Please note the following sentence before you answer the question: you may assume the light itself is not affected by the observer perceiving the light.
Imagine the following schematic:
- A = Source
- B = Observer
- C = Destination
Light wants to travel from point A to point C. Imagine an observer is standing in between A and C. You may assume the light itself is not affected by the observer perceiving the light.
The observers task is to stop the light from point A getting to point C, however, it can only undertake action (e.g. put up a barrier) once it has perceived the light.
Can the observer B, stop light from travelling from A to C after it has perceived the light? Not a single ray of light should ever reach point C.
My own guess is no as nothing is faster than light, so there is no way I can interfere with the light after it has passed
Edit: something I thought of myself is the gravitational deflection of light, I'm not an expert on this topic so i'm curious if there is an answer using this.