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The dazzling blue of a morpho butterfly's wings contains no blue pigment; it comes from microscopic ridges on the wing scales that reflect light in a way that strengthens blue.

Optics (structural colour)

ScienceArt

The story behind the card

Morpho butterflies live in the tropical forests of Central and South America. Their blue is a structural colour. Instead of a pigment absorbing some colours and reflecting others, tiny layered ridges on each wing scale, far thinner than a hair, bounce light back so that blue light waves line up and reinforce each other while other colours cancel out. Peacock feathers and soap bubbles make colour in the same way. Because the colour lives in the shape, it shifts as the viewing angle changes and disappears if the scales are crushed. In flight the blue flashes on and off as the wings open and close, which may help males signal to one another and make the butterfly harder for birds to follow.

Türkçe oku
Morpho kelebeğinin kanatlarındaki göz alıcı mavide hiç mavi boya maddesi yoktur. Bu renk, kanat pullarındaki mikroskobik çıkıntıların ışığı mavi tonları güçlendirecek biçimde yansıtmasından doğar.

Morpho kelebekleri Orta ve Güney Amerika'nın tropik ormanlarında yaşar. Mavileri bir yapısal renktir. Burada bir boya maddesi bazı renkleri soğurup ötekileri yansıtmaz; her kanat pulundaki, saç telinden çok daha ince, kat kat dizilmiş minik çıkıntılar ışığı öyle geri yansıtır ki mavi ışık dalgaları üst üste binip güçlenir, öteki renkler birbirini söndürür. Tavus kuşu tüyleri ve sabun köpüğü de rengini aynı yolla üretir. Renk yapının biçiminde saklı olduğu için bakış açısı değiştikçe renk de değişir, pullar ezilirse mavi kaybolur. Uçarken kanatlar açılıp kapandıkça mavi bir yanıp bir söner; bu, erkeklerin birbirine işaret vermesine ve kuşların kelebeği gözden kaçırmasına yardım ediyor olabilir.

Sources and further reading

Background reading: Morpho (genus)
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