Life at the Boundary of Physics and Biology Stephen C. Harvey Professor, School of Biology GRA Eminent Scholar in Computational Structural Biology Shortly after World War II, a number of distinguished physicists moved into biology, inspired in part by Erwin Schrödinger’s classic book “What is Life?”. In the early days, biophysicists were primarily known for contributing a series of very powerful experimental tools – x-ray crystallography, NMR, and other spectroscopic methods – that helped lay the foundations of molecular biology. As computers became more and more powerful, these methods were complemented by computational biophysical approaches to study macromolecular structure and dynamics. In the past decade, biophysicists have begun to visualize and manipulate individual macromolecules, providing important structural, thermodynamic and kinetic insights not available from traditional bulk measurements. In this colloquium I will discuss the interface between physics and biology from both a molecular perspective and from a personal perspective, focusing on some of the systems on which I have worked. The talk will be aimed at physicists with little or no formal background in biology.