【英语时差8,16】蓝鸟为什不蓝？（下）

（单词翻译）

 The glittery blues¹ seen on bird wings are often caused not by pigment², but by the way light waves interact with the feather. Physicists³ call this “structural⁴ color”. Because of the layered structure of the feather, light waves entering it bounce back at different times and thus collide, or “interfere” with each other. Certain wavelengths⁵ get cancelled out while others become reinforced. The reinforced colors that come back strongly to your eye are mostly in the blue range. The result is that eye-catching display of blues. As it turns out, there aren’t many blue pigments⁶ used by birds in general. So any time you see blue or purple on a bird’s wing, you can suspect that at least some of it is structural color. Especially if it’s got that razzle-dazzle effect.