Paul Matisse's glass-enclosed liquid sculptures contain an object whose movement through the liquid creates whorls that can be seen only because elongated particles trailing the object align with the direction of the current; light reflects off the particles, making the current visible to the viewer. Researchers have recently demonstrated that this same phenomenon is responsible for the swirling patterns scientists typically see when they agitate a flask containing microbes in water; many microbes are themselves elongated particles that make the whorls visible....