COLLOQUIUM 1-5pm, Main Lecture Room, Peyton Hall, Princeton (see below and attached for directions)

The Colloquium will be comprised of two sessions; each talk will be15 minutes.

SESSION ONE — 1-2:45pm

# J.R. GOTT III — Welcome

SIOBHAN ROBERTS on “Unfashionable Pursuits,” an excerpt form King of Infinite Space

FREEMAN DYSON on ''How Polyhedra Fit Into Each Other'' “This is the problem that first got me interested in polyhedra long ago, when I first encountered Coxeter's writings,” says Dyson, a physicist and polymath at the Institute for Advanced Study. Dyson was introduced to Coxeter by Leopold Infeld in the 1940s. The two polyhedra enthusiasts hit it off and maintained a leisurely correspondence about, of course, polyhedra, which developed into a lifelong friendship from afar— Dyson counted Coxeter as “one of my favorite people.”

MICHAEL LONGUET-HIGGINS on “Snub Polyhedra and Organic Growth” Michael Longuet-Higgins, a geophysicist and geometer at UCSD, and a Fellow of Trinity College, Cambridge, met Coxeter via Freeman Dyson — Dyson put the two men in touch when he learned they were both trying to enumerate the class of uniform polyhedra. Longuet-Higgins and Coxeter, together with J.C.P. Miller, published what they believed to be a complete enumeration of uniform polyhedra in 1954 (it was proven to be complete, by a computer, in 1975). Longuet-Higgins will describe a new application of polyhedral theory to the growth of the outer sheath of viruses. These structures are often modular with cheiral (unselfreflexible) symmetry. The growth can be simulated by a time- dependent process applied to equal-sized circles on a sphere. First the circles are jostled by random perturbations, then their radius is enlarged, then they are jostled, and so on. The limiting arrangement of the circles is one with the maximum coverage of the surface of the sphere and is related to a snub polyhedron. Coxeter's interest in "Vegetable Staticks" suggests that he would have liked this "yin-yang" method."