#structural color

[entomologize]

Fun fact: common buckeye butterflies (Junonia coenia) can be selectively bred to be blue fairly easily!

It turns out the only thing needed to go from brown to blue is a slightly thicker lamina, which is a flat layer at the bottom of the wing scale:

The lamina's iridescence is caused by the same phenomena as soap bubbles: thin-film interference. When light hits the transparent film of the lamina, it reflects off both the top and bottom of the layer.

Depending on the thickness and refractive properties of the material, the two reflected light waves can be in sync (image below) or cancel each other out. At the perfect thickness, the blue waves of light are enhanced and the butterfly becomes iridescent!

Because the difference in thickness needed to cause iridescence is so slight, it took less than a year to shift a population from just a few blue scales to full-on fabulous blue.

Photos & figures by Rachel Thayer, Nipam Patel, and Edith Smith.

[materialsscienceandengineering]

Beetle exoskeleton and conductive polymer create novel light-modulating material

Some beetles, such as Anomala albopilosa, strongly reflect left circularly polarized light (electromagnetic waves that oscillate leftward relative to the direction of light reception). This property originates from the formation of a cholesteric liquid crystal phase with an optically active, helical structure during chrysalis during exoskeleton formation and the solidification of this phase into a rigid skeleton while retaining its helical structure. Researchers at the University of Tsukuba have coated the surface of its exoskeleton with an electrically conductive polymer, polyaniline. The polymer does not reflect circularly polarized light; however, electrical or chemical oxidation of the polymer changes its coloration, thereby changing its light transmittance. By combining the color change caused by the oxidation and reduction of polyaniline with the exoskeleton's properties of reflecting circularly polarized light, the researchers have crafted a new polymer element that can modulate the reflection intensity of the circularly polarized light. The work is published in the journal Next Materials.

Read more.

[slimefox]

Hi! No real credentials I just love bugs and colors.

Blues like this in nature are usually structural coloration! The way the surface of the exoskeleton/wing/feather/etc has tiny little bits that are all aligned in a way that reflects light back as blue, and often irridecent! As opposed to a blue pigment on a flat surface that just absorbs most colors but blue and reflects it back (mostly a plant thing). Although it's usually just animals, the most brilliant blue living organism is actually a plant using structural coloration!

I always wonder what color structural colorations on different creatures would be if you flatten them out, like what colors are underneath. They can occur at the same time as pigments so you can have a green surface with blue structural coloration and irridescence! Different animals use different types of structural coloration to get different colors and effects, and there's tons of different microscopic shapes.

my favorite part of structural coloration is that it's the reason that some cuts of meat are iridescent when cut the right way, the muscle fibers just happen to line up in the same way as would reflect or refract just exactly those colors. thank god for gay meat

How are these colors possible in nature?

Caenochrysis sp., a member of the cuckoo wasps

June 27, 2023

John Heinz National Wildlife Refuge, Tinicum, Pennsylvania

[levanlanse]

♪ It's time for Fish Fact Friday! ♪

The African coelacanth is a living fossil, and one of only two extant species of coelacanth! African coelacanths have vivid blue scales, which distinguish them from the brown-scaled Indonesian coelacanth.

They often reside in underwater lava caves, spending the day resting in the caves and hunting in their vicinity at night. Unlike most other vertebrates, they have a hinge in the back of their skull which allows them to move both their upper and lower jaw simultaneously - this allows them to open their jaws extra wide to catch prey!

[famousfredisntdead]

Most animals that are blue or green aren't actually blue or green. The only animal that is truly blue is the Obrina Olivewing butterfly. All other animals we observe as blue seem as such due to what's called structural colour.

Most things (including animals) appear a certain colour because they absorb all colours except the one we observe. When something appears a certain colour because of structural colouring, it means there are tiny structures that only allow a certain wavelength to pass through. If the wavelength is too long, it will not pass through this structure.

When white light containing all wavelengths hits this structure, only blue light (or whichever colour is visible) can pass through these structures, thus appearing blue. This is also why these appear iridescent, changing colour as we move our heads. Because the gap allows a certain range to escape, but from different angles we get both extremes of what it allowed through.

It is for similar reasons the sky is blue, though we call this Rayleigh scattering. The particles in the sky Slattery most light making the sky appear blue. But when the sun sets, the angle makes it so the light has to pass through more of the atmosphere, making the sky appear a different range of colours.

