Hollow Earth

The Hollow Earth hypothesis proposes that the planet Earth is either wholly hollow or otherwise contains a substantial interior space. The hypothesis has been shown to be wrong by observational evidence, as well as by the modern understanding of planet formation; the scientific community has dismissed the notion since at least the late 18th century.

The concept of a hollow Earth still recurs in folklore and as the premise for subterranean fiction, a subgenre of adventure fiction. It is also featured in some present-day scientific, pseudoscientific and conspiracy theories.

Hypotheses

Ancient history

In ancient times, the idea of subterranean realms seemed arguable, and became intertwined with the concept of "places" such as the Greek Hades, the Nordic svartalfheim, the Christian Hell, and the Jewish Sheol (with details describing inner Earth in Kabalistic literature, such as the Zohar and Hesed L'Avraham).

The concept of a subterranean land inside the earth is popular in mythology, folklore and legends in ancient times.

According to the Ancient Greeks there were caverns under the surface which were entrances leading to the underworld, some of which were the caverns at Tainaron in Lakonia, at Trozien in Argolis, at Ephya in Thesprotia, at Herakleia in Pontos, and in Ermioni. In Thracians and Dacians legend it is said that there are underground chambers occupied by an ancient God called Zalmoxis. In Mesopotamian religion there is a story of a man who, after traveling through the darkness of a tunnel in the mountain of "Mashu", entered a subterranean garden.

Chapel, bell tower and penitential beds on Station Island. The bell tower stands on a mound that is the site of the original cave which according to various myths is an entrance which leads inside the earth to a place of purgatory. The cave has been closed since October 25, 1632.

In Celtic mythology there is a legend of a cave called "Cruachan" also known as "Ireland's gate to Hell"; a legendary and ancient cave from which according to legend say that strange creatures would emerge in ancient times, and be seen on the surface of the earth. There are also stories of medieval knights and saints who went on pilgrimages to a cave located in Station Island, County Donegal in Ireland, where they made journeys inside the earth into a place of purgatory. There is an Irish myth which says tunnels in County Down, Northern Ireland, lead to the land of the subterranean Tuatha de Danaan a group of people who are believed to have introduced Druidism to Ireland, and then went back underground.

An ancient legend of the Angami Naga tribes of India claim that their ancestors emerged in ancient times from a subterranean land inside the earth. There are legends from the Taíno people that their ancestors emerged in ancient times from two caves in a mountain underground.

It is the belief of the natives of the Malinowski's Trobriand Islands that their ancestors had come from a subterranean land through a cavern hole called "Obukula". There is an ancient legend held in Mexican folklore that a cave in a mountain five miles south of Ojinaga, Mexico, is possessed by devilish creatures who came from inside the earth.

There was an ancient myth held in the middle ages that some mountains located between Eisenach and Gotha in Germany, holds a portal to the inner earth. There is an old Russian legend that says the Samoyeds, an ancient Siberian tribe traveled to an underground cavern city to live inside the earth. There is also a strange tale about a secret cavern and a tunnel in the Fjeld Kalken mountain, near Yulevolden, Norway which is said to be inhabited by a group of underground people, both the cavern and tunnel are said to be closed by iron gates and guarded by a dog.

In Native American mythology, it is said that the ancestors of the Mandan people in ancient times emerged from a subterranean land through a cave at the north side of the Missouri River. There is also a tale about a tunnel in the San Carlos Apache Indian Reservation in Arizona near Cedar Creek which is said to lead inside the earth to a land inhabited by a mysterious tribe. It is also the belief of the tribes of Iroquois that their ancient ancestors emerged from a subterranean world inside the earth. The elders of the Hopi people believe that a Sipapu entrance in the Grand Canyon exists which leads to the underworld.

According to South American mythology the belief of the Brazilian Indians, who live alongside the Parima River in Brazil, claim that their forefathers emerged in ancient times from an underground land, and that many of their ancestors still remained inside the earth. There are also legends that say the ancestors of the Inca Empire came from underground caves which are located east of Cuzco, Peru.

Early history

Edmond Halley's hypothesis.

Leonhard Euler's purported hollow-Earth thought-experiment, featuring openings at the poles, with an internal star.

Edmond Halley in 1692 put forth the idea of Earth consisting of a hollow shell about 800 km (500 miles) thick, two inner concentric shells and an innermost core, about the diameters of the planets Venus, Mars, and Mercury. Atmospheres separate these shells, and each shell has its own magnetic poles. The spheres rotate at different speeds. Halley proposed this scheme in order to explain anomalous compass readings. He envisaged the atmosphere inside as luminous (and possibly inhabited) and speculated that escaping gas caused the Aurora Borealis.

