“一道残阳铺水中，半江瑟瑟半江红。”古往今来，人们不知留下了多少关于夕阳的优美诗篇，如火的夕阳赋予了人们无限的遐想与灵感。在欣赏这些美妙诗篇的同时，不禁产生一个一问：落日为什么是红色的呢？我们来看看下面这篇文章是怎么说的吧！ 

    As the sun begins to set, the light must travel farther through the atmosphere before it gets to you. More of the light is reflected and scattered. As less reaches you directly, the sun appears less bright. The color of the sun itself appears to change, first to orange and then to red. This is because even more of the short wavelength blues and greens are now scattered. Only the longer wavelengths are left in the direct beam that reaches your eyes. 

    The sky around the setting sun may take on many colors. The most spectacular shows occur when the air contains many small particles of dust or water. These particles reflect light in all directions. Then, as some of the light heads towards you, different amounts of the shorter wavelength colors are scattered out. You see the longer wavelength, and the sky appears red, pink or orange. 

    wavelength: 波长 

    particle: 微粒

    reflect: 反射