# Tagged Questions

Perpetual motion describes "Motion that continues indefinitely without any external source of energy; impossible in practice because of friction." It can also be described as "the motion of a hypothetical machine which, once activated, would run forever unless subject to an external force or to wear"...

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### I need help figuring out what is wrong in this aspiring perpetuum mobile

Credits: My question is motivated from a question from another user (One disk/ring in double rotation and sum of energy), I just reformulated what I think he tried to ask into, what seem to me, ...
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### Violation of the second law of thermodynamics? [closed]

Here is a machine which seems to violate the second law of thermodynamics: $A$ and $B$ are point black bodies of the same temperature (initially). everything is rotationally symmetric around the ...
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### Why doesn't this perpetual motion machine work?

Imagine a non-magnetic tube bent into the shape of a triangle, with two sides forming downhill ramps, and the third side connecting the two ramps. Through this tube travels a metal ball, which is ...
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### Does Newton's first law apply also to non-newtonian physics?

I think I understand than an example of Newton's first law (intertial frames) would be a single asteroid in vaccum with no other bodies around, a comet in such free space or likewise. Then I think the ...
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### Picturing Feynman's argument about perpetual motion

So, there is a certain paragraph in Fenyman's book that I'm struggling with for quite some time. It says: We imagine that there are two classes of machines, those that are not reversible, which ...
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### Perpetual Mobile and Gravitation

I have fundamental question about what is called the “law of conservation of energy”. We all hear about the tidal power stations which using the tidal power. The source of the tidal power came from ...
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### The Spinning Log “Perpetual Motion” problem, and my attempt at a solution

So I was introduced to this "perpetual motion" riddle a few weeks ago. The problem goes like this: we all know perpetual motion machines are not possible, but this riddle seems like it should work as ...
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### “Troll physics”: What is wrong with this perpetual machine? [closed]

I think this will not work because the water can't flow out of the tube. (But what if we make the other end a little wider, will the water stop right before that part? What confuses me is that even a ...
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### Extracting heat energy without a heat engine

Is it possible to extract the molecular kinetic energy from a system directly (without the use of a heat engine / temperature gradient) and convert that to another form of energy, such as electricity, ...
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### Please explain the flaw in this picture [duplicate]

So I saw this picture on my google+ feed and I immediately know why it wont work. But I'm having trouble explaining to myself and others exactly why. Without using anything overly complex, can anyone ...
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### Magnet motor free energy generator [duplicate]

Is it possible to run a fan without electricity? like the one show on this website? http://free-energi.com/index.php?a=2
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I know it's not possible to build a perpetual motion machine, but I still got this concept running in my mind. If you take a (longer)copper coil, and insert an axis through it(right-angled) with a ...
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### Why isn't a pendulum clock considered a perpetual machine?

Why do people say that a perpetual machine is one that runs for eternity? Wouldn't a machine that runs taking no energy from outside but sometimes needs to be restarted, such as pendulum clock, be ...
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### A potential perpetual motion machine?

If I were to freeze a superconductor, the ones made up of yttrium barium copper oxide, with liquid nitrogen and placed it on one of those strong neodymium magnets, it should float right? Now what ...
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### Does perpetual motion machine really exist?

I recently saw a video on Youtube about a perpetual motion machine. Here is the link: http://www.youtube.com/watch?v=OS1KXMsE2qk It's on Robert Boyle's flask. Where does the energy come from?
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### What physical conditions would allow for this kind of perpetual seesaw

I'm working with a simulator(Box2D) and need to create these conditions. I have a perpetual seesaw with two objects on either side. I'd like for the following conditions to be met. The first ...
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### Free energy device - QEG. Is this for real?

I'm not a physicist but I ran across reports on the web of a so called over unity or free energy device that has been created that supposedly works. It's called the QEG. Does this seem legit or is it ...
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### Is magnetic wheel possible?

I once tried to make a magnetic wheel using different shaped magnets and placing them in different orientations and of different shapes.But it did rotate making a small angle ie it didnt rotate even a ...
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### Magnetic Attraction in Space [closed]

If I were to attach a 1 inch diameter magnet to lets say a half pipe, that it fits perfectly in, and attach a 1 in diameter piece of iron close enough for the magnet to assert its attractive pull, ...
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### Is the universe a perpetual motion machine? [closed]

Is the universe a perpetual motion machine?
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### Generating unlimited electricity through magnets

Well i had seen a toy, which i till date don't know was it battery powered or not? and also could it be used to actually create energy (I know that it is not possible but whats the problem?) ...
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### Would a beam of light moving through a vacuum be considered an example of perpetual motion? [closed]

I have a very limited understanding of Physics but if the beam of light was moving through a vacuum like space and had saw no obstuctions during its path, would that be perpetual motion in action?
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### Perpetual motion in spaces of different gravity?

