A small amount of water is heated to boiling in a metal can (aluminum soda/pop can or large 20 L solvent can) filling it with water vapor. The can is removed from heat, sealed, and cooled. Alternatively, a vacuum is applied to an empty can, as the air in the can is evacuated, the can collapses. In both cases the can collapses quickly and dramatically. The collapsing of the can is due to the greater applied atmospheric pressure compared to the less pressure inside the can.