Curious device

[Prajna]

Hi all, this is my first post on the forum so please be nice.

I have been contemplating a device that is remarkably simple but, at least to me, somewhat curious.

We all know that if we bring two like magnetic poles together they will repel. Equally, if we insert a sheet of magnetically permeable material in the space between the repelling poles they will attract to the sheet.

Please examine the above drawing (sorry it is just a rough sketch).

On the left is a metal rotor that has slots cut in it so that it resembles a disc with metal fingers around the periphery. When rotated the fingers pass between the two opposing magnets that are fixed to levers. This will cause the levers to reciprocate as the fingers pass in and out of the space between the magnets. The other end of the levers have pins that run in grooves cut around a cylinder - you might consider it as a kind of double swash plate - causing the cylinder to rotate.

I imagine that there will be a cogging effect on the rotor caused by eddy currents in the rotor.

My question is, how does the inductive drag/eddy currents on the disc relate to the output power of the device?

[swansont]

43 minutes ago, Prajna said:

if we insert a sheet of magnetically permeable material in the space between the repelling poles they will attract to the sheet.

True for a single magnet, because you induce a magnetic field in the material, but your system would induce opposite fields which would tend to cancel. i.e. the field halfway between the magnets is small, so the induced field is also small.

[Prajna]

2 minutes ago, swansont said:

True for a single magnet, because you induce a magnetic field in the material, but your system would induce opposite fields which would tend to cancel. i.e. the field halfway between the magnets is small, so the induced field is also small.

Thanks for your response. You can test my assertion by folding a piece of card in half, attaching magnets to the ends of the flaps with their poles opposing and then slide a sheet of soft iron between them. The sheet will want to attract to whichever magnet it is closest to but you will notice that both magnets are attracted to the sheet.

I believe that what is happening is that the fields of the magnets are attracted into the sheet since it has greater permeability than the air gap and that this effect is stronger than the repulsion force in the gap.

Unless I've misunderstood what you were saying.

[Prajna]

Here's a better picture:

[Prajna]

[Prajna]

 

[exchemist]

1 hour ago, Prajna said:

 

What is the point of this machine?

[Prajna]

On 4/14/2024 at 9:03 AM, exchemist said:

What is the point of this machine?

The idea is to use the magnetic force of opposed magnetic poles to drive an output. The magnets are switched by intervening a metal finger between them since inserting a metal sheet between two opposing magnetic poles causes them to be attracted to the sheet (since it has a higher magnetic permittivity than the surrounding air the magnets try to make a magnetic circuit via the metal). This effectively switches the magnets between repulsion and attraction, which causes the rockers to reciprocate between open on one side and closed, driving the flywheel via its diamond-shaped cam groove. It appears to me that the force required to turn the rotor (incurred in the main by eddy currents in the metal finger disposed in the field) may be less than the force produced by the magnets. I have still to build and test such a device, though I am close to doing so now that the design is pretty much complete, so I can't say for sure how it might behave. I thought that perhaps a physicist might have some feel for how the forces are balanced between eddy current drag on the rotor and magnetic force from the magnets. Attached is a simulation of the device running, which may help to illustrate the principle. Thanks for your question.

 

 

[exchemist]

19 minutes ago, Prajna said:

The idea is to use the magnetic force of opposed magnetic poles to drive an output. The magnets are switched by intervening a metal finger between them since inserting a metal sheet between two opposing magnetic poles causes them to be attracted to the sheet (since it has a higher magnetic permittivity than the surrounding air the magnets try to make a magnetic circuit via the metal). This effectively switches the magnets between repulsion and attraction, which causes the rockers to reciprocate between open on one side and closed, driving the flywheel via its diamond-shaped cam groove. It appears to me that the force required to turn the rotor (incurred in the main by eddy currents in the metal finger disposed in the field) may be less than the force produced by the magnets. I have still to build and test such a device, though I am close to doing so now that the design is pretty much complete, so I can't say for sure how it might behave. I thought that perhaps a physicist might have some feel for how the forces are balanced between eddy current drag on the rotor and magnetic force from the magnets. Attached is a simulation of the device running, which may help to illustrate the principle. Thanks for your question.

 

 

 Simple application of the laws of thermodynamics will tell you that the energy input cannot be less than the energy output. 

If this device is an attempt to get more out than you put in, it won't work. 

[Prajna]

1 minute ago, exchemist said:

 Simple application of the laws of thermodynamics will tell you that the energy input cannot be less than the energy output. 

