User blog comment:Interdimensional403/Ttttttime travel!!!!!!/@comment-4844180-20130727182030

Inter, Vissa radiation would make it more dangerous and less predictable, but not impossible. And going to the future does not make an infinite number of copies, going back and getting yoursel can though.

Also, I doubt we are using the theory where the universe can support countless people crossing from their own timeline and keep changing it while the individuals are still there.