Doctor Who fans, you can stop beating on my door now.
Time travel is a pretty tricky ball of wax at the best of times, even in shows and books that don’t take themselves seriously. Most people with even a passing knowledge of science will give you a thousand and one reasons why they usually fall into plot holes, sometimes without even touching the Grandfather paradox. Basically, the only way to deal with time travel is to make it internally consistent and hope. I’m no scientist, and I’m fully prepared to accept “this is how time travel works in this universe”, provided a show stays within its own rules.
But then there’s a whole other side of it. Maybe your plot involves time travelling a short way back, maybe only a day or a week or even a month, to stop yourself from doing something stupid, or to stop a friend from being killed. It’s probably a Deus Ex Machina unless it’s the point of the whole story, but hey, if it works, it works.
What happens if you go back further? This is the part that gets really difficult. Let’s pick some common historial eras that seem to show up pretty often.
Victorian era London sounds easy – let’s start there. That’s 200 years ago, beginning around 1840, after the Industrial Revolution. Well, first off, you’re probably looking at enforced vegetarianism. The Industrial Revolution pretty much killed off agriculture around London as everyone moved in for the factories, so meat took a pretty long trip to get there. With no effective refrigeration. So good, fresh meat was not exactly a common thing. Everyone seems to harp on sanitation and medicine, too, which is fair enough. Not to mention that most clothes worn today would probably get you arrested for vagrancy.
Go back further, and the problems multiply. Our lives are so disinfected today that go back a couple hundred years, and you’re unable to eat food without being violently ill from several orifices.
But hey, time travel books aren’t about being historically accurate or true to life. These things can be glossed over, and people who complain too much about them may well just be nitpicking. What’s the one thing that kills time travel plots?
Linguistics. Shakespeare (or Shakespear, or whatever the fashionable spelling is now) didn’t speak Old English, and he didn’t write it. He spoke Early Modern English, at best. Even Chaucer didn’t actually write Old English – he was Middle English.
Beowulf is Old English.
To put that in perspective, you can reliably understand what someone is saying to about 400 years ago – that’s around Shakespeare and John Donne, and yeah, you’re not going to communicate instantly. Chaucer times (700 years ago-ish), English sounded like a combination of French and Scottish (which is kind of hilarious, taken in historical context), and before that, it was pretty much German.
But, OK, linguistic differences going back that far are pretty much the sanitation thing all over again. It’s just nitpicking about facts, after all. The problem is, unless you’re travelling only a few decades back, it’s going to be just about impossible to write dialogue and not sound completely clumsy.
You don’t really have any good options with this one: either everyone sounds the same, which just seems really odd, or you go with a more ‘old-fashioned’ speech for the appropriate characters, in which case they generally sound ultra-formal and stilted. Slang will be much the same, because no matter how hard you try, “Zounds!” will never sound like a strong expletive. It takes an incredibly deft touch to walk the line between anachronism and stilted dialogue, and it’s always a bit painful to watch an author fail.
Or, you know, just time travel to the future and make the whole thing up. That’s cool, too.