If this device is an attempt to get more out than you put in, it won't work. 

I'm sure you're right because laws are laws, eh. But nobody seems interested to show a proof that the drag on the rotor is >= the force produced by the switching magnetic fields, so I'll reserve judgement and do some practical tests. It seems that is a more rapid approach to proving or disproving it than waiting for a physicist to do some calculations to show one way or another that my intuition is wrong. Quite how the thermodynamic balance is disposed in this device is not necessarily obvious and it may be difficult to express the above relationship, I don't know. I do know that there is a reflexive insistence on the laws of thermodynamics whenever such a device 'appears' to put out more energy than is required to run it but maybe that reaction is over resorted to. No probs, I'll just build it and test it and if it behaves as I imagine then you guys will have some explaining to do.

[exchemist]

1 minute ago, Prajna said:

I'm sure you're right because laws are laws, eh. But nobody seems interested to show a proof that the drag on the rotor is >= the force produced by the switching magnetic fields, so I'll reserve judgement and do some practical tests. It seems that is a more rapid approach to proving or disproving it than waiting for a physicist to do some calculations to show one way or another that my intuition is wrong. Quite how the thermodynamic balance is disposed in this device is not necessarily obvious and it may be difficult to express the above relationship, I don't know. I do know that there is a reflexive insistence on the laws of thermodynamics whenever such a device 'appears' to put out more energy than is required to run it but maybe that reaction is over resorted to. No probs, I'll just build it and test it and if it behaves as I imagine then you guys will have some explaining to do.

The advantage of considering the energy changes in a physical system is that it is often the simplest and most powerful way to analyse it, without the need to get bogged down a mass of in tricky mechanical calculations of forces etc. I learned this in the 6th form at school. The "reflexive insistence" you refer to is simply people applying this principle, to save getting into the weeds of mechanical calculations. Such calculations, though far more complicated, would in any case rely on other laws of physics (laws of mechanics and electromagnetism), which are on an equal footing with the laws of thermodynamics. All are equally as reliable as each other, so it really doesn't matter whether you choose the mechanical route or the energy route, from that point of view. 

But free energy cranks are all the same, really. They come up with a contraption that is just complicated enough to exceed their powers of analysis - and then claim they have broken the laws of thermodynamics. Magnets are often involved, as magnetism is particularly poorly understood by such people. (Tesla often comes into the picture too, though thankfully not in this instance.)

By all means build your machine. It won't output more work than the work input. That is guaranteed. 

[Bufofrog]

21 minutes ago, Prajna said:

No probs, I'll just build it and test it and if it behaves as I imagine then you guys will have some explaining to do.

As exchemist said it won't work so building it is a waste of time.  The goesouts can't be more than the goesins, that is just a fact of life.

[Prajna]

38 minutes ago, exchemist said:

The advantage of considering the energy changes in a physical system is that it is often the simplest and most powerful way to analyse it, without the need to get bogged down a mass of in tricky mechanical calculations of forces etc. I learned this in the 6th form at school. The "reflexive insistence" you refer to is simply people applying this principle, to save getting into the weeds of mechanical calculations. Such calculations, though far more complicated, would in any case rely on other laws of physics (laws of mechanics and electromagnetism), which are on an equal footing with the laws of thermodynamics. All are equally as reliable as each other, so it really doesn't matter whether you choose the mechanical route or the energy route, from that point of view. 

But free energy cranks are all the same, really. They come up with a contraption that is just complicated enough to exceed their powers of analysis - and then claim they have broken the laws of thermodynamics. Magnets are often involved, as magnetism is particularly poorly understood by such people. (Tesla often comes into the picture too, though thankfully not in this instance.)

By all means build your machine. It won't output more work than the work input. That is guaranteed. 

Thanks for the further response, @exchemist, I may be a free energy crank but I'm not claiming free energy here (though I don't rule it out), I consider this device to be an exotic transmission system - energy is put in by driving the rotor converted from rotational to reciprocating by the magnets and then converted back to rotation at the flywheel. Interestingly, power can only be passed forward through the system, rotating the flywheel will not cause the rotor to turn. There may be practical uses for such a feature. I'm an engineer rather than a physicist so my thoughts tend towards practice than theory. Maybe you guys believe it a waste of time to investigate but the idea looks pretty interesting to me.

