Whenever my brother complains how unrealistic a tv show, book or movie is I tend to yell at him "Suspend reality, damn it!" And then I tend to call him a bum a couple times. But that might be a bit simplistic for understanding the unreal worlds in fantasy and sci-fi media (I'm going to concentrate on tv, but many of these points apply equally as well if not better to comics, books, movies, etc.). At times, certain works are supposed to be realistic. Battlestar Galactica prides itself on elements of realism (although you have to except the premises of the world they make) and if it becomes unrealistic (like when Adama encountered that crazy vetern who sends him through mental trama which he really shouldn't have experienced and then the vetern just is shoved into the fleet never to be seen again) then it loses some of the touch.
Yet other times you understand that a sci-fi and fantasy show might not act realistic even given the premises of the show. I was watching Gundam Wing and I realized, even given the space colonies and the presence of Gundanium, and Earth Alliance, etc., how did a guy like Treize become virtual ruler of the world, even if it is for but a moment. In the real world, real politics probably wouldn't of let this happen at least not as easily as it did. I also think that the abilities of the Gundams seem inconsistent at times, sometimes they are virtually invincible, sometimes they are very strong but still are not necessarily able to defeat all their enemies. But when it comes down to it, I realized that it doesn't matter. The inconsistencies, the unrealistic politics, the strange actions, they all serve to build a work of art which might not be realistic but is fantastic. It is like an abstract sculpture, it might not mimic a real object, but it can still be beautiful. The unreal elements help build the story, the characters, the setting, the ideas most of all, instead of detracting from them. It is what I would like to call, expressionistic tv. It doesn't really necessarily make sense, but that's ok, it appeals to the mind and summons up feelings that cover for that lack of sense.
I mean, it is nice sometimes to see realism in fantasy/sci-fi TV, I liked Mobile Suit Gundam 0083 in part because it was more realistic, but I've learned that I can appreciate the unreality, even the lack of sense. Serial Experiments Lain for example, although you can piece it all together, it doesn't really have to be all understood for you to get a sense of it, to get ideas from it, to empathize with the characters. It is a gestult, which means the parts build a greater whole and while the parts don't necessarily make sense (and some of the part of Serial Experiments Lain are completely insane and sometimes wildly tangental, only making sense through the deepest of analyses and some stretching of the show's main ideas), the whole does, and the whole is an excellent work of art.
So don't worry if the fantasy show doesn't show the reality of midevil warfare, or if the sci-fi show doesn't necessarily carry through all the implications of a technology, sometimes it's ok to miss that stuff as long as the whole you create is excellent. Creating that greater whole however, is incredibly difficult, but that my friends is a story for another day.
So take it to your head, take it to your heart, and remember Rand rocks. Goodnight Folks!
6 months ago