Say a modern chemist or engineer is landed in a different world with early 1400s Medieval level technology and social problems. She (yes a woman), is immediately considered a witch for many obvious reasons. However this world does not think magic evil, unlike the middle ages on earth, and instead revers it as part of its religion (even though real magic DOES NOT exist, just science). A Lord or King immediately takes her and basically offers her protection in return for her 'magic' and basically marrying him and having his kids. She agrees because she doesn't want to die from the various diseases/poverty/famine that befall the peasants and she's clueless to how this world works. (Also language is not a problem as she was taken in by a kindly priestess organization that taught her in exchange for the things she had with her when she landed in the world, such as her 'fine' clothing and jewelry ect...)

So, would these ideas be realistically implementable with medieval technology and resources, and would a modern chemist/engineer have the knowledge needed?

  • Umbrella (invented by China already but this is a fantasy Europe that has no contact with any fantasy Asia)

  • Better mirrors through use of the silvered-glass method (I doubt this one because of its chemical dependence, but maybe?)

  • Agricultural revolution :four field planting method (which was not pioneered I don't think until 1500s and not popularized until 1600s) using turnips and clovers so no field is left fallow, thereby greatly increasing food production and allowing for livestock to survive winter months where they might not have had enough food to support them - their food being the turnips. And perhaps introduction and creation of the chinese three-shared plow, the lou-li (plow-and-sow) implement, and the harrow (which werent introduced to europe until the 1600s I think?)

  • Discovery of peat and introduction as use in fertilizers?

  • Early introduction of the Ice Trade through use of ice houses and showing nobility how to create 'ice creame.'

  • Method for canning and storing food by putting it in glass jars, corking and sealing it with wax, and then boiling it. Also maybe pasteurized milk. (Neither of which were discovered until the 1800s and lasts longer than medieval methods with honey or lard)

  • Spinning Jenny/Water frame/flying shuttle. (Would these even be viable or are they just for cotton and not wool?)

  • Introduction of modern metric system


closed as too broad by sphennings, John, Andon, L.Dutch - Reinstate Monica, Sec SE - clear Monica's name Jan 7 '18 at 9:48

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    $\begingroup$ Some points: 1. The umbrella was known to the ancient Romans and Greeks and Egyptians before them. (Mind you, the Chinese version was collapsible, so that was handy.) 2. A modern chemist or engineer will probably not know how to make a silvered mirror (or an umbrella). 3. Crop rotation is a good idea. 4. Peat was known from early times. 5. Mesopotamians, Greeks, Romans all knew about ice houses and icy treats. 6. Storing food in jars is old hat, but if she can introduce the Mason Jar, that would be a good thing! 7. A spinning jenny would be useful. 8. Metric system is much overrated. $\endgroup$ – elemtilas Jan 6 '18 at 0:31
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    $\begingroup$ Please limit yourself to one question per post. Questions should be specific. List questions aren't. $\endgroup$ – sphennings Jan 7 '18 at 3:33
  • Umbrellas are mechanically trivial, so yes.

  • Silvering, yes.

  • The agricultural revolution was (a) food types, (b) irrigation, (c) crop rotation and a whole lot of other things, but other than most plows being made of wood at the proposed time, yes.

  • Pointing at peat and saying "that's peat!" is easy. However, peat really isn't a fertilizer. It's nutritionally worth almost nothing. It's great for breaking up the soil and water retention, though. So, refocus the issue, and yes.

  • Ice is easy to make with basic pressure cycling, so yes.

  • OK, heated canning requires rubber, not wax, and rubber's an 1800s thing, so I'm going with "no" on this one. Pasteurization is likely also a "no." It's not mechanically hard, but requires constant heat at specific temperatures. That means well controlled stoves and reasonably accurate thermometers, which didn't exist at the time. Maybe she could invent them, but I'm kinda going with "no" on this one, too.

  • Oh, yeah. Anything that's basically mechanical could be brought into the medieval world (so long as it doesn't require really precise gearing).

