I think I need to clarify the conversation here as I feel ideas are getting crossed.
By backward time travel I personally don't at all mean humans going back visiting themselves, indeed I doubt if human flesh (cuz it exists as part of this time and this space) could actually travel back in time ever.
However, the physics that governs human flesh is not the same physics that governs elementary particles. Therefore, analogies about humans going back in time does not at all apply to (what I think) is the real question about time travel. One is newtonian, the other einsteinian, there is quite simply NO comparison. Therefore I think the conversation should denote what it is talking about. When I read things about people going back in time I feel like this point is being missed and to me it's like saying "oranges can't fly cuz bears do not necessarily shit in the woods". Does it exist? I've read a lot of crap that suggests that it does, and I realize that everything is inherently biased.. yadayada, but it makes sense to me anyway.
Things go forward in time easily enough (which is actually just their own time slowed but it still happens and even humans can go ahead a bit by the same principle. So time isn't constant. Time also can stop in a singularity (a very accepted idea). Other crap I've read suggests that time (the 4th dimension) is very much the same as the other 3 but it is just expressed differently, having a 4th spacial dimension (as has been theorized here) I find a bit far fetched cuz how could it be percieved? The universe is the way it is, we exist in 3 dimensions and time and we humans are evolved to have the experience of 3 dimensions and time, not 4 spacial dimensions and time. I'm not saying it's impossible, I just find it unlikely that it would be perceived as another spacial dimension, we aren't even wired that way to think like that. I think the way dune put is was the best way of looking at it, we exist in these four dimensions and time is defined as motion through space, I feel that it is kind of like a spacial dimension and that time is just how we preceive this other dimension. How else could we see it? I don't know, but if there were four spacial dimensions I'm sure we would've evolved much differently than we did. The real reason why I think there isn't 4 spacial dimensions is cuz if it did exist then it would likely exist *everywhere* in the universe and we would have some hints that it's out there (I'm just speculating). Anyway, I'm babbling incoherently, haha.
So anyway what I meant to say is that there are 2 directions in the other 3 dimensions and I think it's totally possible and very likely that there are 2 directions in time as well, and it would also explain somethings, but I realize this is not actually proof, but no one has proof of anything in the deepest sense so I guess it's not too important when it comes to internet psycho babble.. hehe
Anyway, my point is: whether or not humans will be ever able to travel back (or even forward great distances) in time has very little to do with whether or not time travel is possible for elementary particles. Also, it's relative, if you were an anti-particle traveling backward in time from your point of view it would (could) be forward. I'm whacked in that I think everything has an inverse to which it owes it's very definition. I feel that if there were no up there'd be no down, no light without dark, no time without anti-time. After all, if there were no anti-time, what canvas would the painting of time be painted on? Imo, duality exists in everything cuz of that whole thing about the beginning of the universe and how energy kept dividing and dividing, I dunno, makes sense to me, hehe. Anyway, great topic and great board..
Yippi yi yaaa cal-patty,
Satori
