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It is interesting that the shortest wavelength the human eye can see is very close to half of the longest wavelength the human eye can see. (~380nm - 740nm) In

It is interesting that the shortest wavelength the human eye can see is very close to half of the longest wavelength the human eye can see. (~380nm - 740nm) In musical terms it is close to one ‘octave’ of light that is visible to us. If we could see more frequencies maybe we would see multiple rainbows stacked on top of each other, but the other rainbows would somehow be different (like notes sound the same but can be up or down an octave). I know that sound works a little differently than light with overtones etc but still something to think about.

ethbr0 5y ago
That's a good follow-up. If rainbows have non-visible wavelength components (as it appears they do, from experimentation), where would those spacially appear on the rainbow? The assumption would be "on either side", but I suppose there's also the possibility that you start to get repetition at the same angle from viewer, so you'd have multiple bands overlapping?
- Ekaros 5y ago
  Or somewhere else. Looking at prism it seems possible that they would be totally reflected.
VLM 5y ago
Two cool topics to wikipedia/google for are achromatic lens and achromatic tech in general and chromatic aberration. Turns out to be VERY difficult to manufacture optics that focus correctly even across that one octave. I just think its technologically interesting how camera lenses balance dispersion using multiple types of glass with different properties. There's a resolution issue where eyes and optics run near enough optical law limits such that twice the wavelength is half the resolutions so in theory an ideal camera or eye could run twice the resolution at blue color as red. So deep enough IR you get into snake territory where deep IR "vision" would be like one analog pixel in resolution for a reasonable sized eye. There's a book "Exploring Ultraviolet Photography" about hacking DSLR cameras into UV cams, not to rain on their parade but it seems there's not much "cool" to see out there in nature that radiates in UV except flowers to attract bees. Anyway that's probably why there's not much evolutionary pressure to see UV; "flowers glow a little brighter and more obvious" MIGHT help gather fruiting plants a little better, but apparently not enough to make evolutionary pressure. Its still a cool book from a technological perspective. AFAIK the "problem" with very near IR photography is some dyes and cloths become semi-transparent in very near IR so it turns into creepshot women territory so the community ecosystem is a bit off. From a mother nature evolutionary standpoint I don't recall ever reading anything interesting about near IR forest pictures or whatever. So there's nothing to see until humans invented clothes and dyes and near IR cams to translucently see thru them.
- treeman79 5y ago
  We also tend to see a virtual simulation of what our mind thinks is going on. The actual direct visual input can be very different.
- bXVsbGVy 5y ago
  Most radiation on the UV spectrum is filtered by the atmosphere. Less than 5% of radiation with less than 300 nm reaches the ground. Also, UV radiation is mutagenic. > not enough to make evolutionary pressure At cellular level, plants and animals have several mechanisms to avoid and repair damage caused by UV radiation. Maybe the evolutionary pressure was to NOT see UV light!

ethbr0 5y ago

That's a good follow-up. If rainbows have non-visible wavelength components (as it appears they do, from experimentation), where would those spacially appear on the rainbow? The assumption would be "on either side", but I suppose there's also the possibility that you start to get repetition at the same angle from viewer, so you'd have multiple bands overlapping?

Ekaros 5y ago
Or somewhere else. Looking at prism it seems possible that they would be totally reflected.

VLM 5y ago

Two cool topics to wikipedia/google for are achromatic lens and achromatic tech in general and chromatic aberration. Turns out to be VERY difficult to manufacture optics that focus correctly even across that one octave. I just think its technologically interesting how camera lenses balance dispersion using multiple types of glass with different properties. There's a resolution issue where eyes and optics run near enough optical law limits such that twice the wavelength is half the resolutions so in theory an ideal camera or eye could run twice the resolution at blue color as red. So deep enough IR you get into snake territory where deep IR "vision" would be like one analog pixel in resolution for a reasonable sized eye. There's a book "Exploring Ultraviolet Photography" about hacking DSLR cameras into UV cams, not to rain on their parade but it seems there's not much "cool" to see out there in nature that radiates in UV except flowers to attract bees. Anyway that's probably why there's not much evolutionary pressure to see UV; "flowers glow a little brighter and more obvious" MIGHT help gather fruiting plants a little better, but apparently not enough to make evolutionary pressure. Its still a cool book from a technological perspective. AFAIK the "problem" with very near IR photography is some dyes and cloths become semi-transparent in very near IR so it turns into creepshot women territory so the community ecosystem is a bit off. From a mother nature evolutionary standpoint I don't recall ever reading anything interesting about near IR forest pictures or whatever. So there's nothing to see until humans invented clothes and dyes and near IR cams to translucently see thru them.

treeman79 5y ago
We also tend to see a virtual simulation of what our mind thinks is going on. The actual direct visual input can be very different.
bXVsbGVy 5y ago
Most radiation on the UV spectrum is filtered by the atmosphere. Less than 5% of radiation with less than 300 nm reaches the ground. Also, UV radiation is mutagenic. > not enough to make evolutionary pressure At cellular level, plants and animals have several mechanisms to avoid and repair damage caused by UV radiation. Maybe the evolutionary pressure was to NOT see UV light!