In the morning I gave an informal talk at the Simons SCDA, about my work on The Cannon, and my issues (both good things and bad things) with machine learning. I discussed the point (which inspires our ABC research, and which I also discussed with Kravtsov at Chicago) that quantitative natural science is now almost entirely computational—meaning that the theory is a simulation that makes artificial data—and this leads to changes in how we do inference and speak about realities.
In the afternoon, I spoke with Megan Bedell (Chicago) about the echelle spectroscopy radial-velocity data she has; she has done some dimensionality reduction and there are promising opportunities I think to improve the end-to-end radial-velocity precision. I also worked on my celestial mechanics code for Price-Whelan; it is not working and I don't know why! My only option is to write proper tests. Tomorrow!
While all this was going on, in the background, Dun Wang has been steadily finding cool stuff in the K2C9 data, including, for example, this (previously known from the ground) baby!