Originally posted by Suave
I seem to remember something about sub atomic particals from colisions going back in time from "in search of shroedinger's cat".
They don't go back in time, it's just that the uncertainty of quantum theory can be manipulated so that the myriad of histories can be limited to one we choose (more or less) by what we do in the present.
Feynman theorised that all possible histories (paths) are traversed by a wave/particle to get from point A to point B. By how we perceive them now chooses the most likely past of the particle.
It seems we can manipulate the past by choices today, but it is just the weirdness of quantum phenomenon.