Nanoscopy with Focused Light (Nobel Lecture)

A picture is worth a thousand words—This doesn't only apply to everyday life but also to the natural sciences. It is, therefore, probably not by chance that the historical beginning of modern natural sciences very much coincides with the invention of light microscopy. S. W. Hell shows in his Nobel Lecture that the diffraction resolution barrier has been overcome by using molecular state transitions (e.g. on/off) to make nearby molecules transiently discernible.