|MadSci Network: Physics|
It depends on what you define as being "perpetual motion". The current could theoretically keep going forever AS LONG AS THE APPARATUS THAT PRODUCES THE COOLING FOR THE SUPERCONDUCTOR keeps working! But we all know that in the real world motors and wires and other things eventually break. Also, a lot of energy is required to run the cooling apparatus, so the "perpetual motion" doesn't come for free.
So I would say that the superconducting current is NOT perpetual
1) the superconductor's cooling does not come for free (energy is required to run it), and
2) the cooling apparatus will eventually break.
John Link, MadSci Physicist
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