Wi-Fi is good for more than just getting your computer online – it can be a computer in and of itself. By bouncing Wi-Fi waves around a room in a precise and controlled manner, they can be used as an “analogue computer” to do complex calculations.

This unusual application is the brainwave of Philipp del Hugne at the Langevin Institute in France and Geoffroy Lerosey at tech startup Greenerwave. They created a way to use microwaves like the ones that carry Wi-Fi to perform …