Why does prism split white light

Now write a story about how you can reach the end of the rainbow and what you will find there. In Isaac Newton was a young scientist interested in learning about light and colors studying at Cambridge University in England. One bright sunny day, Newton darkened his room and made a hole in his window shutter, allowing a beam of sunlight to enter the room. He then took a glass prism and placed it in the sunbeam.

The result was a spectacular multicolored band of light that looked just like a rainbow. Newton believed that all the colors that appeared were in the sunlight shining into his room. If this was true, he thought, then he should be able to combine the colors and make the light white again. To test his idea, he placed another prism upside-down in front of the first prism. He was right. The band of colors combined again into white sunlight.

Newton needed to prove, however, that the colors came from the sunlight and not from the prism. To do this, he placed a card with a hole in it between two prisms, allowing only red light from the first prism to go through the second prism. The red light going through the second prism did not split into different colors, or turn white again; it remained red. Newton repeated the same experiment with all of the colors and got the same result. Thus, Newton proved that the colors came from the sunlight and were not, somehow, stored inside the prism.

Newton wrote about his discoveries in his book Opticks in His book has become one of the most important scientific books ever written. The following is a description of his experiment in his own words. In a very dark chamber, at a round hole, about one-third part of an inch broad, made in the shut of a window, I placed a glass prism, whereby the beam of the Sun's light, which came in that hole, might be refracted upwards toward the opposite wall of the chamber, and there form a colored image of the Sun.

Role Play - After reading aloud the vignette, have students research Newton's experiments and discoveries. Students can then write a skit depicting the day that Newton made his discovery about the properties of sunlight. Students will include imagined dialogue of Newton talking to his friends and family about his discovery. Each step of Newton's experiment should be depicted in the frames of the comic book. Students could then share the comic book with other students and other classes.

During the s painters often joined government expeditions to the western wilderness of America. These painters rendered beautiful landscapes of the Rocky Mountains, Yellowstone, and Yosemite, which they displayed to the delight of the colonists in the eastern cities upon their return. In the painter Thomas Moran joined an expedition to Yellowstone in Wyoming, a location now well known for its waterfalls, hot springs, and geysers. Moran painted pictures of the beautiful scenes that he saw.

These paintings were reproduced and became very popular. Moran's paintings helped make Americans aware of the natural wonders of the western wilderness. This awareness helped establish Yellowstone as the first national park in One of his paintings, Hot Springs of Yellowstone , shows a rainbow forming in the mist and steam rising from a naturally heated spring. Discussion - After viewing Moran's Hot Springs of Yellowstone, or other landscapes from the same period, discuss with students how pictures can communicate intimacy for places they've never seen.

The light wave then travels through the interatomic vacuum towards the next atom of the material. Once it impinges upon the next atom, the process of absorption and re-emission is repeated. The optical density of a material is the result of the tendency of the atoms of a material to maintain the absorbed energy of the light wave in the form of vibrating electrons before reemitting it as a new electromagnetic disturbance.

Thus, while a light wave travels through a vacuum at a speed of c 3. The index of refraction value n provides a quantitative expression of the optical density of a given medium. Materials with higher index of refraction values have a tendency to hold onto the absorbed light energy for greater lengths of time before reemitting it to the interatomic void.

The more closely that the frequency of the light wave matches the resonant frequency of the electrons of the atoms of a material, the greater the optical density and the greater the index of refraction.

A light wave would be slowed down to a greater extent when passing through such a material. What was not mentioned earlier in this unit is that the index of refraction values are dependent upon the frequency of light.

For visible light, the n value does not show a large variation with frequency, but nonetheless it shows a variation. For instance for some types of glass, the n value for frequencies of violet light is 1. The absorption and re-emission process causes the higher frequency lower wavelength violet light to travel slower through crown glass than the lower frequency higher wavelength red light.

It is this difference in n value for the varying frequencies and wavelengths that causes the dispersion of light by a triangular prism.

Violet light, being slowed down to a greater extent by the absorption and re-emission process, refracts more than red light. Upon entry of white light at the first boundary of a triangular prism, there will be a slight separation of the white light into the component colors of the spectrum.

The amount of overall refraction caused by the passage of a light ray through a prism is often expressed in terms of the angle of deviation. The angle of deviation is the angle made between the incident ray of light entering the first face of the prism and the refracted ray that emerges from the second face of the prism. Because of the different indices of refraction for the different wavelengths of visible light, the angle of deviation varies with wavelength.

Colors of the visible light spectrum that have shorter wavelengths BIV will deviated more from their original path than the colors with longer wavelengths ROY. Some colors bend more than others as they pass through the prism, so they split apart. This means that a beam of white light going into a prism comes out as a spectrum of different colors.

Rainbows appear when raindrops in the air act like a prism , splitting sunlight into different colors. White light is made up of all colors of light, from violet at one end through to red at the other. Sunlight is an example of white light.