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For other uses, see Perpetual motion (disambiguation).
The "water screw" perpetual motion machine from a 1660 woodcut.
The "water screw" perpetual motion machine from a 1660 woodcut.

The term perpetual motion, taken literally, refers to movement that goes on forever. However, the term more generally refers to any closed system that produces more energy than it consumes. Such a device or system would be in violation of the law of conservation of energy, which states that energy can never be created or destroyed, and is therefore impossible. In Physics, the law of conservation of energy states that the total amount of Energy in an isolated system remains constant and cannot be created although it may The most conventional type of perpetual motion machine is a mechanical system which (supposedly) sustains motion while inevitably losing energy to friction and air resistance. Friction is the Force resisting the relative motion of two Surfaces in contact or a surface in contact with a fluid (e In Fluid dynamics, drag (sometimes called fluid resistance) is the force that resists the movement of a Solid object through a Fluid (a

Contents

Basic principles

Main article: Thermodynamics

Perpetual motion violates either the first law of thermodynamics, the second law of thermodynamics, or both. In Physics, thermodynamics (from the Greek θερμη therme meaning " Heat " and δυναμις dynamis meaning " In Thermodynamics, the first law of thermodynamics is an expression of the more universal physical law of the Conservation of energy. The second law of Thermodynamics is an expression of the universal law of increasing Entropy, stating that the entropy of an Isolated system which The first law of thermodynamics is essentially a statement of conservation of energy. The second law has several statements, the most intuitive of which is that heat flows spontaneously from hotter to colder places; the most well known statement is that entropy tends to increase, or at the least stay the same; another statement is that no heat engine (an engine which produces work while moving heat between two places) can be more efficient than a Carnot heat engine. In Physics, heat, symbolized by Q, is Energy transferred from one body or system to another due to a difference in Temperature In Thermodynamics (a branch of Physics) entropy, symbolized by S, is a measure of the unavailability of a system ’s Energy A Carnot heat engine is a hypothetical engine that operates on the reversible Carnot cycle. As a special case of this, any machine operating in a closed cycle cannot only transform thermal energy to work in a region of constant temperature.

Machines which are claimed not to violate either of the two laws of thermodynamics but rather are claimed to generate energy from unconventional sources are sometimes referred to as perpetual motion machines, although they are generally reported as not meeting the standard criteria for the name. By way of example, it is quite possible to design a clock or other low-power machine to run on the differences in barometric pressure or temperature between night and day. [1] Such a machine has a source of energy, albeit one from which it is quite impractical to produce power in quantity.

Classification

It is customary to classify perpetual motion machines as follows:

  1. A perpetual motion machine of the first kind produces energy from nothing, giving the user unlimited 'free' energy. In Physics and other Sciences energy (from the Greek grc ἐνέργεια - Energeia, "activity operation" from grc ἐνεργός It thus violates the law of conservation of energy. In Physics, the law of conservation of energy states that the total amount of Energy in an isolated system remains constant and cannot be created although it may
  2. A perpetual motion machine of the second kind is a machine which spontaneously converts thermal energy into mechanical work. This need not violate the law of conservation of energy, since the thermal energy may be equivalent to the work done; however it does violate the more subtle second law of thermodynamics (see also entropy). The second law of Thermodynamics is an expression of the universal law of increasing Entropy, stating that the entropy of an Isolated system which In Thermodynamics (a branch of Physics) entropy, symbolized by S, is a measure of the unavailability of a system ’s Energy Note that such a machine is different from real heat engines (such as car engines), which always involve a transfer of heat from a hotter reservoir to a colder one, the latter being warmed up in the process. The signature of a perpetual motion machine of the second kind is that there is only one single heat reservoir involved, which is being spontaneously cooled without involving a transfer of heat to a cooler reservoir. This conversion of heat into useful work, without any side effect, is impossible by the second law of thermodynamics.
    1. What may prove more useful is to explain the existence of hot reservoirs to begin with. A hot reservoir inside an internal combustion engine is created by a spark igniting fumes which contain stores of chemical energy. The temperature of the fumes increases above that of the surroundings. This is not a perpetual motion machine since the ability to raise the temperature above that of the surroundings depends on finite chemical reactions always less than the total heat energy and mass-energy contained within the system. Since there are far more states in which heat distribution is closer to thermodynamic equilibrium than states in which heat is concentrated in small regions, heat will tend to smooth out over time to lower power densities of increasingly unusable forms.