A friend who frequents another physics forum posted about it there (no mention of free energy or more out than in, he's a very sober and serious guy) and the thread was immediately locked. When he enquired about it the mods replied, "Don't drag rubbish out of the gutter on to this forum! That will never work, it's a useless machine and looks like a perpetual motion machine." How a physicist can say that something "looks like a perpetual motion machine" implies that such an impossibility exists with which to make a comparison. Oh well, a long period of lack of substantive response here is a far better reaction than was received here. Thanks for being patient and (mostly) respectful.

... "than was received there", sorry, can't edit the above.

[exchemist]

37 minutes ago, Prajna said:

Thanks for the further response, @exchemist, I may be a free energy crank but I'm not claiming free energy here (though I don't rule it out), I consider this device to be an exotic transmission system - energy is put in by driving the rotor converted from rotational to reciprocating by the magnets and then converted back to rotation at the flywheel. Interestingly, power can only be passed forward through the system, rotating the flywheel will not cause the rotor to turn. There may be practical uses for such a feature. I'm an engineer rather than a physicist so my thoughts tend towards practice than theory. Maybe you guys believe it a waste of time to investigate but the idea looks pretty interesting to me.

A friend who frequents another physics forum posted about it there (no mention of free energy or more out than in, he's a very sober and serious guy) and the thread was immediately locked. When he enquired about it the mods replied, "Don't drag rubbish out of the gutter on to this forum! That will never work, it's a useless machine and looks like a perpetual motion machine." How a physicist can say that something "looks like a perpetual motion machine" implies that such an impossibility exists with which to make a comparison. Oh well, a long period of lack of substantive response here is a far better reaction than was received here. Thanks for being patient and (mostly) respectful.

... "than was received there", sorry, can't edit the above.

Well, as someone who once long ago trained as a patent agent, I rather like perpetual motion machines. It can be fun sometimes to analyse them mechanically, without resorting to the easy thermodynamic way to dismiss them, just as an exercise. But at the same time I have some sympathy for the moderation at this other forum you mention. When one sees an apparently pointless machine like yours, which has a shaft output nominally the same as the input but with a needlessly complicated mechanism, especially one involving magnets for no obvious reason, alarm bells ring, (especially if one has been around on science forums for a few years as I have) and one tends to think, "Hello, that smells like a perpetual motion machine to me". Some of the stricter forums don't encourage mental exercises with perpetual motion cranks. 

By the way, it seems to me your machine can pass power backwards: if you were to give your rotor a spin so its arms passed through the magnet gap at a rate similar to the rate at which the magnets were made to reciprocate by turning the output shaft, I think it would align its speed with the reciprocating motion, rather like a synchronous motor aligning with the frequency of mains AC.

 

  

[Prajna]

36 minutes ago, exchemist said:

Well, as someone who once long ago trained as a patent agent, I rather like perpetual motion machines. It can be fun sometimes to analyse them mechanically, without resorting to the easy thermodynamic way to dismiss them, just as an exercise. But at the same time I have some sympathy for the moderation at this other forum you mention. When one sees an apparently pointless machine like yours, which has a shaft output nominally the same as the input but with a needlessly complicated mechanism, especially one involving magnets for no obvious reason, alarm bells ring, (especially if one has been around on science forums for a few years as I have) and one tends to think, "Hello, that smells like a perpetual motion machine to me". Some of the stricter forums don't encourage mental exercises with perpetual motion cranks. 

By the way, it seems to me your machine can pass power backwards: if you were to give your rotor a spin so its arms passed through the magnet gap at a rate similar to the rate at which the magnets were made to reciprocate by turning the output shaft, I think it would align its speed with the reciprocating motion, rather like a synchronous motor aligning with the frequency of mains AC.

 

  

Interesting. Thanks for another considerate response. I'm very interested to have a play with it and get a feel for how it behaves. You may be right that some energy can be passed back, I'll investigate. Hopefully I will be able to visit FabLab on Wednesday to see if they can help out with some 3D printing, laser cutting and sourcing nuts, bolts and shafts.

3 hours ago, exchemist said:

But free energy cranks are all the same, really. They come up with a contraption that is just complicated enough to exceed their powers of analysis - and then claim they have broken the laws of thermodynamics. Magnets are often involved, as magnetism is particularly poorly understood by such people. (Tesla often comes into the picture too, though thankfully not in this instance.)

It's not only 'free energy cranks' who don't understand magnetism. For instance, I've never seen a good explanation of what's going on when you stick a magnet to the bottom of an overhead steel beam. The magnet is obviously doing work, holding its own weight, certainly if I was holding up a magnet against the force of gravity it would feel like I'm doing work. So where's the energy coming from to do that work? If it's from the magnetic field then is the magnet's strength depleted by it? If not then why?

