# Uncertainty principle | ðŸ—– nosplit | â†‘ parent "Schrodinger equation" | 251, 7, 504

The wave equation contains the entire state of a particle.

From mathematical formulation of quantum mechanics remember that the wave equation is a vector in Hilbert space.

And a single vector can be represented in many different ways in different basis, and two of those ways happen to be the position and the momentum representations.

More importantly, position and momentum are first and foremost operators associated with observables: the position operator and the momentum operator. And both of their eigenvalue sets form a basis of the Hilbert space according to the spectral theorem.

When you represent a wave equation as a function, you have to say what the variable of the function means. And depending on weather you say "it means position" or "it means momentum", the position and momentum operators will be written differently.

This is well shown at: Video 54. ""Visualization of Quantum Physics (Quantum Mechanics)" by udiprod (2017)".

Furthermore, the position and momentum representations are equivalent: one is the Fourier transform of the other: position and momentum space. Remember that notably we can always take the Fourier transform of a function in $L_{2}$ due to Carleson's theorem.

Then the uncertainty principle follows immediately from a general property of the Fourier transform: https://en.wikipedia.org/w/index.php?title=Fourier_transform&oldid=961707157#Uncertainty_principle

Bibliography:

- https://www.youtube.com/watch?v=bIIjIZBKgtI&list=PL54DF0652B30D99A4&index=59 "K2. Heisenberg Uncertainty Relation" published by doctorphys