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

Say you go back in time Terminator style, bringing nothing along but your natalis veste. Say, to (1) the Middle Ages, or (2) to ancient Rome.

In either scenario, for some reason you have obtained the full favor and support of the reigning monarch, and he or she will indulge whatever innovative effort you care to strive for, but for only one year. Any material or resource that can reasonably be found within that era and that time frame will be provided to you. And, say, after your year of effort, you’re granted one more year of observation for your efforts to see if they bear fruit.

Your patron is a benevolent despot, but a despot nonetheless. Drawing upon your personal knowledge, and given the resources available, what invention, idea, innovation, or social benefit can you implement that will bring some tangible benefit that your patron will appreciate?

Oh, and by the way, if after two years you have failed to bring any such benefit, you’ll be either (1) broken on the wheel, or (2) crucified.

So what do you have to offer, Mr. Future Man? (Ms. Future Lady?)


Personally, I’ll start everybody washing their hands, but I don’t know that will bring any demonstrable benefit that can’t be attributed to chance and/or the gods.

Water filtration, sewer and irrigation. Basically water management.

Canned goods.


Should have added, can you give a rough sketch of how you’ll go about obtaining the necessary materials and how you’ll use them? How will you frame the request? “Good King Friday, I will need a thousand barrels of lard and ten thousand serving wenches to boil them and . . . [whatever else goes into the process] . . . and then ten thousand knights to deliver a bar of “soap” to every household in the kingdom.”

How will you implement this? Remember you only have a year, and if the King is overthrown by an angry populace, your head will be on a pike right next to his. Game over, man, game over!

Ancient Rome: Musical notation. All it would take would be pen & ink that they’ve already got, as far as materials are concerned.

Getting people to agree on an A440 might be a little tricky, so I’d probably skip that; however, given a year, I could do a survey of the various instruments in use and come up with a best guess as to how most of them are tuned.

Obviously the value of having the local musicians play “Hail to the Caesar” whenever he arrives in town is of inestimable value.

Actually, in medieval times wasn’t a king’s right to rule derived from god? … yeah, I’d last five minutes.

Something just occurred to me: Semaphore flags and/or signalling with mirrors. I’ve never had experience with either one, but I’ve always been puzzled why they didn’t have flags or sequences of mirror flashes that corresponded to letters of the alphabet; AFAIK the telegraph was invented first, and then telegraph-style signalling was adopted to non-electric methods (or am I wrong?). Given a year I think I could invent my own system, gain transport to a frontier legion and explain to the local commanders how to use it.

Not a problem. All major waterworks require little more than manpower to accomplish great things. Gravity and river flow can do the rest. Making cement is a simple procedure, and well designed sewers in a city center alone will make a tremendous difference in the the health and readiness of the populace. For larger projects, we can forgo cement and stone as a a bonding agent and simply cut canals that follow the topology to assist in watering crops and livestock.

The Canon AE-1. So advanced, it’s simple.
I guess a Fotomat kiosk would be my next trip.

Serious post: I wonder how hard it would be to teach modern math to a less advanced civilization? All you would need to take back in time would be your knowledge. Same with basic sanitation ideas.

ETA: (I was assuming further back in time than Rome, obviously. Sorry)

but . . . didn’t the Romans already have that? (Water management, I mean)

Yeah, see my edit. :smack:

Carry on

Oh… you meant Acid’s post.

I’m a firm believer that societies will not readily adapt technology that they are unready for in terms of political organization, etc.

Water management, for example, requires a fairly advanced political organization to work. This is a part of why the Roman waterworks often fell apart during the Middle Ages. It’s also why plenty of modern countries, who are well aware of the principles of sanitation, continue not to have usable water systems.

All right… all right… but apart from better sanitation and medicine and education and irrigation and public health and roads and a freshwater system and baths and public order… what have the Romans done for us?

Actually you’ve got a really interesting idea, I think: the introduction of a numbering system that can be used to calculate, not just describe, was apparently a pretty revolutionary thing and one of the catalysts for Renaissance thinking, or so I’ve read. Could that, and the concept of zero of course, been introduced earlier than when they were? And how could you demonstrate practical usefulness for such a thing within a relatively short time frame?

yep, but not in a comprehensive fashion, and certainly not utilizing a host of modern innovations that ought to make the whole thing more efficient and available to the entire populace. I intend to reshape entire city projects, villages and towns to take advantage of passive systems.

The optical telegraph predates the electric telegraph. Guy on a hill… watching for motion of signal flags or lanterns on another hill. Places were often named “Signal Hill” because they were the sites of optical telegraph stations.

Optical telegraph. Replaced by the electric telegraph in the mid-nineteenth century.

No one has suggested a printing press yet?