Orientation of sphere magnet inside sphere magnet

[JW]

[magnO]

is that yours? I'm mostly working in software in what I build at the moment since a few years.

[JW]

Yes that's me 

[magnO]

here is what I work on, a social coordination system,
telegra (dot) ph/Multi-hop-swarm-redistribution-what-is-the-BIG-idea-04-21

[magnO]

Why I'm interested in concentric ball magnets, if example 2 is the preferred configuration then that supports a model, or design, I am interested in. If example 1 is true, then it falsifies the model.

[JW]

-By the way, you have 20 posts you can publish links now 

[magnO]

Are the Sphere's solid or hollow?

Even then at perfect balance, the inner one will orient itself towards opposite poles (still using opposites attract ).

The outer one is hollow. I had someone say that the magnetic field on the inside of a hollow sphere is reverse, so that the rest orientation would be example 1. My intuition is example 2. I am interested in a model that is supported if example 2 is correct and falsified if example 1 is correct.

[richhagen]

If you model the magnetic flux lines through the sphere, it would appear that it would be as on the left if held in the physical position at the center but allowed to rotate and the overall field was as described by the original poster.  Magnets are generally aggregates of smaller magnetic particles.  The magnetic fields of the particles are vectors which add to each other to make up the whole field. 

[magnO]

That makes sense. I have gotten contradictory answers so far, as I mentioned, roughly 50-50. Could I ask you about possible exceptions to get a better understanding? The magnetic flux lines in a horseshoe magnet are like in this image.



In a diametrically magnetized ring magnet, which is like a horseshoe magnet bent into a closed loop, do the magnetic field lines also follow same path as in horseshoe magnet, like this?

[CraigM]

My two cents.

The flux path will follow north/south orientation whether there is an air gap as horseshoe magnet or through magnetic material as conventional (any shape) magnet. The inside of a hollow sphere will have flux lines running directly north/south through the air gap.

Take two block magnets and they will attract with N/S orientation. Physically separate them and flux lines will “jump” the air gap. Now introduce a smaller magnet into the air gap. It will orient itself N/S and stick to one side or the other.

This is what will happen with the scenario you suggest, the inside sphere will stick to one of the poles and will not suspend in the middle.

No change required 🙂

[magnO]

The flux path will follow north/south orientation

Could I ask just to avoid misunderstanding which one of these examples?

[CraigM]

I'd say illustration on the right. The illustration doesn't show a wall thickness but safe to presume there is something reasonable. Believe the inside sphere would attach itself somewhere along the inside wall of the hollow sphere... probably closer to the equator then one of the poles.

Edit - second thought, inside sphere will attach nearer one of the poles because magnetic flux is stronger through magnetic material than in the air gap.

[magnO]

Thanks. What is contradictory is that I have asked a few people, and get roughly 50-50, half say that there is a "northern surface interior of the south pole" and therefore example 1. My intuition is that it is example 2, and, I am interested in a model that works if example 2 is the preferred orientation. In this thread there has been one person suggesting example 1, and 2 or 3 suggesting example 2.

Since answers have been contradictory I am still interested in input. Since the model I am interested in requires example 2, I would not mind at all if it is the alternative that is true, but I want to be certain as it is the model is worthless otherwise.

Here is another drawing I made with cube shaped magnets, I assume it is exact identical situation to sphere magnets.



and in support of example 2, these drawings from this scientific paper show a hollow cylindrical magnet with magnetic field lines as in example 2,



[img]https://i.imgur.com/udMTO0R.png[img]

[CraigM]

Search “diametrically opposed cylinder magnet” and you'll find some with a hole running through the middle just like in your last illustration. Buy one of these and a small spherical magnet smaller then the hole diameter. Shove that sphere into the hole and see what happens!

Experiments get results, questions sometimes only get opinions.

Would be interested in what you find out!😊

[magnO]

I'm looking to experiment. What I have done for now is to buy 6mm magnet balls, was thinking I'll build a hollow sphere magnet. A cylindrical magnet could also be an easy way to go about. But ideally I would like to sort out how it would work in theory, as I have a broader model in mind that just happens to require example 2 to be correct but the model itself has a bit more parts to it. Usually questions get somewhat consensus answers, it is interesting that this one has people divided.

[magnO]

If you are interested by any chance in my broader model, consider a shell, like the hollow sphere magnet, but non-magnetised metal. Place an electric coil in the middle of it, and run a current through the coil. This induces an electromagnetic field in the metal, I would assume like this, the shell gets same polarity as the coil,



Then if the magnets prefer orientation in example 2 in the question in this thread, I assume the coil would repel the shell. Why I am interested in which of the orientations the magnets would prefer.

That model, if correct, could be applied to certain astrophysics, why I am interested in it.

