The Realism of SF

While I was at Bubonicon for some reason I got to thinking about the comic strip Get Fuzzy. About how realistic it is in comparison with other strips with talking animals. In some ways it really is, the animals act a bit more like animals with voices. They aren't just little humans in costumes. But really, though it is better though out than many fantasy or science fiction books I've read, it still isn't a totally realistic setting. Really how could it be?

I mean it would change everything if there had been talking animals since the beginning. The effects upon theology alone are mind boggling. And we wouldn't understand the issues or the culture of such a world. The same would be true for really visiting the future rather than getting there at the same steady pace as everyone else.

I think that speculative fiction as a genre can only go so far in creating realistic settings. If it ends up too far away from our present day and no one will wish to read or watch it. SF is a genre of speculation about if the world were other than it is, but still recognizable enough for a reader from our Earth to understand it.