collective behavior
Fluid mechanics and statistical physics aim to understand how macroscopic properties emerge from a multitude of interactions at the microscopic scale. Recently, physicists have tried to apply the same principles to swarms and flocks and crowds of animals and humans. By analyzing the trajectories of animals in groups, we want to understand how local information propagates.

surface science
Interfaces are discontinuities between two media, and have properties distinct from each constituent of a system. This is true at various length-scales, and in particular in the nanoscopic world. By tracking single molecules on surfaces, we can understand more about how fluids flow or crystals grow!

soft matter physics
Soft matter scientists study systems that are at the edge between solid and liquid, or whose mechanical properties change a lot under stress. This includes a lot of things that we encounter in our everyday life, notably in what we eat. Many biological materials fit in this description as well, from cells to tissues. Click for more!