[joestue]

one problem in understanding this is your drawing of the hollow magnetic sphere is wrong.

how i would approach this with a physical model is to buy a bunch of cube magnets, and glue them together to make two halves of a cube with a cube shaped hole in the middle. use ceramic ones so you can play with them without hurting yourself.

now you can easily see that, if you glue a bunch of magnets together, all N facing up, S down. when you remove the one in the middle you have a S and a N pole where.. there would not have been one before. so as much as the flux in a spherical magnet flows around the outside of the sphere, when you remove the sphere in the middle, some of it will now flow back inwards on itself through the inside.

basically, the preferred orientation is the least energy state, rotating all the magnetic poles of every atom.. so they all point in the same direction takes energy.

a pile of bar magnets all chucked in a bucket, taking them out and fitting them together into one large bar magnet requires work.

[magnO]

when you remove the one in the middle you have a S and a N pole where.. there would not have been one before.

I am open to that. It is just that I get contradictory answers, some say, as you say, that the interior surface of either pole will be the opposite pole, as in example 1, others say that example 2 is correct.

I try to find the signal in the noise between those divided opinions. What supports example 2 is drawings like the one from this scientific paper, it shows that the interior surface of either half of a diametrically magnetized cylinder magnet has same polarity as exterior. Based on that drawing it seems possible that it would be the same for a diametrically (same as axially on sphere) magnetized spherical magnet.



Overall I am just interested in what is right, so trying to take in what people say.

[joestue]

i'm pretty sure they were just being lazy with their drawing.
https://ars.els-cdn.com/content/image/1-s2.0-S002197971731069X-fx1_lrg.jpg



anyhow if you put a coil inside a pipe, wrap a cylinder magnet around it and magnetize the magnet via the coil, i suppose you could get a nearly zero external magnetic field on the outside of the cylinder magnet, the magnet will end up magnetized just like the stator of a 2 pole induction motor...(actually it wouldn't because the permeability of most magnets is about 1, same as air) so, who knows what you would get.

https://www.researchgate.net/profile/Mircea_Popescu3/publication/224622572/figure/fig14/AS:668743646584834@1536452318456/FE-model-of-a-2-pole-induction-motor-with-the-distribution-of-specific-core-losses-shown.ppm


anyhow, my point is you need to think of magnets as consisting of an infinite number of discrete magnets.. each one can point in any direction you want it to. this is how halback arrays are made, and you can make a circular halback array which will have a very nearly uniform field inside a cylindrical cavity.

[magnO]

The

i'm pretty sure they were just being lazy with their drawing.

I have considered that as well, if they were and that is the case then that would favour the idea that example 1 is correct. One thought is that horseshoe magnets also show similar field lines as in that scientific paper so it seems not entirely impossible that a diametrically magnetized hollow cylinder magnet would have field lines running from north side to south side across lumen.

I am interested in what the consensus is, or, what is true. Very thankful for your comments for that reason.

[magnO]

also, re: lazy with their drawings, a two-pole brushed DC motor has very close to a ring magnet / hollow cylinder magnet for the stator, and it has a magnetic field that flows like in the drawings in that scientific paper I took examples from





I have not seen a two-pole brushed DC motor with a full ring magnet around it, maybe there is a difference but it seems, without being an expert, that it would be similar.

[CraigM]

Believe that joestu is on to something with the model made from many smaller magnets. In this scenario there is a N/S pole on the top outer/inner side of the cube and a N/S pole on the bottom inner/outer side of the cube. The magnet in the two pole motor is the same with it having opposite poles on the inside and outside diameter.

With a hollow sphere is this the same? With a diametrically opposed cylinder that has a hole in the middle does the ID have a N/S pole?

Your hollow sphere illustration doesn't suggest a pole on the inside wall. Not sure this is possible.

[JW]

Im at work but I want to point something out.

I see in your example you are using a DC motor with a commuter as an example.

You know those RC model airplanes using a 3 phase AC motor that's much more efficient for comparable example, (ducted fan)

Shift your theory to that.

When we make power it is a 3 phase system.     

[JW]

Here is an image if you PM me your address I will ship it to you

[MagnetJuice]

magnO, I see that you are pursuing a theory as to what is causing the Earth expansion.

We have a section on this Forum called “User Diaries” where users can post projects or ideas that they are working on.

It would be helpful for everyone if you posted your idea or theory there. It could help everyone here to understand what you are trying to accomplish and maybe even suggest a better way to test the theory.

Could there be another way to test it besides trying to determine the behavior of one spherical magnet inside another?

Your question has generated substantial interest here, so if they can see what your ultimate goal is, there is a possibility that someone could come up with a more appropriate way to test your theory.

