Okay, that's … what the fuck? That's amazing!
We tend, I think, to imagine that the days of simple scientific 'miracles' – Newton and his prism, Fleming and penicillin – are at an end. Anything really useful will take years of work and a mountain of kit to make happen.
Nope. Take tartrazine, the food colouring used in Doritos, and paint it onto your skin. Shine a red light on it. Your skin is transparent!
How many medical applications does that have?!