I got bored with the topic; I felt this was 19th century physics. I was wondering if there was still something profound that could be made with light microscopy. So I saw that the diffraction barrier was the only important problem that had been left over.

It's childish, but it still gives me great pleasure to see high-res pictures everyone told me would be impossible.

Eventually I realised there must be a way by playing with the molecules; trying to turn the molecules on and off allows you to see adjacent things you couldn't see before.

Stefan Hell Quotes