What are technologies that a time traveler could easily introduce to ancient times?

[gomipile]

Indeed. In the classic version of this trope A Connecticut Yankee in King Athur's Court (which clearly isn't sufficiently widely read based on how often questions along these lines get asked - it can be read free and more people should do so), the titular Yankee acquires his position at Arthur's Court by pretending he controls the sun via a convenient eclipse. Without some similar trick all the knowledge in your time traveler's head isn't very helpful.

I don't see your point. I read A Connecticut Yankee in King Arthur's Court decades ago, yet I still find these sorts of discussions interesting.

Also, there's plenty that has been discovered since 1889 that can be relevant to such discussions. And aside from initial discovery, in the past century we've vastly improved our understanding of many things which were discovered long ago. That improved understanding can help understand what to apply to a low-tech situation, or understand how to apply a technique more effectively or avoid various pitfalls.

And in any case, I often like to see different takes on the same sort of idea. Not all stories with the same initial premise play out the same way.

I had a friend who once claimed to be unable to enjoy most fiction since he'd read Campbell's Hero With a Thousand Faces, since all stories seemed the same to him. I thought, and still think, his reasoning on that was pretentious and shallow. He's since come around and started seeing the joy in variations on theme and character.

[Bohandas]

Crossbow. Just slap a lock and a stock onto a bow and your conscripts can fight at range. I'm not sure how the triggering mechanisms historically worked but in a pinch a simple piece of metal in a hole would work, and if you wanted to get fancy you could add a second piece to lever it up and down with

[factotum]

If we disregarded the no books rule, you could kickstart the computer age 2000 years early by getting Charles Babbage's designs with Lady Lovelace's annotations into the hands of the people who built the Antikythera Mechanism

One of the reasons Babbage never built his Analytical Engine in his lifetime was because he couldn't get the huge numbers of precisely-made gears made using the manufacturing techniques of his time. How do you think the Ancient Greeks would do better in that regard? Doesn't do them any good to have a design to work from if they're simply incapable of building it.

[Bohandas]

scale it up

[Eldan]

Which comes with hugely increased energy requirements. And likely problems with materials failing. Things don't scale linearly.

[veti]

One of the reasons Babbage never built his Analytical Engine in his lifetime was because he couldn't get the huge numbers of precisely-made gears made using the manufacturing techniques of his time. How do you think the Ancient Greeks would do better in that regard? Doesn't do them any good to have a design to work from if they're simply incapable of building it.

This, exactly.

The "difference engine" combined the physical size of a mechanical loom with the cost of a naval frigate. It took Babbage over 20 years to fail to complete it, and by the time the government pulled his funding, he himself had already lost interest in favour of the even-more-ambitious "analytical engine".

The analytical engine itself - remains unbuilt to this day.

Nobody, no matter how good their books, is going to build one of those things in ancient Egypt or wherever we're talking about. You'd be better off trying to generate electricity and invent semiconductors.

Things I would try to introduce that I don't think have been mentioned yet:
1. Paper (from wood pulp).
2. Blown glass.
3. Antiseptic surgery (using whatever kind of alcohol the locals have - even simple wine is a lot better than water for cleaning wounds).
4. The pendulum clock. I couldn't make one myself, but I'd look for a clever tinkerer to partner with on that one.
5. Bicycles.
6. Pianos. Again I'd seek help from a skilled carpenter, but if you've got a harp, you should in principle be able to make a piano - and harps have been around for millennia.

And definitely maths. Depending how "average" I am, exactly, I might be able to make huge strides in algebra, calculus and statistics. The basic ideas of all these seem laughably simple to us, and don't have any particularly difficult dependencies - but it took our ancestors a ridiculously long time to work them out.

[Eldan]

Aren't bicycles fairly complicated? I think I've seen a documentary on that, they need some fairly involved mechanisms to work right, even simple ones. Without a chain, gears and some other complicated stuff, you just end up with a velocipede, which won't revolutionize anything.

[veti]

Aren't bicycles fairly complicated? I think I've seen a documentary on that, they need some fairly involved mechanisms to work right, even simple ones. Without a chain, gears and some other complicated stuff, you just end up with a velocipede, which won't revolutionize anything.

The penny-farthing didn't have chain or gears. But chain and gears aren't particularly difficult to describe to a skilled smith, although whether he'd be able to reproduce them is another matter.

I think the big problem with that one would be the lack of rubber for tyres. Maybe you could make some kind of substitute out of leather, I don't know, but I suspect it would be a very bumpy ride.

[factotum]

I think the big problem with that one would be the lack of rubber for tyres. Maybe you could make some kind of substitute out of leather, I don't know, but I suspect it would be a very bumpy ride.

Maybe just introduce vulcanised rubber and hope they're smart enough to realise what they can do with the stuff?

