I see in the main page an article touting a record setting 20,000 amps flowing in a superconductor. Normally, with resistance in the circuit, it is a simple matter to multiply volts times amps to come up with watts or joules/second. But in a superconductor the resistance is zero so 20,000 amps times zero resistance would be in that case zero watts. So how do you calculate the power of those 20,000 amps when there is zero resistance? I am thinking it would have to do with counting the number of electrons passing by a point in a given time or something but don't know how you would do that. Anyone help with this?