Magnetic fields attracting two disc-shaped magnets

Click For Summary

Discussion Overview

The discussion revolves around the behavior of disc-shaped magnets, particularly focusing on the forces at play when two magnets are brought together. Participants explore concepts related to magnetic attraction, the nature of magnetic poles, and the implications of material stiffness on magnetic interactions. The conversation includes both theoretical and conceptual aspects of magnetism.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • One participant questions whether a single magnet is attracted to its center due to the strength of its magnetic field, considering it has both north and south poles.
  • Another participant warns about the dangers of using small magnets, highlighting potential health risks if swallowed.
  • Some participants discuss how the north pole of one magnet is attracted to the south pole of another, with the force depending on distance and alignment.
  • There is a suggestion that the stiffness of the material prevents a magnet from collapsing on itself, leading to questions about the nature of magnetic forces and material properties.
  • A participant introduces the idea of magnetic dipoles at the atomic level, suggesting that each atom behaves like a small bar magnet and interacts with its neighbors.
  • Discussion includes the complexity of applying concepts from solenoids and inductors to ferromagnets and permanent magnets, noting the need for quantum mechanics to fully understand these interactions.
  • One participant proposes thinking of magnetic materials as liquids rather than solids to explore their behavior under magnetic forces.
  • Another participant emphasizes that the rigid structure of materials is maintained by quantum effects, which prevent atoms from collapsing due to electromagnetic forces.

Areas of Agreement / Disagreement

Participants express various viewpoints on the nature of magnetic attraction and the implications of material properties, indicating that multiple competing views remain. The discussion does not reach a consensus on the specific mechanisms at play.

Contextual Notes

Participants acknowledge the complexity of the topic, with references to quantum mechanics and the atomic structure of magnetic materials. There are limitations in the assumptions made about material behavior and the simplifications in discussing magnetic interactions.

PlanTer254
Messages
6
Reaction score
1
TL;DR
North pole and south pole attraction
I had 2 small magnets in my mouth for distraction while working on something else,and I had this weird question.the two magnets were not that strong,so just a force was easy to separate them with my teeth.then they would attract to be attached to each other and then the question hit me,the 2 magnets would be attached to each other at a certain force,based on the strength of the magnetic fields...but a one magnet has both north and south poles,is it being attracted to the centre itself,based on the strength of the magnetic field?
 
Physics news on Phys.org
PlanTer254 said:
I had 2 small magnets in my mouth for distraction
Dangerous. If you accidentally swallow them and they enter the coiled parts of your gut separately they can attract each other from adjacent coils and come together, pinching a bit of your gut between them. That cuts off the blood supply to the pinched part completely and kills it. You would need surgery urgently. Reference.
PlanTer254 said:
but a one magnet has both north and south poles,is it being attracted to the centre itself,based on the strength of the magnetic field?
I'm not sure I understand what you are asking. The north pole of one magnet is attracted to the south pole of the other with a force that depends on distance and alignment. Magnets with flat north and south poles and uniform magnetisation, like the disc shaped ones that are in everything these days, will generally try to align the centers of their circular faces, if that's what you are asking.
 
Last edited:
  • Like
  • Love
Likes   Reactions: berkeman, topsquark and vanhees71
Ibix said:
Dangerous. If you accidentally swallow them and they enter the coiled parts of your gut separately they can attract each other from adjacent coils and come together, pinching a bit of your gut between them. That cuts off the blood supply to the pinched part completely and kills it. You would need surgery urgently. Reference.

I'm not sure I understand what you are asking. The north pole of one magnet is attracted to the south pole of the other with a force that depends on distance and alignment. Magnets with flat north and south poles and uniform magnetisation, like the disc shaped ones that are in everything these days, will generally try to align the centers of their circular faces, if that's what you are asking.
Yes,they are disc shaped,I mean,is a single magnet has a North pole and south pole,which should be attracted to each other,but the stiffness of the material makes it not to collapse on it self,right or am I assuming something.
 
Ibix said:
Dangerous. If you accidentally swallow them and they enter the coiled parts of your gut separately they can attract each other from adjacent coils and come together, pinching a bit of your gut between them. That cuts off the blood supply to the pinched part completely and kills it. You would need surgery urgently. Reference.

