One of the hands-down favorite, perennial attractions at Maker Faire is the “Diet Coke and Mentos guys,” aka Fritz Grobe and Stephen Voltz, aka EepyBird. Huge crowds excitedly gather to watch explosive geysers of carbonated combustion and to be showered with plumes of sticky sugar-water (which must be so much fun to wear around the Faire for the rest of the day).
Fritz and Stephen are always looking to up the ante, to see what else they can do with the combustive power of the “nucleation” that occurs when you combine the CO2 gas of soda with the unique sugar-coated surface of the Mentos (which forms “nucleation sites,” nooks and crannies that cause the rapid formation of bubbles and a resulting foam that can be directed into a jet).
In this video, they show off their latest wacky stunt, turning a specially-built trike, some PVC pipe, 108 2-liter bottles of soda and 648 Mentos tablets into a rocket car.
On their site, they have a 3D version of the video, if you have the glasses (or want to make your own).