Fascinating to see how water has remained an unsolved problem for so long. In some ways we know less now than before. When I was an undergraduate physical chemistry student 137 years ago, it was a well-known fact that ice skates worked because the phase diagram for water said it would be a liquid at the pressure and temperature underneath the blade. Now, all we know is that that is not the case.
Nice to see the occasional physical chemistry article in HN (or, in Quanta for that matter.) Some of my professors and colleagues have dedicated their lives to the fundamentals of water; theory and experiment from gas phase spectroscopy of water dimers, trimers, and clusters to stat-mech of the condensed phases of which there are so many.
On the macro scale, water availability or the lack of it, will loom large in the coming years. My late father dedicated a lot of his life to the implications.