  • If what you mean is decimal measurements, that would be trivial. If what you mean by "modern metric system" is (e.g.) a meter is the length of the path travelled by light in a vacuum in 1/299,792,458 second, heck no. The tech didn't exist to create the materials or make the measurements.


This started out as a comment but got too large.

I'm just going to touch on points that the other answers have not touched on in the way I would have stated them.

People with engineering and chemistry backgrounds tend to have a general curiosity about the world in general, so their professional training doesn't decribe their knowledge or skill boundaries well.

Even in the 20th century, it was hard for a woman to make a mark in the world. My own mother (a chemist) developed one of the first latex emulsion paint formulations for a national brand, to the pre-production stage, then the project was turned over to a male chemist because women weren't allowed in the plant.

In the medieval period, anything to do with the kitchen and food would have been a good place for a woman to make a mark without challenging the social boundaries too much and being burned as a witch.

Some form of canning is feasible. However, mason jars are not feasible because mass manufacture of precision glass jars was not feasible. However, the same effect (sealed sterile storage) can be had with pottery jars sealed with wax and topped with waxed leather.

By leveraging her new reputation for food storage with heat, a pasteurization process could be worked out. Blacksmiths had worked out methods for maintaining steady temperatures. Those methods could be adapted for the much lower temperature of pasteurization.

If she has been playing the part of a strongly religious (Proverbss 35) woman, then her rising reputation for the handling of foodstuffs would allow her to introduce crop rotation. Crop rotation was practiced in ancient mesopotamia (6000 years ago), and could be explained to medieval folks as a religious observance for the pious farmer, expanding upon the direction of Exodus 25:10.

Silvering was known as early as the 10th century, although it was not used for mirrors yet. I'm not a chemist, but my mother was, and I spent much of my childhood around chemicals. One of her college exercises was to silver glass to build some other instrument.

I believe a modern chemist should know enough to figure out the technique of silvering glass for mirrors (although medieval glass wasn't that flat, so I suspect the bronze mirrors would have been better)

In my edit I changed "would" to "should" because of this story. About 20 years after my mother retired, she got a panicked phone call from a lab she used to work at. They were disposing of old chemicals an had found a squirt bottle labeled "hydrogen hydroxide". After she stopped rolling on the floor she walked them through the exercise of translating the name into a formula. "H-OH" "Yup. Now reduce to simplest terms" "H2 .... oh < click >". They had stumbled on to one my distillled water bottles from when I washed dishes at the lab (35 years previously).


Short answer: your average chemist or engineer, whose interests & education is limited to chemistry & engineering, will not have the requisite knowledge or skill sets required to implement any of these things.

Long answer: a chemist or engineer with some basic knowledge of history and an interesting hobby or two might be able to pull off the top two or three and really change lives for the better.

I'd rank them in this order, from most to least important:

  1. Storing food in Mason Jars is number one. Even with relatively poor agricultural practices, a community Grange Hall where surplus preserves and veggies can be stored against hard times will be a boon to everyone. Convincing her kingly husband not to ransack the local Halls in an attempt to grab tax revenues will be the harder part methinks. Technology is relatively easy: glass casting, or at the very least, the ability to work thin tin into secure lids. Rubber will be the hard part, but thin leather and wax seals might work well.

  2. Crop rotation & improved agriculture in general I'd say ought to tie for first place. If she can get her new homeland into a better food situation, this will a) make everyone better fed and healthier and b) free up some people for non-agricultural jobs.

  3. Third place goes to ice houses, and the ice trade. Though long known about, a scientician ought to be able to encourage their multiplication in the realm not only for cold drinks and ice cream, but for perishable food preservation and air conditioning.

  4. Though well known since ancient times, the umbrella --- be it a parasol or parapluie --- is a good and hygienic implement to keep about, especially if her new homeland suffers from bouts of sun and rain.

