To view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 video Movie S1. Top view of a cholesteric shell undergoing a topological transition where two defects merge into a single defect. During the transition, the defects turn around each other in an intriguing “defect waltz.” Waltzing route toward double-helix formation in cholesteric shells Alexandre Darmon, Michael Benzaquen, David Seč, Simon Čopar, Olivier Dauchot, and Teresa Lopez-Leon PNAS. 2016. 113:9469-9474 DOI: 10.1073/pnas.1525059113 Download Original Video Browse All Videos »