Sunrays generate quivering in the sky current by waves that is traced by our tiny nerves through the eyes. Light is tiny from outside. If light is called as nature’s excitement, it will not wrong. When we pass sunlight (white light) through a prism, it will be divided into seven colors. It is known as ‘Spectrum’. We can see red color at one end of it and purple (violet) color at another end. Appearing seven colors in the spectrum does not mean that the sunrays are made by the combination of only seven colors. But there are few rays also found outside both the ends of spectrum those we can not able to see with our naked eyes.
Invisible rays after violet band are called ‘Ultraviolet rays’ and invisible rays after red band are called ‘Infrared rays’. Besides of both the rays, there are also other invisible rays. Few of them have been discovered by scientists like- X-rays, Alfa rays, beta- rays and gama-rays.