https://www.youtube.com/watch?v=4a0FbQdH3dY
https://en.wikipedia.org/wiki/Rayleigh_scattering
I do have a question though.
The article says:
> blue and violet have the closest frequencies to a “resonant frequency” of nitrogen and oxygen molecules’s electron clouds
I thought it was more to do with the photon frequency matching the physical size of the air molecules? Or is that the same as its resonant frequency?
Direct link to timestamp 33:56
So it’s a combination of the composition of the thing and the environmental coupling with other vibrating things
Size and material composition are the primary factors
So for this case, the photon spectrum interact with nitrogen-oxygen mixture most efficiently at the frequency that reflects blue
I mostly studied sound frequency mixing with static objects (matching or cancelling the fs of room/space with the fs of a driver) but the principles of resonance hold across media
Can you be more specific?
https://sunwindsolar.com/blog/solar-radiation-spectrum/?v=0b...
Both the "because that's what the sun emits" and "because we are mostly water" explanations are incomplete. There are plenty of other animals [1] that can "see" infrared.
The real reason is simply because that's how we evolved. That's how the "because those are the frequencies that pass through water" explanation comes into play: vision first evolved in aquatic animals, so frequencies that don't penetrate water wouldn't have been all that helpful to their survival and reproductive success, and so wouldn't be selected for. But that's incomplete too: salmon are one of the top IR-sensing animals and they live in water, so when there's an evolutionary need to select for IR vision, it happens. The reason we "see" in the visible light range is simply that that's how we've defined "visible".
There are some physics reasons as well, notably that most mammalian body structures emit heat, which would blind an animal that relies on infrared to see (notice how most of the animals that can see infrared are cold-blooded reptiles, fish, and insects), and that most of the high-resolution biochemical mechanisms that can convert electromagnetic waves to electrochemical nerve impulses operate in the visible light range. Structures that convert infrared radiation to nerve impulses are more complex and more costly to support, so unless there's a clear survival benefit for the species, they tend to get selected away.
[1] https://a-z-animals.com/animals/lists/animals-that-can-see-i...
"There's air in my room, it appears transparent. The sky is made of air, it appears blue. Why the difference"
Also, if you took a sufficiently large quantity of air and put it into empty space and shined very bright white through it, it would experience rayleigh scattering—-meaning that air, when you have enough of it and shine a bright enough light through it, is blue.