If I snapped you back in time 650 years right this very second, how would you use your current knowledge to succeed?
Its the 14th century and you've had no time to prepare, after you're done reading this post you are snapped. What do you do?
Double entry accounting system.
I'm an accountant by trade. The double entry system wasn't invented until the 15th century.
I could account for any lords various assets, goods, and livestock in an efficient, reliable and accurate manner
Die because my medications haven’t been invented yet.
Or be murdered because I’m not christian
Die as you forgot to teleport me to where the earth was at the time.
Otherwise I guess my main knowledge that could be useful is some basic first aid. Secondary to that, a little bit of electrical stuff.
Assuming you live in the west, you want to get executed by the catholics?
I'd use my knowledge of history, politics, psychology and science to become an influential advisor to powerful lords and help them conquer the world in exchange for living in luxury.
I know thousands of songs. Also, musical instruments like the saxaphone haven't been invented yet.
Oh I think you're the first person to suggest music! That is a really good idea, provided you don't die of dysentery of course.
Fly under the radar as much as possible, find a cute girl and settle down and have a lot of kids.
This is something I often wonder about, what could one person even do with all of today's common knowledge? You can't very well just invent the printing press and have the same impact as Gutenberg - you need something what the few people who can read would, and most people can't translate the bible from Latin into renaissance German and/or don't know enough about the catholic church to write scathing remarks on it like Luther.
You can write and read - that's something. Maybe more importantly, you can do math with arabic numerals - boom, easy accounting job. With a bit higher education, you may even just invent calculus once more. You know how long it took for people to figure out you can put pi on the number line? Proving all the formulas in your head is the hard stuff, but you have a head start just by knowing them. We all clown on the wormhole explanation with the paper, but it does prove Euclid wrong 400 years early.
Ah, and you can just become a medical genius by using soap and bandages - "do no harm" is better than most.
Heres the thing though, you can write, but can you write and read Middle English from the 1300's? There are some similar words but its a very different language than what you and I are used to, it's another 200 years before Shakespeare and most English speakers struggle with even as far back as that.
I just asked AI to write my above comment in Middle English
"Lo! Her is the thinge, but thou mayst writen, canstow yet writen and reden in the Englissh of the thrittene hundred yere? Certes, ther ben som wordes ylich, but it is ful divers from that which thou and I ben y-used to. Two hundred wynters yet moot passen er Shakspere shal come, and fele folk that speken now Englyssh han gret strif to undirstanden that tyme."
That reads like Dutch to me. Perfect! I'll be fine.
Even that is very modern-looking to this Chaucer enjoyer.
You probably can read middle English sooner than you can speak it. Like writing with a feather on parchment, I assume you don't just die and have time to learn.
Side note, I now want to translate all my emails to my supervisors into middle English
Should be noted though, even with the best plan, your frail body, weird language and no local knowledge will mean you probably still die in 2 - 72 hours.
Good thing I binge isekai anime
Anyone else a fan of Nate Bargatze?
I'm on the Gregorian calendar, 650 years ago is the year 1375. I'm in North Carolina, so if I were to snap back in time at my present location I would be a blue eyed white guy in pre-contact North America. And while I think I'm an above average candidate for the Connecticut Yankee in King Arthur's Court scenario I'm not realistically able to start "from scratch." I'd probably make it the summer on forage and my own body fat. I don't picture encountering the natives going particularly well, for me or them. I'm not sick and I'm vaccinated against a lot of shit but watch I'll give them 6 centuries worth of influenza updates.
I don't think it would help that much being plunked down in 14th century England; we're talking Geoffrey Chaucer's lifetime here, to them I'd sound insane. Modern English is a few hundred years off. If they didn't trepan me to let the demons out of my skull and I didn't die of smallpox, I'd try to invent the electric motor 500 years early and be burned for heresy or some shit.
The only non-delusional answer lol
Yeah, I'm here thinking my ass in America pre Columbian exchange is not doing well. Maybe if I make it clear somehow I do not want to do anything but help I could...idk, be part of a native tribe and maybe give them a slight help to the upcoming horrors for them?
