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

[cragar]

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.

 

[Vorde]

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.

 

[cragar]

why can't accleration just be absolute

 

[tris_d]

why can't acceleration just be absolute

https://www.physicsforums.com/showthread.php?t=653105

In this thread that's exactly what they told me. While velocities are relative, acceleration IS absolute, indeed. I'm looking into it.

 

[Vorde]

why can't acceleration just be absolute

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