Why Is the Sky Blue?

课文

1. Sunlight looks white, but it actually contains all colors of the rainbow mixed together.

   阳光看似白色，实则混合了彩虹的所有颜色。

2. When sunlight enters Earth’s atmosphere, tiny air molecules scatter the light in all directions.

   当阳光进入地球大气层时，微小的空气分子会将光线向四面八方散射。

3. Blue light has shorter wavelengths and scatters much more easily than red or yellow light.

   蓝光波长较短，比红光或黄光更容易被散射。

4. This strong scattering makes blue light reach our eyes from many different angles across the sky.

   这种强烈的散射使蓝光从天空各个角度进入我们的眼睛。

5. At sunrise or sunset, sunlight travels through more atmosphere, so most blue light is scattered away.

   日出或日落时，阳光穿过更厚的大气层，大部分蓝光已被散射掉。

6. The remaining light that reaches us directly is richer in red and orange wavelengths instead.

   最终直接到达我们的光线则富含红光和橙光波长。

7. That’s why the sky near the sun appears golden or fiery during those times.

   因此，此时太阳附近的天空呈现金黄色或火红色。

8. Without an atmosphere—like on the Moon—the sky would always look black, even at noon.

   若没有大气层（如月球），即使正午天空也始终是黑色的。

9. Scientists use this same scattering principle to study the composition of distant planetary atmospheres.

   科学家利用同一散射原理分析遥远行星大气的成分。

10. You can even see a hint of this effect by shining a flashlight through a glass of water with a drop of milk.

    你甚至可用手电筒照射一杯加了一滴牛奶的水，直观看到这一效应。