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 ...

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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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460 views

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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What's wrong with this idea for recover energy from pressure?

In this case : It's a theoretical study, just for find my error. No gravity. No buoyancy. All volumes are constant. I suppose no friction. Outside the pressure from air is constant at $P$ (atmospheric ...
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50 views

Why won't this Casimir effect perpetual motion machine work?

So the Casimir effect is caused by an imbalance in radiation pressure(caused by virtual particles) on two sides of a metal plate. This is typically shown with two close plates getting pushed towards ...
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Extract energy from the atmosphere? [closed]

Let's say we would fill a long tube with water. Let's say the tube is 1km in height. At the bottom of this tube, the pressure should be much higher than the top. Also, the tube would lead into a ...
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Why can't I do this to get infinite energy?

I know that I cannot do this because of conservation of energy, so I am looking for an answer as to why this will not work. So by my understanding of Einstein's whole famous $E=mc^2$ thing it is ...
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185 views

What is the secret of this perpetual motion machine with neodimimum magnets?

The following device is apparently based on magnetic forces only and has no visible energy source: Where is it's energy source? Full video: http://www.youtube.com/watch?v=eA0b-8pqUCk UPDATE One ...
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401 views

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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411 views

Why does this capillary action generator not work?

So I was doing a bit of reading. Apparently the the obstacle to generating energy from the forces driving capillary action is breaking the surface tension at the top of a capillary tube. It is just ...
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63 views

Will spinning DC motor in space generate infinite energy?

If I take a DC motor far in space and spin it, will it continue to spin forever and generate infinite electrical energy? If so, then won't it violate law of conservation of energy?
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Is it a law of physics that all machines will break?

The question sounds kinda dumb when I say it out loud but at the same time I'm very curious. When things break, is it solely due to an intrinsic design flaw or is it due to entropy? And is the ...
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104 views

Why is it so hard to explain that the Brownian Ratchet doesn't work?

The Brownian Ratchet stood up to a lot of scrutiny before it was finally shown why it would not work as a perpetual motion machine, but it seems weird to me that all of that was necessary. If the ...
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Can u explain below diagram is possible or not [closed]

If I takes 3 balloons with same size they r connected with same thred frist end have 2 balloons and second end have 1 balloon I put same manner as shown in diagram then frist end is gos up or not or ...
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I m just try to make Free energy using buoyancy [duplicate]

Can I make power (electricity ) using buoyancy see diagram. if this diagram is possible then how much power i get . I just need formula for upwards speed.
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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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Disregarding the claim of perpetual motion. Does this design have any merit at all?

I'm wondering, in reference to this youtube video Whether or not this design would actually make the wheel move. Any big brains out there wanting to help me out would be greatly appreciated
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128 views

How does the second law of thermodynamics forbid the possibility of perpetual machine of the second kind?

Fermi in his lecture asserts: The second law of thermodynamics rules out the possibility of constructing a perpetuum mobile of the second kind. So, this means there can be no machine which just ...
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90 views

Do Magnets ever lose their magnetism, and if so how long does it take? [duplicate]

I was talking with a friend about a design for a perpetual motion machine that used magnets, but he said that magnets eventually lose their magnetism. I don't want anyone to go into how Thermodynamics ...
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557 views

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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Pseudo-Perpetual Motion Machine

Clearly, the Second Law of Thermodynamics precludes the existence of any theoretical device that would continue running throughout the lifetime of the universe. However, is it possible to construct a ...
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76 views

Particles radiating energy when accelerating?

Let us say we have a charged particle moving in the positive $X$ direction with velocity $v$. If we give the particle a nudge in the $-X$ direction causing it to decelerate. Then from the saying ...
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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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1answer
214 views

Why can't it work? Perpetual motion machine [duplicate]

Lets assume that the red ball is more dense than the white fluid and less dense than the blue fluid. The fluids are of very low viscosity and the machine can be of any height. The flaps open when ...
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58 views

Is a convergent-divergent nozzle a perpetual motion machine of the second kind?

