made with VMD
Most life forms exist near temperatures of about 300 Kelvin where thermal disorder is significant. Understanding how life copes with this disorder, in fact, most often exploits it, poses a deep intellectual challenge. Two recent publications investigate thermal disorder for electronically excited bioelectronic systems that harvest sun light and funnel its energy into the metabolism of so-called purple bacteria. One study borrows mathematics (supersymmetric calculus) from the physics of elementary particles to describe the optical properties of randomly distributed, but otherwise immobile, aggregates of chlorophylls. The second study goes a step further and investigates optical properties affected by thermal motion. The paper draws its insights from a pioneering 87,055 atom molecular dynamics simulation of a membrane-protein-chlorophyll system that monitored thermal motion of atoms and electrons and extends a mathematical description, the polaron model, used in advanced solid state physics.