Magnet Myths and Misconceptions

[allcanadian]

@tinman

I have modified your pic MH,so as it looks more like what i believe is to be true. From this you can see how by having more turns with the same current builds a higher magnetic field strength at each end of the magnet. What is happening is you are simply building on from the two wire pic i posted,and the center turns (mid point of the dipole)has the lowest value,and thus the lowest field strength. The further away from center we get,the larger and stronger the field become's. As in the pic i posted with the two wires,we are forming the very same peanut shaped field,only on a larger scale,as we have more turns of wire. It is just the same as adding magnets together,but insted we are adding wires together.

This is not directed at you but moreso a general thought relating to what you have said.


You know it is odd that more people have not bothered to understand the underlying principals of the circuits they build. For instance, in a wire the free electrons jump from one proton shell to the next while the protons remain relatively stationary. The electrical pressure from a source provides the force to move the free electrons however there are always two forces involved. One the negative terminal (more electrons)repelling the free electrons from the source towards the resistance/impedance and second the positive terminal (less electrons) attracting the free electrons back to the source.


Electrostatics 101, and yet we tend to use general terms such as lumped sum Voltage and Current which gives no real insight into what is actually happening. Now if we use an electrometer we may see that the source is little more than a pump with a discharge (Negative terminal-more free electrons) and a suction (positive terminal-less free electrons). Our Sink the resistance on the other side of our circuit then does something which is kind of amazing.


On one side of our resistance we have an abundance of electrons(negative) and on the other side a lack of electrons(positive). At which point we might understand that what we call the dissipation of energy relates to the points at which the two separate conditions of high electron density and low electron density meet. Now if we have a high electron density on one side and a low electron density on the other side then what do we get when the two meet?, we get ambient conditions which is neither a high nor low condition. At the exact center of every resistance an electrometer will measure no charged state and will see ambient conditions.


We should remember the free electrons are energy carriers and the energy in the circuit relates to the difference in electron density not the electrons in themselves. Why it is no more difficult to understand than a water pump producing a high/low water pressure and a water motor diffusing this pressure difference to ambient conditions or no pressure. Again the water is not the energy in the system the condition of the water is, the water is an energy carrier.


As such it is common sense and intuitive to understand that the energy source divides ambient conditions into two distinct conditions while the energy sink unites the two distinct conditions to become ambient conditions once more. At the exact center of the source/sink we will always find ambient conditions...zero. This is called " The Trinity of Unity", the three conditions of High, Ambient and Low. The Energy moving inward or outward from a singular point of ambient conditions.


AC

[MarkE]

I have modified your pic MH,so as it looks more like what i believe is to be true. From this you can see how by having more turns with the same current builds a higher magnetic field strength at each end of the magnet. What is happening is you are simply building on from the two wire pic i posted,and the center turns (mid point of the dipole)has the lowest value,and thus the lowest field strength. The further away from center we get,the larger and stronger the field become's. As in the pic i posted with the two wires,we are forming the very same peanut shaped field,only on a larger scale,as we have more turns of wire. It is just the same as adding magnets together,but insted we are adding wires together.

P.S-i only done the top half of your pic-the bottom will of course be the same as the top in our two dimensional pic

What you believe is wrong.  It is easily demonstrated using a $2.00 Hall effect sensor, or just by suspending two parallel wires so that they can deflect or attract when you apply current.

[minnie]

   Anyone on here actually believe in particle physics and the research that's going on
at CERN? Or is it a load of crap?
               John.

[TinselKoala]

What you believe is wrong.  It is easily demonstrated using a $2.00 Hall effect sensor, or just by suspending two parallel wires so that they can deflect or attract when you apply current.

I have some ratiometric Hall effect sensors, but unfortunately they only cost me about 50 cents each. Allegro A3503, data sheet attached below. Will those do, even though they are not $2.00 sensors?   

But I don't have a bar magnet! Can you believe it. All I have are disk magnets, ball magnets, small block magnets etc. 

1)Do we think that the community here will accept an experimental result obtained from a stack of disk magnets, instead of a solid bar magnet? If not, why not?

