nix85

Can field of a stronger magnet pass through the opposing weaker magnet?

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I assume not unless big magnet is in TESLA range and able to remagnetize the little magnet in opposite direction. Here is an example of 2.5T field magnetizing small non-magnetized neodymium.

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Moderator Note

I'm not sure what connection the video has to your question, as it does not appear to be an example of the phenomenon you are inquiring about, and posting videos is subject to certain rules we have  (specifically rule 2.7). The video has been removed.

 

Magnetic fields obey superposition. The answer is yes, the magnetic field of a strong magnet can pass through the weaker magnet.

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2 hours ago, swansont said:
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Moderator Note

I'm not sure what connection the video has to your question, as it does not appear to be an example of the phenomenon you are inquiring about, and posting videos is subject to certain rules we have  (specifically rule 2.7). The video has been removed.

 

Magnetic fields obey superposition. The answer is yes, the magnetic field of a strong magnet can pass through the weaker magnet.

And you are wrong, unless stronger magnet is in tesla range and thus able to remagnetized the weaker magnet in opposite direction.

Edited by nix85

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Just now, nix85 said:

And you are wrong, unless stronger magnet is in tesla range and thus able to remagnetized the weaker magnet in opposite direction.

Why did you ask the question if you think you already know the answer?

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5 minutes ago, DrP said:

Why did you ask the question if you think you already know the answer?

I wasn't 100% sure, now i am. There is obviously a need to correct this misconception.

Whole point is that magnetic field lines never intersect, they can add up as in attracting magnets or divert as in opposing magnets, NEVER intersect. This has been addressed at stackexchange, interesting read.

https://physics.stackexchange.com/questions/81603/can-the-magnetic-lines-of-force-of-two-or-more-magnets-intersect-each-other

Edited by nix85

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1 minute ago, nix85 said:

This has been addressed at stackexchange, interesting read.

"Magnetic lines of force of same magnet can't intersect each other, but magnetic lines of force of different magnets can intersect each other"....   From you link.

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6 minutes ago, DrP said:

"Magnetic lines of force of same magnet can't intersect each other, but magnetic lines of force of different magnets can intersect each other"....   From you link.

Didn't you read the rest of his post, he is asking a question and that is one of two offered answers and the wrong one as confirmed by all contributors. We can IMAGINE the two (or 2000) fields intersecting, but this does not happen as fields naturally always form a new SINGLE field (or divert away in case of repulsion).

Edited by nix85

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11 minutes ago, nix85 said:

We can IMAGINE the two (or 2000) fields intersecting, but this does not happen as fields naturally always form a new SINGLE field

You will have to excuse my ignorance in the matter.  It has been 20 years since I done Maxwell equations and magnetic field stuff.  I would ask though - is this 'forming a new field' just another way of saying they have intersected? Is the suggested 'they pass through each other' above not similar to them merging into a single field as they pass?  If they merge into a single field...  then does this mean there is only ever one single field everywhere? I guess that at a distance great enough they wont interact at all, or so weakly they do not notice.   

Maybe I'll have to brush up on fields when/if I get the time and the enthusiasm...  I used to find it hard to stay awake through lectures and lessons on electromagnetism though - my ignorance on the subject might just be something I can live with. :-)  

 

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3 hours ago, nix85 said:

And you are wrong, unless stronger magnet is in tesla range and thus able to remagnetized the weaker magnet in opposite direction.

Magnetic fields don't obey superposition? Please explain.

(and DrP's question is salient here, since if you asked the question just so you could post the video, which is expressly forbidden by the rules)

2 hours ago, nix85 said:

  fields naturally always form a new SINGLE field (or divert away in case of repulsion).

Please reconcile this observation with your claim. (this is what superposition is)

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14 hours ago, DrP said:

1. Is the suggested 'they pass through each other' above not similar to them merging into a single field as they pass?  If they merge into a single field... 

2. then does this mean there is only ever one single field everywhere?