It's not going well for anyone.
Probably die
Wash my hands
Where do you wash your hands? Hope you brought a big bottle of disinfectant.
Running water would allow for 30% reduction in bacteria, according to some sources.
Also, in that time period soap was known in Spain, France and Italy, and I personally made it in the summer using either olive oil or pork fat.
Any body of sufficiently rapidly running water should suffice.
The definition of succeeding just becomes not dying.
Given the rate at which people would become mentally or physically disabled because of diseases, you could argue it would have a network effect (probably a better term exists): I would have more chances to meet people and influence them, to learn something useful, to accumulate and use wealth for the above, so yeah...
Now you're a witch
That would be a warlock I guess.
I'd die pretty quickly.
Depends what clothes I'm wearing when it happens.
If I'm wearing anything that could remotely be seen as fancy back then (which I mean a lot of modern clothes could pass off as), since I'm near the ocean, I'd immediately run into the water not seeing anyone, and then pretend I'm a royal foreigner who ended up shipwrecked. Since I usually wear a watch, have a tungsten (Wolfram) crystal wedding band as well, that would help me in passing off as royalty as well. This is assuming the people helping me aren't brigands. There's things we do and know of that we take for granted that could be used to pass off as someone upper class too, like reading.
Then next steps would be to get to an aristocrats home, and eventually I'd imagine somewhere where I could work with scholars so they can teach me the language and we can work on translation so we can understand each other. Would have to be extremely careful of smallpox during all this of course.
Once we could, that's when I'd finally whip out my phone to trusted scholars and pull up my survival books, books on plumbing, etc specifically, and to explain that this is a special metal and glass book that can hold many books that's common in the land I'm from, and that I can teach them how to build them. But that we'd need to build plumbing because I'd like a shower by then.
There's a book with almost the exact same premise.
Destiny's Crucible.
It's fairly good, can be a bit slow though. (I'm 7 books in)
There's also Lest Darkness Fall which is pretty good.
I really enjoyed that series (don't remember which book I stopped on). I think the slowness of it gave a sense of finding a home along with the main character.
I would fall from a very high place
As an Australian I would struggle significantly unless you were to also transport me geographically.
Fuck I think I could just vibe with the Noongars, hunting, fishing and sleeping til I died of old age.
Maybe use basic science and chemistry to improve sanitation and quality of life. Not too much, just enough to be regarded as a clever fella, not a warra wirrin bad spirit.
I would imagine the east coast / tasmania could be interesting. There used to be hundreds of different peoples that are now extinct and we know nothing about. A struggle nevertheless.
There's a former nunnery down the road. I suppose I'd try to join. Or maybe find a farmer who's looking for someone to look after his kids because his third wife died in childbirth.
Many years ago when I thought about this, I realised I wouldn't be able to put much of my modern knowledge and skills to use. I decided I'd learn to make basic matches by distilling urine into phosphate, which wasn't invented until the 19th century, but I've forgotten the process. Collect lots of urine and boil it? Also, if you make white phosphate it can cause horrific toothache and they have to remove your jaw... So, I'm hoping another commentor will suggest a safer skill I can brush up to be ready for travel.
612 years in the past
In Brazil. So almost a century before the first europeans landed here. I'm assuming I just plop exactly in my relative earth-location, but in the distant past. (... It would be really funny if this was overly literal, because I'm currently in the 12th floor, so I'd thanos snap into the past and immediately fall to my death)
Well
As a person from modern times -- From AFTER the Americas came into contact with Europe, if I went near a person here in the Land of Palms (that's what the natives called Brazil!) from those times we'd both get horribly infected and die a lot due to how antibodies work. Viruses did a lot of the legwork in genociding the natives. Euros would deliberately do things to infect natives so they'd die of illness.
The place I currently live in is slowly turning into a desert, but was a deep jungle back then (... It was still a deep jungle in the 1910s tbqh).
.......... I think I'd just die? Become food for a jaguar or eat a poisonous fungus or sth.
