We've all seen test-tube reactions that overflow in long snakes, but this one is so quick it's like someone used a jump-cut on a film. The resulting foam has been studied by NASA for its fire-resistant properties. Too bad it takes sulfuric acid to make the stuff.
Welcome to io9's Word of the Day. Today's word is "aphrogen." An aphrogen is something, generally a liquid, that spontaneously forms a foam when it's heated. (I've tried to find out if butter is an aphrogen, as it foams in the pan if you heat it enough, but so far I've had no luck. Scientist cooks? Let me know.) P-nitroaniline is certainly an aphrogen. We see it at work, when combined with sulfuric acid.
We've seen sulfuric acid at work with sugar. It initiates a process of dehydration, setting the water molecules free while generating a lot of heat. The heat essentially boils the water, and the water turns to steam, escaping the solidifying carbon. The escaping steam creates bubbles the carbon structure, causing it to rise up from a container in a black column. It's impressive to watch, but sulfuric acid and the p-nitroaniline is something else.