Voltage is force. Current is velocity. Impedance — the ratio of the two — is a resistor, or a damper. A transformer with an N:1 turns ratio scales impedance by N²; a gearbox with ratio n scales inertia by n². This is not a metaphor that runs out after a paragraph: it is the same algebra with the symbols renamed, and it means a theorem proved for radios is already proved for robots. Servo engineers have long known that a motor accelerates a load fastest when the gear ratio makes the reflected load inertia equal the motor's own. That is the maximum-power-transfer theorem, and nobody had to reprove it.