I’m the type of person who goes through the IKEA catalog and instead of circling things I like, I take a big Sharpie marker and I cross out the things that don’t make sense or aren’t practical. I mean, sure that huge wire cabinet of freshly peeled carrots looks nice in the background, but who has an entire cabinet full of freshly peeled carrots? There’s no way they will get used up before they go bad. Why would you peel them all at once and then just leave them there? Or, yes that wicker swinging seat looks nice hanging there in the corner, but don’t you realize there’s no room to swing when it’s in a corner?
Choosing to look with a critical eye at the things that have been designed for us to gloss over has given me much amusement. The next time you watch tv or look through a magazine, don’t look at what they’re trying to get you to look at. Try looking at the other people, the edges, the background. Or try to imagine that situation in real life and see how it holds up.
As writers, we sometimes resort to creating fictions that are lovely to look at but totally unrealistic. An example is Neil Gaiman’s Stardust in which he describes an evil witch sharpening her blade on a whet stone. Except throughout the entire book, he mentions that the blade is made of volcanic glass. You can’t sharpen glass on a whet stone. But hardly anyone noticed because they were looking where he wanted them to look.
Or take Holes as an example. It won an award for being excellent fiction. Only after the award was given out did someone realize that it was historically inaccurate: lipstick was not produced in tube form until a later time period than when the book claims Kissin’ Kate Barlow was alive.
There’s no way you will ever catch every anachronism in your story. So how do writers deal with this?
William Goldman decided to take the silly route in his book The Princess Bride, and makes references to inventions and historical events out of order on purpose, then explains in parentheses his new order of things.
“Buttercup’s mother whirled on him. ‘Did you forget to pay your taxes?’ (This was after taxes. But everything is after taxes. Taxes were here even before stew.)”
Not everyone can use that style, though, and not everyone should otherwise books would be boring.
The important thing, I think, is to look at your story from an angle. Look at the things in the background, the side characters, the edges. Imagine what it would be like in real life. I often discover some very odd and amusing things about my stories this way. Usually, I assume that I can have my side characters say whatever they want as long as it sounds good and moves the plot along. But when I look at the story from their point of view, I realize that they wouldn’t actually say such a thing, and I need to re-write how it sounds.
Again, it’s almost impossible to catch every anachronism. But it is possible to think critically about your own story and weed out the most obvious mistakes.