What do bird flocks, migrating cell layers, the cytoskeleton with its motor proteins, catalytic particles in a reactant bath, and needles on a vibrating surface have in common? Answer: in all of them, energy is injected directly to the individual constituents, so each particle can propel itself, stir its surroundings, and influence its neighbours. Based on these shared features, condensed-matter and statistical physicists now refer to collections of homogeneously energized particles as active matter. This new framework for understanding the mechanics and fluctuations of living materials has attracted vast numbers of researchers in nonequilibrium, soft-matter and biological physics, and many dramatic predictions of active-matter theory have seen experimental confirmation. My talk will present the general framework, our group's achievements, and a survey of the field. Among the topics I will discuss are: active hydrodynamics in the cell and membrane; experiments, simulations and theory on a true flock in non-living matter; designable active colloidal matter; surprises in signal propagation in flocks.

Sriram Ramaswamy, born Lucknow, India, 1957; Education: High School -- The Modern School, New Delhi 1973; B S (high hons) University of Maryland 1977; PhD University of Chicago 1983. Career: Postdoc, U Penn 1983-86; on the faculty of the Dept of Physics, Indian Institute of Science, 1986-present; Professor since 2002. Since 2012 on leave as Centre Director of the TIFR Centre for Interdisciplinary Sciences, Hyderabad. Current research interests: Nonequilibrium, soft-matter and biological physics (early research publications: general relativity and gravitation); widely recognised for his research on active matter, a field he helped create. Honours: Infosys Prize for the Physical Sciences 2011, Shanti Swarup Bhatnagar Prize for the Physical Sciences 2000; G. D. Birla Prize for Science, 2006; Fellow, Indian National Science Academy & Indian Academy of Sciences; Editorial Boards: Annual Review of Condensed Matter Physics, Advances in Physics, European Physical Journal E, Journal of Statistical Mechanics: Theory and Experiment; Soft Matter (Editorial Advisory Board).