A Model Of A Magnet
This model of a magnet was developed from an experiment I did to determine the properties of magnets.
Using the inexpensive equipment pictured below I first tried to determine the strength of individual magnets and then determine the force between them.
I then created a model of a permanent magnet (pictured below) in order to do more experiments.
I attached one of those composite round magnets to the end of a brass rod then lowered it towards a steel block on an electronic scale.
By recording the distance between the magnet and the steel and the amount of weight the magnet lifted off the scale I could determine the lifting power of the magnet, in grams, at different distances.
I then could, by graphing the values, determine the strength of each magnet at zero distance.
After measuring two magnets I then attach one magnet to an aluminum block on the scale in order to determine the force between the magnets at various distances.
The experiment didn’t work. It turned out that the measured force between two magnets wasn’t very different than the force of one magnet.
The problem was that when measuring the strength of the single magnet I was creating another induced magnet in the steel block so I was actually measuring the force between two magnets, a constant permanent magnet and an increasing induced magnet.
I could only guess that the strength of the individual magnets was half the value I measured but even using this value the results did not meet expectations.
This result caused me to think about how magnets are made and their structure.
An iron alloy is made into the desired shape and then a current is passed through it.
The current restructures the electron configuration in the alloy creating structures radiating a magnetic force.
The alloy determines the strength of the magnet by how many magnetic structures are created so the magnet is composed of little magnets and non magnetized structures.
The model magnet produced a lifting force on the magnet on the aluminum block that registered as grams on the scale.
By using a permanent magnets to measure the force of the model the problem of induced magnetism would be eliminate.
Since the force of magnets is measured from the center of a magnet I wanted to see what would happen as the steel washer was lowered from the top magnet in the model to the bottom magnet in the model.
Unlike a computer model, this model did not produce the expected results.
I will not report my interpretation of the results in the hopes that someone else will perform the experiment and be able to report an independent interpretation, but I will say the results demonstrate to me that the formula for the force between magnets, F=M1M2/d^2, is not the correct formula and this brings into question the use of the equation with other forces.
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David Walton
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The formula you quote igives the hypothetical force between a pair of magnetic monopoles. In fact the hypothesis of magnetic monopoles is an oversimplification. The actual physics requires a more complex analysis.
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nohomehere
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I am curious, is science right about the dipole . I’ve heard that the toroidal dipole a plane. Some say the sun is electric as is all creation being created and returning to the ether on an eternal cycle. they say matter and its attributes of time and space are manifestation or perturbations of space and reletively our perception of time. Every thing is expanding or contracting in on their on time marked by the dipole moment! I like magnets 🙂
https://youtu.be/etaYzqtEnDw
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Robert Beatty
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Hi Herb,
Thanks for specifying your previously discussed interesting magnets experiment. My first house keeping reaction is does the weigh scale see any influence from the magnets?
This reminds me of the famous conundrum of why can a magnet pick up a metal object against gravity over a small distance, but when that distance is increased, gravity overcomes the magnetic attraction force? The answer is that the magnetic strength only follows the inverse square law over small distances. The square factor quickly becomes a cube and greater factor as the distance increases.
The formula you quote has the separating distance d changing on a square relationship, which applies over short distances. This is the main reason why I prefer gravity as the universal force rather than electromagnetism.
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Herb Rose
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Hi Robert,
I was hoping you’d see the experiment and now be able to do it. I would like to hear your interpretation of the results and what implication those results have on our current beliefs about magnetism. I am refraining from making any substantive comments on the results until I hear others interpretation so as not to influence their thoughts.
Herb
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Robert Beatty
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Hi Herb,
There is an interesting outcome. I find my electronic weigh scale will not zero set when under the influence of a magnetic field. QED.
This is fortunate, because I do not have the time to set up the whole experiment you describe.
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Jerry Krause
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Hi Robert and Herb,
First Robert, I would expect, if you are following Herb’s initial description, that the reason your balance will not zero, is the mass of the steel block before one even brings a magnet near it.
Second Herb, the initial design of your simple experiment is really great if you are using the threads of the brass rod to measure the distance. However the brass nut would need to be held securely in a fixed position as one turns the rod. One should not begin counting turns until a turn results in a change of one gram on the balance. Only then begin recording the balance weight for each successive turn until the weight being begin to increase because the magnet is now pushing down on the steel plate.
Then one should add the second magnetic on top of the first and again begin the process of turning the rod. lowering the two magnetics. This to see if the magnetic strength of the two magnets is greater than only one. If the strength is greater, I would add the third magnet and repeat. And because you had three magnets, I would add the third to see what happened.
It’s a really great experiment!!! Which I cannot do because I do not have an electronic balance even though I have the magnets and can afford the threaded brass rod and nuts. However, I have contacts with a few middle schools. So I will make an effort to locate an electronic scale
For again, this is a great experiment to demonstrate the SCIENTIFIC METHOD for middle school students.
Have a good day, Jerry
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Robert Beatty
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Hi Jerry,
“First Robert, I would expect, if you are following Herb’s initial description, that the reason your balance will not zero, is the mass of the steel block before one even brings a magnet near it.”
The ‘steel block’ I used was a permanent magnet salvaged from an unserviceable hard drive. It weighs 10grams on a spring balance scale, but nothing on an electronic balance. The lesson in this exercise is to be very careful when you are mixing electronics with magnets.
