Perpetuum Mobile Machine

A Perpetual Motion Machine (also Perpetuum Mobile, Latin for 'forever moving') is an old dream of mankind: A machine that creates more energy than it receives from the outside. (A weaker version just keeps moving on and on, without creating new energy you could put in use.) 'Free Energy Device' is another name for it.

Those who remain game. Perpetual motion Engraving of a 'closed-cycle water mill,' a perpetual-motion machine designed by English physician Robert Fludd in the 17th century. The energy delivered by water falling from a reservoir onto a mill wheel was erroneously purported to be enough to turn an Archimedes screw and return the water to the reservoir, thus keeping the machine in perpetual motion.Perpetual motion, although impossible to produce, has fascinated both inventors and the general public for hundreds of years.

The enormous appeal of perpetual motion resides in the promise of a virtually free and limitless source of power. The fact that perpetual-motion machines cannot work because they violate the laws of thermodynamics has not discouraged inventors and hucksters from attempting to break, or ignore those laws.Basically, there are three kinds of perpetual-motion devices. The first kind includes those devices that purport to deliver more energy from a falling or turning body than is required to restore those devices to their original state. The most common of these, and the oldest, is the overbalanced wheel. In a typical version, flexible arms are attached to the outer rim of a vertically mounted wheel. An inclined trough is arranged to transfer rolling weights from folded arms on one side of the wheel to fully extended arms on the other. The assumption is that the weights exert more downward force at the ends of extended arms than is required to raise them on the other side, where they are kept closer to the axis of rotation by the folding of the arms.

This assumption violates the first law of thermodynamics, also called the, which states that the total energy of a system is always constant. The first such device was suggested by Vilard de Honnecourt, a 13th-century French architect, and actual devices were built by (1601–67), and, known as Orffyreus (1680–1745). Both machines gave impressive demonstrations by virtue of their ability to operate for long periods of time, but they could not run indefinitely. Get exclusive access to content from our 1768 First Edition with your subscription.Perpetual-motion machines of the second kind attempt to violate the —namely, that some energy is always lost in converting into work. One of the more notable failures in this category was the ammonia-filled “zeromotor” developed in the 1880s by John Gamgee in Washington, D.C.Perpetual-motion machines of the third kind are those associated with a continuous motion that would supposedly be possible if hindrances like mechanical and electrical resistivity could be eliminated. In fact, such forces can be greatly reduced, but they can never be completely eliminated without expending additional energy.

A prime example is the metals, whose disappears completely at low temperature, usually somewhere around 20 K. Unfortunately, the energy required to maintain the low temperature exceeds the work that results from the superconductive flow.Other types of perpetual-motion machines have been proposed based on misunderstandings of the nature of certain energy sources. An example is the clock that derives energy from changes in the temperature or pressure of the atmosphere. It depends upon the energy delivered to the Earth by the Sun and is not, therefore, a perpetual-motion machine.Scientific and governmental sanctioning bodies have looked askance at perpetual-motion claims for many years.

Since 1775 the has refused to correspond with anyone claiming to have invented a perpetual-motion machine. The British and U.S. Offices have long refused to expend time or energy on such claims. This article was most recently revised and updated by, Managing Editor, Reference Content.