为什么蓝天是蓝色的，而夕阳是红色的？
发布日期：2023年07月16日 分类：物理学
当太阳光穿过大气层时，光线会与大气中的分子和微粒相互作用。蓝天之所以呈现蓝色，是因为气体分子中的氮氧化合物、尤其是氮气分子和氧气分子会散射短波长的光，而蓝色光波的波长较短，因此更容易被散射。
当太阳处于地平线上方时，阳光需要穿过较长的大气路径到达我们所在的位置，这时光线受到更多的散射。在这个过程中，多数蓝光已经被散射了，只有较长波长的红光能够较好地穿透大气，因此我们看到夕阳时，光线中的红色成分较为明显，给予云彩和大气中的微粒以温暖的红色调。
当太阳处于地平线上方时，阳光需要穿过较长的大气路径到达我们所在的位置，这时光线受到更多的散射。在这个过程中，多数蓝光已经被散射了，只有较长波长的红光能够较好地穿透大气，因此我们看到夕阳时，光线中的红色成分较为明显，给予云彩和大气中的微粒以温暖的红色调。
Why is the sky blue and the sunset red?
When sunlight passes through the atmosphere, the light interacts with molecules and particles in the air. The reason why the sky appears blue is because nitrogen compounds, particularly nitrogen and oxygen molecules, scatter short-wavelength light, and blue light has a shorter wavelength, making it more easily scattered.
When the sun is above the horizon, sunlight needs to pass through a longer atmospheric path to reach our location, resulting in more scattering of light. During this process, most of the blue light has already been scattered, and only longer-wavelength red light can penetrate the atmosphere better. Therefore, when we see a sunset, the red component of light is more pronounced, giving clouds and particles in the air a warm red hue.
When the sun is above the horizon, sunlight needs to pass through a longer atmospheric path to reach our location, resulting in more scattering of light. During this process, most of the blue light has already been scattered, and only longer-wavelength red light can penetrate the atmosphere better. Therefore, when we see a sunset, the red component of light is more pronounced, giving clouds and particles in the air a warm red hue.