Why is the B field affected by distant stars in a rotating shell?

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    Accleration
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Discussion Overview

The discussion revolves around the relationship between a rotating charged spherical shell and the influence of distant stars on its magnetic field, particularly in the context of Mach's principle. Participants explore the implications of reference frames and the nature of acceleration in this scenario.

Discussion Character

  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • One participant suggests that if distant stars rotate with the same angular velocity as the spherical shell, there would be no magnetic field inside the shell, questioning why the stars would affect the B field.
  • Another participant clarifies that it is not the movement of the stars themselves that matters, but rather being in a reference frame of equal rotation, which leads to the absence of a magnetic field in that frame.
  • Several participants express skepticism about the nature of acceleration, questioning why it cannot be considered absolute.
  • A participant references a previous discussion asserting that while velocities are relative, acceleration is absolute, indicating ongoing exploration of this concept.
  • Another participant acknowledges the complexity of the question regarding absolute acceleration and expresses uncertainty about addressing it.

Areas of Agreement / Disagreement

Participants exhibit disagreement regarding the nature of acceleration, with some asserting it is absolute while others question this view. The discussion remains unresolved on the implications of Mach's principle and the influence of distant stars on the magnetic field.

Contextual Notes

Participants have not reached a consensus on the nature of acceleration and its implications for the magnetic field in the context of rotating frames. The discussion includes references to previous threads and ongoing inquiries into the topic.

cragar
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Lets say I have a uniformly charged spherical shell. that is roating with an angular
velocity w. Now machs principle says that acceleration is relative to the distant stars.
If the distant stars are rotatingng with the same w as the spherical shell, there will be no B field inside the shell. This seems strange. Why should the distant stars have anything to do with the B field of the rotating shell? And let's say the stars started moving relative to the shell why would this all of a sudden create a B field to appear in the frame.
 
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It's not about the 'stars themselves moving', it's about being in the reference frame of equal rotation. In that reference frame, it appears as if there is no magnetic field in the shell as your said. But its not the movement of the stars than cause that, it's the fact that they are in a reference frame where this appears to be the case.
 
why can't accleration just be absolute
 
cragar said:
why can't acceleration just be absolute

Good question, and it's a tricky one I don't trust myself to address.
 

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