system
Given the following post, respond as if you're commenting on Reddit:
human
How is air clear?

I know this is probably a really dumb question, but I was driving home today randomly thinking about this and realized I couldn't answer this question.

Is it because the molecules are so tiny?  Is it because the air molecules are so far away from each other (the density of air, compared to water or solids) that my eyes can't make it out?  If air had more molecules in it, or a different kind of molecules in it, could I see it?  What is happening with the light passing through air?

Not even sure if I'm asking this in the right way, but as I was watching the leaves of a tree rustle in the breeze, I was suddenly amazed.
gpt
"Clear" is merely what we call something that doesn't absorb in the visual spectrum that our eyes can detect. 

That being said, air is indeed mostly empty space between rather small molecules moving pretty fast. Certainly the vacuum between molecules isn't absorbing light.

The molecules in air don't absorb visual spectrum light because they do not match the energy needed to excite the electrons to the next highest molecular orbital, and these amounts of energy must match exactly since you can't have spare change in energy, either the whole photon is absorbed, or it passes on by.