Would love to indulge in the fantasy of giving the Guarani people guns and a warning to shoot white people on sight just to see how history would change, but that ain't happening.
650 years ago this place was a sea. So I’d end up having to swim at least a couple of kilometers. Considering the current sea temperatures, I’d probably die of hypothermia before I could reach the shore.
Learn to build dams
like Amsterdam, which would already be a 100 years old
I'd make some fucking soap.
Do you know how to make soap? I'd want to but I'd have no idea how. If it already existed the hard part will be how to make enough money to buy it, as a software dev I'm not sure I'd have any sellable skills
Well, I would give you the answer, but since I snapped back as soon as I read the post, I'm now responding what has been 650 years later for me, and I'm too fucking old for this shit a second time. I bypassed getting snapped back this time by just not reading the post and coming straight in to comment.
Now, what will happen if I read the
Wait 612 years and buy Microsoft.
Edit: I’m taking the middle road here and assuming something around year 1250 or so, not 1100 or 1400 as confusingly set in OP.
Okay, so unlike most other scenarios, I think I would be fine for a while at least. The peoples living where I live would have made and kept more or less regular contact with the sons of bitches from the south that would later crusade us (or I think maybe one of the crusades is presently ongoing at the time…) so while I would both introduce and be hit with diseases or more likely strains of familiar ones new to my body/their bodies, I think it wouldn’t be as destructive as entirely separated landmasses like America vs Europe.
So if I survive the shock my body gets hit with, and I don’t kill everyone around me, I think I would be fairly well received. As far as I’ve read, the languages and dialects were different than after the formalization of the written form, and at this time these lands were just starting to get forced under Swedish rule, so with my basic understanding of Swedish and of course my native language, I think I would be able to communicate well enough to not get instantly killed as a demon or something.
I think my best bet would be to introduce myself as some sort of demi-god, a bastard son of the god of forests and the hunt probably, which would hopefully explain my alien attire and materials used to make them. And the alien accent/dialect of both the local language or Swedish, depending on where I’d land. If the first contact I make aren’t local but crusaders, I suppose I’d have to try and push myself as a wandering preacher of Christ or something. I’d have to hope they’d speak Swedish, since I do not know German well enough to form two words together, and they’d likely be the next likely encounters. Novgorodians I think were fine with the Swedish language in general, so if our current knowledge of history was off enough that I’d meet them here, I’d still be fine. No idea what I’d pretend to be to them though. My limited knowledge of history doesn’t help there. But as far as I understand, they were sort of a melting pot of close-by cultures, and not so focused on these lands at this time, they’d just take me for a local hermit and let me run off clumsily.
If I was able to survive the first encounters and get myself to a village or a hillfort, I’d try and establish myself as a wise one, helping with calculations and engineering and whatnot to the best of my capabilities, which I would think honestly should far exceed those of the locals at the time. So maybe I’d get by just for being useful and knowledgeable.
But I don’t think I’d live a long life. These were a turbulent and violent time and one village elder or the other, fancying themself a king or whatever, would just send assassins to off me for being an asset for the local leader where I’d end up in.
Even if I’d travel to avoid this problem, it probably wouldn’t take until my old ages to have someone or something off me just by happenstance. And I wouldn’t want to live a hermit in a time where internet or computers aren’t a thing. I think the only way to cope would be to focus on a family, try and bring up children and have that fulfill my life as best it can, as long as it can.
Honestly, I consider myself lucky in this scenario. We still have our language alive and in use, the same the locals would speak at that time. This together with the general superstitious nature of the local tribes — which the crusades and Christianity, with overt blood and sadistic violence, would (thankfully later, I hope for my sake here, at least according to our current knowledge) succeed in some amount to water down and turn them to its specific flavor of lame ass superstition — would make it probably at least somewhat likely I wouldn’t be killed on sight or something to that effect.
I would pretend to be super-religious. Throughout the whole of human history, pretending to be super-religious has always been a viable path to survival and personal advancement.
Apart from that, I'd probably just die.
