Today was the second day of The Galactic Renaissance. Two scientific themes of the day were globular-cluster star abundance patterns, and stellar models that account for 3-d and non-thermal-equilibrium (NLTE) effects. On the former, it was even suggested by one speaker that the existence of chemical-abundance variations of certain kinds might be part of the definition of a globular cluster! There are some extreme cases, and various claims that the most extreme examples might be the stripped centers of ancient accreted galaxies!
On the stellar modeling front, there were impressive demonstrations from Frebel (MIT), Bergemann (MPIA), and Thygesen (Caltech) that improving the realism of the physical inputs to stellar models improves their precision and their accuracy. Thygesen did a very nice thing of using (relatively cheap) 1-D models to inform functional forms for interpolation across grid points of a (relatively expensive) 3-D model grid. That got me interested in thinking about physics-motivated or physics-constrained interpolation methods, which could have value in lots of domains.
In a session about Judy's scientific and intellectual life, Steve Shectman (OCIW) described what the world was like in 1967, when Judy Cohen (Caltech) started graduate school. It was a time of optimisim, disruption, and violence. This resonated with things I know about Cohen, because she and I used to discuss the historical context of her origins as an astronomer back when I was a graduate student.
Another highlight of the day was a discussion with Kim Venn (Victoria) and Matt Shetrone (Texas) about persistence effects that damage a significant fraction of spectra in a significant fraction of APOGEE exposures. We discussed the trade-offs between correction and avoidance, and what it might take to fix the problem.
Over dinner, I and others delivered tributes to Judy Cohen. She really has had an amazing scientific impact, and also been a wonderful person, and had a big influence on me. She also said nice things about me in her own speech!