What happens when you spin a powerful magnet at high speeds?

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Discussion Overview

The discussion explores the effects of spinning a powerful magnet at high speeds, particularly focusing on the theoretical implications of centrifugal force on the magnetic field. Participants consider various types of magnets, the mechanical stability of such a system, and the potential relativistic effects involved.

Discussion Character

  • Exploratory
  • Theoretical
  • Debate/contested

Main Points Raised

  • One participant proposes that spinning a powerful spherical magnet at 300,000 RPM could stretch the magnetic field along its equator or increase its force.
  • Another participant questions the feasibility of spinning such a magnet, suggesting that materials like neodymium and cobalt/samarium would likely fail under the centrifugal forces at that speed.
  • A different viewpoint suggests that spinning an electrically charged object could strengthen the magnetic field due to relativistic effects, depending on the motion relative to the object.
  • One participant hypothesizes that if the mechanical stability of the spinning magnet is assumed, the magnetic field might propagate at the speed of light, raising questions about potential changes in the field at relativistic speeds.
  • Another participant introduces the concept of a strong solenoid magnet spinning at relativistic speeds and questions whether this would alter the magnetic field at large distances.
  • Discussion also touches on astrophysical phenomena, such as spinning black holes and neutron stars, which possess strong magnetic fields and spin at relativistic speeds.
  • A participant raises the question of whether the non-axial magnetic field from a rapidly spinning neutron star radiates electromagnetic energy.

Areas of Agreement / Disagreement

Participants express various hypotheses and questions regarding the effects of spinning magnets, with no consensus reached on the outcomes or implications of such spinning. Multiple competing views and uncertainties remain throughout the discussion.

Contextual Notes

Participants acknowledge limitations related to the mechanical stability of the magnets and the assumptions involved in their theoretical considerations. The discussion does not resolve the mathematical or physical implications of the proposed scenarios.

nution
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Lets say we have a spherical shaped and very powerful magnet. Let's say it has a 3" diameter and has some good weight to it.

What would happen if you spun the magnet at great speeds. Let's say for the sake of argument say some 300,000 RPM.

Could the centrifugal for created by the spinning actually alter the magnetic field any? I would assume would stretch it out along its equator? Or would it increase the force of the magnetic field, not actually "stretching it"?
 
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If and i mean a big IF u were able to spin a magnet that fast and was really powerfull ( only two i know are neoden. and coblalt/sal. they would cumble under the centrivical force of trying to spin that fast and/separate compisition so i guess the first question would be what kind of magnet would hold up to that ?
 
Not sure about permanent or electromagnets.

But if you spin an electrically charged metal object, the magnetic field should get stronger the faster you spin it - in this case, the effect is relativistic, meaning the magnetic field will depend on your motion relative to the object.
 
Lets assume for a moment the spinning problem has been resolved. No issues of the system or the magnet being unstable. Thats more of a mechanical problem, but I am not really interested in that. Anyhow this is more of a theoretical question. I don't know of any reason this would actually be implemented. More or less looking at the physics behind it.

I was also thinking, since we believe that gravity propagates at the speed of light, I would assume a magnetic field does as well? If so, and the magnetic field does change from centrifugal force, what would happen if we spun the magnet as the speed of light, possibly being able to bend light as gravitational fields can but on a smaller scale if there is some change in the field from spinning.
 
The really interesting theoretical spinning-magnet problem is a strong solenoid magnet spinning about an axis that is perpendicular to the axis of the solenoid at a speed such that the solenoid field at a large radial distance sweeps azimuthally at a relativistic speed. Would this alter the magnetic field?

Bob S
 
One thing to look at is spinning black holes and spinning neutron stars. They got very strong magnetic field around them and they spin at relativistic speeds tangentially.

Additional topics to look for are Active Galactic Nuclei (AGN) and galactic jets.
 
crapworks said:
One thing to look at is spinning black holes and spinning neutron stars. They got very strong magnetic field around them and they spin at relativistic speeds tangentially.

Additional topics to look for are Active Galactic Nuclei (AGN) and galactic jets.
Does the sweeping non-axial magnetic field from a rapidly spinning neutron star radiate electromagnetic energy?

Bob S
 

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