Monday, February 11, 2019 at 4:00pm to 5:00pm
Rockefeller Hall, Schwartz Auditorium
General Physics Colloquium, Professor Lisa Manning, Syracuse University.
Refreshments from 3:30-3:50 pm.
Title: What do Guitar Strings and Balloons have in common with Biological Tissues?
Host: Jim Sethna
Abstract: Both guitar strings and balloons are floppy until they are pulled or stretched, when they undergo a rigidity transition induced by changes to their shape or geometry. Similar kinds of rigidity transitions have recently been discovered in both biopolymer networks and cellular biological tissues. Recent work suggests that these rigidity transitions occur surprisingly frequently, regulating the mechanical material properties of tissues and exerting exquisite control over processes in development and disease. Here, we propose a general, geometric approach to quantitatively describe such rigidity transitions. Based on a minimal length function, which scales linearly with intrinsic fluctuations in the system and quadratically with shear strain, we make concrete predictions about the mechanical response of these materials, which we verify numerically and which are consistent with previous experiments. I will also discuss a specific biological example, left-right symmetry breaking in the body plan of vertebrates, where the mechanical material properties of the tissue appear to play an unexpected and important role.