The geyser hisses and squirts like the hot springs in Iceland - only on command!
One end of a 1.5 metre long hose is placed in an Erlenmeyer flask, with the other end positioned above the flask and attached to a large funnel. Both flask and funnel are filled with water. The water that is inside the flask is heated up by Bunsen burner. It just doesn’t just boil, but rather creates huge splashes that reach between 1 and 2 meters high, as well as a huge vapour cloud.
How does it work?
The water inside the hose causes the pressure of the water inside the flask to increase to around 1150 mbar (instead of 1013 mbar, the normal atmospheric pressure). Due to this pressure increase, the water's boiling point rises from 100°C to approximately 104°C. As it starts boiling, vapour clouds arise, pushing the water out of the hose and up into the funnel. When there is no more liquid water inside the hose, pressure is no longer applied on the water inside the flask. Therefore, the pressure on the flask corresponds to the atmospheric pressure. However, the water's temperature is still 104°C - too hot to stay liquid under normal atmospheric pressure. As a result, it abruptly turns into water vapour, and the geyser erupts!