 

1. Like i said we can only imagine them intersecting, draw vectors and resultant vectors, but they never do.

2. Indeed! That is a very good point as in fact, whole creation is but one big magnetic field, one big electron-antielectron pair.

12 hours ago, swansont said:

Magnetic fields don't obey superposition? Please explain.

(and DrP's question is salient here, since if you asked the question just so you could post the video, which is expressly forbidden by the rules)

Please reconcile this observation with your claim. (this is what superposition is)

Video is not important, i linked it to show how very strong field can magnetize neodymium, which is relevant to the subject.  It would be even better if small magnets were already magnetized and forced into the field opposing it, we can assume they would get remagnetized in opposite direction.

Yes, magnetic fields don't obey superposition. We can't speak of superposition of magnetic fields as of EM waves. There is no constructive or destructive interference with magnetic fields.

When in attraction they  add-up, that is, increase density of the field, when in opposition they bend away from each other. They do not superimpose. This is addressed in this article.

http://subato.blogspot.com/2011/03/how-can-magnetic-fields-interfere.html

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5 hours ago, nix85 said:

1. Like i said we can only imagine them intersecting, draw vectors and resultant vectors, but they never do.

What do you mean they never do? 

Here's an experiment you could potentially do.

1.Get a coil and run a small current through it. It will produce a magnetic field. It's an electromagnet.
2. Bring a stronger magnet nearby. See how the field changes. (With a probe, or even a compass). Watch the field reverse, inside the coil, if the magnet has a much stronger field.

 

5 hours ago, nix85 said:

 Yes, magnetic fields don't obey superposition. We can't speak of superposition of magnetic fields as of EM waves. There is no constructive or destructive interference with magnetic fields.

These aren't the same thing. Waves aren't vectors, and magnetic fields have to obey Maxwell's equations. Wave amplitudes add as scalars. Magnetic fields add as vectors.

But if you think you can't cancel out a field by adding one in the opposite direction, I have to tell you that you are sadly mistaken. It's a standard practice in my kind of work where you use trim coils to zero out the earth's magnetic field, and use coils in a Helmholtz configuration (a pair of coils with current in the opposite direction) to give you a zero field at the center, because the fields obey superposition. I have years of experience demonstrating what you claim doesn't happen, so you must excuse me if I don't believe you.

5 hours ago, nix85 said:

When in attraction they  add-up, that is, increase density of the field, when in opposition they bend away from each other. They do not superimpose. This is addressed in this article.

http://subato.blogspot.com/2011/03/how-can-magnetic-fields-interfere.html

You need to look at better sources. Anyone expecting interference doesn't understand the physics well enough. That there is no interference shouldn't be a surprise. But there is superposition.

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3 hours ago, swansont said:

What do you mean they never do? 

Here's an experiment you could potentially do.

1.Get a coil and run a small current through it. It will produce a magnetic field. It's an electromagnet.
2. Bring a stronger magnet nearby. See how the field changes. (With a probe, or even a compass). Watch the field reverse, inside the coil, if the magnet has a much stronger field.

 

These aren't the same thing. Waves aren't vectors, and magnetic fields have to obey Maxwell's equations. Wave amplitudes add as scalars. Magnetic fields add as vectors.

But if you think you can't cancel out a field by adding one in the opposite direction, I have to tell you that you are sadly mistaken. It's a standard practice in my kind of work where you use trim coils to zero out the earth's magnetic field, and use coils in a Helmholtz configuration (a pair of coils with current in the opposite direction) to give you a zero field at the center, because the fields obey superposition. I have years of experience demonstrating what you claim doesn't happen, so you must excuse me if I don't believe you.

You need to look at better sources. Anyone expecting interference doesn't understand the physics well enough. That there is no interference shouldn't be a surprise. But there is superposition.

That is exactly what i said, if one magnet is strong enough it will remagnetize the weaker (electro)magnet in opposite direction but that is not superposition but neutralization of the weaker field. You might think of it in a way that weaker field will oppose the stronger field to a certain point only.