The next thing to do of course is to try to imagine, that is _hypothesize_, what the sensor reading would look like in the various test conditions and under the two competing claims of the shape of the field. As a general principle of experimental design, this should be done _before_ any actual data gathering is done in an experiment.

2)The Hall sensor of course will read its maximum value for a given field strength in a given location if the "field lines" are exactly perpendicular to the sensor surface. Right?

3)At the same location, an angled field, or equivalently an angled sensor, will give a lesser reading. Right?

4)In the "peanut waist" picture, the field lines are not parallel to the long axis of the magnet stack, but dip in at the waist or "Bloch wall"("arrow" pointing toward magnet body) and come back out again ("arrow" pointing away from magnet body) on the other side of the BW. In the conventional picture, the field lines are parallel to the long axis of the stack and there is no "dipping" in and out at a "Bloch Wall" waist or equator. Right?

5)So a Hall sensor held with its plane at right angles to the magnet's long axis, and scanned along the length of the magnet, would read very differently in the two cases. Right?

6)If the "peanut waist" picture is true, the sensor being held at right angles and scanned along the magnet will experience a changing angle of the field as the field dips toward the "Bloch wall" waist, and then an also changing angle as the field dips up out of the equator on the other side. This will cause changing readings as the sensor is scanned past the "Bloch wall equator".  Right?

7)But in the conventional case, with the field lines strictly parallel to the long axis except near the end poles, the sensor will experience the field lines straight through the plane of the sensor, and thus the sensor's reading will remain constant, and _at the maximum value_  as it is scanned along the magnet's long axis. Right?


I have asked seven specific questions, some in the form of testable hypotheses, related to an experiment. Before I proceed further, I would like to hear some opinions about these seven questions. Especially, if a stack of disk magnets is not an acceptable substitute for an actual one-piece bar magnet, please let me know right away, and be sure to tell me why.



p.s. Minnie, particle physics and the CERN research are not a load of crap. But then you knew I'd say that. The hypotheses of the researchers may turn out to be unsupported or even falsified by the data they gather, but that's not crap, it's science.

Of course _some people_ evidently can't tell the difference, even as they sit at their computers designed by people they think are idiots using models they think are crap. It's a good thing they aren't still using CRT monitors... that would be yet another layer of "crap" they have to look past and ignore in order to bolster their pet "theories".

[NoBull]

2)The Hall sensor of course will read its maximum value for a given field strength in a given location if the "field lines" are exactly perpendicular to the sensor surface. Right?

Right. That's what I call B_B measurement in Method #3.

3)At the same location, an angled field, or equivalently an angled sensor, will give a lesser reading. Right?

Right

4)<snip>... In the conventional picture, the field lines are parallel to the long axis of the stack and there is no "dipping" in and out at a "Bloch Wall" waist or equator. Right?

Right and if  Hall sensor is parallel to the long axis of the stack, then it will read zero there.  Giving an illusion of dipping at the midpoint of this axis.  I call this the measurement of B_X  in Method #1.

5)So a Hall sensor held with its plane at right angles to the magnet's long axis, and scanned along the length of the magnet, would read very differently in the two cases. Right?

Right.  I call this the measurement of B_Y  in Method #2.

7)But in the conventional case, with the field lines strictly parallel to the long axis except near the end poles, the sensor will experience the field lines straight through the plane of the sensor, and thus the sensor's reading will remain constant, and _at the maximum value_  as it is scanned along the magnet's long axis. Right

Right

I have asked seven specific questions, some in the form of testable hypotheses, related to an experiment. Before I proceed further, I would like to hear some opinions about these seven questions. Especially, if a stack of disk magnets is not an acceptable substitute for an actual one-piece bar magnet,

I don't know but I expect someone to have an issue with the discrepancy.

Besides the mapping the magnet with a Hall sensor there are also methods of mapping it with a piece of ferromagnetic blob (Methods #4, #5, #6) ...but you'd need a Load Cell for that.
Newbie amateurs usually begin with this test because it can be done with a nail and their fingers as the force sensing instrument.