It was the tomatoes that got me. My wife was watching a chick flick set in an small Alberta town in 1910, which was my cue to be elsewhere. But I happened to be passing through, and there was a scene where a character made an elaborate sandwich, and mentioned the fresh sliced tomato.

Where would they get the tomatoes? I thought. This is around 1910, in a small, remote-ish town in Alberta. Local farmers? Possibly. Folks south of the 49^th Parallel tend not to realize it, but Alaskan and Canadian farmers grow some mighty fine vegetables. But at first glance it seemed to be out of season. Railroad? Didn’t have one. The arrival of the railroad is apparently a new plot. Ship? Too far from sea ports or river docks. In most of North America, circa 1910, you simply didn’t have fresh fruits and vegetables all year long. They were only found in season, even those shipped in refrigerator cars (which had been in use over thirty-five years by 1910), but that meant access to rail. Otherwise, your vegetable choices were canned or dried. That fresh sliced tomato was an anachronism.

There were a few others in the show, such as character attitudes more in line with 2010 than 1910. But, like those fresh sliced tomatoes, such things are easy to slip into writing. There’s Thailand in Raiders of the Lost Ark, except in 1936 the country was known as Siam. Then there’s the line in Star Trek: The Wrath of Kahn were Kahn tells Chekov he never forgets a face. Neat trick, considering Chekov wasn’t a character in the episode that introduced Kahn. And so forth and so on. These things arise when a writer has unfounded assumptions. So it is we have Kahn recognizing Chekov, on the assumption that Chekov was always a character on Star Trek, or the assumption that Thailand was always known as Thailand; or that fresh tomatoes could be found out of season in a small Alberta town in 1910.

L.P. Hartley once wrote “The past is a foreign country; They do things differently there.” This is certainly true, in ways we may not be aware, just as we are likely to miss some small but significant detail in setting a story in a foreign country unless we’ve been there ourselves. Since time travel isn’t a reality, the best we can do is immerse ourselves in that world through research to have a better chance of getting things right. Unless we realize that fresh fruits and vegetables all year long are a fairly recent thing, we’re apt to put an improvable tomato on a sandwich. Unless we realize the names of countries change, we might think Thailand was always Thailand.

Even when we think we know a subject cold we can run into surprises. I grew up on a farm, were one of the crops was tobacco. If I were to write a scene were a mid 20^th Century family was harvesting tobacco, I would have had sleds pulled by a mule dragged between the rows as workers pulled mature leaves from the plants, carried beneath a shed build around a tobacco barn where they were tied with cotton twine to sticks, and hung on racks in the barn to be “cured” with gas heat. If set in the region where I grew up, all well and good. But if I set it in another, a farmer would be convinced I didn’t know what I was writing about, and he’d be right. For some places harvest the entire plant and others use spears in place of string and sticks and some air dry tobacco. Until a couple of weeks ago the only variation I knew was air drying. What I knew about tobacco was correct for the time and place, but move it to another part of the country and it would be as out of place as an improbable tomato.

I don’t know if we can completely eliminate this sort of  “gotcha” because none of us know everything and we all make mistakes. This is why some authors keep an record of their character’s description and background, lest hair and eye colors change from one part of a book to another. It’s also why we research as much as we can, or should. The problem is knowing what we don’t know in order to do the research to get it right.

How? If I knew that, I’d never have assumed that everyone harvested tobacco the same way. The best we can to is to research everything, even the things we think we know, and do our best to create consistent believable worlds as accurately as possible.

We can count on one thing, though: If we make a mistake, someone is bound to point it out, whether it’s harvesting crops, the name of a country, or an improvable fresh sliced tomato. Readers are very good at this sort of thing.