# Quantum mechanics

This resource is for organizing the development of **Quantum mechanics** content on Wikiversity.

Quantum mechanics is a branch of physics providing a mathematical description of the waveâ€“particle duality of matter and energy.

Quantum mechanics is closely related to SchrÃ¶dinger's Cat, where the tester sealed a cat in a box. Also in the box, there was a Geiger counter (radioactive detector), a radioactive source, a hammer, and a flask of poison. If the radioactive source is detected by the Geiger counter, the flask would be shattered by the hammer, killing the cat. However, it may go undetected, thus letting the cat live. When you opened the box, the cat would be both alive and dead, but you would only see one.

## Contents

## Lessons[edit]

- Origin of quantum mechanics
- The essential ideas
- Wavepackets
- Particle in the box
- Harmonic oscillator
- Further particles in the box and polar coordinates
- Rigid rotor
- The hydrogen atom
- Operators and measurements
- Heisemberg principle
- Magnetic fields and spin
- Many electron systems
- Atomic spectra
- Molecular orbital theory

## Resources[edit]

**Wikimedia resources**

## Essays[edit]

For discussion of the origins and theoretical background of quantum mechanics. A good way to learn quantum mechanics is to try to explain it yourself. Edit an essay that is already posted, or create your own. It should be possible to avoid most "edit wars" by splitting essays.

**How things work college course/Quantum mechanics timeline**, by Guy vandegrift is abbreviated version of Wikipedia's timeline with full mathematical explanations that should be edited only if the intent is to reduce its level of complexity. For a more advanced discussion please read or edit Timeline.**Photoelectric effect**, by Guy vandegrift: An entry level discussion that focuses on the difficult question of why the classical picture of reality seems to fail.**Casimir effect in one dimension**, by Guy vandegrift: Not too much physics is needed, but the reader should have had one or two semesters of college calculus. It explores the "astonishing" claim that 1+2+3+...=-1/12.**Quantum field theory on a violin string**, by Guy vandegrift: At the level of a first or second semester undergraduate course in quantum mechanics.**Wave equations in quantum mechanics**A non-technical look requiring minimal mathematics.