Can Magnetic Fields Be Focused?

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Discussion Overview

The discussion revolves around the possibility of focusing magnetic fields, exploring various methods and theoretical implications. Participants consider both practical applications and conceptual understandings of magnetic field behavior.

Discussion Character

  • Exploratory
  • Debate/contested
  • Technical explanation

Main Points Raised

  • One participant inquires about the possibility of focusing a magnetic field, drawing a parallel to focusing light with a lens.
  • Another suggests that a cone-shaped piece of iron can concentrate a magnetic field at its tip, referencing methods involving iron alloys.
  • It is proposed that focusing light, as an electromagnetic wave, implies a focus on the associated magnetic field, although this is contested.
  • A participant argues that while magnetic fields can be manipulated, they cannot be directed to be strongest at a distance from their source without intervening materials.
  • Concerns are raised about the misunderstanding of focusing magnetic fields in the same manner as light, with references to Maxwell's equations and the behavior of magnetic field lines.

Areas of Agreement / Disagreement

Participants express differing views on the feasibility and methods of focusing magnetic fields, with no consensus reached on the validity of the proposed techniques or the implications of electromagnetic theory.

Contextual Notes

Participants highlight limitations in understanding the behavior of magnetic field lines, including their tendency to spread out in empty space and the conditions under which they can be concentrated.

[darkside]
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Is it possible to focus a magnetic field?

Thank you
 
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you mean, like a laser?
 
Well, not necessary like a laser (that would be good too) but more like to focus it to go where I want it to go. Like when using a lens and focusing Sun rays.
 
Yes you can. For example with a cone shaped piece of iron. Place the magnet on the wide end of the cone and you get a concentrated field at the tip. Another method is shown in this video using 2 flat pieces of iron. (actually an iron alloy maybe similar to the stuff used in transformers)


It's all about magnetic flux and magnetic circuits.
This article may help you.
http://en.wikipedia.org/wiki/Magnetic_circuit
 
Last edited by a moderator:
Light is just an electromagnetic wave, so if focus light, you are focusing a magnetic field. If you are interested in a magnetic field without the electric field, you can focus it next your device, as Dr. Zoidberg shows, but you can't direct a magnetic field to be strongest far away from your sources of current.
 
Khashishi said:
Light is just an electromagnetic wave, so if focus light, you are focusing a magnetic field.

Did I understand you correctly, I can use magnifying glass and focus magnetic waves the same way I would use it to focus light in one point?
 
[darkside];3928176 said:
Did I understand you correctly, I can use magnifying glass and focus magnetic waves the same way I would use it to focus light in one point?

no you cant. Khashishi is leading you astray somewhat

you originally asked about a magnetic field and for some reason Khashishi started on about a laser which had nothing to do with what you asked

I liked K^2 response in this forum a couple of years ago to a similar question to yours

Magnetic field lines arrange themselves in a way that satisfies two criteria.

1) Lines shall not cross. (Maxwell's Eqns)
2) Integral over H*B is minimized. (Minimum energy)

There is also a condition on curl (vorticity) which will govern how many field lines you have.

What this tells you is that field lines will bunch up only within certain objects. Magnets for example. In empty space, the field lines will try to spread out as much as possible to minimize energy.

Without placing something at the target, or very near it, you cannot make field lines converge there.

full thread...
https://www.physicsforums.com/showthread.php?t=394402


cheers
Dave
 
Last edited:

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