On 2/28/2013 5:07 AM, Quadibloc wrote: > On Feb 27, 1:40 pm, Shmuel (Seymour J.) Metz > <spamt...@library.lspace.org.invalid> wrote: > >> The stories in which the actions of a time traveller spin off another >> branch of the Universe are on shakier grounds; ask me about them when >> we have a viable Quantum Gravity. > > I see it the other way around; anything that allows a possibility of > causality violation is clearly fantasy.
If you are referring to genre definitions, that is not true. I realized a while ago that genres are defined by where the author gets inspiration from. If the work shows primary inspirations from HG Wells Time Machine, or something from quantum physics, no matter how misunderstood, or Tipler cylinders or Michio Kakiu then while it may be "a" fantasy in the sense of not being something that could ever really happen, it is still something that fits into the science fiction genre.
Of course if it also shows a lot of inspiration from fairy tales, Middle Earth, Lankhmar or mythology, it can drift toward the the fuzzy border zone, but merely violating principles like causality or conservation isn't enough to do it.