Yesterday we celebrated the birth (in 1828) of legendary science fiction novelist Jules Verne, who penned such classic works as Twenty Thousand Leagues Under the Sea and From the Earth to the Moon.

The latter is one of the earliest depictions of space travel in popular fiction, featuring a capsule shot out of a cannon. It seems absurd by modern standards, but there's a hint of solid science underneath the fiction.

Set a few years after the resolution of the American Civil War, the novel centers on the disaffected members of the Baltimore Gun Club. The men are bored and restless; there are no new artillery weapons to construct and test, nothing left to blow to smithereens.

So their leader, Impey Barbicane (!), proposes they build a gigantic cannon to fire a projectile to the moon. Ultimately the plucky Gun Club succeeds in launching not just a projectile, but three men into space.

Verne's notion of launching men to the moon with a cannon seems implausible at best, but some of the underlying principles are quite sound, given how little was known at the time.

Newton's third law of motion says that for every action there is an equal and opposite reaction. Firing a projectile from a cannon produces a powerful recoil force in the opposite direction, capable of propelling an object a considerable distance....