Dry ice is one of the few substances that sublimes, or vaporizes from a solid state. The noise produced when a metal touches dry ice is an effect of the Bernoulli principle.

Bernoulli’s principle describes what happens when a gas moves. There is a pressure drop associated with the increase in the speed of a fluid. The dry ice vaporizes into carbon dioxide gas when a comparatively warm metal comes in contact with it, creating a change in pressure.