I've read my share of short stories by Edgar Allan Poe, but I was nonetheless intrigued by a caption in an article in the latest Smithsonian special issue, Mysteries of the Universe. It read: "The hollow Earth theory inspired authors from Edgar Rice Burroughs to Edgar Allan Poe." I knew that Poe, like many writers, drew from the world around him. But it wasn't until I started reading up on Poe's scientific interests that I realized how far they went.

The Hollow Earth theory envisions the planet as something like a huge chocolate truffle with us living on its exterior surface. Inside, the theory states, there are continents and oceans floating on the interior of the outer shell surrounding a gooey, heavenly center. The idea was promulgated by Captain John Cleves Symmes, who toured the country in the 1820s, talking up his fantastical idea and trying to scrounge up funding for a trip to one of the poles where, he maintained, there were holes that would allow access to the center.

Poe used this theory in his sole novel, The Narrative of Arthur Gordon Pym of Nantucket, published in 1938, as well as the short stories "MS. Found in a Bottle" and "A Descent into the Maelstrom." Each involves a sea journey, though none of the adventurers ever reaches that place where they could enter the center of the Earth.

But Poe's work went beyond this early science fiction and into the world of science itself. He published a textbook on shell collecting, for example, during a time when these pretty beach finds were intriguing both scientists and obsessive collectors. But his biggest contribution is the prose-poem "Eureka," published shortly before his death. "I design to speak of the Physical, Metaphysical and Mathematical -- of the Material and Spiritual Universe:- of its Essence, its Origin, its Creation, its Present Condition and its Destiny," he wrote before then pondering such things as Olbers' Paradox, which argues that the night sky should be so full of stars as to appear as bright as day. It can be hard to read but is truly fascinating.

"No thinking being lives who, at some luminous point of his life of thought, has not felt himself lost amid the surges of futile efforts at understanding, or believing, that anything exists greater than his own soul," Poe writes in "Eureka." He was more than a bit of philosopher as well, it seems.

PS -- Happy 202nd birthday, Mr. Poe!