Polymers that crawl like worms: How materials can develop direction without being told where to go

Researchers at the University of Vienna have uncovered a surprising phenomenon: polymer chains with segments that simply fluctuate at different intensities can spontaneously develop directional, persistent motion when densely packed—even though nothing in the system points them in any particular direction. This "entropic tug of war," driven by fundamental physical constraints, could help explain how DNA organizes and moves inside living cells and may lead to new materials. The study is published in Physical Review X.