Imagine two locations with different amounts of gravity. I carry up a weight in low gravity, move it on this height over to the other place, and let it fall down there with higher gravity. Wouldn't ...
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### Pendulum water pump - apparent free energy

I've seen plans for a pendulum oscillator water pump that is claimed to pump a large volume of water (100 gallons) from a well of 100 feet deep. The pendulum consists of a 100 pound weight raised 6 ...
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### Simple pendulum and perpetual motion [duplicate]

Is the oscillation of a simple pendulum in vacuum a case of perpetual motion? I recently read Feynman's lectures and he said perpetual motion is impossible in real life. But this pendulum in vacuum is ...
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### Why does this perpetuum mobile not work?(Gases and Densities) [duplicate]

I recently came up with the following concept. It is very simple, and may have been thought of before. A picture says more than a thousand words, so here is it explained in a picture: Note that ...
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### Superfluid Fountain

I was wondering how a super fluid fountain can flow indefinitely without violating energy conservation.
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### Are the perpetual machines in this video really perpetual?

This video lists a number of perpetual motion machines that have been proposed throughout history: Robert Boyle's Self-Flowing Flask A "perpetual train" using rolling cones F. G. Woodward's hoop ...
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### Magnetic field of solenoid in cone shape

I have done some drawings of the magnetic fields of cone shaped solenoid electromagnets. I based this on the work of Tesla and some explanations of Bashar, known as the Bashar Cones. I found very ...
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### How to understand Feynman's reasoning about perpetual motion?

I'm studying Feynman's Lectures on Physics, and I'm not really understanding his reasoning here: Consider weight-lifting machines $\overline{}$ machines which have the property that they lift one ...
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### Perpetual motion machine of the second kind possible in nano technology?

First of all sorry for my English - it is not my native language. During my engineering studies at the university the thermodynamics professor told us that the "second law of thermodynamics is not ...
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### What prevents this magnetic perpetuum mobile from working?

As a child, I imagined this device, which may seem to rotate indefinitely. I have two questions. Is this perpetual motion machine already known? If it is, could you please give some references? What ...
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### Why this perpetuum mobile can't be possible? [duplicate]

I know that this won't work but I'm asking Why? Becuase as far as the vehicle POV - there is a force which drags him to the right. Isnt $F=ma$ applies here? What is that im missing?
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### Perpetual motion

Does this video have a physics behind or it is fake? Where the energy comes from? It looks like a perpetual motion!
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### Why isn't perpetual motion possible, even though we are so technologically advanced?

Why perpetual motion wouldn't be possible if we are so technological advanced? It is just a thing that I was wondering for too long. I mean, we are able to create so powerful permanent magnets, like ...
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### Repulsive Magnetic Hammering Experiment

I have been thinking about something thing... I want to attach four or any number of magnets with arms to an axle.. Blue dots be magnets. Its is not a wheel configuration, all arms can move ...
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### Why can't a superconductor make a DC motor self sustaining?

Superconducting wire can host a low current magnetic field. I do not know if it supports a corresponding electrical field. Can a superconducting wire that sustains a current accelerate a DC motor? ...
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### Energy Conservation Law validity

I will probably be laughed out of town for saying this, but why can't the Energy Conservation Law be broken? Everybody thought electricity to motion was impossible until Faraday made his motor, ...
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### greenhouse trap and perpetual motion

Greenhouse gases keep the planets warmer than they normally would. But, as with electrons trapping photons, I feel that thermodynamics is violated here. Is the violation allowed if energy is trapped ...
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### Vacuum energy and perpetual motion

The part of the Einstein equations of general relativity referred to vacuum energy, introduce a repulsive term in gravity. This means that as the space become bigger and bigger, vacuum part become ...
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### Thought Experiments on black holes, (im)possible perpetual motion and minimum mass for photographic plates

Consider a black hole in vacuum at Temperature T. The setup that I am interested is a one that collects thermal photons from a black hole by enclosing in a spherical photographic plate and then ...
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### “This is not a perpetual motion machine, because reservoir temperatures are changing.” Is it a valid argument?

I've already faced this situation several times: given a statement (in area of thermodynamics) I used it to provide an example of some perpetual motion machine (of first or second kind). Therefore, I ...
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### Does Nantenna (nano antenna) violates 2nd Law of Thermodynamics?

Does Nantenna (nano antenna) violates 2nd Law of Thermodynamics ? Nantennas absorb infrared heat and convert it in direct current. Quote from Wikipedia: He did not discuss whether or not this ...
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### Can anyone analyze this perpetual machine that a Norwegian built?

Take a look at this video: http://www.youtube.com/watch?v=tlx2PgESXhs It shows a machine that a Norwegian artist built. It seemingly keeps going forever. They filmed it over 3 days and it kept going ...
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### Infinite Energy from Bobbing

Could this device theoretically continue in motion forever? If not, why not? (click below for images): Device description. Device process. The device is less dense than air, so it rises. The ...
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### Matter - Antimatter Reactory Practicality

With current technology, would the energy released by a matter-antimatter annihilation be more than the energy needed to created the antimatter in the first place? Would it be worth it? Just curious, ...
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### Are perpetual magnetic motors a scam? [duplicate]

I read articles and watched videos and more videos where people say they've built perpetual magnetic motors. I do not see any proof that this can work and also I do not see proof that it is wrong. I'...
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### Can someone explain the science behind MIT's 230% efficient LEDs?

I was reading Gizmodo the other day and I didn't quite understand the Physics behind this. Could anybody shed some light on how this effect actually works?