[exchemist]

1 hour ago, Prajna said:

Interesting. Thanks for another considerate response. I'm very interested to have a play with it and get a feel for how it behaves. You may be right that some energy can be passed back, I'll investigate. Hopefully I will be able to visit FabLab on Wednesday to see if they can help out with some 3D printing, laser cutting and sourcing nuts, bolts and shafts.

It's not only 'free energy cranks' who don't understand magnetism. For instance, I've never seen a good explanation of what's going on when you stick a magnet to the bottom of an overhead steel beam. The magnet is obviously doing work, holding its own weight, certainly if I was holding up a magnet against the force of gravity it would feel like I'm doing work. So where's the energy coming from to do that work? If it's from the magnetic field then is the magnet's strength depleted by it? If not then why?

This comment of yours illustrates exactly what I feared about your grasp of physics when it comes to magnets. No work is done by a static magnet sticking to a beam.  Mechanical work is a force applied through a distance, F x d. You would not think a bolt screwed into the beam was continuously doing work by staying there, would you? So why do you imagine a magnet sticking to a beam is doing work? 

[Prajna]

2 hours ago, exchemist said:

This comment of yours illustrates exactly what I feared about your grasp of physics when it comes to magnets. No work is done by a static magnet sticking to a beam.  Mechanical work is a force applied through a distance, F x d. You would not think a bolt screwed into the beam was continuously doing work by staying there, would you? So why do you imagine a magnet sticking to a beam is doing work? 

Fair enough, however energy is being employed to sustain the weight of the magnet against the force of gravity (at least I accept that gravity exists, count your blessings, you could be talking to a flat earther rather than a simple free energy crank). As I say, were I to hold the magnet in the air I would hope to have tucked into a decent bowl of porridge before the task, certainly if it was a heavy magnet. So, excusing my technical ignorance on the subject for a moment, what's holding the magnet there and what's the energy accounting?

[KJW]

6 hours ago, exchemist said:

Well, as someone who once long ago trained as a patent agent, I rather like perpetual motion machines. It can be fun sometimes to analyse them mechanically, without resorting to the easy thermodynamic way to dismiss them, just as an exercise. But at the same time I have some sympathy for the moderation at this other forum you mention.

...

Some of the stricter forums don't encourage mental exercises with perpetual motion cranks.  

I'm strongly opposed to forum moderators locking threads about perpetual motion machines. I think perpetual motion machines can be interesting as well as instructive. I have even discovered an interesting principle as a result of considering a design that could be used to construct a perpetual motion machine:

Neither lenses nor mirrors can produce an image that is brighter than the source.

 

 

Edited April 15 by KJW

[MigL]

In this 'transmission', no energy is gained by incorporating magnets, and you would be better off using simple gears.
I don't think you understand what the magnets are doing in your design.
They are simply used as a force generating mechanism, as would be the teeth of gears.
One big difference is that this force is limited by the strength of the magnets and the geometry of the magnet/finger system, as opposed to the the tensile strenth of hardened steel, which limits forces in a gear system.

IOW, at best you have the same frictional losses in your system so you will always get less output than input, and the amount of power you can transfer is severely limited by the magnetic coupling.

( I tried to be as nice as possible and gave a serious response, without laughing )

[exchemist]

2 hours ago, Prajna said:

Fair enough, however energy is being employed to sustain the weight of the magnet against the force of gravity (at least I accept that gravity exists, count your blessings, you could be talking to a flat earther rather than a simple free energy crank). As I say, were I to hold the magnet in the air I would hope to have tucked into a decent bowl of porridge before the task, certainly if it was a heavy magnet. So, excusing my technical ignorance on the subject for a moment, what's holding the magnet there and what's the energy accounting?

Magnetic attraction.

If you have a bolt screwed into the beam, all that holds it in place is actually electrostatic attraction, because that is what is responsible for the chemical bonding in the metal that enables it to keep its shape and resist deformation under stress. There is no difference in principle. 

Don't be fooled by how biological muscles work. Those do expend energy to hold a weight in a static position, but that's to do with the biochemistry of muscle fibres. 

My example of the bolt screwed into the beam is what you need to consider. That does not expend any energy, not even if the bolt supports a 1 tonne weight suspended from it! Or think of a concrete support holding up a weight. If you did that by your muscles, you would get tired, but the concrete is not doing any work to hold the weight up. Work is only done if something moves under the action of a force. So a crane lifting a weight does work against the force of gravity. But if the operator stops work for lunch and leaves the weight hanging there from the cable, no work is being done.  

