Jim Peebles (Princeton) spent the day at NYU to work on a synthesis of galaxy evolution observations and predictions. We are trying to write a document that draws out tensions with the dominant (CDM) paradigm, and advocates new observations and new theoretical work, in the service of understanding galaxy evolution and the dynamics of the dark sector in the context of the standard model of cosmology (which is extremely well tested on large scales—scales much larger than galaxies). We ended up spending a lot of time talking about massive central black holes, whose abundances, masses, and locations in galaxies all are very constraining on the hierarchical picture of structure formation. If galaxies grow by merging, and the pre-merger galaxies contain black holes, then in general there ought to be non-central and ejected massive black holes. None have been observed, to my knowledge.