[Sheriff Rhys Chatham]

Time travel is only possible if there were infinite dimensions, and then it wouldn't be time travel because you would just be visiting other dimensions that were running on a slightly different time line.

And if time travel were to happen in a single plane of time then you wouldn't see your self in past of present because the matter that made you exist in space is/would be currently making up the you that went back or foward into time. Because there is a defined amount of matter in existence the latter way of time travel would be impossible, kind of.