors that we see. it has to do with different colors bending. and we know why they bend differently, because they got different speeds in the medium, different average speeds. the sun beats down, emits light. why does the sun emit light? honey, those electrons in that sun are shaking like crazy. all kinds of frequencies, okay? and so what you get is you get all kinds of frequencies of light coming down to us. and if we made a graph of the frequencies of light versus the brightness, we'd get something like this. we'd get something like this. over here, you can't even see, that's the infrared. over here, you can't see, that's the ultraviolet. but it turns out that right in here, that's the frequency of light that most of--that is emitted mostly by the sun. a