From Butterfly Wings to Metamaterials

I was on Denbies Hillside a couple of years ago and I got this rather lovely shot of the Adonis Blue. It's quite rare in most places, but on Denbies Hillside, near Dorking, it's prolific in the spring time. Not only is it a very beautiful butterfly, but also it has a particular scientific interest for optics because the blue color it has isn't generated by chemicals, by dyes. It's caused by the structure of the wings. There's a microstructure in the wings which diffracts light and it just diffracts the blue light, which is what produces that very intense blue. And that hinges on some ideas I've been developing in my scientific life, which is to control light with a new class of materials, called metamaterials. And their function is due to their structure. But the butterfly got there first. I'm John Pendry and I'm a professor of physics at Imperial College London. I work on the theory of how to control light.