This begs the question how could stationary contacts measure a volt on the disk while a meter spinning with the copper disk says there is no voltage?? Is it the scraping of a contact along a copper disk that is generating the voltage ? Is it a relativistic effect that the spinning meter would share with the spinning disk leading to a null result More questions than answers. Have a video that demonstrates how rotating the contacts only will generate a voltage.
There are hills on the ocean. It is caused by under water mountains. the mountain is denser than water so there is more gravity causing a slight hill on the ocean surface. The interesting thing about these ocean gravity hills is you can not water ski down them as from gravity's point of view it is a straight line not a curved hill. With the gravity ocean hill in mind I would like to return to the Faraday paradox. Turning the copper disk only will generate a voltage on the contacts. Turning the contacts only will generate a voltage. ? Turning the copper disk or turning the contacts is equivalent. Either one turned will generate a voltage. Turning the disk clockwise = positive voltage . Turning the contacts clockwise is a negative voltage. One more step into the abyss. If disk is positive and contacts are negative for clockwise turning then turning both contacts and disk clockwise turning clockwise equals 0 volts. This is somewhat like the ocean gravity hills where the hill is there but you can not water ski down the hill much like the meter and contacts that are rotating with the disk can not measure the voltage as the same voltage is being generated in the meter leads to make the measurement therefore no current therefore no voltage.
The implication of this is one meter spinning with the disk will read 0 voltage while an identical meter stationary with sliding brushes on the disk will read a voltage. If I could take a picture at the exact time the sliding brush is in the same place as the spinning meter probe on the outside of the spinning disk one meter would say 1 volt while the other meter says 0 volts measuring the same location at the same time
In the original post I mentioned that my imaginary setup has a magnetic pole piece that does not allow any external field to escape and induce an EMF into the brushes or measuring leads.
There are hills on the ocean. It is caused by under water mountains. the mountain is denser than water so there is more gravity causing a slight hill on the ocean surface. The interesting thing about these ocean gravity hills is you can not water ski down them as from gravity's point of view it is a straight line not a curved hill. With the gravity ocean hill in mind I would like to return to the Faraday paradox. Turning the copper disk only will generate a voltage on the contacts. Turning the contacts only will generate a voltage. ? Turning the copper disk or turning the contacts is equivalent. Either one turned will generate a voltage. Turning the disk clockwise = positive voltage . Turning the contacts clockwise is a negative voltage. One more step into the abyss. If disk is positive and contacts are negative for clockwise turning then turning both contacts and disk clockwise turning clockwise equals 0 volts. This is somewhat like the ocean gravity hills where the hill is there but you can not water ski down the hill much like the meter and contacts that are rotating with the disk can not measure the voltage as the same voltage is being generated in the meter leads to make the measurement therefore no current therefore no voltage.
The implication of this is one meter spinning with the disk will read 0 voltage while an identical meter stationary with sliding brushes on the disk will read a voltage. If I could take a picture at the exact time the sliding brush is in the same place as the spinning meter probe on the outside of the spinning disk one meter would say 1 volt while the other meter says 0 volts measuring the same location at the same time
Did you try what I suggested, without the disk?
Couldn't you lay 100 metres of wire in a north-south direction and have your long meter leads encased in steel tubing? Would the field be diverted around the meter leads, enabling you to measure any EMF in the wire?
Magnetic shielding for a changing magnetic field is possible as the shield will develop a counter EMF to null it out. However for a magnetic field that is not changing such as the earth's field it is not that easy.
I don't have a video of it but the experiments have been done. The magnet rotates even when shielded from the turbulence of the boiling LN2.
Next experiment: suspend the magnet in a vacuum vessel above the superconductor.
My guess is the pendulum torque is due to small differences in surface temp of the magnet acquired from the surrounding temp-gradient gas, and differences in the statistical vector of average force due to gas molecules rebounding from the magnet surface.
Prediction: in a vacuum, it won't rotate.