Assume that you are living in the time when the Gregorian calendar was introduced by Pope Gregory XIII in October 1582, when
Galileo Galilei was about eighteen years old. However, he was tried by the Inquisition, found "vehemently suspect of heresy", and forced to recant 1632, and then he spent the rest of his life under house arrest.
The most noticeable thing in this matter is that people of those years could realize the rotation and subsequently, they could calculate the rate and the duration of the rotation but what was not clear for them was what is rotating around what. At that time what would be your solution?
Now, if I can take this sad historical event as the fact, then I would ask myself if the integral theorem of Helmholtz and Kirchhoff plays a central role in the derivation of the scalar theory of diffraction along with the concept of the wave-particle duality, or it obtains the propagation of light in the diffracted space with an inhomogeneous refractive index?