As answered in this question, a convergent-divergent nozzle (de Laval nozzle) accelerates a gas flow by converting its heat energy into kinetic energy. My intuition says that this violates the second ...
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Was the impossibility of the second degree perpetuum mobile in the General Relativity ever proven?

Somewhere I've heard, that gravity often likes to work against the entropy. For example, the surprisingly low temperature of the black holes. Or see the gravitational separation of different elements ...
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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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Why doesn't this magnetic perpetual motion machine work?

I know that this machine does not work, via thermodynamics. I am asking for an analysis in terms of mechanics and magnetism. Anyway, so here is the machine: The magnet (the red ball) pull the ball ...
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176 views

How does this capillary-action setup not become a perpetual motion machine?

If you have a very thin glass tube and you place it into water, let's say the water in the tube rises to the height of $x$ mm from the surface of the water. What would happen if you poked a hole in ...
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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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138 views

NOT Perpetual Motion; Could It Work?

TL;DR The energy is not being created freely, so why shouldn't it work? We have all seen the YouTube "perpetual motion" machines. You know, the computer fans with magnets taped on them and hidden 9 ...
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124 views

Why is this not considered a perpetual motion machine?

You have to assume some wacky things for this scenario, but nothing that defies physics as far as I can tell. I'm going to describe this with a human being initially, because I think it makes the ...
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132 views

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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172 views

Energy conversion (conceptual) question

Suppose I have a electronic car. It runs by electrical energy. So when wheels rotate, mechanical energy is produced. Then why can't we convert it back to electric energy and produce somewhat unlimited ...
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Can energy be extracted indefinitely from a mass dipole/mass negative mass pair in perpetual motion?

Some days ago I have read this short piece of article by Hammond which caused me to revisit the theoretical properties of negative mass. It is known that a pair consists of ordinary mass and negative ...
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108 views

Why this is not a perpetuum mobile [duplicate]

If we imagine a device like one shown on the picture above, why can't we say that it would work? Here is a cylinder somehow placed in the fluid by one of his sides (one in the box). Due to ...
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181 views

Auto spinning turbine generator

This might be dumb question but I'm so curious to know if this actually works or is impossible. I was researching how you could generate electricity from magnets and copper wire and also have read how ...
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Long life energy usage

Im doing a project on school. I want to re-use energy. I know that it will not run forever (but i hope it runs very long). So i wanted to ask if the image below is right and i could use it at school. ...
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Is it, and if so, why, impossible to build perpetual motion machines (PMMs) in GR?

I am wondering about this. I have heard that in General Relativity (GR), the energy in a space-time may not be well-defined. If that is the case, then it would seem "conservation of energy" would not ...
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Can orbital energy be a source of perpetual power?

A thought just came to me, and I want to comfirm it here: If we figured out a way to harvest the energy from the orbit of the Moon, would that be perpetual? The Moon has been orbiting the earth for ...
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Brownian Ratchet Plausibility

Alright I'm going to throw whatever reputation I have on the line here. And yes this is a serious question. Apologies for the shoddy imagery. I had a couple ideas to get the Brownian Ratchet to ...
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Law of maintaining energy flow [closed]

Wouldn't machine that can create constant flows of energy be possible if we eliminate mechanically created energy losses? The time limitation of resources, the magnet half-life time duration isn't ...
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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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274 views

Why will this plan for a perpetual motion device not work? [duplicate]

I have made a plan for a perpetual motion device, but I am sure that it won't work because otherwise the world would be relying on it right now. I know that perpetual motion defies the laws of ...
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1answer
262 views

Thought experiment about fluid mechanics (reductio ad absurdum)

In an interview a philosopher said: "Suppose I cut the handle off your coffee mug leaving two holes. Would the coffee flow out of one hole faster than the other? If we tried to figure this out by ...
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1answer
220 views

What prevents this rotational perpetuum mobile from working? [closed]

As a newbie in physics I imagine this device and I would like to know why it can't increase its energy. Note I study the sum of energy during one second (or less) after set friction ON. The device: ...
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209 views

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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450 views

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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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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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 ...