Is it theoretically possible to encode information in particles which travel back in time? I realize this is a can of worms question. I am also not too sharp with QP. Isn't there a theory in Quantum Physics that there are "forwards" and "backwards" photons which meet each other in time? So I am wondering if data could be carried that way. Feel free to speculate. I'm writing a story and I am simply looking for a general excuse for a hypothetical device being able to send back messages in time. So the audience won't care whether the theory holds up in a room of qualified scientists, only whether it sounds "believable" that messages can be sent backwards.