What Quantum Computing Actually Is

Classical computers store information as bits — either 0 or 1. A quantum computer uses qubits, which can exist in a superposition of 0 and 1 simultaneously until measured. This isn't magic — it's a consequence of quantum mechanics that allows certain computations to be performed exponentially faster than any classical machine. The key insight: quantum computers aren't faster at everything. They're dramatically faster at a specific class of problems — factoring large numbers, simulating molecules, optimising complex systems. For most everyday tasks, your laptop will always win.

Quantum computing has been 'ten years away' for thirty years. What's changed: NOISY INTERMEDIATE-SCALE QUANTUM (NISQ) ERA: We now have real quantum processors with 50–1000+ qubits. IBM, Google, IonQ, and others have publicly accessible quantum hardware. GOOGLE'S WILLOW CHIP (2024): Demonstrated a computation that would take the world's fastest supercomputer 10 septillion years — completed in 5 minutes. This wasn't a practical application, but it proved quantum advantage is real. CRYPTOGRAPHY THREAT: A sufficiently powerful quantum computer could break RSA and elliptic curve encryption — the backbone of internet security. This is why governments are mandating post-quantum cryptography now.