I'm not sure if you're employing irony, though it's subtle if you are. I'm not sure if I'm misinterpreting your writeup completely (I sure hope not!) And I'm not sure if I'm just plain wrong... but to me the opposite is true.

What doesn't make sense to me is the 'fading' aspect in Back To The Future. I think this implies a pantheistic universe that knows when you're about to screw-up the time line. Not that there's anything wrong with an intelligent universe but I think it should be explained. If the only tool you're utilizing in your fiction is 'time-travel', that is everything that takes place takes place in a normal universe exactly like ours but with the addition of time-travel, then 'fading' seems a bit superfluous.

In 'Bill and Ted's Excellent Adventure' it doesn't matter that the future is a fact of the matter already. It still makes sense that retrocausality is necessary to achieve that future. For example: Someone greets you from the future with schematics for a time-machine, you build the time machine and then realize that you're the person who gave yourself the schematics originally. What do you do? You go back in time to give yourself the schematics. It doesn't matter that you already have the time machine, what matters is you know the causality behind you having the time machine.

You might say 'What if I don't go back in time and give myself the schematics?'. Sorry, bud, the event already occurred. In fact, in a four-dimensional universe every event that ever occurred and will occur is a fact of the matter already.

Two types of Time-Travel make sense, at least to me: Time-Travel with multiple universes (as explored in the Back to The Future Sequels) or Time Travel with fatalism (IE. Everything, past, present and future is a fact of that matter at all given times. The kind of universe where Laplace's demon would feel at home.)

As for Dragonball Z. Well, I stopped watching that after I realized there was nothing at stake for the protagonists. No matter how many times they died the other characters would always find a way to bring them back to life. When you have nigh invincible superheroes they should either have a weakness that every villain has access to (Superman) or personality disorders that cause them to be somewhat antagonistic (Dr.Manhattan).


I appreciate the points put forward by Orange_Julius about there being 'different concepts of time travel' but I think there are only two (the two I've mentioned) concepts of Time Travel that work paradox free. I'd be happy to be proven wrong, though.