You seem to be under delusion that two opposing magnetic fields can overlap each other. In attraction they merge, in opposition they divert, NEVER overlap.

Waves are not vectors? Waves have magnitude and direction, so they are vectors. Magnetic field is technically not a wave but they have direction and amplitude (field density), so they add as vectors and this is not a question. http://www.emfs.info/what/adding/

You can EFFECTIVELY cancel the magnetic field, for example two similar conductors in opposite directions "cancel out" their fields. But they do not REALLY cancel, they reinforce inbetween the wires and cancel on the outside.

What really happens is:

"Between the wires, the magnetic fields from the two wires point in the same direction so the resulting or total magnetic field will be large. Outside the wires, the two magnetic fields from the two currents are in opposite directions so they will tend to cancel each other and the resulting or total magnetic field will be small."

Quote from http://www.ux1.eiu.edu/~cfadd/1360/30MagSrcs/HmwkSol.html

You can also place two magnets facing with same pole and you will create a spot where fields are "canceled". Well, not really. Only apparently.

In Helmholtz coil however two currents are in same directions so they add up creating a uniform field in the middle. In the very center aka bloch wall point of no magnetism is achieved.

It matters not what you believe, facts are facts. My sources are good. Magnetic fields do NOT superimpose, only merge or divert.

In this video i demonstrate that in case of ring magnets, same poles can ATTRACT (with quite force).

 

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28 minutes ago, nix85 said:

That is exactly what i said, if one magnet is strong enough it will remagnetize the weaker (electro)magnet in opposite direction but that is not superposition but neutralization of the weaker field. You might think of it in a way that weaker field will oppose the stronger field to a certain point only.

That doesn't necessarily re-magnetize the magnet.

28 minutes ago, nix85 said:

You seem to be under delusion that two opposing magnetic fields can overlap each other. In attraction they merge, in opposition they divert, NEVER overlap.

"Overlap" is to add, as vectors. The field at any place only points in one direction. If all they did was divert, you could never have a situation where a field becomes smaller by combining fields in two directions. And, as I have pointed out, I have done this. It is not an unusual situation.

28 minutes ago, nix85 said:

Waves are not vectors? Waves have magnitude and direction, so they are vectors. Magnetic field is technically not a wave but they have direction and amplitude (field density), so they add as vectors and this is not a question. http://www.emfs.info/what/adding/

The solution to the wave equation is a sinusoid, which is a scalar. Amplitude is a scalar.

 

28 minutes ago, nix85 said:

You can EFFECTIVELY cancel the magnetic field, for example two similar conductors in opposite directions "cancel out" their fields. But they do not REALLY cancel, they reinforce inbetween the wires and cancel on the outside.

Which you just finished saying was impossible. Which is it?

28 minutes ago, nix85 said:

What really happens is:

"Between the wires, the magnetic fields from the two wires point in the same direction so the resulting or total magnetic field will be large. Outside the wires, the two magnetic fields from the two currents are in opposite directions so they will tend to cancel each other and the resulting or total magnetic field will be small."

Quote from http://www.ux1.eiu.edu/~cfadd/1360/30MagSrcs/HmwkSol.html

IOW, they add as vectors. They obey superposition.

28 minutes ago, nix85 said:

You can also place two magnets facing with same pole and you will create a spot where fields are "canceled". Well, not really. Only apparently.

In Helmholtz coil however two currents are in same directions so they add up creating a uniform field in the middle. In the very center aka bloch wall point of no magnetism is achieved.

It matters not what you believe, facts are facts. My sources are good. Magnetic fields do NOT superimpose, only merge or divert.

You have contradicted yourself a number of times. It doesn't matter what the quality of your sources is if you don't understand what they are saying.

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8 minutes ago, swansont said:

That doesn't necessarily re-magnetize the magnet.

"Overlap" is to add, as vectors. The field at any place only points in one direction. If all they did was divert, you could never have a situation where a field becomes smaller by combining fields in two directions. And, as I have pointed out, I have done this. It is not an unusual situation.