[Accelerator]

Here's a crazy idea. Presuming that this isn't breaking any rules, how about electricity? Yes yes, it's slightly insane, but hear me out. Power is literally one of the things that civilization breaks its back over, and electricity is one of those gamechangers. The concepts of electrical heating, lighting, and such are all life-changing. It's basically pretty easy to experimentally figure out. A rotating magnetic field with a conductor, irrelevant whether it's the magnet that's rotating or the conductor. Which lets you create electricity. A voltaic pile might work, if you know your periodic table well enough. But you only need stuff like lead sulfate, mild sulfuric acid, and lead oxides suspended in a gel to get a bargain basement battery.

This lets you do pretty cool stuff. Like electrical motors that you can control by virtue of breaking and reconnecting the circuit. And as long as you have ceramics to cover it or any other kind of lacquer, you won't accidentally kill yourself. Then you've got something interesting as long as you can attach something like hydro power to it. Like heating using bimetallic strips. Or powering electrical motors or pumps so you can get a working system.* Or maybe just get the battery to do niftys ****, like cars.

*Protip: If you can splurge invest in making utilities like water piping. It'll be awesome. Pay per neighbourhood to keep costs low.

[Peelee]

Fun fact about bicycles, they are surprisingly hard to draw. And I don't mean realistically, I mean try to jot down a quick bicycle drain of just frame, wheels, and handles, and it has a good chance of being wrong.

Bicycles, like most things mentioned in this thread, probably wouldn't fit the bill.

[Accelerator]

Fun fact about bicycles, they are surprisingly hard to draw. And I don't mean realistically, I mean try to jot down a quick bicycle drain of just frame, wheels, and handles, and it has a good chance of being wrong.

Bicycles, like most things mentioned in this thread, probably wouldn't fit the bill.

And yet, the concept is simple enough. Pedal. Crank. And gear on the back wheel. Using springs to ensure that the shocks aren't too horrible. And then using some soft material for the wheel, whether it's leather or you know, anything else. The gears don't need to be too complex.

[Tvtyrant]

And yet, the concept is simple enough. Pedal. Crank. And gear on the back wheel. Using springs to ensure that the shocks aren't too horrible. And then using some soft material for the wheel, whether it's leather or you know, anything else. The gears don't need to be too complex.

I don't know if this is true. Wood or bronze bikes would weigh a ton, to say nothing of lead. Light materials often make simple devices worth using, like wheelbarrows or rickshaws.

I think the inventions that are based on knowledge they couldn't develop would probably be most effective. Hand washing with soap, water purification methods, etc.

[Radar]

I very much agree with the idea of introducing silage as any method of increasing food use efficiency is vital as only very recently (and sadly not really everywhere in the world) constant risk of starvation stopped being a thing. In general, the more food you can produce and prevent from being spoiled, the more people can do something other than farming. This is why I would try to introduce improved farming tools - scythe was already mentioned here, but even the simples threshing machine would save up loads of work hours and there are many other improvements one could make in plow design and so on.

Already mentioned float glass is also a good idea as the technology is relatively simple and the monetary gain from it would be huge, which would enable the time traveler to bring in other technologies requiring more time or resources. Even proliferating basic (by our standards) mathematics or chemistry would require you to first be in a position, where people would listen. Being rich helps immensely.

[factotum]

And yet, the concept is simple enough. Pedal. Crank. And gear on the back wheel. Using springs to ensure that the shocks aren't too horrible. And then using some soft material for the wheel, whether it's leather or you know, anything else. The gears don't need to be too complex.

The critical bit you're forgetting here is the chain, the bit that connects the pedal/crank to the back wheel. We were able to build bicycles long before we could make chains reliable enough to use for drive, which is why the penny farthing exists in the first place. It's another of those things that looks simple on the surface, but if you were to look how the thing is put together would be pretty darned complex.

[Tvtyrant]

The critical bit you're forgetting here is the chain, the bit that connects the pedal/crank to the back wheel. We were able to build bicycles long before we could make chains reliable enough to use for drive, which is why the penny farthing exists in the first place. It's another of those things that looks simple on the surface, but if you were to look how the thing is put together would be pretty darned complex.

To be fair, Shaft Driven bikes are fairly old (1890) and while not as good as chained bikes are better than penny farthings.

[warty goblin]

I kinda feel like before reasonably smooth hard surfaced roads being common, pneumatic tires, and shock absorbers, a bicycle is basically a complicated way to bruise your bottom.

I'm also not sure whether the light, all metal spoked wheel would be in the technological or metallurgical reach of a society much before bicycles were actually invented. Absent that they start to look a lot less appealing, since a heavy wooden wheel would just be leg murder. And they'd be direct drive rather than geared, so you'd be working at a substantial mechanical disadvantage.

[Tvtyrant]

This seems like a decent design you could replicate anywhen.

