A pink and yellow exhibit table, with a white and blue information panel on top. In front of the panel sits two clear plastic bottles joined together at the opens. There is water flowing from the top bottle down to the lower one.

Water drains more efficiently through vortices.

How it works

Pouring water between two connected bottles is most efficient if a vortex is generated.

Things to try or ask around the exhibit

  • Turn the bottles upside down. Does the water flow slowly or quickly into the bottom bottle?
  • Turn the bottles upside down again, but swirl the bottles a few times as the water begins to flow. Does the water flow faster or slower?


When you swirl the bottles, you create a vortex with a hole. The hole in a vortex allows air to move into the top bottle as water flows into the bottom bottle. Without the vortex, the water flows more slowly into the bottom bottle. A vortex can occur when air or water moves quickly from one place to another.

Finding the science in your world

Tornadoes, cyclones and even a draining sink’s plug hole are naturally-occurring vortices.