Two qubits become entangled. Measure one, and the other instantly collapses — no matter the distance. Run the experiment and see the statistics.
The experiment: Click Entangle to create a Bell pair (|00⟩ + |11⟩)/√2.
Then Measure Alice — her qubit collapses to |0⟩ or |1⟩.
Bob's qubit instantly becomes the same. Run 100+ times to see: always perfectly correlated.