I'm sorry if I made you think I was discouraging.
But indeed, we have to be serious about the origin of something.
I would say, the uncertainty of gaussian wave packet is a consequence of the uncertainty principle, not the origin.
Dirac, Schrodinger and those physicists developed the Quantum...
what you are saying is correct, but it's not the origin of uncertainty principle.
the uncertainty principle can be purely a mathematical theorem, based on the mathematical formulation of quantum mechanics
you can read 《Modern Quantum Mechanics》by J.J. Sakurai, P34-36
or even wikipedia gives...
I read your explanation again and I think your explanation proves that the matrix element of W(t) is diagonal only. It is not guaranteed vanishing for α=β
The Quantum Theory of Fields, Steven Weinberg, P.120
above 3.3.24, it says,
If the matrix elements of W between H0 - eigenstates are sufficiently smooth functions of energy, then matrix elements of W(t) between smooth super-positions of energy eigenstates vanish for t→±∞
I can't get...