In an otherwise completely empty Newtonian universe, a single particle could travel forever at a constant velocity with no violation of the laws of physics – though of course no energy could be extracted from it without slowing it down. For example, in an isolated system consisting of two objects orbiting each other gravitationally, the two objects will remain orbiting forever, as long as they are not disturbed. However any attempt to extract useful work from this system would lead to a loss of energy. This would result in the objects slowing down and getting closer to each other, until at some point the objects would collapse together and no more energy would remain to extract.

Use of the term "impossible" and perpetual motion

Scientists and engineers accept the possibility that the current understanding of the laws of physics may be incomplete or incorrect; a perpetual motion device may not be impossible, but overwhelming evidence would be required to justify rewriting the laws of physics.

The conservation laws are particularly robust. Noether's theorem states that any conservation law can be derived from a corresponding continuous symmetry, and the theorem can be proven. Noether's theorem (also known as Noether's first theorem) states that any differentiable symmetry of the action of a physical system has In other words, as long as the laws of physics (not simply the current understanding of them, but the actual laws, which may still be undiscovered) and the various physical constants remain invariant over time — as long as the laws of the universe are fixed — then the conservation laws must be true, in the sense that they follow from the presupposition using mathematical logic. Mathematical logic is a subfield of Logic and Mathematics with close connections to Computer science and Philosophical logic. To put it the other way around: if perpetual motion or "overunity" machines were possible, then most of what we believe to be true about physics, mathematics, or both would have to be false.

Of course the universe does not have to conform to our belief of how it works. In this case it is easy to check whether or not the theory is correct. Using telescopes we can examine the universe in the distant past; the fact that stars even exist and are, to the limits of our measurements, identical to stars today, is a direct visual demonstration that physics was similar in the past. Combining different measurements such as spectroscopy, direct measurement of the speed of light in the past and similar measurements demonstrates conclusively that physics has remained substantially the same, if not identical, for all of observable history spanning billions of years. Spectroscopy was originally the study of the interaction between Radiation and Matter as a function of Wavelength (λ SN 1987A was a Supernova in the outskirts of the Tarantula Nebula in the Large Magellanic Cloud, a nearby

The principles of thermodynamics are so well established, both theoretically and experimentally, that proposals for perpetual motion machines are universally met with disbelief on the part of physicists. Any proposed perpetual motion design offers a potentially instructive challenge to physicists: one is almost completely certain that it can't work, so one must explain how it fails to work. The difficulty (and the value) of such an exercise depends on the subtlety of the proposal; the best ones tend to arise from physicists' own thought experiments and often shed light into unique aspects of physics. A thought experiment (from the German Gedankenexperiment) is a proposal for an Experiment that would test a Hypothesis or Theory

The law that entropy always increases, holds, I think, the supreme position among the laws of Nature. In Thermodynamics (a branch of Physics) entropy, symbolized by S, is a measure of the unavailability of a system ’s Energy A physical law or scientific law is a Scientific generalization based on empirical Observations of physical behavior (i If someone points out to you that your pet theory of the universe is in disagreement with Maxwell's equations — then so much the worse for Maxwell's equations. The Universe is defined as everything that Physically Exists: the entirety of Space and Time, all forms of Matter, Energy In Classical electromagnetism, Maxwell's equations are a set of four Partial differential equations that describe the properties of the electric If it is found to be contradicted by observation — well, these experimentalists do bungle things sometimes. But if your theory is found to be against the second law of thermodynamics I can give you no hope; there is nothing for it but to collapse in deepest humiliation. — Sir Arthur Stanley Eddington, The Nature of the Physical World (1927)

Thought experiments

Serious work in theoretical physics often involves thought experiments that test the boundaries of understanding of physical laws. Sir Arthur Stanley Eddington, OM (28 December 1882 – 22 November 1944 was an English Astrophysicist of the early 20th century Theoretical physics employs Mathematical models and Abstractions of Physics in an attempt to explain experimental data taken of the natural world Some such thought experiments involve apparent perpetual motion machines, and insight may be had from understanding why they either don't work or don't violate the laws of physics.

Techniques

“ One day man will connect his apparatus to the very wheelwork of the universe [. . . ] and the very forces that motivate the planets in their orbits and cause them to rotate will rotate his own machinery. ”

—Nikola Tesla

Some common ideas recur repeatedly in perpetual motion machine designs. There have already been discussions about Tesla's ethnicity on the talk page

The seemingly mysterious ability of magnets to influence motion at a distance without any apparent energy source has long appealed to inventors. A magnet (from Greek grc μαγνήτης λίθος " Magnesian stone" is a material or object that produces a Magnetic field. However, a constant magnetic field can do no work because the force it exerts on a charged particle is always at right angles to its motion; a changing field can do work, but requires energy to sustain. In Physics, mechanical work is the amount of Energy transferred by a Force. A "fixed" magnet can do work, but energy is dissipated in the process, typically weakening the magnet's strength over time. Thus, when a magnet does work by lifting an iron weight, potential energy is converted to kinetic energy. Once the iron hits the magnet its kinetic energy is converted to heat and sound. In order to release further energy, the iron must be moved away from the magnet. This converts the energy of your arm to potential energy again. Since the energy of parting the magnet and iron is identical to the energy released as the magnet and iron come together, no net energy can be gained by changing the iron – magnet distance.

Perpetuum Mobile of Villard de Honnecourt (about 1230).
Perpetuum Mobile of Villard de Honnecourt (about 1230). Villard de Honnecourt lived in 13th century France and may have been an itinerant master-builder of Picardy in northern France.

Gravity also acts at a distance, without an apparent energy source. Gravitation is a natural Phenomenon by which objects with Mass attract one another But to get energy out of a gravitational field (for instance, by dropping a heavy object, producing kinetic energy as it falls) you have to put energy in (for instance, by lifting the object up), and some energy is always dissipated in the process. A typical application of gravity in a perpetual motion machine is Bhaskara's wheel in the 12th century, whose key idea is itself a recurring theme, often called the overbalanced wheel: Moving weights are attached to a wheel in such a way that they fall to a position further from the wheel's center for one half of the wheel's rotation, and closer to the center for the other half. Bhaskara (1114 &ndash 1185 also known as Bhaskara II and Bhaskara Achārya ("Bhaskara the teacher" was an Indian mathematician Since weights further from the center apply a greater torque, the result is (or would be, if such a device worked) that the wheel rotates forever. A torque (τ in Physics, also called a moment (of force is a pseudo- vector that measures the tendency of a force to rotate an object about The moving weights may be hammers on pivoted arms, or rolling balls, or mercury in tubes; the principle is the same.

Gravity and magnetism are an attractive combination indeed, and a frequently rediscovered design has a ball pulled up by a magnetic field and then rolling down under the influence of gravity, in a cycle. (At the highest point, the ball is supposed to have acquired enough speed to escape the magnet's influence. )

Yet another theoretical machine involves a frictionless environment for motion. This involves the use of diamagnetic or electromagnet levitation to float an object. This is done in a vacuum to eliminate air friction and friction from an axle. The levitated object is then free to rotate around its center of gravity without interference. However, this machine has no practical purpose because the rotated object cannot do any work as work requires the levitated object to cause motion in other objects, bringing friction into the problem.

To extract work from heat, thus producing a perpetual motion machine of the second kind, the most common approach (dating back at least to Maxwell's demon) is unidirectionality. Maxwell's demon was an 1867 Thought experiment by the Scottish Physicist James Clerk Maxwell, meant to raise questions about the possibility Only molecules moving fast enough and in the right direction are allowed through the demon's trap door. In a Brownian ratchet, forces tending to turn the ratchet one way are able to do so while forces in the other direction aren't. The Brownian ratchet is a Thought experiment about an apparent Perpetual motion machine conceived by Richard Feynman in a Physics lecture at A diode in a heat bath allows through currents in one direction and not the other. These schemes typically fail in two ways: either maintaining the unidirectionality costs energy (Maxwell's demon needs light to look at all those particles and see what they're doing), or the unidirectionality is an illusion and occasional big violations make up for the frequent small non-violations (the Brownian ratchet will be subject to internal Brownian forces and therefore will sometimes turn the wrong way).

Invention history

Main article: History of perpetual motion machines
Orffyreus Wheel. The device was designed by Johann Bessler.
Orffyreus Wheel. The history of perpetual motion machines dates back to the Middle Ages. The device was designed by Johann Bessler. Johann Ernst Elias Bessler ( 1680 - November 30, 1745) was born in Zittau, Germany.

Hero of Alexandria created what might be considered the first near-perpetual motion machine. Hero (or Heron) of Alexandria ( Ήρων ο Αλεξανδρεύς) (c However, it is not recorded that he claimed his fountain ran by perpetual motion. Heron's fountain is a hydraulic machine invented by the first century inventor mathematician and physicist Heron also known as Hero of Alexandria. The recorded history of referenced perpetual motion machines date back to the 12th century. Proponents of perpetual motion machines use a number of other terms to describe their inventions, including "free energy" and "over unity" machines. The second law of Thermodynamics is an expression of the universal law of increasing Entropy, stating that the entropy of an Isolated system which The earliest references to perpetual motion machines date back to 1150, by an Indian mathematician-astronomer, Bhāskara II. India, officially the Republic of India (भारत गणराज्य inc-Latn Bhārat Gaṇarājya; see also other Indian languages) is a country Indian mathematics &mdashwhich here is the mathematics that emerged in South Asia zero, Negative numbers, Arithmetic, and Algebra. Historically Astronomy was more concerned with the classification and description of phenomena in the sky while Astrophysics attempted to explain these phenomena Bhaskara (1114 &ndash 1185 also known as Bhaskara II and Bhaskara Achārya ("Bhaskara the teacher" was an Indian mathematician He described a wheel that he claimed would run forever. Villard de Honnecourt in 1235 described, in a thirty-three page manuscript, a perpetual motion machine of the second kind. Villard de Honnecourt lived in 13th century France and may have been an itinerant master-builder of Picardy in northern France. Robert Boyle's self-flowing flask appears to fill itself through siphon action. Robert Boyle was a Natural philosopher, chemist physicist inventor and early Gentleman scientist, noted for his work in Physics and Chemistry A siphon (also spelled syphon) is a continuous tube that allows liquid to drain from a reservoir through an intermediate point that is higher than the reservoir the flow being This is not possible in reality; a siphon requires its "output" to be lower than the "input".

In 1775 Royal Academy of Sciences in Paris issued the statement that Academy "will no longer accept or deal with proposals concerning perpetual motion". Johann Bessler (also known as Orffyreus) created a series of claimed perpetual motion machines in the 18th Century. Johann Ernst Elias Bessler ( 1680 - November 30, 1745) was born in Zittau, Germany. In the 19th century, the invention of perpetual motion machines became an obsession for many scientists. The 19th century of the Common Era began on January 1, 1801 and ended on December 31, 1900, according to the Gregorian calendar Many machines were designed based on electricity, but none of them lived up to their promises. Another early prospector in this field was John Gamgee. Gamgee developed the Zeromotor, a perpetual motion machine of the second kind.

Devising these machines is a favourite pastime of many eccentrics, who often come up with elaborate machines in the style of Rube Goldberg or Heath Robinson. In popular usage eccentricity refers to unusual or odd Behavior on the part of an individual Reuben Garret Lucius Goldberg ( July 4, 1883 - December 7, 1970) was an American Cartoonist who received a 1948 Pulitzer William Heath Robinson ( May 31 1872 &ndash September 13 1944) was an English Cartoonist and Illustrator These designs may appear to work on paper at first glance. Usually, though, various flaws or obfuscated external power sources have been incorporated into the machine. Such activity has made them useless in the practice of "invention". An invention is a new form composition of matter device or Process.

Patents

Devising such inoperable machines has become common enough that the United States Patent and Trademark Office (USPTO) has made an official policy of refusing to grant patents for perpetual motion machines without a working model. The United States Patent and Trademark Office ( PTO or USPTO) is an agency in the United States Department of Commerce that issues Patents to A patent is a set of Exclusive rights granted by a State to an inventor or his assignee for a fixed period of time in exchange for a disclosure of an One reason for this concern, according to various skeptics, is that a few "inventors" have used official patents to convince gullible potential investors that their machine is "approved" by the Patent Office. The USPTO Manual of Patent Examining Practice states:

