Dawn of the 20th century. Experiments and new discoveries begin showing signs that the classical laws of physics that have been used to explain the phenomena till now have profound shortcomings and the new experimental results can no longer be explained by them. It becomes clear that it's time for a new order in the world of physics. The long revered classical physics must be replaced by a new theory that explains the truth of nature.
The phenomena that are unexplainable by the classical theory - Blackbody Radiation, Photoelectric Effect, Atomic Spectra, Rutherford model of the atom, will play an important role in the development of the new order - QUANTUM PHYSICS.
Quantum Physics comes up with revolutionary ideas like The Uncertainty Principle, Quantization of Energy, Wave-Particle Duality which shake the foundations of physics and are almost unbelievable. But they go on passing every test - experimental and theoretical. Will quantum physics go on to become the theory of nature?
Yes, it will.
A large number of physicists come together and contribute to its development. Max Planck, Werner Heisenberg, Schrodinger, Niels Bohr, De-Broglie and Albert Einstein are some of them.
The theory is developed further by physicists like Paul Dirac ( relativistic quantum theory ) and Richard Feynman
( quantum electrodynamics or QED )
21st century. Quantum Physics has been develped and is wonderfully efficient in explanation of nature. Lots of new technologies have come up or are on the brink of coming up using the concepts of quantum physics. There still remain a few shortcomings, but soon they might also be resolved.