A type of polar self-propelled particle generates a torque that makes it naturally drawn to higher-density areas. The collective behaviour this induces in assemblies particles constitutes new form phase separation active fluids.

expressionism in painting, existentialism in philosophy, the final forms of representation in the novel, the films of the great auteurs, or the modernist school of poetry (as institutionalized and canonized in the works of Wallace Stevens): all these are now seen as the final, extraordinary flowering of a high modernist impulse which is spent and exhausted with them. . . . the younger generatio...