Honestly, Special Relativity is really hard to sink in your head. Even though I did some basic study on the subject, my mind keeps reverting back and trying to reason in Newtonian ways. It is very hard to accept that light has always the same speed c.

So this should be an experiment that, as countless others before did, verify the accuracy of this brilliant theory.

You make a glass cilinder, very good quality in optical terms, with a hole on the center. You glue that to an axis, and puts it in a setup to rotate the cilinder as fast as you can, hopefuly to values comparable to c. I really don't know if we have glasses sturdy enough for that.

Then, you shine light with a laser, through one of the sides of the rotating cilinder. A pulse for example. There are two options, either the cilinder rotates in the same direction as the laser beam, or against it.

What do you observe? Does the rotating cilinder speeds up the light, or slows it down in any way?