Visual Explainer
Entanglement — Visualized
Toggle between entangled and independent qubits. Measure both and watch the correlation pattern emerge over many shots.
Qubit A
Qubit B
What makes entanglement special
With independent qubits, each outcome is its own coin flip — matches happen about 50% of the time by chance. With entangled qubits (specifically a Bell state), measuring one qubit instantly determines the other — every time, regardless of any distance between them. This correlation is stronger than anything achievable classically, which is what John Bell's theorem proved in 1964.
Why it's not faster-than-light communication
Even though the correlation is instantaneous, neither qubit's outcome is controllable — both are genuinely random. You can't choose what value you'll measure, so no message can be encoded. Only by comparing results over a classical channel does the correlation become visible.