De Camp and Ley have claimed (in their Lands Beyond) that Leonhard Euler also proposed a hollow-Earth idea, getting rid of multiple shells and postulating an interior sun 1000 km (600 miles) across to provide light to advanced inner-Earth civilization but they provide no references; indeed, it seems that if Euler did propose a hollow-Earth then it was as a thought experiment.

De Camp and Ley also claim that Sir John Leslie expanded on Euler's idea, suggesting two central suns named Pluto and Proserpine (this was unrelated to the dwarf planet Pluto, which was discovered and named some time later). Leslie did propose a hollow Earth in his 1829 Elements of Natural Philosophy (pp. 449–453), but does not mention interior suns.

Le Clerc Milfort in 1781 lead a journey with hundreds of Creek Indians, to a series of caverns near the Red River above the junction of the Mississippi river, according to Milfort the original Creek Indian ancestors are believed to have emerged out to the surface of the earth in ancient times from the caverns. Milfort, also claimed the caverns they saw "could easily contain 15,000 - 20,000 families."

19th century

In 1818, John Cleves Symmes, Jr. suggested that the Earth consisted of a hollow shell about 1300 km (800 miles) thick, with openings about 2300 km (1400 miles) across at both poles with 4 inner shells each open at the poles. Symmes became the most famous of the early Hollow Earth proponents. He proposed making an expedition to the North Pole hole, thanks to efforts of one of his followers, James McBride. United States president John Quincy Adams indicated he would approve of this but he left office before this could occur. The new President of the United States, Andrew Jackson, halted the attempt. It is possible this is the source of the (untrue) legend that Jackson believed in a Flat Earth, and was consequently the only United States president to do so.

Jeremiah Reynolds also delivered lectures on the "Hollow Earth" and argued for an expedition. Reynolds went on an expedition to Antarctica himself but missed joining the Great U.S. Exploring Expedition of 1838–1842, even though that venture was a result of his agitation.

Though Symmes himself never wrote a book about his ideas, several authors published works discussing his ideas. McBride wrote Symmes' Theory of Concentric Spheres in 1826. It appears that Reynolds has an article that appeared as a separate booklet in 1827: Remarks of Symmes' Theory Which Appeared in the American Quarterly Review. In 1868, a professor W.F. Lyons published The Hollow Globe which put forth a Symmes-like Hollow Earth hypothesis, but failed to mention Symmes himself. Symmes's son Americus then published The Symmes' Theory of Concentric Spheres in 1878 to set the record straight.

20th century

The Nazi era Thule Society reported much about Tibetan myths of openings into the Earth. There is even a theory that Hitler ordered a research journey for such an opening in Antarctica, based on a speech of Admiral Dönitz in front of a German submarine in 1944, when he claimed "The German submarine fleet is proud of having built an invisible fortification for the Führer, anywhere in the world." During the Nuremberg Trials, Dönitz spoke of "an invisible fortification, in midst of the eternal ice."

An early twentieth-century proponent of hollow Earth, William Reed, wrote Phantom of the Poles in 1906. He supported the idea of a hollow Earth, but without interior shells or inner sun.

Marshall Gardner (distinct from Martin Gardner, mentioned below) wrote A Journey to the Earth's Interior in 1913 and an expanded edition in 1920. He placed an interior sun in the hollow Earth. He even built a working model of the hollow Earth and patented it (U.S. patent 1,096,102). Gardner made no mention of Reed, but did take Symmes to task for his ideas. In the same time Vladimir Obruchev wrote a fiction novel Plutonia, where the hollow Earth's interior possessed one inner (central) sun and was inhabited by prehistoric species. The interior was connected with the surface by a hole in the Arctic.

Other writers have proposed that "ascended masters" of esoteric wisdom inhabit subterranean caverns or a hollow Earth. Antarctica, the North Pole, Tibet, Peru, and Mount Shasta in California, USA, have all had their advocates as the locations of entrances to a subterranean realm referred to as Agartha, with some even advancing the hypothesis that UFOs have their homeland in these places.

The writer Lobsang Rampa in his book The Cave of the Ancients wrote that an underground chamber system exists beneath the Himalayas of Tibet, and is filled with ancient machinery, records and treasures.

A book allegedly by a "Dr. Raymond Bernard" which appeared in 1964, The Hollow Earth, exemplifies this idea. The book rehashes Reed and Gardner's ideas and ignores Symmes. Bernard also adds his own ideas: the Ring Nebula proves the existence of hollow worlds, as well as speculation on the fate of Atlantis and the origin of flying saucers. "Bernard" argued that the inhabitants of Atlantis took refuge in the Earth's interior before the city was destroyed in great calamity. It was Atlanteans who piloted the flying machines known in ancient India as vimanas and in the modern world as flying saucers. After the US bombings of Hiroshima and Nagasaki, Bernard claimed, the Atlanteans became concerned that radioactive air might flow into the world's interior, and so some emerged in their flying saucers in an act of self-defense. An article by Martin Gardner revealed that Dr.Walter Siegmeister used the pseudonym `Bernard', but not until the publishing of Walter Kafton-Minkel's Subterranean Worlds: 100,000 years of dragons, dwarves, the dead, lost races & UFOs from inside the Earth, in 1989, did the full story of Bernard/Siegmeister become well known.

