On one hand, one can take many liberties when writing about time travel because to my knowledge, no one has ever traveled into the past or future. Who is to say how it happens? Can you affect the future by changing the past? If I go into the past and kill my mother, do I disappear from the future (the grandfather paradox)? Do I disappear from the now, in which case I could not commit the murder? Is the future a parallel world? If the future exists already, does it mean that we cannot make our own decisions? Authors can make up their own answers to those questions, the only limit is their imagination.
On the other hand, as I suggested above, time travel is a circular topic and difficult to handle without slipping up. In many books on time travel, one can find an inconsistency or something that just does not makes sense. It doesn't make the book a bad one, not at all, it just underscores the thin line between creating a fantasy world and losing your reader's ability to ignore reality.
Why is all of this on my mind, you may ask. In my books, the Caribbean Adventure Series, the children travel through time into the past. In the first two books, I avoided all difficult issues. I ensured that the book never skirted over into the area of science fiction, I leave that to my able co-bloggers KeVin and Shauna. The children participated in actual historic events, but their actions had no effect on the outcome of the event or on the future. Not so in the third book. In this book, they affect the life of one person and as a result, their future ... or is it their present (see, I am confused already) is changed. This was the major delay in my (now complete) WIP. It took me a long time to build up the confidence to try to convince my readers that, not only were these children traveling effortlessly through time, but they were also affecting their present by changing the past.
What is your view on the issue of time travel? Do you read it critically or do you let your imagination take abandoned flight into the fantasy?