The solution to the wave equation is a sinusoid, which is a scalar. Amplitude is a scalar.

 

Which you just finished saying was impossible. Which is it?

IOW, they add as vectors. They obey superposition.

You have contradicted yourself a number of times. It doesn't matter what the quality of your sources is if you don't understand what they are saying.

Yes it does if we are talking permanent magnets. Opposing field cannot penetrate the magnet except by remagnetizing it in opposite direction.

You are clearly unable to understand that opposing magnetic fields never overlap, we add vectors to predict the resultant field which always has a single value for a certain point in space, vector, scalar or tensor-wise. It is just a way of calculating things, not what really happens.

Your confusion makes you see contradiction where there is none. 

"Waves aren't vectors" - needless to say who doesn't understands his sources. #facepalm

Go back to first grade.

 

To repeat once again one of basic laws of magnetism.

"LINES OF MAGNETIC FLUX NEVER INTERSECT"

 

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49 minutes ago, nix85 said:

Yes it does if we are talking permanent magnets. Opposing field cannot penetrate the magnet except by remagnetizing it in opposite direction.

You can't easily do a measurement like this, inside of a solid, but a weak field will not re-magnetize a magnet, so you would have to explain what magical thing happens when the field is suddenly able to penetrate.

 

49 minutes ago, nix85 said:

You are clearly unable to understand that opposing magnetic fields never overlap

Do you just not understand what I mean by superposition?

49 minutes ago, nix85 said:

, we add vectors to predict the resultant field which always has a single value for a certain point in space,

Which is what I said

49 minutes ago, nix85 said:

vector, scalar or tensor-wise. It is just a way of calculating things, not what really happens.

It's what we calculate and what we measure, so I don't see how you can claim that it's not what happens, since an experiment is the only way to confirm what happens. And what we measure is the vector sum of the fields.

But feel free to propose an experiment that would confirm your assertions.

—————

You might be able to explain something — how do magnetic shields work? Some material with a high permeability, surrounding a volume, so that the field inside the volume is very small. But it does not "re-magnetize" the shield. 

Standard physics says the field goes inside the shield but you seem to be claiming that the field doesn't penetrate the material. 

Here's a site that shows that they think magnetic fields penetrate magnetic materials, but what do they know?

https://www.mushield.com/magnetic-shielding/how-magnetic-shielding-works/

49 minutes ago, nix85 said:

Your confusion makes you see contradiction where there is none. 

"Waves aren't vectors" - needless to say who doesn't understands his sources. #facepalm

Go back to first grade.

One of us has  PhD in physics and I'm pretty sure it's not you. I do wish I had the confidence of someone who watched a youtube video once, though.

 

49 minutes ago, nix85 said:

To repeat once again one of basic laws of magnetism.

"LINES OF MAGNETIC FLUX NEVER INTERSECT"

 

This is irrelevant to my argument. I never claimed they intersect. I said they add as vectors.

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1 hour ago, swansont said:

You can't easily do a measurement like this, inside of a solid, but a weak field will not re-magnetize a magnet, so you would have to explain what magical thing happens when the field is suddenly able to penetrate.

You don't have to measure inside the magnet to know that field is not able to penetrate the magnet, as it will affect the field on the opposing side. This is easy to test by putting a small magnet inside a stronger magnet's field and measuring the field on the "shaded" pole of the smaller magnet. Field will get compressed by the flux of the bigger magnet but will not let it pass through up to a certain point when it will "break down" just like dielectric breaking down under high voltage. From that point on smaller magnet is remagnetized in opposite direction.

1 hour ago, swansont said:

Do you just not understand what I mean by superposition?

Yes i do, but you clearly do not.

1 hour ago, swansont said:

It's what we calculate and what we measure, so I don't see how you can claim that it's not what happens, since an experiment is the only way to confirm what happens. And what we measure is the vector sum of the fields.

But feel free to propose an experiment that would confirm your assertions.

