Commitment to realism on film and television is more thorough and nitpicky than it’s ever been, mainly because its audience is also more nitpicky than we’ve been in the past. If you’re going to show us “grounded” superhero stories and dragons that obey the laws of aerodynamics we’ll be on the lookout for anything that doesn’t fit in with this commitment to realism.

Sometimes people can get a little too nitpicky — Who cares if the Star Wars spaceships make noise when there’s no air (and therefore no sound) in space? — and in those cases it’s better to just let the experience wash over you and appreciate it for what it is. But in other cases, the movie or show in question shows us something that truly challenges our suspension of disbelief, and makes us wonder if perhaps one or more characters aren’t actually time travelers.

Period-set TV shows that take place either before our current era or in the future have it the hardest, because if something onscreen looks out of place, the creators will never hear the end of it. Anachronistic items don’t often appear on highly regarded period TV shows, but when they do, there’s at least a week of articles, posts, and memes that travel around social media. For this list, we’ve picked ten of the most famous examples of times when an out-of-place object has made an appearance on a show that otherwise looks like it was filmed in exactly the time period it was set. At least we have errant coffee cups and blue jeans to remind us that even the best shows are all smoke and mirrors.

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