Threads and fragments of an inspiring visit.

Boris Zilber visited us for about a week. His was an inspiring, illuminating visit. Conversations took place at the two universities, but also (and most wonderfully) on the mountains surrounding Bogotá: on Saturday up La Cruz from Chía, on Tuesday early morning up to the páramo via La Vieja, on the eastern side of Bogotá. Conversations went from math to life events to math to physics to non-commutative geometry to model theory to math to physics to poetry to math to books to math to nature to math to historical events to geometry to continuity to physics to discontinuity to geometry to life events to history of Russia to Oxford to math to model theory to logic to infinitary logics to abstract elementary classes to number theory to modular functions to math to physics to life events to poetry to Heisenberg to probability to math to model theory to unbounded operators to operator algebras to ${\mathbb F}_1$ to model theory to categories to model categories to homotopy to physics to math to Oxford to Wiles to Clay to continuous model theory to approximation structures to sheaves to sieves to flavors to Zariski. And so on.

Here are a few fragments and visual threads: