Is it possible to create perpetual motion

In the real world, this hypothetical machine would simply be a type of energy storage. Remember, energy always has to come from something. It can never be created. So, even if you could make a machine, you would need the energy to begin the motion. Science is always changing. What once seemed impossible is now possible, and as scientists discover more and more about the universe, things that now seem impossible could well become possible in the future. However, to build a perpetual motion machine, we would have to gain new knowledge that actually breaks the rules of physics as we know them.

Rob is an ecologist from the University of Hawaii. He is the co-creator and director of Untamed Science. His goal is to create videos and content that are entertaining, accurate, and educational. When he's not making science content, he races whitewater kayaks and works on Stone Age Man.

The Search for a Perpetual Motion Machine People have been attempting to make perpetual motion machines for centuries. Why is building a perpetual motion machine impossible? Never Say Never? Choose one of the following categories to see related pages:. Share this Page. You can follow Rob Nelson Facebook. Science Newsletter:. Full List of our Videos. Teaching Biology? How to Make Science Films. Read our Wildlife Guide. On the Trail of the Egret. Tips for Shooting Smoke Grenade Photos.

Pacific Sleeper Shark: Giant of the Deep. The Burmese Python - A docile ish giant. Australia's Most Dangerous Creatures. White-nosed Syndrome in Bats. Gluten and You. Arctic Tundra Biome. The Science of Breadmaking.

How does water move in plants? What is the molecular clock? Plants Can Make Memories. What happened to the Tasmanian tiger? How does your stomach work? Where can I buy suitable magnetic shields?

Advertisement for a magnetic corset. Magnetic shields are useful for keeping the magnetic component of electromagnetic radiation away from sensitive electronic circuits. They are not as effective for steady or slowly varying magnetic fields.

Magnetic shields work by redirecting magnetic field lines so that they are mostly kept away from regions where we don't want them. They do this by re-routing magnetic field lines through the shielding material instead of somewhere else. Therefore the magnetic material still experiences forces from the magnets, and Newton's third law still applies. A magnetic shield and a permanent magnet are strongly attracted to each other.

So in analyzing a device with magnetic shields you must include all forces acting on the shields and the forces shields exert on other parts of the device.

Inventors usually totally neglect even considering the forces on the shields and the work done on and by these forces. For rapidly varying AC fields, the average force exerted on the shield can be nearly zero, but considerable mechanical energy is still lost by heating the shield. While the electric field component of AC radiation can be almost entirely shielded from a finite volume by a full metal enclosure around that volume acting as a Faraday cage , the magnetic component can never be completely shielded.

Nickel-Neodymium magnet on top of a sheet of mu-metal magnetic shielding easily supports unmagnetized ferrous objects on the bottom side.

Commercial shielding materials are ferromagnetic alloys. They cannot create or eliminate magnetic fields, only redirect them. You can't "block" the attraction of two magnets by placing such a shield between them. The magnets will then be attracted to the shield, experiencing forces in nearly the same direction as before.

If you place a strong magnet near one side of a magnetic shield such as mu-metal , the region on the other side of the shield will not be field-free. In fact, a ferrous metal object on the "shielded" side will still be attracted toward the shield. Experimenter's note: Manufacturers of shield materials advise against placing strong magnets in contact with a magnetic shield, for this can induce a residual permanent magnetism in the shield.

I place a 2 mm thick nylon washer between the magnet and shield. When an inventor uses magnetic shields in an over-unity device proposal, he's imagining a kind of shield that does not exist. He assumes a "magic shield" that violates fundamental laws of physics. But most proposals I've seen still wouldn't work even if the magic shields did perform as the inventor hoped. At least one company that sells magnetic shields warns buyers that these shields are primarily useful for radio frequency shielding.

The company must have had quite a few inquiries from perpetual motion machine inventors. I can only imagine letters asking "Which of your many magnetic shielding materials is best for use in a perpetual motion machine?

The inexperienced inventor imagines that magnetic shields act on static magnetic field lines in the same way that an opaque object "blocks" absorbs light. They don't. Only for high frequency electromagnetic radiation does anything of that sort happen. Before anyone asks, there's no such thing as a gravity shield. And magnetic adhesive patches do not relieve the pains of rheumatism, can not increase your gasoline mileage if you put them on the fuel line, nor ionize or detoxify water if placed on water pipes.

Nor are all of those refrigerator magnets making the food inside the refrigerator any healthier to eat. My device uses an innovative method to maintain continual overbalance of mass, force, and torque. But it still stubbornly sits there, unmoving, taunting me. Much ingenuity has been wasted trying to design continually overbalanced devices—clever mechanisms that shift masses from one side of an axle to the other as the wheel turns.

The idea is to continually keep more mass on one side of the axle. This can be done, and if you turn such a wheel by hand there's always more mass on one side. But the wheel never turns continually on its own. The work required to shift masses from one side to the other is always at least as great as the work those masses will provide due to the overbalance. Such devices may turn on their own part of a revolution then settle to an equilibrium position and stubbornly sit there at rest in perfect equilibrium, even though they are in an apparently unbalanced condition.

If examined carefully it is seen that the forces and torques within the structure of the device are, thanks to Newton's third law, perfectly in balance in force and torque equilibrium.

In any wheel-type device, each mass must complete a closed path. The work gained over part of the path as a mass falls is equal to the work required to raise it up again. To try to get around this fact of nature is as futile as finding a round trip walking path that is downhill all the way, in either direction. The closest you can come to perpetual motion is a simple flywheel with frictionless bearings. It would turn on its own for a very long time, but produce no output of useful work.

Any "improvements" you make on this, no matter how ingenious, using gears, shifting weights, magnets, fluids, quantum mechanics, etc. Magnetic perpetual machines can never work because magnets eventually wear out. This isn't the reason they don't work. Magnets can lose their magnetism in several ways; Heat them to very high temperatures. Hit them repeatedly with a hammer. Demagnetize degauss them with a strong alternating current electromagnet, decreasing the strength of the AC field to zero.

But, even if you could make a really permanent magnet that doesn't lose its magnetism, ever, no mechanism using magnets will move perpetually. You can't create something from nothing. Suppose you have a strong box. Put one apple in it and close the lid. Open the lid and find two apples inside. Assuming no trickery you know that can't happen. So why would you think any machine can take in a certain amouunt of energy, and output twice as much energy. Energy is a thing, and you can't create something from nothing.

This simplistic argument is common. But energy is not a "thing". That was realized in the 18th century when physicists found that energy is massless. It helps us understand the change of temperature of bodies that interact thermally.

For physics students, compare entropy, which is not conserved. When bodies interact, their total entropy increases. See: What is Energy. Can I improve the performance of my over-unity wheel or belt device by making it larger?

Making the chain longer and adding more weights won't help. Larger is not always better. So save money and make a small model. It will fail for much lower cost than the larger one. Some inventors have even built wheels as large as a carnival Ferris wheel. They only turn when the wind is blowing. Some have modified an overbalanced wheel device into a belt device, then supposed that the overbalance could be made greater by making the belt longer. It can, but that also adds more mass that must lifted a greater distance up the other side of the belt.

Nature has gotcha again. My wheel with moving masses doesn't work. Would it work if I add more moving masses or make them heavier?

In fact, you can test your idea with fewer masses for less cost. See previous answer. My wheel has many identical moving parts to achieve continual overbalance. I can't afford the expense of building a model. First, even if you do achieve continual overbalance in all positions of the wheel, that won't initiate or sustain motion. Look at the center of mass of the sum of all those parts.

If the center of mass never rises above the wheel's axle, it's a non-starter. Second, consider testing just one of those moving parts in a simpler design, perhaps with a pendulum arrangement. It still won't achieve perpetual motion, but you might learn some physics hands-on. I did a computer simulation of my idea and it works beautifully. But when I build it, the darn thing just stubbornly sits there at rest.

I've heard this story many times. Computer simulations are only as good as the information fed into them. GIGO garbage in, garbage out. So if the simulation shows a working machine, you know you've given the program incomplete or incorrect information. But even the best such simulation program, with perfect data input, uses known, reliable and well-tested physics laws, so it couldn't produce results that violate those laws, could it?

All perpetual motion and over-unity devices must violate physics laws. So why do inventors even bother with such computer simulations? I'm not refering to animated pictures here. They can, of course, depict both possible an impossible situations.

The internet has many examples of such animations of impossible devices and situations, done for amuseuemt. I'm talking about the professional and expensive software programs that engineers use to predict behavior of systems in the real world. These use standard laws of physics and properties of materials, and are incable if properly configured and supplied with valid and complete data of predicting anything that would violate thoe laws.

Similar caveats apply to folks who say "my idea works fine on paper. Too complicated to understand. My design has gone through many changes and improvements. It's now so complicated that I don't understand how it works.

But I'm certain that it will work. Can you help me? If you don't understand it, how can you be so certain that it will work? No, I can't help you. A wise colleague used to say, "The perpetual motion machine inventor concocts a device so complicated that he can't see any reason why it wouldn't work.

So therefore he assumes it must work. Should I buy stronger magnets? Strong magnets can be obtained at small cost, so buy some to experiment with and learn how magnetism works. Be careful, though, for some are strong enough to injure you if your finger gets pinched between them. And keep them out of the hands of small children, who might swallow them. You will soon learn that even with larger magnets your magnet wheel won't turn around even once by itself. My wheel-type device doesn't turn by itself even once around.

Will reducing friction help? Reducing friction won't fix an unworkable device. Friction is never the sole reason for the failure of a supposed over-unity device. Even if you could remove friction entirely it wouldn't work. Look for the real reason for its failure. You can be sure the reason isn't friction. Likewise, viscosity is never the sole reason for failure of perpetual motion and over-unity devices using liquids.

Assume an over-unity machine that is free of friction, viscosity, and all other dissipative processes. Analysis will always show that it still can't work even if completely idealized. Most machines depend on friction to work. Imagine a world without friction of any kind.

You couldn't walk, vehicles could not move, belts would slide over pulleys, knots would come undone, structures would collapse. Removing all friction may not even be a good idea. Looking at books and websites, I conclude that all the simple perpetual motion ideas have been tried, and all have failed. Can some of these ideas be modified, improved or combined to be successful?

Designer hubcaps don't improve the performance of square wheels. That has been tried, too. Any clever improvement or ingenious mechanical gimmick increases a device's mechanical complexity and degrades performance. The closest you'll ever come to a perpetually turning wheel is a simple flywheel with frictionless bearings. Any "improvements" you add will bring it to a stop sooner. I want to tap energy from natural sources. Which would be the best source, gravity or magnetism? These are not sources of energy.

They are natural forces important to the operation of many machines, but no working cyclic machine has ever extracted any energy from gravity, buoyancy or magnetism. All the machinery of mankind has not diminished the strength of the earth's gravitational field by even a smidgen.

If you want sources of energy from nature, try something that moves, like wind, tides, or falling water. Or something that can be burned, like coal or oil. Or something that varies in temperature naturally driven by energy from the sun. Or something that actually emits energetic particles, like the sun, or radioactive ores. But someone objects. Doesn't that come from gravity? When we are talking about perpetual motion we are dealing with cyclic machines, devices that complete a closed cycle of operation, indefinitely.

When you go to the ski resort the potential energy you have at the top of the ski run came from the work you did walking up the mountain, driving up in an automobile, or taking a ski lift. At the top you have potential energy relative to the bottom. That potential energy is what gives you kinetic energy as you ski down the slope. Gravity was not the source of that energy; it was an intermediary agent.

But couldn't gravitational fields provide an unlimited source of energy? All our machinery operates in a gravity field, and some depend on it. Force fields are a mathematical way of describing what will happen when things are placed in the field and move in that field. They a conceptual mathematical convenience, and are not sources of energy. No one has ever extracted energy from a gravitational field. The gravitational field of the earth acts downward toward the earth's center.

Always downward. You never will see a stone rise upward from rest by itself. Cyclic motion of a body in this field may have increases and decreases of kinetic and potential energy, but the net change of energy over one cycle is always zero.

Someone may bring up waterwheels. Isn't that a cyclic motion dependent on gravity? Waterwheels are cyclic, but they are only part of a larger process which isn't a closed cyclic process and doesn't extract energy from gravity. The energy comes from water flowing from higher to lower elevation. The water then flows down streams to lakes or oceans, where radiant energy from the sun evaporates some of it and atmospheric circulation also sun-driven moves it elsewhere and dumps it as rain.

Some of that rain falls at higher land elevations, forming streams which power waterwheels, and so on. This is a cyclic process, but not a closed one. It requires energy input from the sun. And gravity, though necessary to the process, is not a source of energy. The energy came from the sun. The fact that gravity is not diminished by all of our machinery, space satellites, etc. Now some things may steal a bit of energy from the rotating earth they'd have to be pretty massive events , slowing it slightly.

But that doesn't come from the earth's gravity and it doesn't diminish the earth's gravitational strength. The gravitational strength of the earth is strictly dependent on the mass of the earth.

Gravity is always directed toward the center of the earth. We can get energy from the wind with windmills. Couldn't we make a gravity windmill to extract that energy that is blowing toward the earth?

This is a very old, and mistaken notion, going back to the 17 th century at least. As I said above, a gravity field is a mathematical model, not anything material, and field lines pointing toward the earth do not represent a "flow" of anything. The error here is to use a false analogy between gravity and wind. I know people today who still think a gravity windmill is possible, but I won't name names.

But don't magnets have unlimited stored energy? A refrigerator magnet will support itself on the wall of the refrigerator forever, continually exerting force against gravity to keep itself from falling. So isn't it capable of unlimited work? So I suppose the nail driven into the wall is also doing unlimited work supporting the picture frame hanging from it? I have heard the "refrigerator magnet" example from many people over the years, and find it incredible that they can so confidently make this absurd claim without even thinking of obvious counter-examples.

Force and work are different things. Work requires motion. A force that produces no motion does no work, and consumes no energy.

Some magnet motor and magnet engine proposals have continually moving magnets. Can't these extract energy stored in the magnets? Permanent magnets are used in motors and generators worldwide, and none of these machines ever extracts any energy from their magnets.

The magnets merely facilitate the conversion of mechanical to electrical energy or vice versa. After many years of operation, the permanent magnets in these devices still retain their original magnetic properties.

The stored energy in a magnet is only that due to the magnet's manufacturing process. It is a small amount. In normal use, the internal stored energy of a magnet is not used or diminished at all. Heating or hammering the magnet can, however, destroy its internal domain alignments, and therefore, its magnetic effect. Besides, if the magnet did "contain" such a tremendous amount of energy, it must have required at least that much energy to manufacture it, and magnets would be far more expensive.

It's irrelevant, but interesting, to consider just how much energy is stored in a small experimenter's magnet. That information isn't easy to find on the web. I was astounded at how small it is, and asked Rick Hoadley to do an independent calculation, which agreed with mine. The energy stored in an Alnico-5 magnet bar of that size is 1. A typical hair dryer uses Watts while it is running.

If, however, you had a similarly sized NdFeB magnet, it could run the same hair dryer for almost 13 ms! Wow, one hair might get dry! So anyone supposing they could "extract" considerable energy from magnets to solve the energy crisis had better rethink the matter. Is centrifugal force a good energy source? Centrifugal force is a widely misunderstood concept, often badly presented in physics courses. It is not some exotic kind of force found in nature.

It is nothing more than a convenient mathematical concept used when physicists and engineers do analysis of rotating systems using non-inertial rotating coordinate systems as the reference for measurremenets. Is perpetual motion possible? According to Frey: No, but things can be engineered to approximate or mimic it.

Only by engineering a solution by which an object in motion can consume some store of energy or gather energy from an external source can we approximate perpetual motion. Related Questions How do birds sit on high-voltage power lines without getting electrocuted? Is it possible to collect energy from foot traffic? Could we use exercise machines as energy sources?

Can sound be converted to useful energy? Which engine is better at high altitude: diesel or gasoline? What is the energy of gasoline compared to the same cost of other fuels in BTUs per dollar? Which is more likely to happen first: solar panels on every home, or giant solar power plants?