Quantum theory describes the behavior of matter and energy on the atomic and sub-atomic levels.
In the Quantum World, three fundamental forces govern the nature and behavior of matter and energy: Electromagnetic force, the Strong and Weak nuclear force.
Let’s say, there are two protons in a nucleus. The electromagnetic force repels the protons in opposite directions, the strong nuclear force(which is approximately 137 times as strong as the electromagnetic force) glues them tightly together. The weak nuclear force is responsible for the radioactive decay of atoms(Uranium and Cobalt).
At these smaller scales, the laws of classical mechanics as we know it doesn’t work.
In Classical mechanics, you can predict the exact position of an object at a specific point in space and time. In Quantum mechanics, a position of a particle cannot be predicted with absolute certainty. For example, an electron orbiting around a nucleus disappears at one point in an orbit and reappears at one point in another orbit. This is called a quantum leap. Physicists can’t explain this bizarre behavior.
So the whole theory relies on the probability to define the subatomic world.
Einstein wasn’t comfortable with this. He believed that the theory is true but incomplete.
He said, “God does not play dice with the universe”. He was convinced that the understanding of the universe could not be based on probability.
