I’d be pretty useless if the standard is to hew logs and stone to make an iPad. I could share concepts like the relationship between cleanliness and health, sanitation, pasteurization (soon to known as Jophielization) and stuff like crop rotation or the theory of gravity but any actual “build it” tech would be me saying “So… uhhh… you could totally push a piston with steam.”
Of course, if I knew I was going back in time I might take a couple days to read a book or two.
The most you can hope to do in your remaining productive lifetime of what, 40 years at best, is to advance their tech from wherever it you find it somewhat faster than it was advancing already.
For the early industrial age, tech was already moving at a good clip. Your incremental improvements may not be huge since you’re one person amongst thousands pushing that rock forward.
If you were put back in a time when things were going very slowly, you could have a pretty powerful amplifying effect. But only if, as the OP stipulated, the King supports you against the mob that wants to burn you as a heretic.
So your specialist knowledge of the tech of the 21st century is useless, unless you’re transported all the way back to the 1960s. Back around 1900 knowledge of applied electricity and early electronics might be useful. Back at 1800 primitive chemistry and fundamental electromagnetism would be useful. At 1700 metallurgy basics would be huge.
At 1000 (BC or AD) your useful knowledge will be more business practices, basic math, bookkeeping as **CalMeacham **mentioned, and some applied agriculture.
Some useful knowledge will be simply awareness of what’s possible. IOW, if you find a society of goat herders, but they have no idea of selective breeding, you could introduce the idea even if you have no specific knowledge of how to tell a good from a bad goat.
But that art of the possible has to be grounded in what’s already *almost *possible in that society when you arrive. Even with the best of help, the ancient Romans are never going to develop integrated circuits in your remaining lifetime, so don’t even start down that path.
You beat me to it.
Just to elaborate on the first question, there’s a world of difference between (a) going back to America in 1850, where I could probably manage pretty well and might even speed up some advances, particularly if I took along the time travel cheat sheet, (b) going back to England in 1450, where I’d probably say something that would get me burned at the stake, or (c) going back to some more distant past than that, where I’d be totally out of my depth.
I once wrote a brief “biography” of myself as a Time Traveller from the future who had memorized the winners of all the Roman Chariot races, hoping to get them to pay off, but found myself in the wrong era.
Yeah, I;ve read several treatises onmaking gunpowder from scratch. I haven’t done it, though, and I doubt if I could tell saltpeter from random outhouse waste. My best bet would be to find some natural nitre on rocks, I suspect, but that’s still iffy.
It occurs to me, thinking more about gambling, that Arabic numerals and decimal notation are powerful technologies in themselves. You could do a lot and make a lot of money with that knowledge alone, if you go back to a time and place where they didn’t exist.
What could I do? Well I could invent calculus (although truth to tell, Archimedes really understood integration, but I could systematize it). I could invent logarithms. More to the point, I used to know who Napier created a natural log table and could probably reproduce it. I am less clear how he and Briggs succeeded in converting it to a table of common logs. I have a vague idea how electric generators and motors work, at least enough to get started, assuming I had some magnets and copper wire. I could also probably build a Leyden jar. I could grind some lenses and make primitive telescopes and microscopes. I probably could not convince people of the necessity of antisepsis or clean water. Too bad.
On the other hand, would I want to? I am really a slave to modern technology.
You could use the same technique to precipitate the potassium nitrate to remove impurities. It forms needle like crystals that are easy to distinguish from other dissolved substances. But if you found it in a cave somewhere you’d be in a better position to get some volume of lower grade stuff suitable for demonstrating the magic instead of spending a long time ending up with a couple of tablespoons of purer stuff.
I was one of those pyromaniac kids and got the black powder working pretty well just by following the instructions. The other kids usually got hold of something that wasn’t pure potassium nitrate, didn’t grind it well or mix it wet, used crushed charcoal briquettes, and didn’t bother weighing. The result was as you described, a fizzle at best. I got lucky and found a bottle of drugstore potassium nitrate. I can tell you that over time it solidifies into a rock which is not easy to crush into powder.
I think I would do OK in some time periods.
I’m not an end-product guy in terms of building much, but I do know/remember enough calculus and chemistry to put the Roman Empire 1500 years ahead of its time.
The one thing I know extremely well is accounting. I suppose I could also give them a 1500 year boost in that respect too, since double-entry accounting as we know it came out Venetian merchant shipping. It’s hard to say exactly how that might affect history, but proper accounting techniques make it easier to audit/control funds. That’s important to governments. Proper techniques also make it easier to set up corporations that let individual pool resources for profit. That might weaken the power of kings, emperors and popes, which might not be a bad thing either.
Handwashing and germ theory. That’s about all I got. And it would completely revolutionize health care and set us on an accelerated timeline towards modern medicine…if only I weren’t a woman.
Or maybe not, and maybe your lack of the male quality wouldn’t matter much one way or the other. Just ask Ignaz Semmelweis, promoter of hand-washing in obstetrical wards, 1840’s-1860’s, reducer of mortality in childbirth, who got rewarded for his pioneering work with . . .
[spoiler]. . . commitment to insane asylum for his unconventional medical ideas, where he was beaten by guards and died after 14 days.
[/spoiler]So, what you should really do is go back to about that time (or earlier) and introduce germ theory first, along with microscopes to prove it (you need to do this prior to 1650’s in order to beat out Anton van Leeuwenhoek).
Sure, but it might be more fun if she were a naughty time traveler. And if she was really hawt. 
I hate it when that happens.
I wouldn’t want to end up any farther back than 1920. Electricity everywhere, decent transportation, decent heating, lots of jobs I could do that wouldn’t involve breaking my back, vacuum tubes and radio about to be everywhere, modern English language — in short, the beginnings of civilization.
I’d have a ball while lazily accumulating wealth on the stock market, selling just before the crash and have an even better ball forever after, while not fucking up the timeline in a big way with too-early inventions. Because if I did, I might not end up in 1920.
I’d change my name to Diktor, though, just for the hell of it.
Now there’s a man who thought things through.
I’m an English professor, so … yeah, not so much on the technological front. On the other hand, I wouldn’t have any problem communicating with people if I got sent back to, say, 14th-century England, and I know enough Latin that I could probably manage, with difficulty, to get by anywhere else in Europe from the Roman empire on forward. I could introduce the population to movable type, I guess? That’s probably about it.
Could you become Shakespeare?
I’d tell everyone to wash their hands. If I travel back more than 200 years, that one trick will probably save millions.
::Points back to post 31::
The problem is getting them to believe you. Without proof, you might as well be telling them to carry four-leaf clovers.
Yep. Semmelweis is why I hope that some sort of afterlife or reincarnation actually exists, 'cause dude he was soooooooo vindicated post-mortem.
I don’t think I need to beat out van Leeuwenhoek. Pasteur didn’t. The key is to show transmission from material things to knock out spontaneous generation theory, and I think I remember enough about his growth of anthrax in medium to do that project, only sooner.
But that’s where the gender thing comes up again. I wouldn’t be allowed access to the materials, much less a receptive audience. I’d make good kindling for a witch burning, though.
Wash your hands…or I cut them off!
