Where does the angular momentum go in Feynman's disk paradox?

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SUMMARY

The discussion centers on Feynman's disk paradox, specifically addressing the transfer of angular momentum in a system with a solenoid and a disk. When the battery is disconnected, the decrease in current leads to a reduction in magnetic flux, inducing an electromotive force (emf) that causes the disk to rotate counterclockwise. The conversation explores the origin of the angular momentum, suggesting it stems from the swirling electric field within the solenoid's wire during the current reduction. This phenomenon is likened to the classic problem of a rotating disk interacting with a stationary disk, emphasizing the role of the electric field in mediating angular momentum transfer.

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FallenApple
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There is a solenoid on top of a disk with charges attached to it. and there is a clockwise current through the solenoid.

E&M(rotating_disk).png


So by disconnecting the battery, the current will lower, and hence the flux of the magnetic field though the disk will lower, and according to faraday's law, there will be an induced emf in space.

So this is an explanation that the angular momentum of the field is transferred to the disk. It makes sense. I can imagine the e field swirling around the disk, causing it to rotate counterclockwise. (the induced current must be counterclockwise to oppose to decrease in flux)

But where was the angular momentum before? Was it from the decrease of clockwise swirl of the E field inside wire of the solenoid? When the current was being decreased, wouldn't there be a counterclockwise swirl of the E field to reduce the current?

This seems very analogous to the classic rotating disk falling on another stationary disk problem. Except here it isn't internal friction that mediates the transfer of angular momentum. So it seems like the counterclockwise E field's swirl inside the wire during the I reduction was transmitted though space.
 
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Have you tried googling around for the solution to this problem? Feynman has even supplied an answer himself.
 
https://www.researchgate.net/profile/Gabriel_Lombardi/publication/243489921_Feynman%27s_disk_paradox/links/5646523408ae9f9c13e7503e.pdf
 
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