09:00 to 09:45 Topological colloids and particle-induced defects in liquid crystals We fabricate colloidal particles with nontrivial surface topology, including colloidal handlebodies, knots, links, Mobius strings, and Seifert surfaces. When introduced into a nematic liquid crystal with a uniform far-field director, these particles induce three-dimensional director fields and topological defects around them. We use director switching by electric fields, laser tweezing of defects, and local photothermal melting of the liquid crystal to promote transformations among many stable and metastable particle-induced director configurations and then explore them by means of a direct label-free three-dimensional nonlinear optical imaging. This reveals many peculiarities of the interplay between topologies of colloidal surfaces, director fields, and defects, which we find being in agreement with Gauss-Bonnet and Poincaré-Hopf index theorems. The lecture will conclude with a brief discussion of how these findings may lay the groundwork for new types of topology-di ctated elastic self-assembly in liquid crystals and experimental study of low-dimensional topology. 09:45 to 10:30 Colloidal Doping of Cholesterics and Blue Phases At the interface between a cholesteric phase and an isotropic fluid, an array of defects arises. This creates for embedded colloidal particles a free energy landscape that depends on the ratio of colloid size to cholesteric pitch and on the strength of anchoring at the colloid-cholesteric interface. I shall outline recent experiments and simulations that probe this landscape. A somewhat similar situation arises when colloids are added to blue phases, for which the defect array is not interfacial but permeates the bulk phase. Preliminary simulations suggest a variety of structures, many metastable, with interesting transitions inducible by external fields and/or flow. 10:30 to 11:00 Morning Coffee 11:00 to 11:45 Modelling actomyosin droplets, and their consequences for cell motility We present a lattice Boltzmann study of the dynamics of an actomyosin droplet, described in terms of a continuum model which follows the time evolution of actomyosin density, actin polarisation and flow. This analysis offers a simple representation of a “cell extract”, which is a highly simplified system used in vitro to understand cell dynamics, and which essentially only comprises the actin cytoskeleton and an enclosing cell membrane. In the absence of polymerization and depolymerization processes (‘treadmilling’), the dynamics of our actomyosin droplet arises solely from the contractile motion of myosin motors; this should be unchanged when polarity is inverted. Our results suggest that motility can arise in the absence of treadmilling, by spontaneous symmetry breaking (SSB) of polarity inversion symmetry. This motility mode driven by myosin contractility alone may be relevant to cell motion in three dimensions, where frictional forces, which are crucial to convert actin polymerisatino into motion, are likely to be modest. We also show of active droplets crawling on a substrate, when both treadmilling and contractility are taken into account. Our droplets can adopt a number of morphologies and motility modes found experimentally in cells, such as lamellipodia, pseudopodia and oscillatory cell motion. 11:45 to 12:30 Polar Active LCs: Non-equilibrium steady states and fluctuations 12:30 to 13:30 Lunch at Wolfson Court 14:00 to 14:45 J Yeomans (University of Oxford)Active Nematics Active systems, such as the cytoskeleton and bacterial suspensions, provide their own energy and hence operate out of thermodynamic equilibrium. Continuum models describing active systems are closely related to those describing liquid crystal hydrodynamics, together with an additional ‘active’ stress term. We discuss how the behaviour of the active continuum models depends on model parameters, such as the strength of the activity and the liquid crystal tumbling parameter, and we compare our results to recent experiments on cytoskeletal gels. 14:45 to 15:30 Z Dogic (Brandeis University)Hierarchical active matter: from extensible bundles to active gels, streaming liquid crystals and motile emulsions The emerging field of active matter promises an entirely new category of materials, with highly sought after properties such as autonomous motility and internally generated flows. In this vein, I will describe recent experiments that have focused on reconstituting dynamical structures from purified biochemical components. In particular I will describe recent advances that include: (1) assembly of a minimal model of synthetic cilia capable of generating periodic beating patterns, and conditions under which they exhibit metachronal traveling waves, (2) study of 2D active nematic liquid crystals whose streaming flows are determined by internal fractures and self-healing as well as spontaneous unbinding and recombination of oppositely charged disclination defects, (3) reconstitution of active gels characterized by highly tunable and controllable spontaneous internal flows, and (4) assembly of active emulsions in which aqueous droplets spontaneously crawl when in contact with a hard wall. 15:30 to 16:00 Afternoon Tea 16:00 to 16:45 J Toner (University of Oregon)Rice, Locusts and Chemical Waves: A Hydrodynamic Theory of Polar Active Smectics We present a hydrodynamic theory of polar active smectics, by which we mean active striped systemsactive systems, both with and without number conservation. For the latter, we find quasi long-ranged smectic order in $d=2$ and long-ranged smectic order in $d=3$. In $d=2$ there is a Kosterlitz-Thouless type phase transition from the smectic phase to the ordered fluid phase driven by increasing the noise strength. For the number conserving case, we find that giant number fluctuations are greatly suppressed by the smectic order; that smectic order is long-ranged in $d=3$; and that nonlinear effects become important in $d=2$. 17:00 to 21:00 Walk to Grantchester, pub dinner* (either on Tues or Thu)