Event:     Fifteenth Leonard C. Sulski Memorial Lecture
   College of the Holy Cross, Worcester, MA

Speaker: Donal B. O'Shea, Mount Holyoke College

Title: The Shape We're In: The Poincare Conjecture

Date: Tuesday, April 22, 2008

5:30 pm Appetizers and cash bar, Hogan Campus Center Suite B

6:15 pm Dinner, Hogan Campus Center Suite B

8:00 pm Lecture in Hogan Room 519


Choice of entrees: Poached Salmon, Chicken Picatta or Vegetarian
 (Please indicate your choice when you send your check)


Price: $15.00

Make checks payable to: Holy Cross College

Send registration to:

Tom Cecil
Department of Mathematics and Computer Science
College of the Holy Cross
Worcester, MA 01610-2395

email: cecil@mathcs.holycross.edu
phone: (508) 793-2719

Deadline: April 11, 2008

Abstract:  In the last paragraph of the last page of the last of his great topological papers, Poincare stated a conjectural characterization of the three-dimensional sphere. That conjecture resisted sustained attempts by the twentieth century's greatest mathematicians to prove or disprove it. I describe the conjecture and its recent stunning resolution.  I also describe the deep irony that lies at the heart of that resolution:  Poincare's conjecture has always been seen as purely topological, but the unexpected proof depends crucially on geometry. Poincare's apprehension, and ultimately proof, that a two-dimensional manifold carries a unique geometry guided his intuition and propelled him to fame.  Neither Poincare nor anyone else (until 1980) imagined that something similar might hold for three-dimensional manifolds, much less be central to the proof of topology's most famous open problem.