I was wondering why moving faster than light violates causality. I understand Relativity of Simultaneity(or think I do).
Example why it makes my brain hurt to think it does:
Person A sends message to Person B as some distance d at the speed of light at time t0. Person B receives the message at time t0 + cd. He then sends message back at t0 +cd. Person A receives message at time t0 + cd + cd.
Person A sends message to Person B at same distance d at speed faster than light x at time t0. B receives message at time t0 + xd and so on.
This is with messages though. I know that if you move faster than light, then the record of your existence can cause someone to see you in two places at once as they will see the record of your location at A and receive the record of your new location B at the same time, but I'm just confused why that would change causality. Does moving faster then light make you move back in time or something or am I missing something completely?
Thank you very much.![]()