When light travels through a medium like glass, its speed does indeed change, but it does not change direction due to the rotation of the medium. The rotation of the glass itself does not affect the direction of the light.
When light enters a medium, such as glass, its velocity decreases compared to its speed in a vacuum. This reduction in speed is due to the interactions between the light and the atoms or molecules of the medium. It's important to note that the change in speed does not alter the fundamental direction of the light. The light continues to travel in a straight line, but its velocity is reduced.
As for the rotation of the glass, it does not directly influence the path of the light. The light will follow the same trajectory as it would in a non-rotating glass. However, the rotation of the glass may have other indirect effects, such as inducing additional optical phenomena or changing the polarization of the light.
Regarding the rotation slowing down as a result of light passing through the rotating glass, the answer is no. The rotation of the glass is independent of the light passing through it. The speed and direction of rotation of the glass are determined by other factors, such as external forces or torques acting upon it. The presence of light inside the rotating glass does not directly influence the rotational motion.