Why full - fledged quantum computers might always be five years away

When exactly do qubits and cables and cooling systems become a quantum computer?Niplot/Alamy When exactly do qubits and cables and cooling systems become a quantum computer? What is a quantum computer? The question feels deceptively simple. It is a computer that uses quantum effects to run calculations – or at least, that is what I have been saying to friends and acquaintances for years. Because I report about the latest advances in quantum computing nearly constantly, I have felt confident in this answer. Recently, however, I have had to re-examine that confidence. A more detailed question makes clear why: though I can name many different components and functions of a quantum computer, could I identify exactly when they all become a quantum computer? One recent philosophical study suggests that this is at the root of the difficulty of forecasting the future of quantum computing. For Christophe Jurczak at investment firm Quantonation, it all started at a conference that had nothing to do with quantum computing. Researchers were…