【英语时差8,16】蓝鸟为什不蓝？（上）

（单词翻译）

 One of the loveliest sights an ornithologist¹ runs across is the iridescent² blue found in some birds’ plumage. Sure, cardinals⁴ have red feathers and finches have yellow feathers, but if you ever run across the gleaming, almost metallic-looking blue of an indigo⁵ bunting, you won’t forget it. The colors shimmer⁶ and shine like oil on water. You might be surprised, then, to learn that the feathers which produce such impressive displays are in themselves largely colorless. Take some cardinal³ feathers — after the cardinal is done with them — and grind them up into powder. The powder will still be red. That’s because the color is the result of actual pigment⁷ in the feather. Take those shiny feathers from a bluebird or indigo bunting and grind them up, however, and their color will disappear. Why?