Last week I enjoyed following the Nobel Prize announcements in Physiology or Medicine, Physics, and Chemistry. Reading the popular accounts behind the science is enjoyable, as they are well-written and accessible. Here are a few things I found interesting.
I found the Physics prize a bit surprising. On the one hand, the creativity and vision needed to construct the IceCube neutrino observatory is beautiful and impressive. They have clearly detected high-energy neutrinos, and there is potential for some important astrophysical discoveries. On the other hand, the key word is potential. This prize seems in contrast to earlier prizes for gravitational wave detectors (2017) and for observations of cosmic neutrinos (2002, 2015). For example, the latter solved fundamental issues in our understanding of neutrinos. But perhaps I am missing something.
A fun cultural side to the Physiology or Medicine prize to Karl Deisseroth is that there is a beautiful novel, Transcendent Kingdom, that centres on the life of a graduate student who works in a fictional lab at Stanford based on his. On the science side, a key aspect was the discovery of the protein channelrhodopsin. The essential photophysics is that the protein contains a chromophore, all-trans retinal, that upon photoexcitation undergoes a conformational change (isomerisation) to a 13-cis configuration. This is similar to the photophysics responsible for vision. In both cases, the conformational change of the chromophore triggers a conformational change of the whole protein and an electrical signal.
The chromophore conformational changes are associated with conical intersections between the potential energy surfaces of the ground and excited states. The essential physics can be understood in terms of a two-site Hubbard model.
The Chemistry Prize was for the development of new synthesis methods to selectively make molecules of definite chirality. The popular science background from the Nobel foundation mentions three important conditions for chiral synthesis that were stated in a short paper in 1953, by Charles Frank, a condensed matter theorist. He was a pretty amazing scientist. He showed in 1951 how topological defects determine the growth rates and strength of crystals and wrote an influential review on snow crystals. In 1958 Frank wrote down a free energy density for nematic liquid crystals, without reference to Landau, and long before Anderson emphasised the importance of generalised rigidity in condensed matter. (Albeit, and perhaps more remarkably, Frank's paper freely builds on a 1933 paper by Carl Wilhelm Oseen.
Aside. There is a fascinating and fundamental question about why chiral molecules do not spontaneously quantum tunnel backwards and forwards between the two possible chiralities. Briefly, this is because of quantum decoherence due to the environment. This question often comes up in discussions about emergence in chemistry.
Was there anything that you thought was particularly interesting about any of these prizes?
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