Oh! You could start Mormonism! Its super new as far as religions go, and it was mad easy to convince the masses it was real, all you do is say you have special tablets of text that only you have been given the ability to read by God, and BAM new religion just launched and you're the leader.
The best way to find hidden treasure is to hide the treasure yourself!
Assuming I’m snapped back to the same part of the earth, climate-wise that’s ideal in the US PNW coming out of spring. Plenty of berries and food to forage, and I’ll probably impress the natives with my watch and well made clothes. I can probably get the native tribes to metals, and gain acceptance with my magic hand tool that will briefly shine light at night for a few weeks. I don’t know offhand where copper would be, but I know gold is in the streams, and I know how to placer mine, so I can get some electricity going with that and magnetized rocks from lava flows.
I think first contact would be the key.
England is in the midst of the Hundred Years war with France and considering I'm ~193cm and the average height of a man in England in the 14th century is about 171cm... looks like in getting my arse drafted and shipped off to France, to act as some kind of intimidating presence. That is until I have to swing a sword, which my body, that's used to sitting in an office looking over excel spreadsheets, absolutely can't do, so I get bum rushed/hit in the face with an arrow and die.
That's the most likely scenario.
Worst case scenario, considering I don't speak middle English or Latin, I'm treated as an enemy and locked up in a dungeon somewhere.
I don't think there is realistically a best case scenario
I'd just like to interject that while traveling was rare in medieval times, it did happen. People usually didn't get thrown in jail for it, even if they didn't speak the local language.
Regular people didn't really speak Latin beyond a few bits of prayer. The lingua franca was a mix of various coastal languages (think of the belter patois in the expanse), but even that was only known to traders.
You'd have a tough time for sure, but wouldn't necessarily get in trouble.
die almost immediately
Yeah, this. I have medications I need. When the pair of contacts in my eyes fall out eventually, I'm functionally blind. All that aside, I'd probably starve quickly since I don't know how to make weapons and other humans haven't made it to where I live yet in 1375 nevermind, I'm high. The humans that are there would probably kill me on sight though.
I'd probably look around for a couple days and then when I got super hungry just find a cliff to jump off.
and if you manage to evade physical harm, sickness will surely catch up with you. the black death was not a 'one and done' pandemic. it lingered and persisted here-and-there for centuries after the widespread pandemic (known today simply as 'the plague') that claimed 50m+ lives, including half of europe's population at the time
I'd try and hold my breath to not set off the European diseases into America early.
If I snapped you back in time 650 years
2025 - 650 =1375
Its the 12th century
1375 is the 14th century. Which do you mean?
Answering the actual question, nothing good would come of it if my location on earth didn't change. Being the only white person in rural northern Japan well before Europeans came in the 1500s would probably not be a good situation for me. The language, at least the written one, was very different. Being the Nanboku-chō era, things would probably be not great since it was in the midst of 60ish years of war with two different people claiming to be in charge. I can't find, at least before my coffee kicks in, exactly what kinda state Mutsu Province, as it was then called, was in at the time.
Yeah, I did it backwards. Like I knew it was the 1300's but when I said the century, I went back a diget instead of forward.
English would also be unrecognizable in 1375. At a glance, it seems like it was Middle English, which means you'd probably get as much intelligibility with any other English speakers as a monolingual Dutch speaker would have with a monolingual English speaker today. Maybe a bit closer, but still.
Shakespeare was still hundreds of years away.
...Not that any of this would matter to anyone living in North America.
Middle English is certainly difficult to understand, but most words still bear some resemblance to modern English. I think it would probably be more like a native German speaker trying to understand a heavy Bavarian dialect, or at worst a Dutch speaker trying to understand the same.
In my case, I'd probably be OK having studied French and German (and reading things by Chaucer and Gauer). Though French != Norman French, so that may cause some issues.
It's not 1825 where you are?
Technologically, it does feel like that sometimes, but it would seem not.
Well, strictly speaking, if your location didn't change you'd be transported into empty space. So you wouldn't have very much to worry about for long.
Heh, that's specifically why I qualified it as 'position on earth'.
