what do you mean with "tomorrow would be empty"?? don't understand that.

there's only two possibilities: eigther there is no future now, and the beings with "free will" can do whatever they wanna do next and nobody knows and only the physical laws will let us foretell things about the (physical) future, everything else could be changed. that's a world where time travel is impossible because of causality.

OR everything is already there. then it is already clear what will happen in the future and we can't change anything anymore. it's already defined what we will think and do next, and if we decide not to do it, then only because that was also alredy defined. then we're only part of a big system, kind of sitting in a movie. and the movie is already complete (not "empty"), it all there yet, we just haven't seen it yet. in such a world time travel could be possible, and also time loops and things like that. (like in the movie 12 monkeys)

i think there is no way to ever find out wich of the cases is true, but it doesn't matter anyway, because also in the second kind described above, people would THINK that they act on free will and won't ever find out. well except if somebody can build a time machine. then we would know that we are living in the second kind of world, but otherwise, how should we find out??

anyway, even though i like theories about that, i still think that time is moving in one direction only and comes into being continuously and hasn't been existing before. there are many mathematical and physical phenomenons that work the same way, so it would be kind of "logic".