I've read about tachyons and still can't see how going faster then light relates to going backwards in time.

Take for example sound and light. Light is faster then sound therfore if I were to be blind. You'd be able to see events happens before I were to hear it. I think same would apply to superluminous particles. Someone detecting these emmited particles would be able to detect an event hapening before you can visually see it with your eyes. Therefore you would wrongfully think this person has knowledge of the future, just because you haven't seen the event with your own eyes yet.

What was, still is, and always will be such is the truth of the eternal now.