I'd be fucked. I'm not succeeding in the present, I see 0 reason to believe that would be different in 1375.
I'm in the US and in a place that native Americans didn't have settlements. I'm very familiar with the area and have hunted, hiked, and camped here my entire life. With no preparation or modern equipment I give myself about a week before I get eaten by wolves or a bear, maybe gored by an elk or bitten by a venomous snake. I don't expect that I would see another human during that week. Native hunting parties visited the area so it's not impossible that I would see someone but it's very unlikely.
Assuming I am physically in the same place, I will fall to my death. If I somehow survive the fall I would be severely injured and alone in the wilderness. Within a few days I would probably die of either my injuries, dehydration, or hypothermia.
Scientifically speaking, the earth is constantly moving in an upward spiral. Your exact physical location would put you in some random outerspace area without oxygen or any protection. Just floating in space until you die.
I'd use my knowledge of the future to do two chicks at the same time
Fucking A
... and B too
"I figure a guy that can time travel 650 years into the past can set something like that up"
well I'm a woman so anything I do will be witchcreaft. I would probably try to get to north america in some way and warn them "the fuckers are coming".
that would mess up the future lol
650 years ago, the place I live was inhabited mostly by the Ojibwe (a Native American people), so I suppose I'd try to find some of them and try to convince them to not kill me and let me stick around long enough to learn their language. Then I could teach them some of my knowledge. Maybe by the time the Europeans come along they'll be a bit more prepared.
If I can't find anyone, I don't like my chances of surviving for any significant amount of time. Maybe I could make it a few weeks foraging for food and fishing or something, but realistically I'll probably end up starving.
You would be surprised how plentiful food is when there are no people eating it. Fishing with a spear would be easy. So as long as you can make a fire, you shouldn't starve. But there would also be plenty of animals that would consider you food.
I'd cry, curse god's name even more than I do currently, and then probably die from boredom.
1375? Bro that's the. Middle ages. Fucking kill me.
Hope that I don't start the early spread of New World diseases to indigenous Americans
And I'd be dead by the end of the week
I'll probably die of dysentery. Just because I know modern hygiene rules doesn't mean I'll survive interacting with all the other people who don't but are used to local bacteria and viruses.
This is probably the most realistic answer. Either you die quickly or you’d wind up, spreading some major contagious disease that nobody has a defense against and wipe out a huge section of the population.
Fuck you buddy, I'm barely getting by with modern medicine, you just ended me.
If I time traveled to the same geographical region, considering I'm in South Brazil, if I don't get immediately killed by some jungle animal or tropical disease, I'd probably end up starting a pandemic among the natives.
I would die quickly because I don't have any wilderness survival skills and the land I live in (USA) was inhabited by hunter gatherer tribes whose language is completely unrelated to anything I know and whose customs are completely unknown to me as well. But beyond that, even if I got teleported to England where I at least know a similar enough language to where I could figure out middle English decently quickly, I think people seriously overestimate how useful just having modern knowledge is.
For example, say you want to build a gun. Do you know how to forge a gun barrel with medieval steel and make gunpowder out of bat shit and sulfur? Because I sure as hell don't. I could probably make gunpowder but how the hell would you get the money to pay someone to make a gun barrel for you? And further, even if you had the skills yourself, basically nobody today deals with raw materials as inconsistent as what they were working with back then and therefore don't have practice working with them. Even if you introduced something like germ theory to them why would anyone believe you? You'd probably get just as sick as everyone else even with following modern sanitation standards for yourself because nobody else would be. Same with math. Want to speedrun introducing calculus to the world? Good luck trying to prove it to medieval mathematicians without having deep knowledge of euclidean constructive proofs and philosophy to even allow for something like an infinitesimal to exist. There's very little one person can realistically do to change the world on their own.
I also feel like suggesting people wash their hands, and having it work, would immediately get you accused of being a witch.
It probably wouldn't work though. Say you wash your hands. Okay that helps some against certain diseases but not against respiratory disease, many types of foodborne illness, the plague, etc. You'd still get all of those just as easily as everyone else without also having a backdrop of the germ theory of disease to explain other ways to prevent disease and antibiotics to cure bacterial infections.
