When raindrops are suspended in the air, light will enter the raindrops and then refract. Inside the water drop, the light will be reflected many times, and then refracted again to exit the water drop. Different colors of light will bend at different angles during refraction and reflection.
Because the refraction angle and reflection angle depend on the wavelength of the incident light, the light will be dispersed in the water droplets, and the white light will be decomposed into seven different chromatograms.
When light is emitted from a water drop into the air, it will refract again. In this process, the light will form a fan angle and an arc, which is the rainbow we see. The formation of the rainbow occurred simultaneously on countless water droplets in the atmosphere, forming a series of arcs.
Rainbow usually has seven colors: red, orange, yellow, green, blue, indigo and purple. This is because light with different wavelengths will show this dispersion at different angles in the process of refraction and reflection. The outside of the rainbow is red, because the wavelength of red light is the longest, and the angle of refraction and reflection is the largest.
The interior is purple, because violet light has the shortest wavelength and the smallest refraction angle and reflection angle. Therefore, when sunlight is refracted and reflected by raindrops, we can see beautiful rainbows at the right angle and under the right conditions.
Rainbow characteristics:
1, color rhythm: Rainbow usually appears as an arc-shaped light band, which consists of seven colors, namely red, orange, yellow, green, indigo and purple from outside to inside. Each color has obvious color changes, forming a beautiful rhythm effect.
2. Bending appears in pairs: the arc formed by rainbow is usually semi-circular or partial arc, which is caused by the reflection and refraction of light inside water droplets. Under ideal conditions, the rainbow can form a second darker bend, which is located outside the first rainbow.
3. Rapid dissipation: The duration of rainbows is usually short, because they are produced by a special combination of meteorological conditions and light angles. Generally speaking, the rainbow will gradually dissipate after the rain until it is out of sight.
4, the center of the circle is the same: the center of all rainbows is located in the opposite direction of the observer, that is, when we see the rainbow, our backs are turned to the sun. This means that the sun is in a straight line and the arc of the rainbow is centered on the observer.
The sky is the background: rainbows usually appear in the sky, and the sun is behind them. So the brightness and color of the sky will affect the clarity and visibility of the rainbow.