At group meeting today, Michael Troxel (Manchester) showed up, as he and Boris Leistedt are working on proposals to modify DES observing strategy. Troxel showed us his convergence maps from the first look or engineering data from DES. Incredible! They look high in signal-to-noise and correlate very well with measured large-scale structure along the line of sight. It appears that this kind of mass density (or convergence) mapping is really mature.
After that, Dun Wang summarized a talk from last week by Jason Wright (PSU); this led to a conversation about the alien megastructures and Tabby's star. We discussed projects we might do on this. I asked what we would need to observe in order to be really convinced that this is alien technology. Since this question is very hard to answer, it is not clear that the “alien megastructure” explanation is really a scientific explanation at all. Oh so many good April Fools' projects.