# Light going through glass to make a rainbow

• relativitydude
In summary, a physics class discussed the possibility of a white light beam passing through a meter of glass and producing a 1 cm rainbow on the other end. However, for this to be possible, the beam would have to be infinitely thin. Even a beam of one micrometer would result in the light overlaying back into white light due to the vast number of points where it strikes the glass. The width of the rainbow would be determined by the chromatic dispersion of the glass, which is where the index of refraction varies with the wavelength of light. This phenomenon is common in many materials and is responsible for the rainbow effect.
relativitydude
Someone in a physics class here proposed, a white light beam going through a meter worth of glass and because different frequences refract at different angles, a 1 cm rainbow would come out the other end. The only way I see this to be possible is for the beam to be infinetely thin. I mean REALLY THIN.

(He even says a 1mm beam would be thin enough to product a rainbow affect)

I think, however, even a beam of one micrometer the light would overlay back into white light because the vast number of points where the light strikes the glass.

No one know? :(

The width of the rainbow would depend on the chromatic dispersion of the glass more than anything.

Claude.

What is this chromatic dispersion?

Chromatic dispersion is where the index of refraction of the material depends on the wave length of the light, i.e. it is not a constant. Most materials index of refration depends on wavelength, so you will see a rainbow effect.

## 1. How does light go through glass to make a rainbow?

Light is made up of different wavelengths, and when it passes through a medium like glass, it bends or refracts. The different wavelengths bend at different angles, creating a spectrum of colors that we see as a rainbow.

## 2. Can light make a rainbow without going through glass?

Yes, light can make a rainbow without going through glass. When light passes through water droplets in the atmosphere, it undergoes a similar process of refraction, resulting in a rainbow.

## 3. Why does light only produce a rainbow when it goes through glass at a certain angle?

The angle at which light enters and exits the glass affects the degree of refraction and the resulting angle of the rainbow. The angle must be just right for the light to be bent enough to create a rainbow.

## 4. Can other materials besides glass produce a rainbow?

Yes, other transparent materials with a different refractive index, such as plastic or acrylic, can also produce a rainbow when light passes through them at the correct angle.

## 5. What causes the different colors in a rainbow?

The different colors in a rainbow are caused by the varying wavelengths of light. Each color has a different wavelength, and as the light is refracted, the different colors are separated and become visible to us.

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