Quantum Darwinism: Pointer-State Redundancy

This simulator visualizes how an "objective," classically-agreed-upon reality emerges from decoherence. A central qubit is prepared in a superposition tilted away from its pointer basis, then coupled to a growing shell of independent environment fragments. As each fragment interacts, the qubit's populations in the pointer basis stay fixed while the coherence between them collapses to zero — and every fragment that finishes interacting ends up recording the same classical bit about the outcome. The redundancy readout tracks how few fragments an outside observer would actually need to sample to learn that outcome with 99% confidence, the central quantity in Wojciech Zurek's theory of quantum Darwinism.