The idea of the Perpetual Motion Machine has been a point of fascination of both science and science fiction for hundreds of years.

The basic concept of Perpetual Motion is that a machine would be created in which the energy output is equal or greater than the energy required for the device to function.

At the dawn of the 20th century, according to all of the widely accepted and utilized models of physics and maths, such a machine is impossible.

However. . .

There have been numerous scientific theories as well as the rumored existence of applied devices which promise the next best thing, that being the collection and utilization of the ambient energy which modern science claims to exist in the fabric of space. (See Zero Point Energy or ZPE).

There are also rumors of technologies, both theoretical and applied, which use low cost techniques to release large quantities of energy from atomic fusion reactions. See Cold Fusion. The existence of such technology is generally disbelieved by both the scientific community and the public at large, but a significant amount of evidence to the contrary does, however, exist. According to some accounts, the metallic rods in which the hydrogen to helium reaction takes place in a Cold Fusion Cell are unstable and can be made to explode on the same scale as a small atomic warhead, though without toxic radioactive fallout. It is believed by some that military applications have been found for Cold Fusion technology.

Pyramid structures, when constructed using specific quantities of metallic impurities, are believed by some to be able to use the magnetic qualities of the Earth to pump water.

There are other such technologies claimed by various sources to exist, but none of them are officially available to the public, the most popular theory for this being that such devices would significantly alter the power structure of the civilized world in such a way that the privileges of the extremely wealthy and power elite would be diminished.