He shook the foundations of Physics !

Werner Heisenberg, postulated the famous Uncertainity Principle. He postulated that we can never know what goes on in the invisible subatomic realm and that " therefore we should abandon all attempts to construct perpetual levels of atomic processes".

Independently of Schroedinger and De Broglie, Heisenberg developed experimental data into tabular form, which he called matrices. His method was called Matrix Mathematics.

The quintessence of his theory is sample. The course of a single electron cannot be predicted and is uncertain. Newtonian Physics do not apply to the subatomic realm. Quantum Theory can predict the distribution ( probable ) with a beam of electrons, but Quantum Theory cannot predict the course of a single electron !

The earlier idea of the causal Universe is totally undermined by the Heisenberg Uncertainty Principle.

Niels Bohr, another New Physicist, wrote

Quantum Mechanics, entails, the necessity of a final renunciation of the classical idea of causality, with a radical revision of our attitude towards the problem of physical reality