Cloud Rings

Have you ever wanted to make a cloud? With this exhibit, you can. “Cloud Rings” uses a mist generator and a large rubber membrane with a hole in the middle to launch a ring of vapor up as far as the ceiling will allow. Push down on the metal plate to force a stream of fog through the hole in the center. Friction between the plate’s edge and the fog flowing through the hole creates a swirling pattern known as a vortex.

A vortex is a mass of liquid or gas with a whirling, circular motion. Whirlpools, smoke rings, and hurricanes are all vortices (plural for vortex). They can take different shapes, depending on what they’re made of and the forces that create them.

Mount Etna, an active volcano in Italy, makes enormous smoke rings 650 feet across that can last up to 10 minutes. Smoke rings are formed around a volcano by the local upward convection of air that is caused by the eruptive column. When a volcano explodes, there is a strong updraft all around the volcano that draws in air. If this air is humid, it will form a smoke ring around the volcano.

Questions to Ask

Why does the cloud ring stay together so long after leaving the chamber? Why does it finally fall apart?

How is the cloud ring similar to the dust swirls created when a car travels on a dusty road?

What conditions are best for seeing cloud rings — warm air entering a pocket of cool air or cool air entering a pocket of warm air?

Why can you see your breath on a cool morning but not on a warm day?

Relevant Arkansas Science Frameworks

ESS.8.2.7, ESS.8.7.18, ESS.8.7.20, PS.5.5.6

"Mini-Vibe" — An activity to do at home or in the classroom