Quantum States, Wave-Functions and Their Existence

Quantum States, Wave-Functions and Their Existence

Parking info: The parking lot may be busy; u can find street parking on Mayview Ave residential area instead.

This is part of a series of sessions on Quantum Mechanics, but from a philosophy point of view. There are various materials to cover.

In this session we discuss what exists in this world according to Quantum Mechanics (QM). We will focus on what are Quantum States and Wave Functions.

See a short video of Sean Carroll on the existence of electrons (in Quantum Field Theory, QFT): https://youtube.com/shorts/1bOdROHI4lc?si=bDxr0GOu8sn-RZcC
“What really exists are the vibrations of electron fields.” – Carroll
Such a statement can be reinterpreted in QM: What really exists are wave functions (or quantum states). We will explicate what this means.

Quantum states: ψ-ontic vs ψ-epistemic debate
“Does the quantum state represent reality or only our knowledge of reality?”
If the answer is "reality," then the quantum state (and thus the wavefunction) is ψ-ontic.
ψ-epistemic means that quantum states are about knowledge and information, and QM is incomplete.

The understanding of mathematics and classical physics are highly recommended but not strictly required.

The series will include topics:

• Electrodynamics - Maxwell’s equation. How to think about classical physics and reality.
• Basics of Quantum Mechanics:
• Vector space, Hilbert space
• Wave function.
• Measurement
• Spin and Classical Magnetic Dipole Moment
• Problems and puzzles of Quantum Mechanics:
• Entanglement
• EPR Paradox (Einstein - Podolsky - Rosen Paradox)
• Hidden variable theory
• Bells’ Theorem (Bell’s inequality)
• Non-locality and hidden variables.
• Philosophy of physics and QM
• Physics and reality: Ontology of objects in physics
• Physics and mathematics: The relation between mathematics and physics
• Beyond QM
• String Theory (TBD)
• Quantum Field Theory and Standard Model (TBD)