Quantum Mechanics
Lesson 1 of 4 11 min +120 XP

Wavefunctions & Superposition

Describing a quantum state.

What you'll learn

  • Interpret |ψ|² as probability
  • Define superposition
  • State what measurement does
The spinning coin

A coin spinning on the table isn't heads or tails — it's a blur of both until it lands. A quantum particle lives in that in-between blur, called superposition, and the wavefunction is the math describing the spin before it settles.

The wavefunction

A quantum system is described by a wavefunction ψ. The square of its magnitude, |ψ|², gives the probability density of finding the particle at a location.

Superposition & collapse

Before measurement a system can be in a superposition of states. Measurement yields one outcome with probability set by |ψ|², 'collapsing' the state.

Simulation · Wave: amplitude & frequency

A wavefunction is a wave. Adjust amplitude and frequency — squaring the amplitude scales the probability density |ψ|².

Knowledge Check

+30 XP / correct

1. In quantum mechanics, |ψ|² represents…

2. A superposition is…