A Diet Coke and Mentos eruption is a reaction between the carbonated beverage Diet Coke and Mentos mints that causes the liquid to spray out of its container. The mints cause nucleation that releases dissolved carbon dioxide so fast it pushes the liquid up and out of the bottle, in what has been described as an eruption or geyser. Though this was demonstrated on television as early as 1999, the reaction went viral in 2005, after Steve Spangler posted a video to YouTube.Photograph: Michael Murphy