[sktarq]

Problem is rubber.

Rubber was a wonder material of parts of the 1800's. And had huge fortunes based around it.
People stopped wrapping electrical wires in basically waxpaper (good) but it set off huge numbers of fortune seekers to enslave people in amazonia (rubber vines-especially bad in Peru) and africa (rubber trees-especially bad in Congo where it was one of if not the major driver of Leopold's attrocities) until major plantations could be set up (in SE Asia mostly)

So without a good latex source you can kiss such advancement good bye. And if you are in an area that had such a supply you'd be stuck by a lack of good roads/industrial use of the wheel/etc to take advantage of such a tyre advancement.

So rubber would need some serious trade lines already in place.

Very much depends on where/when you land but waterworks, locks, could be a productive advancement zone. Would second paper making, having a decent knowledge of world maps and resource location would be a huge boon if you landed at the begining of the european era of exploration, good steel has been mentioned (and ceramics could be used for both the area to melt the iron and the air injection lance), also depends on how personal knowledge but mechanical fiber spinners is something I learned about well enough to recreate it and that would open up lots of time in a civ.

But I'd say certain ideas such as polymerization a century earlier may hit quite well.

[warty goblin]

And now for the distaff equivalent answers to the thread.

First up, the spinning wheel. A spinning wheel produces (and plies) thread and yarn much faster than a drop spindle. Brett Deveroux suggests as high as a 10x efficiency gain over drop spindles for a good treadle wheel, and having used drops spindles a few times I can absolutely believe it. Wheels are mostly to entirely wooden, so don't require expensive raw materials, and the most complex part is the wheel itself. You could easily introduce spinning wheels to anywhere with the know how to make chariots, so potentially as far back as 2000BCE, and certainly by the complex war chariots of, say, New Kingdom Egypt. This would be a vast increase in the productivity of the vast majority of women and girls in one of the most labor intensive and time consuming tasks in premodern society, although I will concede that anything like a working knowledge of spinning wheels is probably not common knowledge.

Upright heddle looms are a fairly recent discovery all things considered, and again are exercises in moderately precise carpentry to create. They will also vastly outperform warp weighted vertical looms. The impact will be less than that of the spinning wheel, since thread production is by far the most laborious part of fiber production, but this would still be a considerable increase in efficiency in cloth production.

In a similar vein, the origin of knitting is, like most fiber arts, extremely uncertain, but there's no evidence for it prior to 1100CE. Knitting can produce much more complex shaped garments than the older nalebinding, to say nothing of colored patterns and textures. Again, the requisite materials will be readily available in any inhabited area, and plenty of modern people know how to knit a scarf or pair of mittens. Having worn both, knit mittens are substantially more comfortable than their nalebinding equivalents. Maybe not as big an advance in some ways, but better fitting, more expressive clothing is certainly worth a fair bit to people.

[Accelerator]

I am not a mechanical engineer, but I think a case can be made for being able to make a mechanical loom, one that moves up and down. As long as you have enough thread, and get a device that and throw a 'bob' (I can't remember the name) from one end to another whilst moving the two layers of strings up and down, you can get mechanised weaving. It'll be a hell to measure and automate, but with enough trial and error you can attach it to a horse or a mechanised wheel, and get something useful.

[warty goblin]

I am not a mechanical engineer, but I think a case can be made for being able to make a mechanical loom, one that moves up and down. As long as you have enough thread, and get a device that and throw a 'bob' (I can't remember the name) from one end to another whilst moving the two layers of strings up and down, you can get mechanised weaving. It'll be a hell to measure and automate, but with enough trial and error you can attach it to a horse or a mechanised wheel, and get something useful.

The word you're looking for is shuttle.

I also am not a mechanical engineer, but I'm mildly familiar with looms. The tricky parts to me seem to be developing a method of throwing the shuttle through the shed (the V shaped space created by the heddles lifting and lowering warp threads) reliably, then catching it and returning it after the beater has pushed the new weft thread into place. You also need to be able to continually advance the warp as you fill it. All of this also needs to be done with enough precision to actually make useful fabric, and getting useful fabric off a loom requires quite a bit more than just tossing the shuttle back and forth.

All of these are obviously quite doable, but they're going to require some degree of replacable precision machined components - if nothing else there's gonna be a ton of synchronization gears and the like. Even after the appearance of upright heddle looms there's no guarantee of that sort of industrial base being available.

Spinning is probably a better target for automation, since the spindle is the only thing that absolutely has to move, and it just needs to spin at a reasonably uniform rate. And spinning is by far the most time consuming part of fiber work.

[Accelerator]

The word you're looking for is shuttle.