So there's no energy accounting to do in the case of the magnet. A magnetic force or an electrostatic force can both equally hold something in position against the force of gravity, in the right circumstances. 

  

54 minutes ago, KJW said:

I'm strongly opposed to forum moderators locking threads about perpetual motion machines. I think perpetual motion machines can be interesting as well as instructive. I have even discovered an interesting principle as a result of considering a design that could be used to construct a perpetual motion machine:

Neither lenses nor mirrors can produce an image that is brighter than the source.

 

 

There have been a few on this forum. My favourite was Tom Booth's "ice engine". He got banned in the end but that was for failing to take in anything anybody said, not because he was proposing a perpetual motion machine. Unusually, that was a perpetual motion machine of the 2nd kind. But it was a crank classic in that it was all based on Tesla [groan]. I had not realised that among his many eccentricities, Tesla thought you could run a heat engine using ambient heat.

There was also, on another forum, aJapanese who thought an IR photovoltaic cell could be put in a fridge, light a bulb and cool the fridge. So that was another 2nd kind example.  

Tom Booth was interesting in that he had researched the history of thermodynamics and put me onto a paper by Sadi Carnot (in translation) in which he, Carnot, was applying the idea of caloric, i.e. before the modern concept of heat even existed, and nevertheless was able to get the right answers!   

Edited April 15 by exchemist

[Prajna]

1 hour ago, MigL said:

 

( I tried to be as nice as possible and gave a serious response, without laughing )

Appreciated.

[KJW]

45 minutes ago, exchemist said:

There have been a few on this forum. My favourite was Tom Booth's "ice engine". He got banned in the end but that was for failing to take in anything anybody said, not because he was proposing a perpetual motion machine. Unusually, that was a perpetual motion machine of the 2nd kind. But it was a crank classic in that it was all based on Tesla [groan]. I had not realised that among his many eccentricities, Tesla thought you could run a heat engine using ambient heat.

The design to which I am referring was also a perpetual motion machine of the 2nd kind. It consisted of a large diameter pipe radiating thermal radiation at room temperature, this radiation being focused onto a smaller diameter pipe, the increased intensity resulting in an elevated temperature of the smaller diameter pipe. I could see nothing wrong with this design and was forced to conclude that it is impossible to focus radiation to an image that is brighter than the source. I raised this on a forum I regularly visited at the time, and my hypothesis was confirmed by another member.

 

[Prajna]

52 minutes ago, exchemist said:

Magnetic attraction.

If you have a bolt screwed into the beam, all that holds it in place is actually electrostatic attraction, because that is what is responsible for the chemical bonding in the metal that enables it to keep its shape and resist deformation under stress. There is no difference in principle. 

Don't be fooled by how biological muscles work. Those do expend energy to hold a weight in a static position, but that's to do with the biochemistry of muscle fibres. 

My example of the bolt screwed into the beam is what you need to consider. That does not expend any energy, not even if the bolt supports a 1 tonne weight suspended from it! Or think of a concrete support holding up a weight. If you did that by your muscles, you would get tired, but the concrete is not doing any work to hold the weight up. Work is only done if something moves under the action of a force. So a crane lifting a weight does work against the force of gravity. But if the operator stops work for lunch and leaves the weight hanging there from the cable, no work is being done.  

So there's no energy accounting to do in the case of the magnet. A magnetic force or an electrostatic force can both equally hold something in position against the force of gravity, in the right circumstances. 

  

There have been a few on this forum. My favourite was Tom Booth's "ice engine". He got banned in the end but that was for failing to take in anything anybody said, not because he was proposing a perpetual motion machine. Unusually, that was a perpetual motion machine of the 2nd kind. But it was a crank classic in that it was all based on Tesla [groan]. I had not realised that among his many eccentricities, Tesla thought you could run a heat engine using ambient heat.

There was also, on another forum, aJapanese who thought an IR photovoltaic cell could be put in a fridge, light a bulb and cool the fridge. So that was another 2nd kind example.  

Tom Booth was interesting in that he had researched the history of thermodynamics and put me onto a paper by Sadi Carnot (in translation) in which he, Carnot, was applying the idea of caloric, i.e. before the modern concept of heat even existed, and nevertheless was able to get the right answers!   

