I was thrilled yesterday morning to learn that super-resolution microscopy is the subject of a Nobel Prize this year. (Or more accurately, that Eric Betzig, Stefan Hell, and William E. Moerner were awarded the Nobel Prize “for the development of super-resolved fluorescence microscopy.”) Super-resolution microscopy is wonderful, as I’ve written before. In all its various flavors, it uses clever optics and statistics to transcend the “diffraction barrier” and allow visualization of sub-100-nanometer structures, such as the inner architectures of cells.
What’s odd, though, is that this is this year’s Chemistry Nobel Prize. There’s nothing very chemical about it — yes, it involves molecules, but so does everything else. It is, of course, hard to define what Physics is, or what Chemistry is, or any other field is these days. Still, it seems fair to state that physicists look for phenomena or build tools that reflect general features of systems, rather than particular details. For super-resolution imaging, part of its beauty is its generality. Stimulated emission (the basis of Hell’s STED method) applies to all fluorescent molecules; the localization-based methods of Betzig and others apply to a very large class of switchable molecules. In addition, both methods make use of very general principles of optics, that again transcend particular details — it’s microscopy after all, a subset of physics!
In contrast, consider this year’s Physics prize, which went to the development of blue LEDs. Yes, it’s important, but is it physics? The principles involved don’t generally apply to semiconductors — that’s in fact why it was so hard to develop blue LEDs! The particular material type matters. To figure out semiconductor light emission requires detailed and difficult considerations of electronic structures in specific systems. This reminds me of… Chemistry!
My theory to reconcile all this is that the Nobel committee was considering two excellent topics, blue LEDs and super-resolution microscopy, and the different subcommittees crashed into one another in a Swedish hallway, scattering their files everywhere. Picking them up, the chemistry group got the physics files, and vice versa. At least the literature subcommittee wasn’t involved, as far as we know…