Hello Herman,

 >>> Also, of course, electrons that are travelling around curved
 >>> parts of the circuit must experience a centripetal force.
 >>> Overall, the net force on the electrons is zero, so there is
 >>> no tendency for the vacuum tube to accelerate through space.

 MvdV>> If it did that would be a violation of the law of
 MvdV>> conservation of momentum.

 > Not if the power supply had an equal-but-opposite momentum to
 > that of the the vacuum tube.

Yes, like you I overlooked that.

Cheers, Michiel

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