Before we look at where one leaves off and the other begins, let’s define each of these terms.
Oxford Dictionaries defines Sci-fi as:
Fiction based on imagined future scientific or technological advances and major social or environmental changes, frequently portraying space or time travel and life on other planets.
I found a good brief description of Fantasy on Wikipedia.
Fantasy is a genre of speculative fiction set in a fictional universe, often inspired by real world myth and folklore.
Of course, there are fantasy books that bring magic, myth, and folklore into our world too. So, a fictional universe isn’t a necessity. A fantasy world can be an alternate universe as in C.S. Lewis's Chronicles of Narnia. The clever author can invent his/her own mythology.
Where the lines tend to blur is in a story where the supposed science bends into the scientifically impossible. Invented technologies that break or bend the laws of physics, such as, a spaceship that flies through a black hole and survives, as I once saw in a Disney film, I can’t remember the title of. (Comment below if you remember it!) The writers of hard science fiction shake their heads at such impossible scenarios.
Authors have fun blending the probable with the improbable and that’s what makes the fluidity between genres so much fun! Most books include sub-themes such as romance, and adventure, to round them out and make the story more interesting and attractive to a wider audience. I did this in book 1 The Dreamers with minor adventures such as Antonia’s escape, and the battles with the rovers in San Francisco and Oregon, plus a romantic element as Antonia and Brian’s relationship deepens through their common struggles.
The science fiction aspect was challenging as I looked at how progress historically happens in waves. How much farther along will we truly be in one hundred years? I pondered. In some books you have a radical difference in all areas, innovative technology affecting many areas of peoples lives; flying cars, spaceships that can travel faster than the speed of light, neural/brain implants that allow people to learn exponentially. Also changes in culture and fashion from a turn back to more primitive wear in time travel sci-fi to wild extremes as we saw in The Hunger Games. But, there are some important things to consider.
How would people react to some of these changes. In the future will people allow themselves to be altered (neural or brain implants) if it also means allowing intrusion/hacking into their minds? Would convenience trump independence? I don’t think so. Would I accept transplant organs or distilled life essence to extend my life indefinitely from unwilling donors, or prisoners of conscience? There are some advances that raise moral, privacy, and personal freedom issues.
It’s very unrealistic to imagine a Utopian society where these issues would not be raised, where these advances would not lead to abuses with no rebellion or push-back. Many novels raise these issues as the core good versus evil theme popular in much of our modern fare.
For me, I wanted to be as realistic as possible, but also raise the issues. It’s a small subplot within my first book, but it’s there. I didn’t want my future world to be unrecognizable. I don’t believe it will be as different as a hundred years back. Look at how clothing has developed throughout history. It went from comfortable and useful in more primitive cultures, to ridiculous, fluffy, and completely impractical, and back to simple and comfortable, with the more ridiculous and impractical used only for special occasions, rebellion against the standard, or questionable occupations.
I believe the comfortable and practical has won out and is here to stay. So, I didn’t change clothing. Too many prefer natural fibers for those to pass away as many people thought would happen when synthetics made their debut. I foresee technology continuing to improve on what is now being developed, but things will slow down as economic downturns play a big part and affordability becomes an issue. So the world I created in Dreamers, is not that much different than ours. Just more of the ugliness that is already spreading like a cancer.
Transportation is bound to change, as well as leaps in space travel. I don’t believe there will ever be a big colonization of Mars or the moon. Conditions are too severe there, and accidents always life threatening. But small research facilities manned by rotating personnel are more probable.
Balancing practicality, a dose of tragedy seasoned with love, fun, and good science is part of the genre. I enjoy novels that blur the lines between sci-fi and fantasy.