Connecticut Yankee - Television Tropes & Idioms

"...we now live in a world where kings and noblemen rule the roost. And they've turned all of central Europe — our home, now, ours and our childrens' to come — into a raging inferno. We are surrounded by a Ring of Fire. Well, I've fought forest fires before. So have lots of other men in this room. The best way to fight a fire is to start a counterfire. So my position is simple. I say we start the American Revolution — a hundred and fifty years ahead of schedule!"

—Eric Flint, 1632

Sometimes, the Time Traveler never intends to go anywhere. He's just minding his own business when a Deus Ex Machina sweeps him into the past, or the future, or an alternate world... and he has no hope whatever of ever getting back home.

Once he has resigned himself to the situation, then, there's nothing for it but to make his new world a better place to live in. Whether this creates a new timeline or wipes out his old one, he'll probably never know.

This trope mostly ignores the implications of language and biology. Individuals who find themselves transplanted in the Medieval period are able to communicate without difficulty with people whose language bears very little resemblance to their own (for example, middle English is not the same as modern English, and so forth). Furthermore, those same individuals never have to worry about the disease or poor hygiene practices that made living during those ancient periods extraordinarily hazardous, by modern standards.

The original victim, Hank Morgan of Mark Twain's A Connecticut Yankee in King Arthur's Court, failed to permanently industrialize Arthurian Britain and was sent back to the nineteenth century as mysteriously as he'd left it (incidentally making this Older Than Radio). Most of his successors, however, have had better luck.

Examples:

Lest Darkness Fall by L. Sprague de Camp. Martin Padway is struck by lightning and finds himself in sixth-century Rome, on the verge of its ruin at Justinian's hands and the onset of the Dark Ages. He may be able to save civilization, if he can only get the ruling Goths to grasp the value of his innovations...
Lord Kalvan of Otherwhen by H. Beam Piper. Pennsylvania cop Calvin Morrison runs afoul of the Paratime Police and is accidentally transported to a medieval alternate Earth where a corrupt theocracy controls the secret of gunpowder.
The Cross-Time Engineer and sequels by Leo Frankowski. Polish hiker Conrad Schwartz, in a drunken stupor, bypasses all kinds of security and stumbles into a historical-research time portal (created, coincidentally, by his cousin) and awakens in thirteenth-century Poland, where he has just ten years to industrialize and unite his nation before the Mongol hordes arrive and kill everybody.
- Language difficulties are handwaved in a justification that "all Slavic languages are pretty much the same." Diseases don't really rear their head until the 6th book, Conrad's Quest for Ruber where they have to deal with unfamiliar diseases in Africa, but is semi-justified by Conrad's cousin going back in time to make Conrad sterile (no, not like that... he's rather prolific, really).
This is how the statues kill in the Doctor Who episode Blink: they send their victims back in time to when they are no longer capable of harm, and let them live their lives to the end.
Temporally inverted in Philip Francis Nowlan's Armageddon 2419 A.D., or as it's better known, Buck Rogers in the 25th Century. Rogers, in the various versions of his tale, brings lost knowledge and a certain 20th-century vitality to future America and/or Earth as a whole.
Parodied repeatedly in this short story (scenario 6).
In the Discworld novel Night Watch, Commander Vimes is eventually torn between trying to fix the timeline so that he can get back to his own time, or attempting a Connecticut Yankee on the Ankh-Morpork of thirty years ago. He eventually decides to take the latter course of action, but historical inertia forces the former one. Mostly.
In Back To The Future Part III, Doc Brown resigns himself to the fate of living in The Wild West - which he's actually quite happy about. He even goes as far as to give Marty instructions to not pick him up. Being an inventor, though, he does manage to invent some technology of the future. He doesn't share his inventions with anyone else, as he's mindful to not risk changing the future. At the end of the film, he does create another time machine out of a stream train. However, it's uncertain whether he chooses to live out the rest of his life in the past - or move back to the future. The Ride and The Animated Series, though, both have Doc ultimately moving back to the future.
It Takes a Village to Raise the Tech Level: A recent twist, this plot sends an entire community into hostile territory. Rather than a single hero, the town as a whole can be considered the protagonist.
- The Islander Trilogy by S.M. Stirling. The island of Nantucket is whisked into 1250 BC, and must contend with Bronze Age cultures and their own crop of power-hungry renegades.
  - This one does contend with language difficulties, uptime diseases, and so forth; the Nantucketers manage to wipe out huge numbers of Native Americans before they even realize what's going on, because the first party sent to the mainland contains someone with a sniffle. Their language difficulties are moderately eased by the fact that the languages of Europe are, at that point, much closer to still being "Proto-Indo-European"...
- The Assiti Shards milieu by Eric Flint and others. Cast-off shards of transdimensional alien "art" bombard Earth and transpose large chunks of it with other times and places. Several alternate histories are planned in this meta-setting, including Timespike (several separate Shard events deposit hapless human settlements in the Cretaceous), 1776 (the American and British armies of the Revolutionary War both find themselves elsewhere), and By Any Other Name (the Assiti themselves make unwilling contact with Elizabethan England), but only one has seen any publishing. That one has, however, seen a lot:
  - 1632 and many, many sequels. The West Virginia coal-mining town of Grantville is translocated to southern Germany in the middle of the Thirty Years War, utterly shattering the power structure and world view of Reformation Europe.
  - Once again, this setting deals with language and diseases fairly well. Although in this case, it's the uptime people of Grantville who have to worry about the risk that the pandemic plagues of the 1600s will devastate their community. On the bright side, they're at a recent enough point in the past that their English is recognizable in England, and their German-speakers are understandable to the Germans around them.
The Arthur C Clarke novel Time's Eye is the extreme form of this, involving Alexander the Great's army, Genghis Khan's Mongol hordes, six people from 2037 (three UN peacekeepers and three Soyuz cosmonauts), and a British outpost from the days of the Raj, with Rudyard Kipling in it.
The anime and manga Zipang sends the Japanese Maritime Self Defense Force vessel Mirai, an advanced version of the Arleigh Burke class destroyer, back to just after the Battle of Midway. A better take on the concept than The Final Countdown where a Nimitz class aircraft carrier gets sent back to just before the attack on Pearl Harbor.
The Marvel comic book 1602 has a time-displaced Captain America sent back to Elizabethan times. When asked to return to the future, he insists on staying to try and build a better America from the beginning - which he does in small ways, such as helping a group of colonists survive a winter that should have wiped them out, or warning the natives against selling their land to unscrupulous capitalists. The final touch comes when, because of his actions, the American colonies declare independence from Britain 174 years early.
- And it's got dinosaurs.
And then there is this troper's personal favourite, the Axis of Time trilogy by John Birmingham. World War 2.1: Weapons of Choice, World War 2.2: Designated Targets, and World War 2.3: Final Impact. A multinational naval task force from 2021 is sent back to World War II, where it (literally) impacts with the American fleet steaming for Midway. The consequences are extremely far-reaching.
Another inversion in The Centurion's Empire by Sean Mcmullan, the premise of which is that ancient Rome developed a medicine that allowed the human body to survive being frozen, and promptly started storing its best and brightest. After the empire collapsed the one survivor set up shop in an English village, being unfrozen when they needed his military expertise.
Deconstructed in Poul Anderson's short story "The Man Who Came Early," in which an American soldier stationed in Iceland is sent back to the Viking Era after being hit by lightning. Luckily the Icelandic language has not changed much since then. All his attempts to change history fall flat on their face. When he tries to show the Vikings how to make compasses, he has no idea where to find or mine magnetic ores. When he tries to show them how to build more modern sailing vessels, the Vikings point out that such vessels are too cumbersome to dock anywhere where there is not a ready built harbor, an obvious rarity in that time period. The Vikings find the matches he brought with him impressive, but he has no idea how to make more. The only knowledge he has of any use is modern martial arts. In the end the soldier runs afoul of his ignorance of Viking legal customs and is killed.The story's main point is that this trope is unrealistic because most advances are useless without an advanced societal infrastructure to support them.