Earth's Magnetic Field: Does it Rotate?

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Discussion Overview

The discussion revolves around whether the Earth's magnetic field rotates with the Earth. Participants explore the relationship between the magnetic field and the Earth's rotation, considering both theoretical and observational aspects.

Discussion Character

  • Exploratory, Technical explanation, Debate/contested

Main Points Raised

  • One participant suggests that the Earth's magnetic field is stationary, arguing that a rotating magnet does not exhibit a rotating magnetic field, and questions why the Earth would be different.
  • Another participant points out that the Earth's magnetic field is not aligned with its rotation axis, indicating that there is a diurnal rotation of the magnetic field relative to an outside observer.
  • A subsequent reply acknowledges the misalignment of the magnetic field and inquires about the speed of its rotation and the reasons behind it.
  • Another participant asserts that the magnetic poles and significant features of the magnetic field move around the rotation axis once per day, suggesting it is reasonable to say that "the magnetic field rotates once per day," despite the complexity in defining an angular velocity for a changing magnetic field.

Areas of Agreement / Disagreement

Participants express differing views on whether the magnetic field can be considered to rotate with the Earth. While some acknowledge a form of rotation, others question the implications and definitions involved, indicating that the discussion remains unresolved.

Contextual Notes

There are limitations regarding the definitions of rotation and angular velocity in the context of a changing magnetic field, as well as the assumptions about the alignment of the magnetic field with the Earth's rotation axis.

Buckethead
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Does the Earth's magnetic field rotate with the Earth? I am figuring it's stationary as a magnet that rotates through it's pole to pole axis does not exhibit a rotating magnetic field so why should the Earth.
 
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The Earth's magnetic field is not aligned with its rotation axis. The magnetic North and South poles are located at certain geographical points on the planet, and therefore there is a diurnal rotation of the magnetic field with respect to an outside observer.
 
That slipped my mind that they were not aligned (even though I knew that). So are you saying that the magnetic field rotates and if so, do you know how fast it rotates and why?
 
The magnetic poles, and all other significant features of the field move around the rotation axis once per day. I think it is reasonable to say "the magnetic field rotates once per day", even if there is no clear general way to assign an angular velocity to a changing magnetic field.
 

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