[The following is an exact transcript of this podcast.]
Physicists study all kinds of curious things, from the missing matter in the universe to the strange behavior of electrons. But none of these is quite as curious, or dramatic, as what happens when you drop a Mentos into a bottle of Diet Coke.
They found that what’s going on is physics, not chemistry. The rougher the stuff that gets dropped in the fluid, and the faster it sinks, the more spectacular the eruption. Microscopic nooks and crannies encourage the growth of carbon dioxide bubbles. That carbonation fuels the geyser. And things that sink quick create lots of bubbles that seed even more bubbles as they rise. The explosive results appear in the June issue of the American Journal of Physics. It’s not rocket science--unless the bottle’s upside down.