Consists of a pair of nested plexiglass cylinders with a cap on the top and bottom of the bigger cylinder, and a handle connected to the inner cylinder. There's a hole in the top that accesses the space between the cylinders, which is filled with glycerol.

Displays an unusual example of a reversible processes in a highly viscous liquid. After some dye has “dispersed” in the glycerol, the handle can be turned to make it all come back together. With a reversible process, it's possible to turn back the hand of time.

• Container with immersed cylinder and glycerol
• Syringes with dye

1. Inject some dye into the container using the syringe.
2. Turn the handle to disperse the dye.
3. Turn the handle in the opposite direction to reverse the dispersion effect.

The handle can be turned a limited number of times before it is impossible to reverse the effect. Turning the handle with a jerky motion may inhibit the dye coming back together.