Watch the whirlwind and alter it with your hands. You can also switch off the top fan or the cloud maker to produce multiple effects. The whirlwind can be disturbed and even made invisible, but it needs air to keep it going out of the top ‘plughole’ to keep it spinning. The main fan in the exhibit is the one at the top which drags air out of the chamber. Three other fans at the sides blow air sideways to create a swirl inside the chamber. Air enters the chamber from the hole in the base. The air is laden with a cloud of water droplets from a humidifier so that you can see the whirlwind easily.