I've been reading www.free-energy-info.co.uk, and I must say I find it unconvincing so far. Below I'll quote some things and comment on them.

But let's first define what free energy is. I would define free energy as energy that seems to violate the known laws of physics which can be paraphrased as "energy cannot be created or destroyed, it can only be transformed into other forms". A device that produces more energy than is put in would meet the definition.

Any other definition would be trivial. The example of the solar panel is a good example.

The electrons in the molecules of rock formations have been orbiting steadily for millions of years without stopping - at what point will you agree that they are in perpetual motion?

First of all, the model of electrons orbiting the nucleus of an atom like the planets orbiting the sun is outdated. Niels Bohr discovered in the 1930 that electrons can only have discrete energy levels, and that there are limits to how much electrons can be at that level. This is very different from planets orbiting a star. Later quantum mechanics showed up, and things got really weird. Quantum physicists don't talk about electrons al little globes, they talk about probability distributions for electrons.

And even it electrons were perpetual motion machines, as long as you cannot extract energy from them, they'd be pretty useless for free energy, no?

OK, on to "zero point energy", by which its proponents usually mean vacuum energy. The real zero point is quite useless. Physics teaches us that energy flows from higher potential to lower potential. With machines we can capture some of this energy and convert it into some form we can use. A quantum system at the zero point has the lowest possible energy, so no energy can be extracted from it. Again, quite useless.

So we turn to vacuum energy. This revolves around pairs of virtual particles and antiparticles that pop out of the void and later annihilate each other again. This causes the Casimir effect, which has been measured in experiments. Recent measurments have yielded results within 1-5% of theoretically predicted values, which is quite good. Stephen Hawking has used these virtual particle pairs to explain how black holes can send out radiation and evaporate (essentially, one of a pair of virtual particles crosses the event horizon of a black hole and disappears, the other becomes a real particle and escapes.) Many people have claimed to have created machines that employ vacuum energy to deliver free energy. But it is unclear as to how this is done.

A related point about energy is that an amount of energy itself does not paint a complete picture as to if we can use it. E.g. the efficiency of a heat engine is directly linked to the temperature difference between the hot source and the cold sink (in a internal combustion engine the hot source is the hot gasses created by burning fuel, and the cold sink is the ourside air.) If you had a gigajoule of energy in the form of water that is one degree warmer than the surrounding environment, you can do very little with that energy because a heat engine will be extremely inefficient at such a temperature difference, and tou therefore can only convert a tiny amount of that thermal energy to mechanical energy.

The chapter about magnet motors displays a lack of understanding of the fundamentals;

How long can the resulting magnet support its own weight against gravity? Years and years. Does that not strike you as strange? See how long you can support your own body weight against gravity before you get tired. Years and years? No. Months, then? No. Days, even? No.

A fridge magnet doesn't do any work when it it sticking to the fridge!

Looking at the figure labeled as "John Bedinis simple design", it is easy to see why it doesn't work. While the two north poles connected by the red arrow repulse each other, so does the north pole from the magnet coming in from the left! This machine will stop at the point where the system of the magnets in the rotor and the stator is in its lowest energy state.

On to the Φ transformer. A transformer converts mechanical energy to electrical energy because a change in the magnetic field strength contained in a coil generates an electrical field in the wires of the coil. But for the most part of the rotation of the permanent magnet in the circular laminated coil, the flux in the coils doesn't change. Only when there the poles of the permanent magnet pass the coils will a pulse be generated. Meanwhile, the rotating magnet will be slowed down by the ring! Try and pass a bar of iron close in front of a strong magnet without touching it; you'll feel drag because the changing magnetic field in the bar induces circular currents that form a magnetic field that acts against the changing field. Therefore I think the claim of 1200 watts output for 140 watts input extremely unlikely.

Ok, that'll have to do for tonight. I'm tired, so I'm off to bed.

As a completely irrelevant side note, did you know that you can create a user account over here too and not have to pass your comments through moderation? Just click on the little "signin" link when you're making your next comment, type in your user name and a password, click register, then get walked through the process. Enjoy!

I have to admit that I stop listening when people talk about perpetual motion machines since energy can be neither created nor destroyed. I'm glad you took the time to think it through rather than dismissing it out of hand the way I did.

I'm intrigued by your comment about electrons as perpetual motion machines. I know you dismiss them as useless, but what I'm curious about is --- are they really perpetual motion machines? Are they more like the sun, which will eventually burn out? My memory of physics/chemistry is a bit vague...I feel like I should talk about radioactive decay?