I find the idea of Earth expansion interesting because it is related to one of my areas of research. For years I have been studying the possibility that the Big Bang is not a Bang but a Big Whoosh, as the remnant of stars, pulsars, quasars, and whole galaxies, in the form of quarks, gluons, neutrinos, etc…, pass through the center of a Black Hole at Planck temperature and at speeds billions or trillions of times faster than the speed of light.

This could be possible if what we call the Universe is in the shape of a Torus similar to this:



If the Universe is shaped like this, there could be billions of other Universes, some bigger and some smaller than ours.

And what if all these Universes are part of a larger Torus with an incomprehensible size Black hole at its center? Oh boy, I better stop there… 

Ed

[magnO]

The magnet in the two pole motor is the same with it having opposite poles on the inside and outside diameter.

If the stator in this motor has radially magnetized magnets with opposite poles on the inside and outside diameter, that would support example 1 then.

[magnO]

For years I have been studying the possibility that the Big Bang is not a Bang but a Big Whoosh.

Cosmological red shift is just energy loss with distance, the photoelectric effect, E=hf. "big bang" is an old Christian (Jesuit) model that was re-packaged by a person named Fred Hoyle who coined the word "big bang" in a BBC interview, it is nonsensical, like epicycles model in old Roman empire to conform a geocentric world view to astronomical data from the Greeks.

[magnO]

I see that you are pursuing a theory as to what is causing the Earth expansion.

Since the mapping of the oceanic crust in 1950s and 60s, along with observation of continental drift that goes back long time, it is known that the Earth radius has increased, causing the continents to drift apart. This work here from James Maxlow is a good introduction,
https://www.researchgate.net/profile/James_Maxlow/post/What_is_your_opinion_about_Impact_of_the_Evolution_of_Continents_and_Oceans_on_Climate_of_the_Past/attachment/59d642dd79197b807799e732/AS%3A440522641809408%401482040190648/download/Modelling+the+Earth+Book+Proposal.pdf

You see an interesting correlation with decline in dinousaur speciation and increase in extinction throughout Cretaceous, it parallels the formation of oceanic crust (and so increase in Earth radius. ) The loss of positive selection for large size, of course a result of increased weight, an increase in electric attraction, Coloumb's law F=k(q1q2)/r^2.

The Earth is fed by Birkeland currents from the sun, you see that very easily in polar "hot spots" for example, and it is overall known even by "astro-physicists".

Given those scientific proofs, one possible model to tie together that is a central plasmoid, when increasing in "power" also repelling the Earth shell more strongly. That would cause stronger electric attraction to crust, as well as an increase in radius, exactly what you see in for example Cretaceous period.

The idea of a central plasmoid is very fringe, and most people are not even up to date with 70 year old geological data.

References,
https://www.researchgate.net/publication/301483774_Dinosaurs_in_decline_tens_of_millions_of_years_before_their_final_extinction

https://www.researchgate.net/profile/James_Maxlow/post/What_is_your_opinion_about_Impact_of_the_Evolution_of_Continents_and_Oceans_on_Climate_of_the_Past/attachment/59d642dd79197b807799e732/AS%3A440522641809408%401482040190648/download/Modelling+the+Earth+Book+Proposal.pdf

https://www.researchgate.net/publication/311735496_Ancient_Life's_Gravity_and_its_Implications_for_the_Expanding_Earth

[JW]

Hi MJ

We have a section on this Forum called “User Diaries” where users can post projects or ideas that they are working on.

Currently the diary's section displays on the open forum.

We would have to make the "diary's section like the pub. So it is not on the open forum.

I can make that section with you and magnO  help

Im going make the section now and we can move all posts into that section

[magnO]

No need to feature this on "diary section" as it is not a diary. It was a question. It is not in my self-interest to have that turned into a "personal story section", feel free to not do so. Thanks.

[JW]

Describe a little more of what you recommend

[magnO]

The point is that the post seems like a simple question. Whether a hollow, spherical, diametrically magnetized magnet has opposite poles on inside diameter than outside. This forum is not a Q&A so it was probably the wrong place to ask, I can see that you move the post to try and fit it inside fieldlines.com is about, but the question still seems pretty simple, it seems like people should easily converge on and agree around what the answer is.

[magnO]

The Earth shell is a good example of such a magnetized sphere. But I have to make abstractions, most people are not read up on now 70 year old geological data showing a 1/40% increase in surface area just to fit the oceanic basins, that is sqrt(2.5) increase in radius, and a sqrt(2.5)^3 = 4x increase in volume. The mass increase problem is answered with that there has not been mass increase, the Earth is hollow. The Earth is a hollow, spherical shell, diametrically magnetized (as everyone knows, south pole above greenland and north pole at Antarctica although we use opposite terminology. )

So, I could ask the question differently: are the poles on the inside of the Earth opposite that on the outside? But then, you have cultural conflicts since people are, in general, not even up to date with expansion tectonics, much less that the Earth is just a shell.