Homopolar generator with co-rotating magnet

[LeoFreeman]

I was hoping someone could possibly point out why this arrangement would not not generate a current to light the bulb?
The whole circuit is monolithic, with no brushes or articulating parts. The entire device would be rotating in free space.

The copper disk is gripped around the edge between the poles of numerous closely-spaced horseshoe magnets.
Their magnetic fields only cut across the copper disk in a narrow band close to the rim, where the velocity is greatest. Electrons in that band would be forced radially to the very edge of the disk and into the "spokes" that run from the rim to the wheel axle.
The spokes pass through the gaps between the ring magnets where the magnetic fields should be very weak, and thus not cause any back-resistance to the electrons trying to leave the disk.
The current would then flow out along the conducting sheath to the light-bulb, and return to the disk via the axle..

[Cadman]

You have ~72 individual magnets, each with their own magnetic field. The magnets and their fields rotate with the disk so there is no relative movement between the disk and magnetic fields, so no induction and no current.
The field would be stationary I think if there were a one piece magnetic torus with a single north and south pole at a slit for the disk. That would be an interesting experiment.

[LeoFreeman]

I thought that the "Faraday Paradox" dealt with exactly that case, where a current is generated even though the magnet turns with the disk? Sorry if I misinterpreted your remark.
BTW, you,re spot on with your magnet count!

[Cadman]

Your question now makes me think the torus field would also move with the torus.

Correct me if I'm wrong but I think the magnetic field is only stationary when the magnet is rotated on it's own NS axis.

Your idea has every magnet orbiting the disk axis and each magnet carries it's field along with it in the same orbit.

[LeoFreeman]

I'm not sure, but I thought that, topologically, all these horseshoe magnets just form one large ring magnet,
corresponding to a normal pair of large disk magnets, just with a big hole drilled down the middle.   

The middle section of the disk is not moving very fast, so that part doesn't need a strong field, but I could be mistaken.