Google Willow

Willow's headline result is the one quantum computing had been waiting years for: below-threshold error correction, the point at which adding more qubits actually reduces the logical error rate instead of just adding more noise to manage. Google's Nature paper tested the 105-qubit superconducting chip across 3x3, 5x5, and 7x7 arrays and watched the error rate drop exponentially at each larger scale, exactly as the theory predicted it should. The chip also ran a specific benchmark computation in under five minutes that would take a classical supercomputer roughly ten septillion years — a number so large it stops meaning much beyond 'longer than there has been a universe.' The real news isn't the speed stunt, though; it's that scaling now behaves like an engineering problem instead of a hope.