Question

What is reversiblity? and where can we apply this reversibility? In stock's relation he used reversibility bt how the light can be reversible without hitting any object?

Answer 1

In thermodynamics, a reversible process is a process whose direction can be "reversed" by inducing infinitesimal changes in certain properties of the system via its environment. Throughout the reversible process, the system is in thermodynamic equilibrium with its environment.

Answer 2

Explanation:

The law stating that if the direction of a light beam is reversed, despite the number of times the beam is reflected or refracted, it will follow the same path.