Materials exhibit ferromagnetism mostly because of the quantum mechanical property of spin (although orbital momentum of electrons also contributes a bit). From the last page a quote;

The spin of an elementary particle is a truly intrinsic physical property, akin to the particle's electric charge and rest mass.

So you could describe electrons are perpetal motion machines, in a sense. The question is how we define perpetual motion machines, which is more like a philosophical question. To the best of our current knowledge, even our universe isn't really perpetual. Similarly, calling an an intrinsic property of a particle a machine is stretching the definition of a machine beyond the breaking point.

A real perpetual motion machine would allow you to extract energy from without slowing down. This would violate the law of convervation of energy. This is known as an empirical law because it has never been shown to have been violated. Any person who were to build a machine that conclusively shows that this law is incorrect can pretty much book a ticket to go and pick up a Nobel Prize for physics!

A system that moves for a long time without slowing down is nothing special, however. Just imagine a couple of Kuiper belt object spinning around each other (formally around their shared center of mass) in the vacuum of space. So far from the sun and barring collisions and other energy inputs they will keep doing so for a long time. Indeed, these are just examples of the conservation of energy law in action.

I was just reading the chapter about pulsed energy systems on the free energy site, and the part on how generators work actually made sense!

But then again, that part was written by someone who is a college instructor in automotive electronics...

The rest is just schematics and claims without proof. And might I point out that if someone is making claims that seem to violate the currently known laws of physics, the burden of proof rests on their shoulders. And as I've said before, anyone who can show such a machine that really works can pretty much pick up a Nobel Prize!

Reading gravity pulsed systems now.

First the two falling balls on a wheel concept. These machines are supposed to produce energy from gravity. The potential energy of gravity depends on the position of an object in a gravitational field. Let me observe that after a full rotation of each of these wheel devices, all the balls are returned to the same height and thus to the same potential energy. So in one rotation there is no net gain of energy. Indeed, with the balls rolling around in the tubes and bumping against the end, you will only lose energy because of friction and inelastic collisions.

Next, flywheels. Let me first point out that a flywheel is just a storage device for kinetic energy. Because any part of the flywheel returns to the same position after a full revolution there is again no net gravitational energy gain! Let's turn to the formula "2mgr" mentioned in the text, and focus on the "r" which is

the distance from the axle to the point at which the weight of the wheel appears to act

and it goes on

If all of the flywheel weight is at the rim of the wheel, the r would be the radius of the wheel itself.

Hmm, no.

In any normal (i.e. rotationally symmetric) flywheel the point where the weight of the wheel appears to act (the center of mass) is at the axle because of the symmetry! So r equals zero, and there is no net energy gain. The figure that puts r as the distance from the axle to the heavy rim of the wheel is misleading. Yes, most of the mass is at the edge of the wheel, but since it is symmetric the center of mass is still in the center of the wheel! This is basic classical mechanics.

In the text it is stated that

However, this stream of very short pulses in the drive chain, generates a considerable amount of excess energy drawn from the gravitational field.

Again, I have to call bullshit. It doesn't matter if a belt is just rotating or if it is also oscillating, as long as the parts of the belt return to the same height after a rotation and/or oscillation there is no net energy gain from gravity.

A slipping belt will spend a convert a of energy to heat because of friction though.

OK, turning to the magnet pendulum. Such a machine could easily be powered by a electromagnet in the base driven by a pulsed electric current tuned to the frequency of the pendulum. A shame we are not shown the bottom of the case. But suppose it isn't. This "machine" has no output punt where one can use the "perpetual motion", so it is quite useless.

Now on to the "Dale Simpson gravity wheel". The picture "Fig19.gif" shows a balance of moments around the center of the wheel for two weights. This picture is incomplete, and therein lies its failure. It omits the forces acting on the wheel by the curved ramp that pushes the weights to the center of the wheel against the forces of the springs and gravity.

Looking at the videos of the pendulum/lever system you can see that the inventor uses his hands to keep the pendulum swinging. If he doesn't it slows down. No excess gravitational energy there.

The analysis of the hinged plate system is flawed similarly to that of the gravity wheel; it only looks at part of the system, not at the forces acting in the chain.

With regard to the "Luciano Gravity Chain" let me point out that the only way for the chain to be stretched out on the right is for the top wheel to be driven by a motor; the amount of weight going down per unit of time must equal the amount of weight going up. Otherwise all the weights would end up at the bottom.

I think I've shot quite enough fish for today. Time to catch some sleep.

