Isaac Newton is considered one of the greatest figure in the history of science.In addition to his numerous contributions to science and mathematics,he made a systematic study of light and published it in the form of a book in 1704.In thos book, Newton described his experiment,first reported in 1672,on despersion,or separation of light into spectrum of its component colors. Gerimaldi had earlier observed light entering the shadow of a needl—Newton explained this by saying that the needle exerts a force that pulled the light from the straight path.