The pages of the science fiction pulp magazine Amazing Stories promoted one such idea from 1945 to 1949 as "the Shaver Mystery". The magazine's editor, Ray Palmer, ran a series of stories by Richard Sharpe Shaver supposedly claimed as factual, though presented in the context of fiction. Shaver claimed that a superior pre-historic race had built a honeycomb of caves in the Earth, and that their degenerate descendants, known as "Dero", live there still, using the fantastic machines abandoned by the ancient races to torment those of us living on the surface. As one characteristic of this torment, Shaver described "voices" that purportedly came from no explainable source. Thousands of readers wrote to affirm that they, too, had heard the fiendish voices from inside the Earth.

Fantastic stories (supposedly believed as factual within fringe circles) have also circulated that Adolf Hitler and some of his followers escaped to hollow lands within the Earth after World War II via an entrance in Antarctica. (See also Hitler's supposed adherence to concave hollow-Earth ideas, below.)

Some writers have proposed building megastructures that have some similarities to a hollow Earth – see Dyson sphere, Globus Cassus.

21st Century

In 2011, Horatio Valens and Paul Veneti presented a two-hour "Lazeria Map Collection" video on centuries-old maps of the Arctic region and the North Pole, making a case for a 100-mile wide canyon in the center of the physical North Pole, into which north-flowing rivers drain into a hollow Earth. The maps were collected by Harry Hubbard.

Concave hollow Earths

An example of a concave hollow Earth. Humans live on the interior, with the universe in the center.

Instead of saying that humans live on the outside surface of a hollow planet, sometimes called a "convex" hollow-Earth hypothesis, some have claimed that our universe itself lies in the interior of a hollow world, calling this a "concave" hollow-Earth hypothesis. The surface of the Earth, according to such a view, might resemble the interior shell of a sphere.

Purportedly verifiable hypotheses of a "concave hollow Earth" need to be distinguished from a thought experiment which defines a coordinate transformation such that the interior of the Earth becomes "exterior" and the exterior becomes "interior". (For example, in spherical coordinates, let radius r go to R²/r where R is the Earth's radius.) The transformation entails corresponding changes to the forms of physical laws. This is not a hypothesis but an illustration of the fact that any description of the physical world can be equivalently expressed in more than one way.

Cyrus Teed, a doctor from upstate New York, proposed such a concave hollow Earth in 1869, calling his scheme "Cellular Cosmogony". Teed founded a group called the Koreshan Unity based on this notion, which he called Koreshanity. The main colony survives as a preserved Florida state historic site, at Estero, Florida, but all of Teed's followers have now died. Teed's followers claimed to have experimentally verified the concavity of the Earth's curvature, through surveys of the Florida coastline making use of "rectilineator" equipment.

Several twentieth-century German writers, including Peter Bender, Johannes Lang, Karl Neupert, and Fritz Braun, published works advocating the hollow Earth hypothesis, or Hohlweltlehre. It has even been reported, although apparently without historical documentation, that Adolf Hitler was influenced by concave hollow-Earth ideas and sent an expedition in an, obviously unsuccessful, attempt to spy on the British fleet by pointing infrared cameras up at the sky (Wagner, 1999).

The Egyptian mathematician Mostafa Abdelkader wrote several scholarly papers working out a detailed mapping of the concave Earth model.

In one chapter of his book On the Wild Side (1992), Martin Gardner discusses the hollow Earth model articulated by Abdelkader. According to Gardner, this hypothesis posits that light rays travel in circular paths, and slow as they approach the center of the spherical star-filled cavern. No energy can reach the center of the cavern, which corresponds to no point a finite distance away from Earth in the widely accepted scientific cosmology. A drill, Gardner says, would lengthen as it traveled away from the cavern and eventually pass through the "point at infinity" corresponding to the center of the Earth in the widely accepted scientific cosmology. Supposedly no experiment can distinguish between the two cosmologies.

Gardner notes that "most mathematicians believe that an inside-out universe, with properly adjusted physical laws, is empirically irrefutable". Gardner rejects the concave hollow Earth hypothesis on the basis of Occam's Razor.

Contrary evidence

Gravity

The picture of the structure of the earth that has been arrived at through the study of seismic waves is quite different from the hollow earth theory.