This is the state of biology in the middle ages. This is a medieval Scottish bestiary, a book of animals, which contains many interesting facts about animals such as beavers biting their testicles off to throw away pursuers, several animals spontaneously generating from nothing, and many animals that don't exist (my favorite is the Bonnacon, a bull that spews firey shit as a defense mechanism). Medieval scholars also didn't accept experimentation as a valid means of gaining knowledge - they were stuck on Plato's ideas about matter being flawed and untrustworthy and true knowledge only being able to come from Reason (and in the case of the medieval era, Divine revelation). Obviously you could show them bacteria (if you could somehow fashion a powerful enough microscope with medieval tech, which is not a trivial task) and they'd have to believe in it but how would you get them to believe that those little guys cause disease when that took us a couple hundred years in actual history?
It's 1375 and I'm asphyxiating somewhere in the Milky Way about 600 light years from Earth.
But let's assume that somehow my latitude, longitude and altitude relative to Earth somehow remain the same. Now I'm spawning several feet in the air probably in sight of several villagers. If I'm lucky, they'll think I was sent by God. If not I'm gonna have a real bad time. There's a good chance I'll break a bone in the fall, and that's not going to go well at all.
But let's assume there are trees here. Lots of them. That's actually pretty likely. They hide my sudden appearance and mitigate bone breakages.
Now I'm on the outskirts of a village, battered and bruised and very strangely dressed. I don't speak any language they'll understand despite technically being from that area. Middle English is the language of the day, and I speak something that won't evolve for at least another 200-250 years. Shakespeare is technically modern English and is hard to comprehend sometimes. Here we're talking Chaucer and that's pretty much opaque.
I'm literate, but not in Latin, and that's the language of the Church. I'm numerate, but they haven't got beyond Roman numerals yet.
I'm not even sure where the church is. I know where it is in the modern day, but that building's no more than 200 years old. Maybe it's on the same site. I'd head there for shelter at least.
I know the Lord's Prayer in modern English. Chanting that quietly might spark some recognition in anyone present but then it might count as blasphemy to say it in anything other than Catholic-Church-approved Latin.
Come to think of it, I could probably blow a couple of minds by writing the alphabet they know and then the same with the extra letters that have been added since.
And then I'd be burned as a witch.
Pretty sure the Earth isn't traveling the universe at light speed
Yeah, I was about to go to bed when I was writing that. "Several" or "a few" would have been better.
Unfortunately in that circumstance, I'd likely be a horrible vector for disease. Not much chance of survival if I spread devastation wherever I go.
casually ends humanity with time traveling covid
Blame OP, she's the one who sent me back in time.
The Ring of Fire series which is about this concept was such an amazing read. Unfortunately the infinite branching plotlines became way more than I could handle.
Market myself as a powerful man of religion and/or magician, depending on the local vibe. Then use knowledge of science and tech to build myself a reclusive retreat where I can have regular baths and write books with predictions to mess with the world 650 years after I would die.
I like your style. If you really wanna have some fun, don’t name the United States as the United States, but name the year and then say something to the effect of the most powerful nation in the world will come under rule of an authoritarian individual who has dreams of becoming a dictator.
I love it! Predict that a large empire of equals will fall after 250 years.
I don't have the knowledge to survive in the 12 century so either some Native Americans find me and are kind enough to teach me to survive
Or I just die.
1375....
We can work with metals, so we can probably make boilers.
I invent steam power 400 years early.
You'd need metallurgy which was only invented in the process of building bigger naval guns, much later.
The issue was pressurizing the steam, which wasn't possible in the middle ages. You had no rubber for seals, no steel that would hold, and no tools to drill holes precisely enough.
That's why the Romans already used steam for simple parlor tricks but it couldn't be made to do actual work until the modern era
Real science and innovation comes in increments
no rubber for seals
Modern synthetic rubber would indeed be unavailable, but I vaguely recall reading something to the effect that early steam engines used leather seals or something like that.