With the exception of cases involving perpetual motion, a model is not ordinarily required by the Office to demonstrate the operability of a device. If operability of a device is questioned, the applicant must establish it to the satisfaction of the examiner, but he or she may choose his or her own way of so doing. A patent examiner or patent clerk is an Employee, usually a civil servant, working within a Patent office. [2]

And, further, that:

A rejection [of a patent application] on the ground of lack of utility includes the more specific grounds of inoperativeness, involving perpetual motion. A rejection under 35 U. S. C. 101 for lack of utility should not be based on grounds that the invention is frivolous, fraudulent or against public policy. [3]

The USPTO has granted a few patents for motors that are claimed to run without net energy input. These patents were issued because, skeptics claim, it was not obvious from the patent that a perpetual motion machine was being claimed. Some of these are:

Howard R. Johnson, U. S. Patent 4,151,431

In 1979, Joseph Newman filed a US Patent application for his "energy machine" which unambiguously claimed over-unity operation, where power output exceeded power input; the source of energy was claimed to be the atoms of the machine's copper conductor. Year 1979 ( MCMLXXIX) was a Common year starting on Monday (link displays the 1979 Gregorian calendar) [4] The Patent Office rejected the application after the National Bureau of Standards measured the electrical input to be greater than the electrical output. Newman challenged the decision in court and lost. [5]

Other patent offices around the world have similar practices, such as the United Kingdom Patent Office. The UK Intellectual Property Office, or UK-IPO is the operating name of what was until April 2 2007 called The Patent Office. Section 4. 05 of the UKPO Manual of Patent Practice states:

Processes or articles alleged to operate in a manner which is clearly contrary to well-established physical laws, such as perpetual motion machines, are regarded as not having industrial application. [6]

Examples of decisions by the UK Patent Office to refuse patent applications for perpetual motion machines include:

Decision BL O/044/06, John Frederick Willmott's application no. 0502841[7]
Decision BL O/150/06, Ezra Shimshi's application no. 0417271[8]

Apparent perpetual motion machines

Even though they fully respect the laws of thermodynamics, there are a few conceptual or real devices that appear to be in "perpetual motion", while a closer analysis reveals them to actually "consume" some sort of natural resource or latent energy like the phase changes of water or other fluids, solar energy and natural, small temperature gradients. Water is a common Chemical substance that is essential for the survival of all known forms of Life. Solar energy is the Light and radiant heat from the Sun that powers Earth 's Climate and Weather and sustains Life In general, extracting useful work out of similar devices is very hard or almost impossible, as those devices usually work with low-grade heat and with very low efficiency. In Physics, heat, symbolized by Q, is Energy transferred from one body or system to another due to a difference in Temperature

So, these devices can mostly be classified as low-power, low-efficiency energy converters (not free energy producers) which are able to use low grade energy sources, but which would be impractical or impossible to use at a large scale for mass energy production, as efficiency would be extremely low, as well as any power output – if any.

Some examples of real such devices include:

Some examples of imaginary such devices:

In all of these cases the "free" energy would, in any case, come from "lesser" forms of energy already present in the environment in small quantities, and the net power outputs would be extremely small to build a large-scale generator. While it certainly is possible to convert some of the ambient's low-grade heat into useful work, that would not be, by definition, "perpetual motion", and the efficiencies are so low that such devices can only be used as toys or novelty items. This article is about playthings For other uses of the term see Toy (disambiguation. A novelty is a small manufactured adornment especially a personal adornment

Ubiquitous energy from atomic and chemical bonds

See also: Activation energy, Entropy, and Thermodynamics

All working energy devices require either a heat reservoir (such as solar radiation) or a process of utilizing dense stores of energy (such as nuclear energy or chemical energy). In Chemistry, activation energy, also called midnight energy, is a term introduced in 1889 by the Swedish scientist Svante Arrhenius, that is defined In Thermodynamics (a branch of Physics) entropy, symbolized by S, is a measure of the unavailability of a system ’s Energy In Physics, thermodynamics (from the Greek θερμη therme meaning " Heat " and δυναμις dynamis meaning " Nuclear Energy is released by the splitting (fission or merging together (fusion of the nuclei of Atom (s In Physics and other Sciences energy (from the Greek grc ἐνέργεια - Energeia, "activity operation" from grc ἐνεργός Heat pumps are capable of transporting this waste heat in excess of the heat used to run them (cf. A heat pump is a machine or device that moves Heat from one location (the 'source' to another location (the 'sink' or 'heat sink' using work. Coefficient of performance>1), but are not perpetual motion machines because the transferred heat is part of the input. The coefficient of performance, or COP (sometimes CP of a Heat pump is the ratio of the change in Heat at the "output" (the heat reservoir of interest