I'm going to have to skip commenting on chapter 5, 6 and 7 of the free-energy-info.co.uk website. Most of these deal with electronical devices and I'm not versed well enough in electronics to comment.

So on to chapter 8, "self-powered engines". It kicks off with a bang;

We have been raised with the idea that it is necessary to burn a fuel to produce power which we can use.

Hmm, no. Let me point out;

• bicycles
• windmills
• pv solar panels
• sailing boats
• water turbines
• geothermal power stations
• nuclear power stations

All of those produce power that we can use. None of them burn fuel. Actually Mr Kelly names most of these in the subsequent text, invalidating his initial argument!

if I state that it is perfectly possible for a compressed-air engine to produce mechanical power with burning any fuel, then there is an immediate and strong reaction where people will say 'Impossible' that is perpetual motion !!

Again, no. An engine running on compressed air is not perpetual motion. Compressed air has potential energy compared to the standard pressure air around us. So an engine running on compressed air is just another energy convertor. It's easy to build one, even from wood (notice that this engine is only using the pressure difference generated by a vacuum cleaner, which is much less than the 7-8 bars usually generated by a compressor). In essence there is not much difference between an engine running on steam or on compressed air. You could run a toy steam engine easily on compressed air.

They imply that perpetual motion is impossible

No, it is impossible to extract work from perpetual motion. A small but crucial difference.

I'll not go into the conspiracy theorie stuff more than quoting Bruce Sterling that "conspiracy is for losers" (Go and read the whole article, it's fun and enlightening).

An ordinary refrigerator outputs three or four times as much heat power as the electrical power driving it, and it could be twice that efficient if it were used properly. This is a Coefficient Of Performance (COP) of 3 or 4, which is supposed to be "impossible" but unfortunately, all refrigerators work like this and you can't exactly say that refrigerators don't exist, just because their performance does not appear to fit in with some theories.

Let me point out that this fails Kelly's argument about usable power. There is not much we can do with the heat output from a refrigerator.

A heat pump is the exact opposite of a heat engine, in the sense that it uses mechanical energy to pump heat from the cold to a hot reservoir, whereas a heat engine taps the flow from hot to cold to extract energy. So whereas a heat engine generally is able to extract 25% of the generated heat as mechanical power, it is unsurprising that a heat pump puts out 4 times as much heat as the mechanical energy put in. There is nothing strange about this, and indeed this is standard fare in a B.Sc. in mechanical engineering.

By definition, heat pumps will have a COP > 1, while the efficience of a heat engine is always < 1 and is further limited by the efficiency of the equivalent Carnot cycle (whereby equivalent I mean using the same temperatures for the hot and cold reservoirs). [In a nutshell, the Carnot cycle is the most efficient possible heat engine because the parts of it's cycle form a rectangle (occupying the most space possible) in a entropy/temperature diagram.]

All work done in compressing air into a storage tank is converted into heat and then lost to the atmosphere, so the energy in the compressed air inside the tank is the same as that produced by atmospheric heating of that air, but as more of it is now in the tank, there is additional potential for work to be done. This extra energy was fed into the air by atmospheric heating before the air was compressed.

So, here is where we descend into nonsense. Not all of the work is lost as heat; most of it is stored in the compressed air! See the ideal gas law article, or pick up a physics reference book.

Compressing a gas means reducing its volume. According to the ideal gas law, compressing a gas means changing the quotient P/T (absolute pressure divided by absolute temperature), since PV/T is constant. So both temperature and pressure can change, it is their quotient that is determined by the shrinking of the volume! Suppose one compresses a mass of air by a factor N (so the end volume is 1/N times the starting volume). Then P/T at the compressors outlet will be N times the P/T at the inlet. So the pressure will rise more than the temperature.

If the compression is done very fast, you get an adiabatic process and both the temperature and pressure will rise the most. If the compression is done very slowly, you'll get an isothermal process. In a practical compressor, there will always be some heat loss but comprseeion is done quite quickly, so the process will be almost adiabatic, but not quite. In practice, the a warm tank of compressed air will shed its heat to the environment unless it's well insulated.

The US Patent 2,030,759 doesn't make any claims about being fuel-less, so I'll skip that. It's parts are a bog-standard compressor and compressed air engine, so I'm surprised this patent was ever granted.

Moving on to the concept lifted from Scott Robertson's website. Even if the compressors and engine were totally reversible, you cannot extract more work from compressed air than you originally put in it by compressing it. Viewing it as a heat engine, both the hot and cold reservoir are the outside air, so this machine will not generate external work.

