Question

why does light have no mass​

Answer 1

Answer:

Light is composed of photons, which have no mass, so therefore light has no mass and can't weigh anything. Not so fast. Because photons have energy and, as Albert Einstein taught us, energy is equal to the mass of a body, multiplied by the speed of light squared.

Explanation:

your problem's solution here.

Answer 2

Answer:

light is the packets of quanta which is Photon.

and photon has zero mass.

by the special theory of relativity only particle which has their rest mass zero can have velocity of light