Harvard University, Department of Physics
Morris Loeb Lecture Series in Physics
November 14, 2022
M. CRISTINA MARCHETTI
(UC Santa Barbara)
"The Physics of Active Matter"
Abstract:
Birds flock, bees swarm and fish school. These are just some of the remarkable examples of collective behavior found in nature. Physicists have been able to capture some of this behavior by modeling organisms as ``flying spins’’ that align with their neighbors according to simple but noisy rules. Successes like these have spawned a field devoted to the physics of active matter - matter made not of atom and molecules but of entities that consume energy to generate their own motion and forces. Through interactions, collectives of such active particles organize in emergent structures on scales much larger than that of the individuals. There are many examples of this spontaneous organization in both the living and non-living worlds: motor proteins orchestrate the organization of genetic material inside cells, swarming bacteria self-organize into biofilms, epithelial cells migrate collectively to fill in wounds, engineered microswimmers self-assemble to form smart materials. In this lecture I will introduce the field of active matter and highlight ongoing efforts by physicists, biologists, engineers and mathematicians to model the complex behavior of these systems, with the goal of identifying universal principles.