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Herb Rose
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Hi Robert and Jerry,
The magnet does not go directly on the scale but on an aluminum block. The reason it is affixed to the aluminum block is to 1: prevent it from moving and 2 to raise it off the scale to prevent interference with any steel parts in the scale or with the electronics (If you use one of the super magnets it is possible for the attraction to steel in the scale to exceed the scales limit.). I used those composite disc shaped magnets found in hardware stores and had no trouble zeroing the scale before affixing the rod and model over it..
The brass rod is fixed with the model over the aluminum block (with magnet) and it is the steel washer (only) that is rotated lower on the rod to see what change occurs in the lifting power reading on the scale.
The results of the attraction between a steel block and a magnet and between 2 magnets is well known. The reason for the model of a magnet is to see what happens when the internal structure of a magnet changes.
Herb
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Robert Beatty
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Hi Herb,
My guess is that as you wind the steel disc down, there is an increase in the electronic weigh scale reading.
I expect this to happen because the steel disc is taking some of the anomalous magnetic scale influence from the bottom magnet which is then being replaced by the true gravity weight of the mass sitting on the scale bed.
In summary, you are measuring an anomaly inherent in the experimental equipment.
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Herb Rose
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Hi Robert,
No it’s more complicated than that.
Consider what equipment they had back in the eighteenth century to make measurements and arrive at the formula. They could measure distances and weights which means they probably used an apparatus similar to mine. The problem with this method is that when a magnet field encounters an iron object it re-arranges the electrons so that the iron produces a magnetic force (induced magnetism). The strength of this induced magnet increases as the magnetic field from the permanent magnet grows stronger. There is no way to determine the strength of the permanent magnet. Here’s a hint about my assessment of the results. The strength of a magnet does not decrease as an approximate cube of the distance from the magnet.
Since the model magnet is lifting weight off the scale the reading on the scale will be smaller (larger negative number) when the magnetic force between the model magnet and permanent magnet on the scale increases. As I interpret your answer you are predicting the magnetic force will decline as the steel washer descends and more of the weight of the aluminum block and magnet will be registered on the scale. Is this correct?
Herb
Robert Beatty
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Herb,
In the 18 century nobody had access to electronic scales. You will need to replace that piece of equipment before you can expect comparable results.
Jerry Krause.
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Hi Herb and Robert,
Herb, yours is a quantitative experiment and you have not reported one number of the weights of your magnets, steel plate, etc. etc. of your system. Then you do not report one actual quantitative result. Just words and pictures and more words.
Robert, just demonstrated something like Herb has been suggesting to my daughter and grandson. I used the pages of a book to measure the distances and safety pins in a basket hung from the steel plate to crudely measure the strength of the magnet at varying number of pages.. They got the idea about magnetic strength which they could qualitatively feel but now see how the strength, as it varied with distance. could be measured.
And the graphs, which Herb did show us, are critically important for I believe if he had plotted grams (y axis) and 1/distance^2, he might have plotted an approximate straight line.
Which is why I will continue to try to refine my experiment for the 18th Century. However Herb, I doubt if they had magnetic disks as you were using.
Have a good day, Jerry
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Herb Rose
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Hi Jerry and Robert,
No it is purely a qualitative experiment.It is to find out what happens not how much happens and not an effort to replicate 18th century work.
In the 18th century they did not have electronic scale, disc magnets, or even a way to produce consistent metal alloys and magnets. Any results one experimenter got would vary from others depending on the differences in these key ingredients. They were after qualitative answers from which the could deduce general results (Laws). They were able to weight and measure fairly accurately with the crude tools they had, however, which is shown by their results.
The weights of the magnets are irrelevant, it is the strength of magnetic force they produce that matters. In the 18th century they were using lodestones or other natural magnets. Today, with different alloys, the weight or physical dimensions of a magnet has nothing to do with the size of the magnetic force (super magnets).
When a magnet force is attracted to a metal objects it turns that object into a magnet that emits its own magnetic force so the force is not constant but grows as more magnets are created. The magnetic flux lines you see around magnets are not the result of the magnetic force flowing from the magnet on distinct paths but because the iron filing used to illuminate them, become magnets due to induction and produce these lines of higher magnetic force.
Jerry, you are cheating by looking up the answers I gave in my original article rather than doing the experiment yourself and coming to your own interpretation.
Herb
Jerry Krause
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Hi Herb,
I will edit what you wrote to better follow the first part of your experiment.
“Using the inexpensive equipment pictured below I first tried to determine the strength of individual magnets. … I attached one of those composite round magnets to the end of a brass rod then lowered it towards a steel block on an electronic scale. By recording the distance between the magnet and the steel and the amount of weight the magnet lifted off the scale I could determine the lifting power of the magnet, in grams, at different distances. I then could, by graphing the values, determine the strength [by grams lifted] of each magnet at zero distance.” But you did not even show us the graph for one of these three each magnets. So I do not know whether the y-axis was grams and the x-axis was distance (d). Or if on the x axis you plotted 1/d or 1/d^2. Then you and we readers could see the results of this part of your well designed experiments.
I cannot follow your descriptions of the remainder of your experiment.
However, I must comment upon your comment: “The experiment didn’t work. It turned out that the measured force between two magnets wasn’t very different than the force of one magnet.” My comment is that the experiment, whatever it was, did work; but not as the result you expected. I assume you repeated the experiment to test if it was reproducible. Something a SCIENTIST should always do in the case of an experiment as simple as this. In cases such as this, I as a chemistry instructor required my students to do at least three tests to give an idea of the results’ precision..
Have a good day, Jerry
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