Another great example of "structural" blue that can be created artificially by heating steel:
replyNot just butterflies, birds too! But what selection pressure drove the evolution of these structural colors? Presumably signaling, the opposite of muted, camouflaging colors.
replyAlso, as many might know, blue eyes are the result of a lack of pigment (eumelanin). The iris is translucent, but Rayleigh scattering preferentially backscatters blue photons. Green eyes have some pigment, making them a mix of brown and blue.
Also the blood veins that you see as bluish through the skin are blue for the same reason, due to light scattered in their walls.
replyI thought they are green.
replyDefinitely more blue/purple.
replyI wonder if the interference-based-blue of the morpho butterfly evolved because it's difficult to make blue pigment for some reason having to do the chemistry of our biosphere, or if it's an evolutionary response to humans who may have captured the blue ones and ground them up for pigment (much like we did with https://en.wikipedia.org/wiki/Tyrian_purple snails).
replyI'm not aware of any record of us having done so, but it's absolutely the kind of thing we would do, and there's much more pre-history than history when it might've happened.
It's also the trick employed by Iridigm, which Qualcomm acquired in late 2004 (i was there then).
replyhttps://en.wikipedia.org/wiki/Interferometric_modulator_disp...
I'm curious how they were able to patent a technique invented by nature millions of years ago.
replythe displays have an array of switchable mirrors individually addressable, unlike nature in this case.
reply(but sort of like chromophores in an octopus or cuttlefish, perhaps).
I see, but those MEMs mirrors were already invented.
replyInventions can be useful recombinations or applications of other inventions. They don't need to be wholly unique unto themselves. Indeed, the vast majority of them are not wholly unique.
replyWe're talking about a millions year old invention here.
replyAs far as the patent system is concerned, 20 years and a million years are the same thing. If you combine some million year old things in a new way, you can get a patent.
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