Is rainbow the refraction or dispersion of light after rain?

Rainbow is the refraction of light after rain.

Explanation:

Rainbow after rain is formed by sunlight penetrating rain particles. Originally, light travels in a straight line, but once it enters the water, it also has the property of refraction. So sunlight will be refracted when it passes through rain particles.

At this time, because the angle of light refraction varies with different colors, seven colors will refract at different angles. So the seven colors will be arranged beautifully. This is the principle of forming a rainbow.

The difference between refraction and dispersion of light

Refraction of light refers to the phenomenon that when light obliquely enters another medium, the propagation direction changes, which makes the light deflect at the junction of different media. Which belongs to the refraction phenomenon of light.

The dispersion of light refers to the phenomenon that polychromatic light is decomposed into monochromatic light; The phenomenon that polychromatic light is decomposed into monochromatic light by prism; The phenomenon of optical pulse broadening in optical fiber caused by different group velocities of different frequencies in the spectral components of light source.

The refraction of light, like the reflection of light, occurs at the junction of two media, except that the reflected light returns to the original medium and the refracted light enters the other medium. In refraction, the optical path is reversible.

Dispersion is also a description of the relationship between optical fiber propagation parameters and frequency. Newton first observed the dispersion of light with a prism in 1666, and decomposed white light into color bands (spectra). Dispersion phenomenon shows that the velocity v=c/n (or refractive index n) of light in the medium varies with the frequency f of light. The dispersion of light can be realized by prism, diffraction grating and interferometer.

Application of refraction and dispersion of light

Refraction of light and its application

1. Examples related to the refraction of light in life: the position of fish in water looks higher than the actual position (the fish is actually below and behind the position); Due to the refraction of light, the water in the pool looks shallower than it really is, and the people in the water look at the scenery on the shore higher than it really is.

In summer, the position of stars in the sky is higher than the actual position of stars. Looking at the pen through the thick glass, the pen holder seems to be in the wrong position, and the chopsticks inclined in the water seem to be bent upward: (optical diagram is required)

2. People use the refraction of light to see that the image of an object in water is a virtual image (the intersection of the opposite extension lines of refracted light).

Application of light scattering

For example, making mirrors for optical experiments to study the dispersion of objects; Make stained glass to reflect different colors and beautify the appearance of the room; Make color photos and use color filters to change the color of photos in the studio to achieve artistic effects; Manufacture optical instruments, such as telescopes and microscopes. And adjust the color of the light through the filter, so that the observer can see different objects.