Conventional sources of energy such as petroleum and natural gas or radioactive materials such as uranium rely on a small fraction of the inherent and ubiquitous energy of atoms and molecules, although the energy of atoms and molecules are not characterized by an internal temperature. Petroleum ( L petroleum, from Greek πετρέλαιον, lit Natural gas is a Gaseous Fossil fuel consisting primarily of Methane but including significant quantities of Ethane, Propane, Uranium (jʊˈreɪniəm is a silvery-gray Metallic Chemical element in the Electrical power plants can only be profitable by extracting the nuclear and chemical energies in excess of the energy needed to:

Scientists are currently spending many research hours in attempt of getting more power out of nuclear fusion than what it takes to run the power plant. In Physics and Nuclear chemistry, nuclear fusion is the process by which multiple- like charged atomic nuclei join together to form a heavier nucleus If solved, nuclear fusion would supply the world with an abundant source of electricity. The entire energy industry relies on a system where thermal output exceeds the thermal input. The energy industry is a generic term for all of the industries involved the production and sale of Energy, including Fuel extraction manufacturing When determining the present thermal output that exceeds present thermal input, one only considers the time during which the energy of the fuel is consumed, and not the time during which the energy was stored in that fuel.

Perpetual motion in popular culture

Examples

Gallery

This is a gallery of some of the perpetual motion machine plans. Perepiteia is purportedly a new kind of generator developed by Thane Heins

The "Overbalanced Wheel". It was thought that the metal balls on the right side would turn the wheel because of gravity, but since the left side had more balls than the right side, the weight was balanced and the perpetual movement could not be achieved.

The "Float Belt". The yellow blocks indicate floaters. It was thought that the floaters would rise through the liquid and turn the belt. However pushing the floaters into the water at the bottom would require more energy than the floating could generate.

The "Capillary Bowl". It was thought that the capillary action would keep the water flowing in the tube, but since the mass of the water is bigger than the power that the capillary action could generate, the movement will not be perpetual.

Perpetual conspiracy theories

(Main article: Free energy suppression)

Self-taught inventors exploring the topics of perpetual motion are often highly secretive of their work and unwilling to openly discuss what they are doing, instead offering only limited-access demonstrations without explanation or documentation. Free energy suppression is a Conspiracy theory that claims that advanced Technology that would reshape current electrical generation methods is being suppressed They claim to do this for a number of reasons:[10]

Many skeptics believe that such conspiracy claims are merely a cover to avoid being scientifically disproven and to perpetuate a scam on potential investors.

See also

Notes

  1. ^ Cox's timepiece
  2. ^ 608.03 Models, Exhibits, Specimens [R-3 – 600 Parts, Form, and Content of Application]
  3. ^ 706.03(a) Rejections Under 35 U.S.C. 101 [R-3 – 700 Examination of Applications II. Cox's timepiece is a Clock developed in the 1760s by James Cox. UTILITY]
  4. ^ "A Patent Pursuit: Joe Newman's 'Energy Machine', Science News, June 1, 1985
  5. ^ "NBS Report Short Circuits Energy Machine", Science News, July 5, 1986
  6. ^ http://www.patent.gov.uk/practice-sec-004.pdf
  7. ^ Patents Ex parte decision (O/044/06)
  8. ^ http://www.patent.gov.uk/patent/p-decisionmaking/p-challenge/p-challenge-decision-results/o15006.pdf
  9. ^ CERN - Spotlight: Angels and Demons
  10. ^ A Youtube video that covers all the conspiracy bases: Free Energy - Pentagon Conspiracy to Cover up http://www.youtube.com/watch?v=uGRsQZx6zWA

References

External links

Historic

Research

In Popular Culture

Dictionary

perpetual motion

-noun

  1. The motion of some hypothetical device that continues forever with no obvious input of energy in violation of the laws of thermodynamics.
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