冰川，为什么是蓝色的？

Glaciers are huge rivers of ice. 冰川是巨大的冰河。 Ice usually looks white, right? 冰通常看上去是白色的，对吧？ But deep blue ice is hiding inside. 可冰层深处藏着蓝色。 Ice soaks up red light and lets blue out. 冰把红光吸走，只放出蓝光。 Thick ice lets only blue light pass through. 厚冰里透出来的只有蓝色。 That is why glaciers shine in blue. 所以冰川看上去是蓝色的。