The notion that there hasn't been that much change in the last fifty or hundred years is a little shaky. There are numerous films with outside shots where there's something off about the cars. Lots of filmmakers play around with trying for a timeless look, but mainly they just end up looking like they can't make up there minds about when the story takes place. As far as furnishings go, there's customarily a lot left out of movies, like televisions, kitchens and bathrooms. Our notions of what the past looked like are strongly affected by bad representations in the movies, that update the look, whether consciously or not. The same very much applies to fashion. Despite the foolish remark about not wearing metallic spandex, lame is still used in fashion. And spandex can be terrifyingly common. What supposedly futuristic fashions really fail to do is show the variety that you actually find in real people. Firefly and the new BattleStar Galactica fail that test as miserably as most other series.