Google’s Sycamore quantum computerPeter Kneffel/dpa/Alamy
In 2019, Google claimed that its Sycamore quantum computer could perform calculations that would take even the world’s most powerful classical supercomputer 10,000 years to complete – but now it seems that a non-quantum computer crunches the numbers several times faster than Google’s machine, and uses less energy doing so.
Quantum computers have the potential to carry out some kinds of calculations vastly more quickly than classical computers, but are still in their infancy. Google announced in 2019 that Sycamore had achieved  “quantum supremacy” – the point at which a quantum computer can…