Hollow Earth

The phrase hollow Earth refers to the esoteric idea that the planet Earth has a hollow interior, almost invariably including the idea that it has a habitable inner surface. Although at one time adventure literature made this idea popular and even commonplace, the notion now receives little support; substantial geodetic evidence has long controverted it and the scientific community dismisses it as pseudoscience.

Related Topics:
Esoteric - Earth - Geodetic - Pseudoscience

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Newton's law of gravity mathematically implies a gravitational force of zero everywhere inside a spherically symmetric hollow shell of matter, regardless of the shell thickness (ignoring other masses such as the Moon). Thus, contrary to popular belief, persons on the inside of a putative hollow earth would not experience an outward pull and could not stand on the inner surface; rather, they would experience weightlessness (with some slight residual gravity arising from the fact that the Earth does not have a perfectly symmetrical spherical shape). The centrifugal force from the Earth's rotation would pull a person outwards, but even at the equator this force exerts only 0.3% of ordinary Earth gravity.

Related Topics:
Newton - Law of gravity - Weightlessness - Centrifugal force - Equator

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