A touch of glass

Cosmos - - Digest -

When you no­tice a brightly coloured but­ter­fly wing, what you’re ac­tu­ally see­ing is light re­flected and scat­tered off mil­lions of nano-sized scales made of chitin.

The wings of the glass­winged but­ter­fly ( Greta oto) of South and Cen­tral Amer­ica do not have these scales. Light hit­ting them, there­fore, is nei­ther scat­tered nor ab­sorbed.

In­stead of scales, the sur­faces are cov­ered in ran­domly dis­trib­uted and po­si­tioned “nano-pil­lars”, which disrupt the re­frac­tive in­dex be­tween the wing and the sur­round­ing air. This re­duces re­flec­tion to al­most noth­ing. As a re­sult, the but­ter­fly, as its name sug­gests, looks like it is made of glass, mak­ing it one of the most beau­ti­ful in­sects you might never see, even when it’s right in front of you.

CREDIT: ED­U­CA­TION IMAGES / GETTY IMAGES

Newspapers in English

Newspapers from Australia

© PressReader. All rights reserved.