In 1877, Giovanni Schiaparelli, an Italian astronomer, reported seeing canali on the surface of Mars. When his report was translated into English, canali, which in Italian means channels, was rendered as canals, which are by definition man-made.
Lowell's imagination was ignited by Schiaparelli's findings. In 1894, Lowell built an observatory in Flagstaff, Arizona, and focused on Mars. Other astronomers had noticed that some areas of the planet's surface seemed to change with the seasons—blue-green in the summer and reddish-ocher in the winter. These changes seemed to correspond with the growing and shrinking of the polar ice caps. Lowell believed that the melting caps in summer filled the canals with water that fed large areas of vegetation. He filled notebook after notebook with observations and sketches and created globes showing the vast network of waterways built by Martians.
The intricacy of Lowell's canal system is all the more mystifying because it doesn't seem to correspond to any actual features on the planet—yet he apparently saw the same canals in exactly the same places time after time. Even in Lowell's day, most other astronomers failed to see what he saw, and his theory fell into disrepute among most of the scientific community (though the public continued to embrace the notion). To this day, no one knows whether Lowell's maps were the result of fatigue, optical illusions or, perhaps, the pattern of blood vessels in his eye.
Like any romantic idea, belief in Martian canals proved hard to abandon. The possibility of life on the planet closest to ours has fascinated us for centuries and continues to do so. Lowell's canals inspired science fiction writers including H.G. Wells and Ray Bradbury. It took the Mariner missions to Mars of the 1960s and 1970s to prove that there are no canals on the Red Planet.
The Earth Is Hollow!
(and we might live on the inside)
Imagine the earth as a hollow ball with an opening at each pole. On its inner surface are continents and oceans, just like on the outer surface. That's the Earth envisioned by Capt. John Cleves Symmes, an American veteran of the War of 1812. He toured the country in the 1820s, lecturing on the hollow Earth and urging Congress to fund an expedition to the polar openings. His hope was that Earth's inner surface would be explored and that trade would be established with its inhabitants.
The hollow Earth theory wasn't entirely new—the idea of open spaces inside Earth had been suggested by ancient thinkers including Aristotle, Plato and Seneca. Caves and volcanoes gave the concept plausibility, and legends and folktales abound with hidden civilizations deep below the crust.
In 1691, to explain variations in Earth's magnetic poles, royal astronomer Sir Edmond Halley, better known for recognizing the schedule of a brilliant comet, proposed a hollow Earth consisting of four concentric spheres. The interior must be lit and inhabited, he said; the idea of the Creator failing to populate the land and provide its populace with life-giving light seemed inconceivable. Halley proposed a luminous substance that filled the cavity, and he attributed the aurora borealis to its escape through the crust at the poles.
To make a weird idea even weirder, Cyrus Teed, a 19th-century physician, alchemist and experimenter with electricity, concluded that the world was not only hollow but also that human beings were living on its inner surface. He got the idea in 1869, when an angelic vision announced (after Teed had been shocked into unconsciousness by one of his experiments) that Teed was the messiah. According to the angel, the Sun and other celestial bodies rose and set within the hollow Earth due to an atmosphere that bent light in extreme arcs. The entire cosmos, he claimed, was contained inside the sphere, which was 8,000 miles in diameter. Teed changed his name to Koresh (the Hebrew form of "Cyrus"), founded his own cult (Koreshanity) and eventually built a compound for his followers, who numbered 250, in southwestern Florida. The compound is now preserved by the state of Florida as the Koreshan State Historic Site and draws tens of thousands of visitors every year.
In 1950, Immanuel Velikovsky published Worlds in Collision, a book that claimed cataclysmic historical events were caused by an errant comet. A psychoanalyst by training, Velikovsky cited the Old Testament book of Joshua, which relates how God stopped the Sun from moving in the sky. Moses' parting of the Red Sea, Velikovsky claimed, could be explained by the comet's gravitational pull. He theorized that in 1500 B.C., Jupiter spewed out a mass of planetary material that took the form of a comet before becoming the planet Venus.
Velikovsky was one in a long line of catastrophists, adherents of the theory that sudden, often planet-wide cataclysms account for things like mass extinctions or the formation of geological features. His book is remarkable not so much for its theories—which are unexceptional by catastrophist standards—but for its popularity and longevity. A New York Times best seller for 11 weeks, it can be found on the science shelves of bookstores to this day and enjoys glowing reviews on some Web sites.