Evie
Whilst William McCormick has 'interesting' ideas, they're not scienitific mainstream (and not, according to most here, even coherent). So if you're looking for good answers with which to explain textbook statements, be wary of William's.

Originally Posted by
EV33
I have a few question regarding light and the sky.
My text book tells me that violet light is scattered the most, followed by blue, green, yellow, orange, and red in that order. Now is this because most of the particles and molecules in the earths atmosphere absorb the higher frequencies better, or is it because there is more of the higher frequencies?
Scattering is because of refraction, not absorption (in general). As it happens, in the spectrum visible to humans, the atmosphere behaves in that particular manner - refracting the violet end of the spectrum more than the red end (with a relatively smooth gradient in between).
I cannot explain the quantum mechanical interactions of permittivity and so on (primarily through not knowing a thing about it myself), but you can understand these issues without recourse to that, by merely thinking of school level refraction and internal reflection experiments: the violet component of white light bends more as it goes through a prism than the red component, whih is why we can use prisms to create a spectrum. (If I'm talking about something you haven't done/don't understand, I apologise. Tell me and I'll start again from even more basic ideas - but for now I'm assuming you understand and have seen how a prism works.)
Now the scattering comes about because of repeated refraction and some internal reflection of the light as it passes through our atmosphere - all the layers of varying density and the atended water vapour, often in suspended drops of water. Since the blue is affected more strongly, it is what the atmosphere is most able to divert in all directions - the reds and other components being likelier to go in straight lines until they hit something opaque and are absorbed.
That's basically it, as I understand it - though someone more knowledgeable will no doubt be able to explain it better, or even tell me that I'm entirely wrong!

Originally Posted by
EV33
Then later in my book it talks about why the sky turns red at sunset. From my book I get the impression that we see what is scattered. So if more of the high frequency light is scattered because it travels a further distance, then why would the sky begin to turn red?
I always interpret sunsets as simply meaning that from that angle the bluer portions are refracted/scattered so much they do not even get to us, whereas the straighter lines of the red component of sunlight are less bent by the greater thickness of atmosphere between us and the horizon (like looking through a lens sideways inside of from fornt to back) so we get to see them.
Again, someone more knowledgeable could correct me if I'm badly wrong...