Time travel is a very broad trope in science fiction. There are so many stories to tell using time travel and so many ways of doing it. I love time travel stories (particularly Doctor Who), the nitty-gritty, wibbly-wobbley, timey-wimey type of stories that can leave you utterly confused and gasping for breath by the end. For all their intricate potentialities, however, time travel is really only good for two things: observing history, and fucking…