Mike Finn-Kelcey/Imperial College London

John Pendry’s kitchen is dominated by a huge photograph of what looks like the view through a kaleidoscope: dizzying shards of purple, green, yellow and white. Given that Pendry is famous above all else for inventing an invisibility cloak – a device that can bend light around objects – I wonder if I am looking at something related to that.

But no, he tells me, the image simply shows crystals of vitamin C magnified many times. All that invisibility-cloak stuff is in the past, he says, and he has moved on to “more exciting things”.

It is a throwaway remark, but it reveals something of why I have always found Pendry, who is based at Imperial College London, so interesting. This is someone who invented a device 20 years ago that sounds like magic, but his true legacy is barely appreciated. If engineers get their way, Pendry’s ideas will soon shape everything from earthquake protection to self-driving cars.…