Source of light
The sun is the chief natural source of light. When it disappears, darkness falls. After a great deal of painstaking investigation, scientist discovered that the earth itself does not emit light, nor does the moon. They also demonstrated that in our solar system the planets, like the earth and its satellite the moon, revolve around the sun in a perfectly regular orbit. Isaac Newton performed a number of brilliant and amazingly simple experiments which enabled him to define the composition of solar light. What we call ‘white light’ is in face made up of a wide range of different colors. By using a piece of glass called a prism, Newton was able to split light up into its different components.