speed of light with rotating mirrors help?

I assume the measurement is from one facet to the next.

time to travel 35000 m = 35000 / 3e8 = 0.0001167 s
there are 16 sides, so each one is 1/16 of a rotation
0.0001167 s / (1/16) rotation = 0.001868 s/rot

freq = rot/s = 1 / 0.001868 s/rot = 535.3 rot/s



but, don't you start the beam of light at the same spot the measurement, so the distance is 70 km? then time is twice above, and freq is 1/2 above or 267.7 rot/s.


doing a bit of research, the beam of light could go back and forth many times.
One of the last and most accurate time of flight measurements, Michelson, Pease and Pearson's 1930–35 experiment used a rotating mirror and a one-mile (1.6 km) long vacuum chamber which the light beam traversed 10 times. It achieved accuracy of ±11 km/s.