text: something curious in my soda...? here's the situation, in a glass of diet pepsi was placed a stick of stride spearmint gum.  the result was that the gum floated.  a minute later, an ice breaker hot cinnamon mint was also placed in the glass of soda.  the mint remained on the bottom of the glass, after a few seconds the gum fell to the bottom of the glass, then just as suddenly rose to the top again.  there is no other force acting upon the glass, but the stick of gum seems to dance rising to the top and then falling back to the bottom of the glass, and then it rises again.  it happened many times.  what exactly is occuring that would cause this phenomenon? the carbon dioxide coming out of solution formed bubbles on the gum in tiny little pits that act as nucleation sites for the bubbles to grow.  when there are enough bubbles on the gum and it becomes very buoyant, it floats.  at the top of the glass, the bubbles pop and the gum then sinks and the cycle can repeat.