You are missing the point. Superposition may be used to describe cancelation of emission from two conductors carrying alternating current in opposite direction, but if we take two permanent magnets opposing each other and measure the exact middle between them, the fields will be intact (altho deformed), but probe will show 0 magnetism. So we have apparent cancelation, but in reality what we have is point at the boundary of the two repelling fields in an ideal, hypothetical environment, balance between opposing forces, not cancelation of the fields.

Also superposition can be violated for example in a transformer, the iron core does not obey superposition when it has reached saturation.

Point is that opposing magnetic fields do not penetrate each other altho we may observe effect as if they do.

1 hour ago, swansont said:

You might be able to explain something — how do magnetic shields work? Some material with a high permeability, surrounding a volume, so that the field inside the volume is very small. But it does not "re-magnetize" the shield. 

Standard physics says the field goes inside the shield but you seem to be claiming that the field doesn't penetrate the material. 

Here's a site that shows that they think magnetic fields penetrate magnetic materials, but what do they know?

https://www.mushield.com/magnetic-shielding/how-magnetic-shielding-works/

Of course it penetrates the shield. Flux follows the path of least reluctance. This is irreleavant to my point that fields of opposing magnets can not penetrate each other.

1 hour ago, swansont said:

One of us has  PhD in physics and I'm pretty sure it's not you. I do wish I had the confidence of someone who watched a youtube video once, though.

You rather have PtsD. One of your pearls "waves are not vectors". What circus do you come from.

BTW you are talking to a person who defined the 4th LAW OF MOTION, recognized at Quora and veryfied by independed sources world-wide (if it's not self-evident). Simple yet still denied phenomena that violates conservation of momentum and thus conservation of energy. Quote:

"4th LAW OF MOTION simply states that asymmetrical centrifugal force of unbalanced masses converts into linear acceleration of the system. In other words, it means that unbalanced mass oscillating within 180° or less, or spinning with varying speed, accelerates the whole system unidirectionally without interacting with any outside medium apart for the space itself. "

I got more knowledge in a dirt under my nail than you got in your skull.

PS I hope you will deny the 4th LAW, i'm really looking forward to that. ;D

Edited by nix85

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28 minutes ago, nix85 said:

BTW you are talking to a person who defined the 4th LAW OF MOTION, recognized at Quora and veryfied by independed sources world-wide (if it's not self-evident). Simple yet still denied phenomena that violates conservation of momentum and thus conservation of energy.

I'm not convinced that the above statement increases the credibility of other statements in this thread. But possibly an interesting topic; maybe better discussed in separate thread?
 

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3 minutes ago, Ghideon said:

I'm not convinced that the above statement increases the credibility of other statements in this thread. But possibly an interesting topic; maybe better discussed in separate thread?
 

Well, when you realize the reality and importance of the phenomena, you might.

I'll give you a hint, this means you can literally "swim" in space. Of course assuming you swing arms in opposing directions to cancel the back torque.

It also makes the death of Matt Kowalski VERY ironic (or just plain stupid).

 

Edited by nix85

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It is impossible to deny the 4th law of motion, because its authoritative webpage also has  a depiction of the flying spaghetti monster: 

www.quora.com/What-is-Newton’s-fourth-law-of-motion-which-was-a-hidden-mystery

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43 minutes ago, nix85 said:

BTW you are talking to a person who defined the 4th LAW OF MOTION, recognized at Quora

A reference would be good; can't find it accepted anywhere

...:rolleyes:

edit: maybe taeto had better luck

Edited by Carrock

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1 minute ago, nix85 said:

It's got 12 upvotes at quora. Scroll down to Nikša.

12 upvotes?  I think a PhD carries a tad more weight than 12 upvotes.

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Just now, Bufofrog said:

12 upvotes?  I think a PhD carries a tad more weight than 12 upvotes.

I think KNOWLEDGE carries way more weight than ignorance.

Anyone dares to deny the 4th LAW as i defined it?

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4 minutes ago, nix85 said:

I think KNOWLEDGE carries way more weight than ignorance.

That was implicit in my post.

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