“There have been many books recently about important ideas or commodities that have changed the world,” David Standish writes, astutely, in the introduction to his very casual but well-researched “Hollow Earth” (Da Capo, 304 pages, $24.95). His book, he boasts, “traces the cultural history of an idea that was wrong and changed nothing — but which nevertheless had an ongoing appeal.”

Bravo. We are drowning in such books. When did we learn to desire that every object of our curiosity be important?

But Mr. Standish has something important of his own to say, implicitly, in his history of the hollow earth idea. Indeed, it is exemplary to see what happens to an idea, over time, when it is untethered from observation.

Sir Edmond Halley was the first to suggest seriously that our world was merely a crust. Driven by developments in navigation, Halley wanted to understand why the magnetic North Pole moved. Not long after he discovered his comet, Halley suggested to the Royal Society that magnetic drift was caused by the oscillations of smaller globes within our own.

This was in 1692. Halley was not ridiculed; the enlightenment was barely afoot, and notions such as his could of course appear enlightened. The theory of a hollow earth entered the working scientific canon: In 1721 the prolific Cotton Mather devoted three pages to it in his “Christian Philosopher.”

The idea quickly fell into the hands of eccentrics. The specifics changed: Some hollow earth enthusiasts believed that another civilization was prospering beneath our feet, on the concavity of the earth’s crust. Other hollow earthers imagined inner spheres like Halley’s. Both camps imagined holes at the North and South Pole that let in sunlight and allowed chance communication with us surface-dwellers.

Until the polar expeditions of the early 20th century, it was widely believed that the North Pole was an open sea. John Cleves Symmes, a veteran of the War of 1812, started handing out circulars one day, in St. Louis, Mo. For decades a polar expedition became Symmes’s chief mission, and the supposed hole up top is still called Symmes’s Hole.

After Symmes — or perhaps with him — Mr. Standish turns to the fictional. Nathaniel Hawthorne himself applied to lead a South Seas expedition that Symmes’s protégé, J.N. Reynolds, was organizing. Hawthorne instead got the Customs House sinecure that he describes in the long prologue to “The Scarlet Letter.” Meanwhile, Reynolds became a writer. Among his fans was Edgar Allan Poe. Poe’s first published story,”MS. Found in a Bottle,” describes a whirlpool at the South Pole. It was translated by Baudelaire and read by JulesVerne, whose semi-pedantic “Journey to the Center of the Earth” prefigured an era of hollow earth pulp.

Between 1880 and 1915, Mr. Standish can list at least 33 hollow earth novels. Examples include “Pantaletta: A Romance of Sheheland”; “Al-Modad; or Life Scenes Beyond the Polar Circumflex”; “Under Pike’s Peak”; “Thyra, a Romance of the Polar Pit”; “Intermere”; and “Upsidonia.” Together, these novels, recapitulated by Mr. Standish, share a sensational utopianism, a kind of careless sociopolitical fantasizing. But they also represent the hollow earth’s clearest cultural footprint.

Note the progress of the notion from Sir Edmond Halley to Edgar Rice Burroughs. As Mr. Standish notes, the hollow earth theory has always been a vessel for contemporary issues. “It has been equally useful as a late-seventeenth-century scientific theory, an expression of early-nineteenth-century Manifest Destiny, a vehicle for midnineteenth-century musings on paleontology and Darwin, late nineteenth-century religious utopianism, Teddy Roosevelt-style imperialism, a perfect creepy vehicle for 1950s Cold War paranoia, and a cozy home for dreamy contemporary New Age Utopias.”

This list demonstrates the notion’s elasticity, yes, but also its decline. As Mr. Standish himself writes, “by now the idea has become degenerate.” Something that began as a sincere scientific theory became, in Mather’s hands, an ambivalent example of scientific silliness. Just when the idea began to seem unlikely to serious thinkers, it was seized by desperate minds like Symmes’s. Poe liked the idea — it’s almost the ultimate metaphor, the world directly below our own. Soon it became useful to more opportunistic writers, such as Verne, who found it a practical starting point for studious fantasy. After 1910, when any scientific possibility was closed, these fantasies became strictly spurious and lost their pseudoscientific edge — mere action novels with a hint of uncanniness.

But there is another way to look at this story, besides decline. Mr. Standish notes that the same thing that happened to the hollow earth in 1910 happened to Venus in 1960, when that planet was proved inhospitable. Once upon a time, Sir Thomas More needed only to set his Utopia at the farthest point of Amerigo Vespucci’s last voyage. But as exploration of that hemisphere progressed, utopias had to move farther south, to more specific extremities. Science opens frontiers, but it also closes them. Fantasy lives in the interval.

blytal@nysun.com