I don't know how to refine oil, but knowing that its refinable into diesel/gasoline is a pretty good start to looking for it. Steam power easier to figure out. A head start on murdering some sperm whales for lighting industry seems easy enough to figure out. Partnering with metal smiths who might have a clue on making gun barrels, and pipe's in general that could be used for advanced weaponry, would be an easy path to get governments to give me a ton of money for weapons research by just showing them some drawings. Doesn't really matter if I ever figure out how to do it, just the vision of what is possible would make me richer than Musk. Richer if I can help enslave all of humanity to one empire.

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.

I guess I could make a name as a mathematician, though that'd depend where the fuck I'm snapped to.

I'd like to warn the Incas to not trust anyone with white skin, kill them all on sight and NEVER let any of them get within 100km of Potosi, but I don't think I'd be anywhere near the Andes either way.

I would make an IT startup.

Well, staying in the same location? I'm in the US, so... I'd probably try to get writing invented. To my knowledge, besides some of the Central American empires, there's no evidence or even claim of there having been any kind of writing or system for making information durable. I know there's a lot of clay here, I'm pretty sure we could bake clay tablets to store down information. There's also tule reeds here that were already being extensively used, and those could probably be made into a kind of paper as well. As to whether the people would accept that, I have no fucking idea at all; what we know of the California tribes suggests they were always semi-nomadic, but that's all very well into the post-contact period and much of what we know was written down by the Spanish while being the biggest bastards they possibly could to the locals. I dunno how useful record-keeping would be to a nomadic people. It's also entirely possible the people would be like "uh, yeah, we know how to write, dummy", and it was just lost in the multiple waves of pandemics.

I think probably something that -might- be achievable is figuring out glass. I'm mostly sure that if the native Americans had glass, we would have seen some sign of it in the archeological record by now. I'm sure some smarty pants is going to come along and tell me "you can't just throw sand in a kiln and make glass, you need a special kind of sand blah blah blah and here's 99 reasons why that won't work". Yeah, you're probably right, but I don't know any better, so I'd still definitely try. I also remember reading that clear glass was a thing figured out near Venice when they started adding grass ash or some shit to the sand, so I'd definitely experiment with that, too. Glass is just dead useful -and- pretty, so I'm fairly confident I'd get some acceptance that way.

I would say metal smithing, but the only metal deposits nearby that I know of are mercury and gold. You can't make nails and tools out of mercury and gold.

Also, maybe water wheels? To my knowledge, we have no record of native Americans using water wheels for work (I.e. grinding corn or acorns into flour). I think if I managed to put a basic water wheel together, I'd be pretty popular.

Well, first I'd have to learn Old English, I think. Hell, even Middle English isn't understandable.

Hopefully I could get up to speed before they locked me up, or worse.

I'd go live in a cabin in the forest, again.

Basically start digging my grave, wondering if I'm gonna die from my asthma or my dermatitis first in that era. I'm betting on my asthma.

Uhh anyone know where to get estrogen injections in the 14th century?

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.

Assuming I appear naked in a field in England in 1375, I would first try to, in no particular order (at first, then a particular order)

• find cloth to cover my face and hands so I don't transmit or catch any diseases
• distill water so I can drink it without getting diseases
• use yams or horse urine to create HRT
• communicate with the locals and seek a local blacksmith to create a metal tube with metal balls inside it, and mix charcoal, potash, and sulfur to make a primitive gun to defend myself against the people who think I'm a witch or a demon or whatever
• talk to the women and encourage them to rise up against the system and patriarchy, teach them how to make weapons, about 4 field crop rotation if they don't already know it, otherwise about automated steam engines, weavers, hydroelectric dams, etc
• march up to the feudal lord and demand democracy, with the fear of the gun and half the population behind me they will agree
• teach about the scientific method to get them to question things, do their own research, and learn more
• there will be scientific labs, primitive computers can be developed, we can spread our advanced culture to the rest of Afro-Eurasia, also prevent slavery
• warn people about going to America and Australia unprepared, go with them in modern ships and don't spread disease, talk to the locals and trade with them and learn from them, don't kill them or replace them. Teach them the tech advancements too
• Write down lots of things, invent the printing press if not already invented, document human knowledge and encourage more documentation by others

This is all if I have any measure of success at the first things and don't die or kill myself

I could probably discover electricity, depending on where I landed. Jewelers of the time could make wire, copper was common, and magnets (lodestones) had been discovered. Realistically though I'd be a dumb giant (ie, speak no known languages of the time and statistically I'd have like a foot on the "tall" people of the era). I'd probably try to find some party trick that looked like magic to people of the era then hope that people would welcome and try to integrate me rather than burning me as a witch. Then I'd probably die in a week or two anyway to some disease lol

I would be among Native Americans in what is now the Seattle area. To them I would be a gibbering idiot who didn't even know their language, and they would probably kill me.

I'd kill your ancestors.

Prophecy some major upcoming events, subsequently market myself as a saint, grab a comfy church position, sell indulgences, profit. Works in pretty much any era.