For about a day in my childhood, I owned a bottle rocket. A day, I say, because I’m pretty sure that on its maiden voyage the damn thing either exploded or blasted off to explore the final frontier, where no child has gone before: into a tree, or a mean neighbor’s yard, or on top of a roof. In any case, I destroyed or lost it so fast that I purposefully forgot the embarrassment of its destruction. But I never forgot its moment of ignition, the beauty of its ascension. Whether store-bought or made out of a soda bottle, a bottle rocket is an elegant design: Half-filled with water, air is injected into it with a bicycle pump until the internal pressure exceeds the strength of its cork and lift-off is achieved in an explosive spray and a wet contrail.
Jet propulsion in the animal kingdom is exclusively found in aquatic creatures: the nymphs of dragonflies, the sea slug-like Sea Hares, some species of fish, and most famously, the cephalopods: squid and octopuses. By forcing water in the opposite direction of momentum, and thanks to Newton’s First Law of Motion, these animals don’t just swim through the water they live in; they use it as fuel. No bird, bat, or flying lizard ever evolved jet engines in its wings to propel air through them. But isn’t there anything that flies through the air with the power of a bottle rocket? Of course there is.