Interesting article, except that I believe it is somewhat misleading whereas particles can react differently in micro vs macro scales. The article admits as much, but then conveniently ignores this fact when it assumes the results of this CTC simulation may be used to resolve the grandfather paradox.
Hawking and many other physicists find CTCs abhorrent, because any macroscopic object traveling through one would inevitably create paradoxes where cause and effect break down. In a model proposed by the theorist David Deutsch in 1991, however, the paradoxes created by CTCs could be avoided at the quantum scale because of the behavior of fundamental particles, which follow only the fuzzy rules of probability rather than strict determinism. "It's intriguing that you've got general relativity predicting these paradoxes, but then you consider them in quantum mechanical terms and the paradoxes go away," says University of Queensland physicist Tim Ralph. "It makes you wonder whether this is important in terms of formulating a theory that unifies general relativity with quantum mechanics."
In a different experiment when scientists fired photons at a barrier most of the particles would bounce back, yet sometimes they would inexplicably go through. When firing a particle at a barrier with two holes in it the particle seemed to pass through BOTH holes at times. Needless to say, these results have never been observed to happen on a macro scale, effectively throwing a wrench in the works in this new time travel theory regarding the grandfather paradox. Then again, I would assume if one was to build a time travel machine it could simply encase you within a sort of "bubble" which would behave like a micro particle.
