6. The hidden order of a system reappear in this experience: the device is made of two plastic transparent cylinders with the same axis. The volume beetwen the two cylinders is filled with a transparent and viscous liquid. A thread of colouring, which constitute the initial state is injected in the fluid (1). The external cylinder is motionless and the inner cylinder turns (2) until the colouring seems to be fully mixed with the liquid (3). The initial line appears completely lost but if we turn the inner cylinder in the inverse direction (4,5) the particles form back into line and the thread reappars (6): the order is restored.

Ref: Brewer Richard, Hahn Erwin " La mémoire des atomes" , in "Pour la Science" Février 1985