Another set of scientific arguments against a hollow Earth or any hollow planet comes from gravity. Massive objects tend to clump together gravitationally, creating non-hollow spherical objects we call stars and planets. The solid sphere is the best way in which to minimize the gravitational potential energy of a physical object; having hollowness is unfavorable in the energetic sense. In addition, ordinary matter is not strong enough to support a hollow shape of planetary size against the force of gravity; a planet-sized hollow shell with the known, observed thickness of the Earth's crust, would not be able to achieve hydrostatic equilibrium with its own mass and would collapse.

Someone on the inside of a hollow Earth would not experience a significant outward pull and could not easily stand on the inner surface; rather, the theory of gravity implies that a person on the inside would be nearly weightless. This was first shown by Newton, whose shell theorem mathematically predicts a gravitational force (from the shell) of zero everywhere inside a spherically symmetric hollow shell of matter, regardless of the shell's thickness. A tiny gravitational force would arise from the fact that the Earth does not have a perfectly symmetrical spherical shape, as well as forces from other bodies such as the Moon. The centrifugal force from the Earth's rotation would pull a person (on the inner surface) outwards if the person was traveling at the same velocity as the Earth's interior and was in contact with the ground on the interior, but even the maximum centrifugal force at the equator is only 1/300 of ordinary Earth gravity.

The mass of the planet also indicates that the hollow Earth hypothesis is unfeasible. Should the Earth be largely hollow, its mass would be much lower and thus its gravity on the outer surface would be much lower than it is.

Visual evidence

The deepest hole drilled to date is the SG-3 borehole which is 12.3 km (7.6 miles) deep, part of the Soviet Kola Superdeep Borehole project; thus, visual knowledge of the Earth's structure extends that far.

In fiction

Main article: Subterranean fiction

A map of the Interior World, from The Goddess of Atvatabar (1892).

The idea of a hollow Earth is a very common element of fiction, appearing as early as Ludvig Holberg's 1741 novel Nicolai Klimii iter subterraneum (Niels Klim's Underground Travels), in which Nicolai Klim falls through a cave while spelunking and spends several years living on both a smaller globe within and the inside of the outer shell.

Other notable pre-20th century examples include Giacomo Casanova's 1788 Icosaméron, a 5-volume, 1,800-page story of a brother and sister who fall into the Earth and discover the subterranean utopia of the Mégamicres, a race of multicolored, hermaphroditic dwarfs; Symzonia: A Voyage of Discovery by a "Captain Adam Seaborn" (1820) which reflected the ideas of John Cleves Symmes, Jr.; Edgar Allan Poe's 1838 novel The Narrative of Arthur Gordon Pym of Nantucket; Jules Verne's 1864 novel A Journey to the Center of the Earth, which described a prehistoric subterranean world; and George Sand's 1884 novel Laura, Voyage dans le Cristal where unseen and giant crystals could be found in the interior of the Earth.

The idea was used by Edgar Rice Burroughs, the creator of Tarzan, in the seven-novel "Pellucidar" series, beginning with At the Earth's Core (1914). Using a mechanical drill, his heroes discover a prehistoric world, called Pellucidar, 500 miles below the surface, that is lit by an inner sun.

The idea has gradually become a staple of the science fiction and adventure genres, appearing in print, in film, on television, in comics, in role-playing games, and in many animated works. The third season plot of Sanctuary (TV series) deals with the idea of Hollow Earth and that a race of people built a city in it.

Star Trek: The Next Generation "Relics" and Final Fantasy XIII feature a cross between a Dyson Shell and a Concave Hollow Earth where the inhabitants reside on the inside of an outer shell, with an artificial inner sun at the center.

See also

• Agartha
• Etidorhpa
• Brinsley Le Poer Trench, 8th Earl of Clancarty
• Cyrus Teed
• Dyson sphere
• Expanding Earth theory
• Flat Earth

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• Subterranean fiction
• Travel to the Earth's center
• A Journey to the Center of the Earth
• Vril
• Hollow Moon
• Skartaris
• Hollow Earth Expedition

Bibliography

• Seaborn, Captain Adam. Symzonia; Voyage of Discovery. J. Seymour, 1820.
• Kafton-Minkel, Walter. Subterranean Worlds. Loompanics Unlimited, 1989.
• Standish, David. Hollow Earth. Da Capo Press, 2006.

External links

• The Hollow Earth – from The UnMuseum
• At the Earth's Core, by Edgar Rice Burroughs
• Steve Currey's journey.
• The North Pole Inner Earth Expedition official website
• Skeptic Dictionary: Hollow Earth
• What Curiosity in the Structure: The Hollow Earth in Science.