It doesn't have to be completely plausible, obviously, but it would be nice to have something that sounded that way when not explained too deeply.
And this might be making it worse, but possibly the future could be a sort of ceiling over the present, where if you sent anything to the future it would ricochet off the ceiling. Or not.
...If you have any ideas about this I would be extremely grateful. :|
ETA: possibly I should have clarified that this is for the purposes of comedic science fiction, and not an actual theory D: