Thanks all,
So . . . the Special Relativity factors that may prevent an object from achieving C (increased mass, elongation in the direction of travel, time slowing down) would not control in the case of windmill blades (or “objects” rotating around an axis). General Relativity (the...
An acquaintance (my boss, actually, so please be nice) has suggested that, if a windmill could be made large enough, the tips of the blades could travel at the speed of light. Notwithstanding the impracticalities (there's no wind up there; the blades would surely strike the planets; where would...