structural coloration structural coloration production colour structured surfaces fine interfere visible light combination example tail feathers brown microscopic structure makes reflect blue green light structural coloration observed english scientists principle wave interference explained century later young described result interference reflections surfaces thin films combined light enters leaves films geometry determines certain angles light reflected surfaces angles light different colours appear different angles animals feathers birds scales butterflies interference created range mechanisms including selective mirrors crystals crystal proteins vary configuration cuts meat structural coloration exposure periodic arrangement muscular mechanisms correspond elaborate structures visible electron plants brilliant colours produced structures cells brilliant blue coloration known living tissue found marble spiral structure produces law scattering light structural coloration potential industrial commercial military application surfaces provide brilliant colours camouflage efficient optical switches low glass history book described colours feathers parts feathers glorious bird appear microscope feathers naked eye evident stem feather tail sends lateral branches threads microscope appears large long body consisting multitude bright reflecting parts upper sides consist multitude thin bodies exceeding thin lie close like mother pearl shells reflect light light curious manner means positions respect light reflect colour colours ones arise immediately light found water colour parts destroy colours proceed alteration reflection book described mechanism colours brown pigment tail feathers newton noted finely colour feathers birds particularly feather appear colours positions eye manner thin plates found 7th 19th observations colours arise transparent parts feathers fine hairs grow sides lateral branches feathers extended newton particle theory light showing light behave wave showed light sharp edges slits creating interference patterns book frank acknowledged existence structural colours colours animals solely presence definite skin beneath skin partly caused optical effects scattering unequal light rays colours kind spoken structural colours caused structure coloured surfaces metallic feathers birds birds presence excessively fine surface feathers largely dismissed structural coloration firstly case structural colour needs display background dark pigment asserting rarity far source colour animals presence skin definite later admit cape golden mole structural hair rise brilliant colours principles structure pigment structural coloration caused interference effects colours produced material scored fine parallel lines formed parallel thin layers composed scale colour structural coloration responsible blues feathers birds bee roller example butterfly wings beetle wing cases feathers shells pearl reflected colour depends viewing angle turn apparent structures responsible structural colours combined pigment colours feathers brown principle explained created extremely thin films reflect light falling surfaces rest light goes films reflected surfaces sets reflected waves travel upwards direction reflected waves travelled little controlled thickness index film angle light fell sets waves phase waves apart words certain specific angles add interfere giving strong reflection angles phase differences giving weak reflections thin film reflects pure colour given angle different colours different angles thin film structure like butterfly wing bird feather moves change colour mechanisms fixed structures number fixed structures create structural colours mechanisms including selective mirrors crystals crystal deformed structures far elaborate single thin film films stacked strong combine colours balance inevitable change colour angle effect mechanism offers specific solution problem creating bright colour combination colours visible different directions constructed layers air gives rise colours butterfly wing scales tail feathers birds newton correct claim colours created interference structures responsible close light scale smaller structures light way produce tree shaped wing scales brilliantly coloured tropical butterflies drawing variant exists bird paradise feathers brightly coloured breast patch shaped creating thin film strongly reflect different colours bright blue green orange yellow bird moves colour switches sharply colours drifting courtship male bird systematically makes small movements attract females structures evolved sexual selection crystals formed different ways butterfly crystals formed sized holes wing scales holes diameter distance apart holes arranged regularly small patches neighbouring patches contain differing result scales reflect green light evenly different angles instead brazil covered green oval scales contain diamond based crystal oriented directions brilliant green coloration hardly varies angle scales effectively divided wide single crystal reflects light direction different neighbours selective mirrors create interference effects formed sized bowl shaped pits lined multiple layers wing scales butterfly act highly selective mirrors light yellow light reflected directly centres pits blue light reflected twice sides pits combination appears green seen array yellow spots surrounded blue circles microscope crystal formed hollow create bright colours sea mouse non genus marine colours warning predators attack walls hollow form shaped crystal holes apart structure consisted stack making marine organisms deformed consisting randomly oriented matrix create non blue colour blue yellow reflections arranged direction colours magnificent vary angle spiral formed stacked create reflection marble african resulting intense blue coloration known nature surface layers cells thick walls containing transparent spaced allow interference blue light cells layer cells thick containing dark brown produces stronger colour wings butterflies instances structural coloration known plant cell thickness stacked making reflect different colour neighbours producing effect different blues brilliant green purple red dots cell left handed right handed cell light reflects direction organism known random light visual function seed eating birds visit plant species able perceive light spiral found beetles produce colours surface consisting ordered surface features exposure ordered muscle cells cuts meat structural coloration meat cuts appears ordered pattern muscle exposed light proteins coloration light depends angle observation enhanced covering meat translucent surface removing water content drying causes structure collapse structural coloration disappear variable structures animals including cephalopods like squid able vary colours rapidly camouflage signalling mechanisms include proteins switched configurations configuration proteins cells skin squid controlled electric charge charge absent proteins stack tightly forming thin reflective layer charge present molecules stack loosely forming thicker layer contain multiple layers switch changes layer colour light reflected blue spend time hiding whilst displaying effective camouflage patterns dermal cells provoked quickly change colour bright yellow rings flashing bright blue second greater blue octopus rings contain multi layer arranged reflect blue green light wide viewing direction fast flashes blue rings achieved muscles control normal circumstances ring hidden muscles relax muscles outside ring contract bright blue rings exposed examples technology structural coloration exploited commercially research lead applications way direct parallel create active military camouflage vary colours patterns match environments cephalopods ability vary different light lead efficient optical switches function like enabling engineers fast optical computers surface compound eye densely packed microscopic projections effect reducing reflection increasing transmission incident light similarly eyes surfaces pillars smaller light eye create low glass windows solar cells display devices military stealth technologies surfaces eye principle manufactured creating mask gold performing pioneering books account colours markings animals london robert london newton london research fox animal structural colours biologist guide light nature structures inspired nature general books colour lee nature palette science plant color structural color realm nature
Structural coloration