On to the Leroy Rogers engine. Kelly claims;

What is not generally realised is that more energy is available from compressed air than the energy required to compress the air in the first place

The reason this is not generally realized is because would violate the empirical law of conservation of energy. If you have proof, please submit an article to e.g. Nature for peer review and prepare to pick up your Nobel prize for Physics if you are correct. (Or be publicly ridiculed when you are proved wrong, which I submit is more likely to happen)

The density of this cold air is now much higher than the air entering the vortex chamber.

Again, no. According to the picture on the airtx page, air enters a vortex tube at eight bars (absolute) and 21 °C. It exits at 1 bar absolute and -40 °C. An alternative notation of the ideal gas law is: ρ = P/T·R/M, where ρ is the density, P is absolute pressure, T is absolute temperature, R is the gas constant, and M is the molar mass. Since the molar mass and gas constant are, well, constant for a given ideal gas, there is a direct link between density and pressure and temperature. Dividing the pressure and temperature at the inlet of the vortex chamber we get: 8·10⁵/(273+21) = 2721, while the cold output side yields 1·10⁵/(273-40) = 429. So the density at the inlet is about 6.3 times higher, and not lower!

The Eber Van Valkinburg Engine "works" on the unproven premise that it takes less power to pressurize an incompressible liquid than is generated by using that pressure to drive a turbine. If that were true, this machine once started up would keep increasing its speed until it flew apart! Looking at the energy balance for this whole contraption, you have mechanical energy coming out of the output shaft, but no energy going in! Bzzzt, wrong! Again, if you can build a working model of this engine, be ready to collect your Nobel prize. But I'm not holding my breath.

The clem engine seems to rely on the same premise, and is equally busted.

Concerning the "Centrifugal-Thrust-Engine", keep in mind that this is an apparent force. In reality there is only inertia. Now, on to the analysis of inertia and gravitational forces on masses inside a cone.

The cone is revolving at one rotation per second. There where the cone has a radius of a meter, a mass clinging to the inside is moving with a velocity of 2·π·1 = 6.28319 m/s (not 3.13 m/s as stated by Mr Kelly!) At a radius of 0.24 meters, it is moving at 2·π·0.24 = 1.50796 m/s. The required centripetal force in both cases is m·v²/R, and the accelleration by that force is v²/R. In the first case we get 6.28319²/1 = 39.47848 m/s² and in the second case we get 1.50796²/0.24 = 9.47476 m/s². So Mr Kelly's conclusion that

whenever a mass completes one rotation in exactly one second, the centripetal (inward) acceleration is the same as acceleration under gravity.

is clearly busted.

The mentioned "rotor-cylinder"is a very inefficient version of an impulse turbine. A more efficient version is a pelton wheel.

The whole following tedious discussion about combined pumps and turbines essentially boils down to the same premise put forth by Mr Kelly that pumping water costs less energy than using it in a turbine. Since reaction tubines are more or less the same as pumps, and since they encounter both mechanical friction and friction in the working fluid in both directions, one can see that the premise is false. Again let me point out that in all cases of the closed circuit pump/turbine combos every particle comes back to the same height after a cycle. So there is no net energy gain trough gravity!

Indeed, as Mr Kelly mentions at the beginning of this chapter, hydropower depends on the sun to evaporate water and deposit it on higher ground.

The Papp "engine" pretends to work on fission of helium, I quote;

It is calculated that as a result of all the aforementioned interactions, an ignition discharge occurs in which the helium splits into hydrogen in a volume not larger than 2 or 3 x 10-6 cubic millimetres at a temperature of approximately 100,000,000 degrees F.

Allow me to point out that fission is only exothermic for some isotopes of heavy elements like uranium, plutonium and the like. Helium is extremely stable and does not release energy when split. Indeed, it is the inverse reaction of fusion of hydrogen isotopes that produces excess energy.

The "Aerops" engine from its description seems to work like a kind of Stirling engine. It uses eletrical power to heat gas. Only the description of how the hot gasses are cooled after pushing down the cilinders doesn't convince me; there is no plausible heat-sink. Allow me to point out that that a simple electromotor is much more efficient in converting electrical energy to mechanical energy than any heat engine built with current and foreseable materials will be.

As for Eskeli's machines. Turbines are well-understood heat engines, and are bound my the efficiency limits of the aforementioned Carnot cycle. Heat pumps are also well-understood.

His heat-pump does not seem special to me. And the turbine designs require an external heat source to run, as mentioned in the patents. Again, nothing special.