Nature melds living surfaces from the geometry of curvature. Corals, leaves, lichens — even membranes and ears — all living surfaces are shaped through exquisite control over this intrinsic geometry, even as those surfaces flex, twist, and grow. Explore fundamental topological principles with mathematician Chaim Goodman-Strauss, and see the surprising beauty and simplicity of the underlying principles that control the geometry of surfaces. Math Encounters is a public presentation series celebrating the spectacular world of mathematics and presented by the Simons Foundation and the National Museum of Mathematics. For further information, call the National Museum of Mathematics at (212) 542-0566 or e-mail email@example.com.