When the HMS Victory sank in 1744, with it went an inventor named John Serson and a device he’d dreamed up. He called it the “whirling speculum”, but we now know the basic idea as a gyroscope. Serson thought it could help sailors to navigate when they couldn’t see the horizon. Nowadays gyroscopes are tiny and, as Tim Harford describes, they are used to guide everything from submarines to satellites, from rovers on Mars to the phone in your pocket. They are also integral to drones – a technology that some believe could transform how we do our shopping. But for that, they’ll need to work in all weathers.