Newton's Corpuscular Theory

His assumptions

(1)  Newton thought that light is made up of light tiny and elastic particles called copuscles which are emitted by a luninous

body.

(2) The corpuscles travel with speed equal to the speed of light in all possible directions but in straight lines.

(3) The corpuscles carry energy with them. Hence when they strike retina of the eye they produce sensation of vision.

(4) The corpuscles of different colour are of different sizes.

Merits and demerits of the theory.

(1) The corpuscular theory explains that light carry energy and momentum, light travels in a straight line, propagation of light in vacuum, laws of reflection and refraction.

(2) The corpuscular theory fails to explain interference, diffraction and polarization.

(3) A major prediction of the corpuscular theory is that the speed of light in a denser medium is more than the speed of light

in a rarer medium. But actually the truth is that the speed of the light is less in a denser medium. Therefore, the Newton's corpuscular theory is wrong.