The only problem I had with "Timeline"'s viewpoint on that is he said we are standing on the bank watching it go by. That is impossible, it would make us a variable that exists outside of both time and space, which given my understanding can never happen, we are in the boat rowing constantly while the future water (ahead of us, which doesn't exist yet)flows to us and turns to the present, and then flows away from us as the past. However, if there was a way to completely stop atom decay and renewal (as in a complete halt in motion) in a given spot, then that would be as close to time travel as there can be. By the way the concept of time was given to us by the ancient Hebrews (thats what World Civ will do for you).
I also wonder about the concept of alternate dimensions, (I watched "Sliders" way too much, and wonder if it would be more feasible to travel to other possibilities than to actually travel in a given "stream of time." I know that they have proven that there are some sort of particles that can exist in an absolute vacuum and can bend light particles and those particles are thought to be in a alternate plane. Im sorry if I'm way off I'm only in my first Physics class and have read Universe in a Nutshell.