I'm not sure I understand what you are asking. The north pole of one magnet is attracted to the south pole of the other with a force that depends on distance and alignment. Magnets with flat north and south poles and uniform magnetisation, like the disc shaped ones that are in everything these days, will generally try to align the centers of their circular faces, if that's what you are asking.
They are always on my teeth,and if they are not I will realize and noticed am being distracted by something else hence refocus on what I was doing, guess I better search something else for distraction...
 
  • Like
Likes   Reactions: topsquark
PlanTer254 said:
Yes,they are disc shaped,I mean,is a single magnet has a North pole and south pole,which should be attracted to each other,but the stiffness of the material makes it not to collapse on it self,right or am I assuming something.

Are you talking about something like a solenoid inductor that when energized creates a compressive force on its own winding wires?
 
PlanTer254 said:
a single magnet has a North pole and south pole,which should be attracted to each other,but the stiffness of the material makes it not to collapse on it self,right or am I assuming something.
There are no magnetic monopoles. That's what you are missing.
 
  • Like
Likes   Reactions: malawi_glenn
PlanTer254 said:
Yes,they are disc shaped,I mean,is a single magnet has a North pole and south pole,which should be attracted to each other,but the stiffness of the material makes it not to collapse on it self,right or am I assuming something.
Here is a simplified answer. Each atom of the ferromagnet is itself a magnetic dipole. So if subdivided into atoms each atom will be roughly an independent "bar magnet" and interact with its neighbors. Smaller than that and it is much more complicated and of course there is more to it than this simple picture. The stiffness requires Quantum Mechanics.

And be very careful with supermagnets near toddlers for reasons already given. As soon as more than one is ingested the results can very bad indeed.
 
hutchphd said:
Here is a simplified answer. Each atom of the ferromagnet is itself a magnetic dipole. So if subdivided into atoms each atom will be roughly an independent "bar magnet" and interact with its neighbors. Smaller than that and it is much more complicated and of course there is more to it than this simple picture. The stiffness requires Quantum Mechanics.
alan123hk said:
Are you talking about something like a solenoid inductor that when energized creates a compressive force on its own winding wires?
Like one found in earphones...was wondering if there is a force(magnetic) trying to make the material move,bend or flow in such a way to make the poles as close as possible,but it's not strong enough to break stiffness of the material,but if it is quantum stuff..am not there yet
 
PlanTer254 said:
Like one found in earphones...was wondering if there is a force(magnetic) trying to make the material move,bend or flow in such a way to make the poles as close as possible,but it's not strong enough to break stiffness of the material,but if it is quantum stuff..am not there yet
Think of the material as a liquid, instead of solid... would it behave the same?
 
  • #10
PlanTer254 said:
Think of the material as a liquid, instead of solid... would it behave the same?
I know of no simple answer (to what is a pretty interesting question). The only reason atoms do not collapse from from EM forces is because of quantum effects, so the rigid structure of everything is really what you are asking. The magnetic material is a solid consisting of domains. You don't need to understand the Quantum Mechanics to appreciate the structure
Here is a pretty good video:
 
  • #11
PlanTer254 said:
Think of the material as a liquid, instead of solid... would it behave the same?
Taking the solenoid inductor as an example, when the current passes through its winding wire, a magnetic field will be generated, and N pole and S pole will be generated at the same time. But on the other hand, we can notice that the current flows in parallel between adjacent turns. When two wires are placed in parallel, the current flows in the same direction, and the wires attract each other, so there is a compressive force acting on the winding wire of the solenoid inductor.

But if you want to apply this concept to ferromagnets and permanent magnets, then the situation is much more complicated, and as mentioned in #7, you need to use quantum mechanics in this case.
 
  • #12
hutchphd said:
The magnetic material is a solid consisting of domains. You don't need to understand the Quantum Mechanics to appreciate the structure
Quantum mechanics is interesting,but one of those topics which require dedication to grasp...
 

Similar threads

  • · Replies 3 ·
Replies
3
Views
1K
  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 5 ·
Replies
5
Views
761
  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 32 ·
2
Replies
32
Views
3K
  • · Replies 0 ·
Replies
0
Views
243
  • · Replies 5 ·
Replies
5
Views
1K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 12 ·
Replies
12
Views
508
  • · Replies 6 ·
Replies
6
Views
2K