Ψ|Ψ|² THE SCHRÖDINGER EQUATION
Est. 1926 — still unsettled

The equation that changed reality

One equation transformed our understanding of matter, probability, and reality. Explore it one symbol at a time.

i ℏ Ψ(r,t) = Ĥ Ψ(r,t)
Ψ is a good place to start
Nothing selected yet — try Ψ, the wave function.
A free particle wave packet, drifting and spreading
Explore the quantum world ↓
Quantum 101

Six ideas that break your intuition

Everything downstream of the equation — from computing to cosmology — traces back to a handful of strange, testable facts about the universe.

⟩+⟨
Superposition
Can something really be in two places at once?
Δx·Δp
Uncertainty
Nature won't let you know everything at once — by design.
↯
Entanglement
Einstein called it "spooky action at a distance."
⇥|
Tunneling
Particles cross barriers they shouldn't be able to cross.
⟨ψ|
Measurement
What happens when a quantum system is measured?
∿ / •
Wave–Particle Duality
What exactly is a particle, anyway?
The Weird Stuff

Where physics stops sounding like physics

Every entry here is labeled by what kind of claim it actually is — so the strangeness stays honest instead of blurring into vibes.

Thought Experiment Schrödinger's Cat read → Interpretation Many-Worlds: does reality split on every measurement? read → Open Question The Measurement Problem read → Open Question Does reality exist before we look at it? read →