AKA: Why the sky is blue. Probably one of the easiest to understand videos on the phenomenon, without knowing any more than the basics of physics.
One thing that I wish he went into a little more detail is the actual process of scattering as the light travels through the atmosphere, starting at the 9:18 mark. He doesn’t describe what is happening to the red and green wavelengths. The blue we see (in the daytime) is from sunlight more or less passing over us, roughly parallel to the earth’s surface. The blue wavelengths scatter the most, obviously, and it helps to thinking of them as small bits crashing down from the stream of light, and hitting our eyes. The red and most of the green wavelengths continue to stream to eventually become a sunset for the folks westward.
That’s why, when you look more directly at the sun, as when it’s noon or thereabouts, the sky is less blueish and more white with a yellow hue. That’s sunlight hitting our eye more directly, so there’s less of the wavelengths being scattered as it travels through the earth’s atmospheric envelope.
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I didn’t watch the video, but your assessment’s pretty spot on. We see blue during the day because only shorter wavelengths/faster visible light frequencies scatter in the sky while the rest of the light makes it to Earth’s surface (in this sense, the scattered light is more perpendicular than parallel to Earth’s surface). Near dusk, we’re farther from the sun, and so the distance the light travels is greater, meaning more scattering occurs, leaving the longer wavelengths visible (orange and red) visible to us.
I like that you mention our perception of light, too, since that’s an oft-forgotten but equally pertinent discussion regarding light. If our eyes were able to pick up closer-to-UV wavelengths, then the sky would actually look to us more purple/violet than blue.