But yeah, there's a lot of missing prerequisites for machinery. Even simple rotary power -- like from a windmill or waterwheel -- would suffer from being incapable of long distance transmission. Such a limit means the interior lands of a country away from a river or coast would remain unusable for development beyond basic agriculture. No railroads, no A/C, no Phoenix Arizona.
Re-invent. Your still far too late to be first.
People always think that the spark of invention is all that's required, ignoring the social and material tinder and kindling that's required for something to be useful and take off.
Die of bubonic plague, get killed for being a witch/warlock, die of appendicitis...
Basic geography could go a long ways, if people believe you. At this point people were exploring the world trying to find the spice Islands, but didn't know WTF they were doing. Magellan navigating the strait that would be named after him was impressive at its time, but now we know the best way from Europe to Asia (and spices and stuff) by sea without any modern canals is by going around Africa. Like, it still sucks and it's a long trip but it's doable compared to going to damn near Antarctica.
This assumes I don't die, can communicate, and am not in the then-unpopulated (and quite landlocked) current location of Denver, Colorado.
Edit: bonus fact: if a sailor managed to smuggle a knapsack full of cloves back, it was worth about as much a house
I'm in Japan and while I can speak modern Japanese I don't know shit about classical Japanese so I'd be screwed. I'm also not Japanese so good chance I end up getting killed or some shit
I'd write the harry potter series from memory. And all the star treks.
This seems like a good idea, but you would have to make a lot of changes to make it relevant to the times. I think it could work
I'm doing pretty good then. Where I live has been so historically abundant in resources that people were able to just sort of vibe.
I would also establish a calendar, convey it to the locals, and warn them of what is to come along with a timeline.
The first and easiest thing would be to invent calculus. I'm sure other things would pop up situationally, I could probably get basic electricity going with a bit of experimentation.
I claw my way out of a few feet of soil, and walk about thirty minutes to where the local Olhone maintained a ceremonial shellmound from 800 BCE until the arrival of the Spanish in the 1700s. By all accounts the Olhone were chill hunter-gatherers, so my best bet would probably be to befriend and join them.
They’d be more knowledgeable than me about everything in the local environment, so I don’t think I’d have much knowledge that would be of use to them. (They seem to have known of other nearby groups that practiced agriculture, but saw no need for it themselves.) I might eventually consider traveling north or south along the coast, but many other groups in western North America practiced warfare and/or slavery (unlike the Olhone), so I’d probably be best off staying put.
Well, I know about hygiene about various diseases, and even how to treat them. I'm also running for my life to the nearest forest, as I don't have any way to prove I'm not a Vagabound or invader, and I can't communicate.
There's no choice but to try to hide deep inside a forest, and try to find a river or lake. I would eventually be forced to drink dirty, risking parasites, unless I get lucky enough to find what I need to purify it.
As soon as that is taken care of, I would focus on covering up my tracks, digging some sort of shelter to hide from medieval people, my next step would be to ensure a food source like fishing, or finding plants I recognize as edible, which might be where I mess up and die (A lot of plants look similar to poisonous ones, mushrooms too).
Next step would be making bog iron, finding copper, and so on, to make life easier at first, but then to defend myself against being discovered.
Do my best to warn the locals of the coming invasion. Learn their language and teach them English and tell them not to trust any group of strangers who speak it.
Help improve their technology as best I can. I’m not sure how much I’d be able to improve it. At least, teach them to wear masks and wash their hands when around sick people.
I don't think our English is anywhere close to Olde English though, we might be hardly able to understand them ourselves, and I don't think they would understand us at all.
You're a stranger speaking English trying to convince the locals not to trust any stranger speaking English?
Yes. I’d have to learn their language first, anyway. I already know bits of modern versions but not much. Then, introduce the warning of invasions and teach them English with the caution that people speaking groups of people speaking will bring death and destruction.
It’s not like they’ll already have a fear of English or any concept of the language before I teach it to them.
I guess it's worth a shot but you'd a few hundred years after the Norse abandoned their settlements in North America and about 120 years before Columbus's first voyage.