Answer:
The answer is they utilized light in a few spots to enlighten the subjects and to demonstrate their volume as masses.
Explanation:
That is the reason every one of the particles that move at the speed of light (e.g. photons) have zero rest mass. As a molecule with mass methodologies the speed of light, its vitality increments and winds up unbounded at the speed of light, which is the motivation behind why it can never be quickened to achieve that speed. However, you can state that the photon has relativistic mass on the off chance that you truly need to. In current wording, the mass of a protest is its invariant mass, which is zero for a photon.