I also am not a mechanical engineer, but I'm mildly familiar with looms. The tricky parts to me seem to be developing a method of throwing the shuttle through the shed (the V shaped space created by the heddles lifting and lowering warp threads) reliably, then catching it and returning it after the beater has pushed the new weft thread into place. You also need to be able to continually advance the warp as you fill it. All of this also needs to be done with enough precision to actually make useful fabric, and getting useful fabric off a loom requires quite a bit more than just tossing the shuttle back and forth.

All of these are obviously quite doable, but they're going to require some degree of replacable precision machined components - if nothing else there's gonna be a ton of synchronization gears and the like. Even after the appearance of upright heddle looms there's no guarantee of that sort of industrial base being available.

Spinning is probably a better target for automation, since the spindle is the only thing that absolutely has to move, and it just needs to spin at a reasonably uniform rate. And spinning is by far the most time consuming part of fiber work.

Ah. True. But that just means ingenious clockwork and timing. One of the hardest things is to bring new concepts into being, after all, and even the ancient greeks weren't strangers to things like complex automation (Hero of Alexandria).

Now book printing! And copyright! And patenting!

Let it not be said that the very concept of literacy and a widescale academia is not useful. Why, if you set up the equivalent of penguin publishing, you might be able to obtain a fortune from a bored middle and upper class. And it won't hurt to basically start up the medieval/ ancient version of say, the Nature journal or Scientific American. Anything that helps out in the dissemination and extraction of knowledge from the world.

[Bohandas]

The critical bit you're forgetting here is the chain, the bit that connects the pedal/crank to the back wheel. We were able to build bicycles long before we could make chains reliable enough to use for drive, which is why the penny farthing exists in the first place. It's another of those things that looks simple on the surface, but if you were to look how the thing is put together would be pretty darned complex.

Instead of a bike you could always just make a big tricycle

[Gnoman]

Most people would not be able to introduce a technology ex nihilo with only the knowledge in their heads. Even the forbidden engineers and scientists would struggle to do so. Even with the four biggest hurdles - command of the local language, an understanding of what the locals actually know, the ability to turn modern nomenclature into something that the locals will recognize, and the support and resources needed to produce it - magically solved, there are too many precursor aspects and details that you're not going to know. Even if, for example, you are one of the people that build steam engines for a hobby and thus know them in detail, you won't have the tools to build the parts you need, or the exact grades of metal that you're used to using, or even the right grade of coal/charcoal to run the thing. Trying to just build one of your hobby engines will either result in utter failure, or a "success" that will soon blow up and kill you.

What your hypothetical time traveler would have to do is more akin to outright invention - adapting the things you know are possible into the things that already exist in the current when. That's much harder, and is something that cannot be reasonably discussed in a generic sense.

[Radar]

Most people would not be able to introduce a technology ex nihilo with only the knowledge in their heads. Even the forbidden engineers and scientists would struggle to do so. Even with the four biggest hurdles - command of the local language, an understanding of what the locals actually know, the ability to turn modern nomenclature into something that the locals will recognize, and the support and resources needed to produce it - magically solved, there are too many precursor aspects and details that you're not going to know. Even if, for example, you are one of the people that build steam engines for a hobby and thus know them in detail, you won't have the tools to build the parts you need, or the exact grades of metal that you're used to using, or even the right grade of coal/charcoal to run the thing. Trying to just build one of your hobby engines will either result in utter failure, or a "success" that will soon blow up and kill you.

What your hypothetical time traveler would have to do is more akin to outright invention - adapting the things you know are possible into the things that already exist in the current when. That's much harder, and is something that cannot be reasonably discussed in a generic sense.

This is why the most valuable ideas are those that do not require any precursors or advanced infrastructure. If there is technology for making swords and sickles, scythe can be made just as well. If you have a source of salt, silage can be utilized easily. Where salt is a problem, vinegar is most likely available, so at least you can marinate things. If you have basic leatherwork and metalwork, stirrups can be introduced. Granted, you would have to fall in a right time to be the one to introduce those ideas, but there is no general answer anyway as everything will depend on the time you travel to.

[Trafalgar]

The simple distillation of crude oil to make kerosene.

[Accelerator]

The simple distillation of crude oil to make kerosene.

Mineral oil too.

Though that begs the question is we actually get access to oil...

[Trafalgar]

Mineral oil too.

Though that begs the question is we actually get access to oil...

Some parts of the world have relatively easy access to oil. Oil production started in Pennsylvania in the mid 19th century and spread pretty quickly to places like the Black Sea region where you didn't have to dig too deep. I don't think those early wells had any great piece of technology that older civilizations didn't have except for the steam engine, but I bet that could be replaced by manual labor.

[Peelee]

The simple distillation of crude oil to make kerosene.

Yet another thing I doubt the average person knows offhand.

Like, y'all coming up with the Bessemer process and the advantages of scythes over sickles but if you stopped a random person on the street and asked them to describe those things, I highly doubt you'd be getting good answers on anywhere neelar a consistent basis.