Hmmm... I still feel like I'm being fobbed off somewhat. I consider a screw as being 'held', as it were. Actually the object that is being held by the screw is exerting a force downwards, due to gravity, while that force is being countered by the cohesive forces of the screw and whatever it is attached to. Electrostatic forces must be established and maintained. Concrete supporting something can be intuitively understood, as with adhesion and the steel wire rope you referred to.

Magnetism does seem mysterious and different to other mechanical forces we encounter day to day, you can hardly blame free energy cranks for finding them irresistible. Thanks for the anecdotes of previous offenders, I'll have to look that old thread up.

I suppose that part of the difficulty is in differentiating between force, work and energy.

[exchemist]

30 minutes ago, Prajna said:

Hmmm... I still feel like I'm being fobbed off somewhat. I consider a screw as being 'held', as it were. Actually the object that is being held by the screw is exerting a force downwards, due to gravity, while that force is being countered by the cohesive forces of the screw and whatever it is attached to. Electrostatic forces must be established and maintained. Concrete supporting something can be intuitively understood, as with adhesion and the steel wire rope you referred to.

Magnetism does seem mysterious and different to other mechanical forces we encounter day to day, you can hardly blame free energy cranks for finding them irresistible. Thanks for the anecdotes of previous offenders, I'll have to look that old thread up.

I suppose that part of the difficulty is in differentiating between force, work and energy.

I’m a chemist by training, so I am very much aware that chemical bonding is electrostatic. Every solid object gains its solidity due to electrostatic attraction, between atomic nuclei and their surrounding cloud of electrons. It is this that bonds atoms together in solids. Magnetism is only different in that it arises from electric charges in relative motion. In a permanent magnet the atoms have unpaired electrons, which have angular momentum, circulating and/or “spinning” and this motion creates a magnetic dipole on each one. These align and their collective dipoles combine to create the magnetic field of the magnet. Unless it is an electromagnet, in which case, the field arises from the flow of electrons (electric current) in a coil of wire. 

 

 

[Prajna]

8 hours ago, exchemist said:

I’m a chemist by training, so I am very much aware that chemical bonding is electrostatic. Every solid object gains its solidity due to electrostatic attraction, between atomic nuclei and their surrounding cloud of electrons. It is this that bonds atoms together in solids. Magnetism is only different in that it arises from electric charges in relative motion. In a permanent magnet the atoms have unpaired electrons, which have angular momentum, circulating and/or “spinning” and this motion creates a magnetic dipole on each one. These align and their collective dipoles combine to create the magnetic field of the magnet. Unless it is an electromagnet, in which case, the field arises from the flow of electrons (electric current) in a coil of wire. 

 

 

Ok, I hadn't really associated chemical bonds with electrostatics (which I tend to associate with Van de Graff generators and rubbing cats on perspex rods, etc) but I'll accept that chemical bonds are electrostatic.

All the thinking about this device began while watching one of Robert Murray-Smith's early videos where he was discussing Wesley Gary's magnetic motor. He showed that if you place a thin keeper across the poles of a horseshoe magnet then if the keeper is longer than the span between the poles you will get additional poles that appear on the ends of the keeper due to flux leakage. If you then lift one end of the keeper off its pole the pole on the end of the keeper reverses.

The way I interpret what is happening with the keeper is by thinking in terms of magnetic currents. As I see it, a magnet is always trying to close its circuit. Really it is a perpetual motion machine all by itself. There is a large magnetic reluctance in the air but the magnet will complete the circuit will complete itself via the air if there is no path with more permittivity available. The keeper offers a low reluctance path but if it is too thin to contain the full magnetic current then some leaks through the air surrounding the keeper. That leakage flux will be of the same polarity as the pole it is next to. When one end of the keeper is lifted off its pole you have effectively turned your magnet-and-keeper into one long bar magnet (or a kinky horseshoe magnet in this case) and the keeper becomes one end of that magnet - the opposite pole to the one it presented due to leakage flux.

In my terms, a magnet will attract any object that offers a lower reluctance path than whatever is allowing it to complete its circuit currently (if you'll excuse the pun), that a magnet always completes its circuit via the shortest path with the lowest reluctance and the circuit is always closed. This need to reduce the length and reluctance of the magnet's circuit is what we observe as magnetic attraction.

Now this understanding of magnetism may well be wrongheaded but it seems to me to offer a much better description of magnetism than the classical scientific one you offered, which doesn't really tell us anything about how magnets behave.

I think Ed Leedskillin was the only guy who understood magnets but then nobody can understand Leedskillin (including me.)