: Flocks of starlings and self-organizing biopolymers are examples of “active matter,” or matter that consumes energy in order to move. Over the past five or six years, active matter has become a major research subject for physicists, who seek to apply the century-old theory of statistical mechanics to living things. The field of active-matter study was sparked by the publication of a 2010 paper on the collective motion
exhibited by actin filaments when combined with the molecular motor myosin and myosin’s natural fuel, ATP. A better understanding of the motion of active matter could have many applications, including the development of self-assembling artificial tissue, self-pumping microfluidic devices, and new bio-inspired materials.