1. The problem statement, all variables and given/known data Consider a searchlight on the ground that casts a spot on a cloud 1500 m overhead. If the searchlight is rotated rapidly−say, 40 ∘ in 1 μs−how fast does the spot move in the Earth reference frame when the searchlight is directed vertically upward? I have solved this part and found the velocity to by 3.5c. Is this a violation of special relativity? 1. No, this is not a violation of the special relativity, light spot is not a physical object and can move with any speed. 2. Yes, this is a violation of the special relativity, the searchlight cannot really rotate this fast, data given in the problem statement is incorrect. 3. Yes, this is a violation of the special relativity, this situation should be studied using general relativity. 2. Relevant equations 3. The attempt at a solution I think it is a violation, but i'm not sure exactly the reasoning behind it. My educated guess would be number 2 is the correct answer.