The most useful or revolutionary invention you *personally* can bring back in time to the primitives

How to make distilled spirits from grain.

I was thinking I might cheat and have all sorts of useful information tattooed onto me before going, but I’d only end up being flayed and turned into a hide pamphlet. So I think I’d have to try and be a sort of medical consultant, though IANAD. They didn’t grasp the circulatory system after all, as far as I know. How hard can it be?

Ha, this reminds me of a Native American friend of mine from high school. He had a t-shirt showing a native on horseback with a compound bow and the question “What if?”

I’d rate this as the worst contender so far. Making fire quickly and easily was nothing to the Romans or Medieval folks. Flint and steel, tinder and some skill will produce a flame in no time. Further, a piece of tinder, having caught a spark, will not go out in wind or even light rain. Bic lighters are next to worthless under such mildly adverse conditions, and, tehcnically, just a mass-produced, low-skill version of flint and steel.

After the gas runs out (a couple of days of busy demonstrating), the Bic lighter is useless, and there is no way for the “primitives” to make it work. Crucifixion time!

Re-reading the OP, there would be no Bic lighter to begin with, just an idea that is impossible to materialize and offers nothing much even if it was.

I bet I could build a steam engine. It might take a little time as I would probably have to build a water powered lathe first but I could eventually get there.

IIRC, they knew about the steam engine in ancient Greece, but it wasn’t useful as more than a novelty.

Early compound bows, the type most likely recreated under “primitive” conditions weren’t all that effective. A well-designed non-compound bow is an equal or superior weapon in every way, save for the let-off in the compound that enables an unskilled archer to shoot a relatively heavy bow with relatively good accuracy, compared to an equally-heavy non-compound bow. This is exactly how early compound bows were promoted in the '60’s and '70’s: Now the Average Joe can go after big game.

Historical warbow cultures placed great emphasis on the training of archer warriors, ie. producing archers that could shoot heavy bows with required speed and accuracy, as well as producing highly sophisticated, powerful bows and arrows for them to shoot. I bet a Scythian, a Hun, a Mongol, a Turk or an Englishman would’ve scoffed at the compound bow made with period materials. Only recently have the capabilities of the warbows of these peoples been re-realized through extensive replication and experimental research. Per Kinetic Energy, Momentum, effective range, penetration etc., compound bows offer no advantage over historical warbows.

A modern compound bow (as in ones made today) is dependent on computerized cam design, lightweight alloys, fiberglass and carbon fiber. A tremendous amount of R & D over the past 50 years goes into such a bow. They shoot lightweight, deer-killing carbon arrows at very high speeds. Arrows piercing metal armor over distance, such as needed by the Roman or Medieval armies, are much heavier, and typically have smaller yet heavier heads. It’d be interesting to see how the modern compound bow, designed for lightweight carbon ammo, would fare with a 800-grain bodkin arrow.

My first thought was numerals, but I see that’s been taken. My second thought was hygiene, but I see that’s also been taken. My third thought was… you get the idea. So I’ll take tarmac roads to the Romans.

The scientific method.

Most of the best ideas here were already covered in the seminal work “Lest Darkness fall”.

Indeed. The ancient Greeks pioneered many technologies we think of as modern. Hero of Alexandriainvented a coin operated vending machine in the 1st century AD.

Time Travellers T-shirt. :stuck_out_tongue:

Go for a zippo instead - you can’t refill it without visiting a naptha seep or oil seep to get something that you could distill into benzine, but it will make sparks as long as you have flints. Take spare packages of flints.

For an SCA Arts and Sciences project based upon retro designing something to make life in a seige better mrAru and I designed a distillation column with a rotoflex pump based upon Heron’s spinning ball steam engine as the motivational source for the rotoflex. It was designed to lift alcohol from the collector at the base of the column back to the top to filter through the material we wanted to cold distill. We opted for tanned bulls blood vessels as the flextube and egyptian glass for the column and collector. I always wanted to try and build one, though subbing in flextube for the tanned artery tubing.

Good choice! Do you know enough to actually implement this?

My first thought was penicllin.

Guess I’d be fucked then.

I remember a story years ago about a teenage nerd who was crazy about the Middle Ages and did find a way to go back but not return to present day. He was sick of everyone laughing at him, so he took three items with him designed to make the natives fall down at his feet at his amazing powers. One I forget what it was, but it didn’t work out. One was a Polaroid camera, but when he attempted to take the king’s photo, a guard thought he was threatening the king and smashed the device, so that didn’t work out. The third was a radio, with which he claimed he could pluck music out of the air. But … you guessed it … there were no radio stations back then. Some suggested he be executed, but the king found him amusing and so made him his court jester, so he was still laughed at and for the rest of his life.

A modern understanding of disease. That would include sanitation and penicillin, which wouldn’t be very hard to implement at a basic level. The double whammy of fewer wounded soldiers succumbing to their wounds and fewer peasants/taxpayers dying from easily preventable causes should appeal nicely to a primitive despot’s greed.

Penicillin was more or less plucked out of thin air. Good luck finding the exact same mold in the wild, let alone building a laboratory that can properly evaluate the antibiotic properties of anything. It’s possible, but I’d be surprised if you could do it in a year.

Personally, I have a half-decent idea of how a spinning jenny works. I’d like to have more time to study up on it before going, but given the assistance of several master woodworkers and metalsmiths, I’ll bet we could build something workable. It was the machine that more or less kicked off the industrial revolution, as spinning thread was by far the most time consuming part of producing cloth.

I just hope the reigning despot would LISTEN when I warn them about the hazards of the industrial revolution that we had to learn the hard way. Factory safety: not optional.

Vitriol + saltpetre.

People who find this topic interesting might want to read the series of novels about Conrad Stargard, a 20th-century engineer who woke up in 13th-century Poland, and proceeded to industrialize it.

I’m gonna go Warren Zevon on this. Lawyers, guns and money.

Rule of law is a great concept. Hard to get the local despot to replace himself with it through.

1911, or Mr. Browning’s 8 persuasive points.

Money. Banking. That is fiat money on the hindu-arabic decimal system. Green gold. Thurston Howell III’s universal language.

I think money is the one that would be most helpful to older civilizations and least likely to get me killed as a trouble maker.