Light’s Behavior in a Rotating Reference Frame

Question

Let’s say there is a laser on one side of a very large rotating table, and it’s beam is shining onto a target on the other side of this table. The target is equipped with a very sensitive buzzer that will sound if the laser moves off of the target. Here’s what I think will happen and why:

During acceleration the laser will move off of the target and the buzzer will sound. Once a constant speed is maintained the buzzer will continue to sound.

My logic for this is rotating frames are not inertia frames. They are always accelerating. Someone on the table could tell they are moving without looking beyond the table simply by placing a ball onto the table and watch it roll off. The Sagnac Effect influences my answer too. Rotating mirrors can move toward or away from a beam of light to shorten or lengthen it’s path.

The speed of light is constant. In order for the beam to stay on the target it would need to follow a curved path which is longer than a straight path.

Is my logic faulty??? Will the buzzer buzz???? Please set me straight. Thanks.

Answer 1

As it will take time for the photons to reach the sensor after leaving the emitter, once the sensor starts moving away from where the emitter was originally pointed, the photons will no longer hit the same point on the sensor. So the buzzer will sound until the table stops spinning. This will happen in your spinning table situation, or in any situation where the sensor moves in any direction other than directly away from the emitter.