Three short steps, about five minutes: what a quantum computer is, one game whose answer is a theorem, and one public claim we scored. No sign-up. It remembers where you stopped, in this browser only.
Step 1 of 3 · about a minute and a half
A quantum computer is a choir in which every singer slowly drifts off key, and glancing at any one of them to check makes that singer forget the song. (Singer = qubit, the machine's basic unit of information. Off key = the small error every qubit collects just by existing.)
So you cannot fix it by looking. Error correction hires a conductor who never listens to a soloist. The only question it puts, to one neighbouring pair at a time, is do you two match? Two clashes side by side point straight at the singer who drifted, and nobody was ever heard alone.
For thirty years the conductor's rulebook was written by hand. In 2024 Google DeepMind trained an AI, AlphaQubit, to write its own, by listening to one real chip's recordings until it learned that chip's bad habits. It makes about 30% fewer wrong calls than the hand-written rules fast enough to run on a live machine. That partnership, AI fixing quantum and quantum one day feeding AI, is what this site is about.
Check yourself
The conductor never listens to a single singer on their own. Why not?
Measuring one qubit on its own destroys the state it was holding, which is the thing worth protecting. Asking only do these two agree? reveals that something flipped without revealing what either one is.
Step 2 of 3 · about a minute
Four identical doors, one exit. Guessing, you open the exit first time one try in four. A quantum search does better, and for four doors the answer is exact: one round of Grover's algorithm makes the exit certain. That is a theorem (Grover, 1996), not a tuned setting.
Press Amplify to run one round, then Open a door. The bars are the chance each door opens; a real machine never shows them to you, it only lets you open one door.
Rounds so far: 0. Every door has the same 25% chance.
The full game has five corridors, up to 64 doors: Grover's Escape.
Step 3 of 3 · about a minute
This site logs public promises about quantum computing with the rule for judging them written down, then scores each one when its deadline passes. Here is one. Make your call before you see ours.
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Done
You have the idea, one proved answer and one scored claim. Pick the question you care about most; each track lists its lessons in reading order.
Or just play, see every claim on the Ledger, or open your progress page.