4.1 Three paths to Quantum Mechanics

We can get to the quantum mechanics roughly in three equivalent ways:

1. Wave mechanics a la Schrodinger: Schrodinger equation is presumed, the rest is derived.
2. Matrix mechanics a la Dirac: Heisenberg uncertainty is presumed, the rest is derived.
3. Path integral a la Feynman: Necessity of summation of all paths is presumed, the rest is derived.