“What is life?” In 1943, Erwin Schrödinger posed this question in a series of lectures at Trinity College, Dublin. Already famous as a hero of the quantum revolution, he charged scientists with a new mission: to begin to account for the activity of living creatures using tools and intuitions from physics.
Seventy-five years later, the biophysics revolution is ongoing. Schrödinger’s call to action inspired his colleagues to look at the building blocks of life at all scales, from the diminutive DNA molecule to schooling fish and the construction of anthills. My research group at Harvard University focuses on altruism, or why creatures sacrifice themselves for the common good. But rather than relying on psychology or moral philosophy, we approach this problem using thermodynamics – how the laws governing heat and the interaction of microscopic particles might translate into macroscopic behavior. Can we explain altruism by casting humans as atoms and molecules, and societies or populations as solids, liquids or gases?