"You can't see a rainbow without going through wind and rain", this classic lyrics must be familiar to you. After the storm, the sun shines brightly, and a bright rainbow bridge is set up in the opposite sky, which is indeed pleasing to the eye. However, you must also notice that you don't have to meet the rainbow after experiencing wind and rain. What are the conditions for the formation of rainbows?
The color of the rainbow also comes from the sun. After the rain, there are still a large number of small water droplets floating in the sky, which are like lenses like small balls. When sunlight passes through them, it reflects and refracts, and the intensity of the penetrating light line decreases. At the same time, due to refraction, the original white light is decomposed into seven color light, but its color order is opposite to the halo, from outside to inside, from red to purple.
But if the sun is too strong and the temperature is too high, the water droplets after the rain may evaporate quickly; The rain range of Thunderstorm in summer is very narrow, and the distribution of water droplets in the sky is uneven. There may not be water droplets in the sky directly opposite the sun after the rain. There will be no rainbow in any of the above situations.
The brightness and width of a rainbow are also closely related to the size of water droplets: the larger the water droplets, the brighter the rainbow and the narrower the color band; The smaller the water drop, the darker the rainbow and the wider the color band; If the water drop is too small, there will be no rainbow at all.
The formation of rainbows is also related to the height of the sun. The sun shines on the water droplets in the sky opposite it to form a rainbow, so the rainbow is generally located opposite the sun. If the sun rises too high, even if it forms a rainbow, it is below the horizon and we can't see it. That's why it's hard to see a rainbow at noon.
A second rainbow, called neon, sometimes appears above the rainbow bridge. Neon and neon have similar causes, but the sunlight is reflected more than once in the water drop, so the order of color is opposite to that of neon, and the brightness is weakened by one more reflection. The relative position of sunlight and water droplets forming neon is different from that forming neon. The final effect is that the height of neon is slightly higher than that of neon. The beauty of rainbow and neon is amazing. When it appears in front of you, you will be overwhelmed by the uncanny workmanship of nature!
When the rain clears and the sky becomes dry again. Once the remaining water droplets in the air are "cleaned out", the rainbow disappears. Perhaps it is because beautiful things like rainbows are always fleeting, which makes people miss and regret infinitely, and know how to cherish everything beautiful and short in life.