QUANTUM computing has hit the big time. In a paper leaked online just over a month ago, Google said it had performed the first quantum computation that was beyond an ordinary machine, a milestone known as quantum supremacy. Since then, the headlines have been breathless.

Google’s achievement has been heralded as doing everything from breaking the internet to solving the climate crisis. But let’s stop and breathe. Quantum computing’s true potential is still decades away and hitting peak quantum now may scupper the whole endeavour.

Part of the excitement came from the secretive nature of the reveal. Despite …