The Quantum Coin: Bohr & von Neumann's Solution ✎ express
A quantum particle, an inhabitant of the elementary particle world, resembles a coin spinning in the air: neither heads nor tails, but a blend of possibilities. Yet when it lands on the table, the outcome becomes definite. What serves as the table in a measurement?
The mathematician von Neumann showed that if the device is infinitely complex, its collective behavior inexorably squeezes a definite value out of the particle — much like how disorder inevitably grows in a closed system. The new work fuses Bohr's views with this mathematics: classical concepts are not a choice, but a necessity. The measurement problem vanishes. An unexpected twist: the same logic applies to black holes: there, quantum uncertainty hides behind the horizon, just like the faces of a spinning coin.
Von Neumann, who invented computer architecture, also brought his love for infinite systems to quantum mechanics: his measurement mathematics echoes the processing of crisp bits from quantum noise.