knivesout said:
(Should this go in the writer's forum, btw?)
I don't see why not. It is a writing problem, after all, and a valid question at that.
I also don't see why there can't be such disparate cultures represented in the same world. After all, in the real world, stone age groups have (and may still) share the world with industrial civilizations. Think of the Cargo Cults that originated during World War II. Of course, this sort of condition would probably presuppose geographical isolation - but might also be a condition of political separation as well. There are real-world examples of this in the differences between Soviet and Western science during the Cold War era, when science in the Soviet Union had to conform to Marxist-Leninist ideology - this had implications especially in the biological sciences. I've also come across the idea in some fantasy that a culture had lost most or all of their technology through some kind of banning for whatever reason.
SDNess, you might want to look at some cultural anthropology texts for suggestions on where to look for information on the results when such different levels of technology meet for ideas on how this works in the real world. This could give you ideas for how you might want to play off such meetings in designing your world, if indeed your cultures meet. You especially might want to look at - as Foxbat suggested - the meeting between the Aztecs and the Spanish conquistadors, and also at the meetings between North American native cultures and Europeans, and South American and African first contacts with more elaborate (I wouldn't necessarily like to say "advanced") technologies.
Remember, however, that while a true "swords and sorcery" culture in a fantasy work might be at some disadvantages in meeting a more technologically advanced society, the society that possesses magic might also have some advantages over a culture that only possesses material technology and might not even believe that magic exists.
Actually, I think that this sort of story idea is a fertile background for looking at all kinds of interesting conflicts and has some fascinating implications. Good luck on your writing, SDNess.