[cataclysmictide]

Pain's Like Cold Water Your Brain Just Gets Used To It

No Complaints - Noah Kahan/That Funny Feeling - Bo Burnham/Ask Polly: Help I'm The Loneliest Person In The World - Heather Havrilesky/Ladybird (2017)/Tennessee Williams/unknown/No Complaints - Noah Kahan/Perks of Being a Wallflower (2012)/Ask Polly: Help I'm The Loneliest Person In The World - Heather Havrilesky/That Funny Feeling - Bo Burnham/No Complaints - Noah Kahan/That Funny Feeling - Bo Burnham/Unknown/Perks of Being a Wallflower (2012)/'Ectesy' - Georges Bataille/Warsan Shire/Ladybird (2017)/How to Cure a Ghost - Fariha Róisín/That Funny Feeling - Bo Burnham/No Complaints - Noah Kahan

[agentravensong]

thinking about how the extra area added on to a pacifist run of undertale, the true lab, is about alphys's past mistakes. how it ends with the story reaffirming that, despite the pain she's caused, the thing that matters is that she has now made the choice to do the right thing. she's still worthy of her friends' love.

thinking about how undertale doesn't expect the player to get a pacifist ending for the first time. how it's more likely than not that the player will kill toriel the first time they battle her, how lots of players don't initially figure out how to end undyne's fight without killing her, etc. what it expects — not even expects, really, but hopes — is that the player, if they care enough, will use their canonically acknowledged power over time to make up for those mistakes.

no matter how many neutral runs a player has done before committing to the pacifist run, the thing that matters to the characters, to the story, is that you've chosen, now, to do the right thing.

compared to alphys, the player honestly gets off lightly, in that you're the only one (other than flowey) who really remembers any harm you might have caused. and any direct guilting the game could have done about it is long past at this point. instead, as undertale often does, it makes its point via parallels: alphys caused harm, and she knows it. she has committed to being better. in doing so, she has unlocked for herself a better ending to her story. and she deserves it. she's forgiven.

those structural narrative parallels are all over undertale, if you know where to look. and that's one of the things that makes it so fuckin' good.

[crescentfool]

it's that time of year again...

[kyannnite]

murderous tendencies be damned my boy can work a violin

[yorksnapshots]

Crocus in Dean's Park, York, England.

The Arcade in the background is now a War Memorial.

[xiaq]

This house is going to be unrecognizable when I’m through with it.

[salamispots]

more progress

[materialsscienceandengineering]

Innovative film combines cooling efficiency with vibrant structural colors

In a study published in Matter, Song Yanlin's lab from the Institute of Chemistry of the Chinese Academy of Sciences (CAS) and Li Mingzhu's lab from the Technical Institute of Physics and Chemistry of CAS designed a structurally colored radiative cooling film with a hierarchically porous nested structure (SC-RC film), which can preserve highly efficient subambient cooling performance and provide an appealing colorful appearance. The SC-RC film was engineered to reflect sunlight across a broad range of wavelengths while exhibiting distinct reflective peaks at specific wavelengths. It resulted in brilliant structural colors without compromising cooling efficiency. The color can be adjusted by altering the diameter of colloidal nanoparticles. The innovative design embedded colloidal photonic crystals into micropits, ensuring a confined assembly of nanoparticles and reducing defects associated with self-assembly. This process resulted in vibrant structural colors. In addition, the porous polymethyl methacrylate (PMMA) micropit framework provided protective support for colloidal photonic crystals that significantly enhanced the mechanical stability of the structural colors.

Read more.

[iphigeniacomplex]

my brother and i watched the first season of game of thrones together completely unspoiled, so there was a point in the s1 finale where we sat for a moment in a tense silence, and then my brother said "theyre not going to actually do it" at the same time as i said "they always dress joffrey so well" and he looked at me as if he had never truly seen me before and said "how can you even THINK about that right now" in this very grave hushed tone at which point i felt entirely immersed in the show. like we had for a moment become westerosi peasants in the crowd at the confession. and what i couldn't explain to him at the time was that there is no set of morals a person can have which inherently prevents them from appreciating a serve.

[padofwan]

Really kinda curious where they're going with all of this Ahsoka/Barriss visual/thematic mirroring that's suddenly all over the place. also curious to know just how many yuri scholars there are in the LF animation crew because like it's definitely a non-zero number

[apuff]

frankie and dainix shaking hands because they are both orange eyepatch bros

by the way all aurora people should read castoff and all castoff people should read aurora they have a lot in common