Comment by SAI_Peregrinus

I hate the phrase "zero backlash" that gets used right in the intro. Nothing has zero backlash. If it did, that would mean the material is incompressible & unstretchable: it would have an infinite speed of sound. You could implement FTL communication using zero-backlash actuators. Capstan drives have backlash because the rope stretches. It's very low if using a low-stretch rope, but nonzero.