Spark & Anvil Privacy
A calm warm physics study with a globe, a telescope and wooden shelves, a teenager spinning a glowing coin that seems to be both sides at once

🌀

QubitForge

A qubit is just two numbers — a gate rotates them, measurement squares them.

🔮 Open the quantum console →

The whole of a qubit, with no mysticism

A qubit is described by two real numbers — the amplitudes for |0⟩ and |1⟩. A gate is a matrix that rotates those two numbers into two new ones. When you measure, you square each amplitude to get the probability of that outcome (the Born rule) — and the two squares always add to 1. That is it. QubitForge computes the exact amplitudes on your device, so every probability you see is real arithmetic, not a story.

  1. Read the circuit — a start state and a gate or two.
  2. Predict the measurement odds: certain? a 50/50 coin? something surprising?
  3. Reveal the amplitudes and their squares — and see where your intuition was right.

You will meet the four ideas that make quantum computing work: superposition (H makes a coin), phase (a sign a single measurement cannot see), interference (two H gates cancel back to certainty), and entanglement (a Bell pair whose two qubits always agree). No calculus, no complex numbers — just two numbers you square.

The gates you will use

  • X (NOT) swaps the two amplitudes — |0⟩ becomes |1⟩. Purely classical.
  • H (Hadamard) spreads the amplitude evenly — |0⟩ becomes a 50/50 superposition. Apply it twice and it undoes itself: that is interference.
  • Z (phase) flips the sign of the |1⟩ amplitude. Invisible to a single measurement — but it changes what later gates do.
  • CNOT flips a second qubit only when the first is 1. Combine it with H and the two qubits become entangled: you only ever measure 00 or 11.

A console for ages 15–18 — no cast art here by design.

What next? Pick a door

Chosen from what this app is about. What you open is remembered on this device only.