  5. Peat is already known as a source of fuel and other uses. Your average chemist or engineer will probably not anything about it than that. Much will depend on the prevalence of local peat bogs close to her new homeland.

  6. The spinning jenny will be good to introduce when once the food situation is under control and some more agricultural effort can go into wool and cotton cloth production.

  7. The silvered glass mirror. I doubt any ordinary engineer or chemist will know how to make one. Polished bronze mirrors work well enough anyway.

  8. The (base-10) metric system is over-rated and its supposed superiority really is a modern myth. That said, a universal standard would be a terribly good idea, though relatively low on the totem pole. Simply universalising the old Roman (or equivalent in this world) system would be an improvement.

  • $\begingroup$ "The (base-10) metric system is over-rated" - do you happen to make much scientific/engineering calculations in Imperial System? What if this medieval world still using Roman-style numerals? $\endgroup$ – Alexander Jan 6 '18 at 1:23
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    $\begingroup$ Until the SI was adopted ALL mathematics and all calculations were done using whatever base and whatever measurement system was current at the time. It's just a matter of labels, really. For purposes of this question, a base-10 SI type set up is very low priority. $\endgroup$ – elemtilas Jan 6 '18 at 1:39
  • $\begingroup$ My point is that traditional systems, like Imperial, just had no consistent (i.e. 10- 12- or 16-) base at all, and, moreover, measurements standards were inconsistent. This had been a problem for sharing scientific results early in the history. $\endgroup$ – Alexander Jan 7 '18 at 3:58

First off, why would she be considered a witch? Its not like she is arriving with two beakers full of chemicals ready to mix together like the Mad Professor to make some smoke or explosions or something. She's probably just be lost and clueless at first; more like an oddly dressed runaway peasant than a witch.

On to the actual question, bullet by bullet;

  • Umbrellas, as others have stated, are pretty trivial mechanically. No problem.

  • By the 16th century, glass was being silvered with tin or mercury, in Europe. So this is only a century or so earlier. The materials should be readily available, and any competant metalworker, glassworker, or alchemist should be able to copy her idea without too much trouble.

  • The agricultural revolution is a no. All the technology was available in Europe, as early as Roman times, really. The Romans had metal toothed harrows, heavy iron plows, and all the necessary domesticated plants and animals. The problem is organization. In the Middle ages, 90%+ of the population lived on farms, and grew what they ate. There wasn't a big enough market for farm goods in what cities that there were to justify the land tenure changes that came with an agricultural revolution.

  • The Medievals knew of peat and knew they could use it as a fertilizer. The problem here is one of transportation. Peat bogs are not generally close to the best agricultural land. Moving things overland was done by oxen, peat is heavy, and you need a lot of it to effectively fertilize. There isn't enough free capital to invest in fertilizing fields like this.

  • The Romans kept ice houses, when practicable. In the Mediterranean parts of Europe, it was not practicable due to temperature. I'm sure you could invent ice cream though. People would love that; I daresay they might even scream for it.

  • These would be definitely the most useful inventions. Medeival people had the technology, but without germ theory there was no motivation. On the other hand, it might be hard to convince people that this canned food did them any good. Sure they wouldn't die from food poisoning, but you could still die from cholera and its also hard to tell the difference. Dead is dead, there weren't a lot of competent doctors around determining cause of death.

  • A spinning jenny is probably dependent on advanced skills in making and operating machine tools. Even a competent modern engineer wouldn't have the skills necessary to make the parts needed for equipment of this caliber, and nobody (or, nobody that you are likely to find) in 1400 would either. Honestly, a metal shop worker would have a better chance of making spinning jenny than an engineer or chemist.

  • I don't see what good that would do, or why anyone would adopt your funny system of numbers. Keep in mind, in 1400 Arabic numbers didn't have much penetration, only being introduced to Europe by Fibonacci ~1250. Most people still write with Roman numerals, which will make it hard to see the value of the metric system, since Roman numerals aren't a base 10 system.


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