Magnet Myths and Misconceptions

[DreamThinkBuild]

Hi All,

Here are some rudimentary tests I did with 4 cylinders with alternating poles made from disc magnets. These spin on a central shaft.

The measuring device relative to the field is what causes the appearance of a bloch wall. There really isn't a wall or loss of field though I like to think of it as a neutral plane where the two poles have equal force. The coil is picking up the equal fields which cancel.

This can also be tested with a long cylinder magnet and a smaller cylinder magnet. When you place the small cylinder magnet on the side of the long one with opposite polarity it will move to the center where the two fields are equal. If you try to slide the small cylinder up against the long cylinder you will feel the imbalance try to push it back to the center.

Hi Magluvin,

I've also experienced those same effects on magnets. Square magnets are more like round gaussian hills, also stressing magnets can push the field off center or degauss them over time. The ferrite magnets show it the fastest, larger magnets will take a while. Makes it fun trying to replicate a magnet motor.

[tinman]

NoBull,   i tried that, but i can not confirm it 

the output of the Hall effect sensor UGN3503UA  shows a dip in the magnetic field near the midpoint of a bar magnet.
It shows what Tinman describes as a peanut shape field.

I think the field at the midpoint is spread out so much (like a sphere) in the midpoint causing this dip. Right?

The field polarity all along the magnet was the same, so starting left as north, it stays north all the way (with the dip in the middle) to right.

Or is my Hall sensor balancing itselve between the both poles?

Please if possible, try  this simple test yourselve.


Regards Itsu

Interesting Itsu

One thing is for sure, there IS more reserch to be done here. I have developed a test that will once and for all show exactly what shape the field around a magnet is. This test (if go's as planed) will be non deniable as far as results go. Once the parts have turned up, I will be straight onto it. And regardless of wether it prooves me right or wrong (which I've been many times before), I will post my test results via video , right here.

Brad

[EMJunkie]

I have watched all of Dr. Lewin's lectures available online.  He is a brilliant physicist and teacher. Never once did I ever hear him mention a bloch wall at the equator or on a bar magnet.  So, when you say Chris that he backs you up you are not being genuine.

Bill

Bill - I did not ever say what you have implied that I said! Please get your facts straight! I quoted Walter Lewin, I will do it again just in-case you did not read my post: "So the Magnetic Field is INSIDE the Solenoid"

Don't bend FACTS to suit yourself. This is what he said! If you can not hear his words then maybe hearing aids might be of value to you?

https://www.youtube.com/watch?v=FUUMCT7FjaI

Minute 30:17

My original Post just in-case you want to go and check it: http://overunity.com/14974/magnet-myths-and-misconceptions/msg431515/#msg431515

Just for you Bill!

[tinman]

You can't see the forest for the trees Tinman.  What does a compass do in real life?  It lines itself up with the Earth's magnetic field.

I can see far more than just a forrest MileHigh.
And no-a compas dose not always line up with the earths magnetic field. It is solely dependent on position of the compass and the strongest magnetic field of opposite polarity.

[EMJunkie]

I have watched all of Dr. Lewin's lectures available online.  He is a brilliant physicist and teacher. Never once did I ever hear him mention a bloch wall at the equator or on a bar magnet.  So, when you say Chris that he backs you up you are not being genuine.

Bill

Bill,

I quote again, Walter Lewin: "So the Magnetic Field is really confined in the Solenoid, the Magnetic Field outside the Solenoid, as we discussed earlier, is almost Zero. There is only a Magnetic Field right Here, keep that in mind for what follows!"

Minute: 28:00

URL: https://www.youtube.com/watch?v=FUUMCT7FjaI

Ok, just for some more, real, hard core giggles: