Fluids that have a solid-like response to stress: a phenomenon called Discontinuous Shear Thickening (DST). This footage shows a process called viscous fingering. When the concentration of cornflour and the pressure of air were both high enough to force a DST response, researchers observed the air invading through narrow branching fractures, indicating the fluid was behaving like a solid. This footage is filmed at 1000 frames per second but shown at 24 frames per second. So each second of displayed video is equivalent to 0.024 seconds of real time. Footage by the Complex Flow Lab, IMPACT, Swansea University College of Engineering.