The First Year — and What Comes Next

The rest of this repository is organized by topic. This page is organized by time — what to actually do, in what order, starting from the moment you arrive with nothing.

The README roadmap is a dependency-informed priority map. This is a plan, but its dates are milestones rather than promises: language, legal status, season, health, and local institutions can shift every phase by months or years.

Scope and safety. This is a historical thought experiment, not medical, engineering, or food-safety advice. It assumes a settled community whose ordinary tools can be borrowed, earned, or commissioned; “knowledge only” does not make a pot, shovel, scale, or skilled assistant appear. Treat every hazardous or clinical passage as an orientation to the linked guide, not as a stand-alone procedure. See Sources and limits.

The assumption

You arrive with knowledge, the clothes you're wearing, and nothing else, into a settled agricultural society somewhere between the Bronze Age and the medieval period. You do not speak the language. Nobody is expecting you. What already exists may range from stone tools to sophisticated mills, hospitals, and trade networks, so inventory before assuming anything is missing.

The uncomfortable part: you are the fragile one

Before any technology, three things are more likely to kill you than anything else, and none of them appear in the rest of this repo.

1. Disease. Your protection against local infections is unpredictable: prior exposure and vaccination may help against some diseases, may have waned against others, and may not match local strains. Unsafe water, food, crowding, vectors, and respiratory exposure can all matter. Realistically this is a major risk and you cannot fully mitigate it.

What you can do: use the safest protected source available and, when its microbiological safety is uncertain, bring drinking water to a rolling boil as described in the water guide. Boiling does not remove chemical contamination. Wash your hands, prefer thoroughly cooked food while you learn local risks, and avoid known outbreaks and unnecessary exposure to sickrooms; deliberately acquiring infection is not a safe route to immunity. See medicine and public health.

2. Other people. A stranger with no kin, no patron, no language, and inexplicable knowledge is, in most pre-modern societies, somewhere between a curiosity and a threat. Being taken for a spy, a heretic, a witch, or simply being robbed are all realistic outcomes. Foreigners without protection had few rights in many settings.

3. You carry disease too. You may carry an infection unfamiliar to the population. You cannot make the risk zero, but you can reduce it: minimize close contact at first, isolate when ill, cover coughs, wash hands, handle waste carefully, and avoid vulnerable people when symptomatic. The Columbian Exchange shows why this duty runs in both directions.

Weeks 1–2: Don't die. Don't get killed. Listen.

Do not announce that you're from the future. Do not try to demonstrate anything. Do not correct anyone's cosmology, religion, or medicine. There is no upside and considerable downside, and the history of clever outsiders in closed societies is not encouraging.

Priorities, in order:

1. Water. Identify and protect the best source; boil microbiologically uncertain drinking water and store it without recontamination. Test or avoid a source suspected of fuel, metal, salt, pesticide, or other chemical pollution, because boiling can concentrate nonvolatile contaminants.
2. Food and shelter. Seek lawful, low-risk work suited to the season and your abilities. Demand for labor, the rights of outsiders, and the danger of coercion vary enormously.
3. Attach yourself to someone. A patron, a household, a workshop, a monastery, a merchant. In a society organized by kinship and obligation, an unattached person may have little standing. A lawful, non-coercive relationship with a trusted household or institution may be safer than remaining isolated.
4. Learn the language. This is your highest-return activity for the entire first year and everything else is gated on it. Point at things. Work alongside people. A functional working vocabulary may develop quickly with immersion; fluency is not guaranteed and depends heavily on the language and community.
5. Watch and inventory. What do they have? What breaks? What do they complain about? What's expensive? What kills people here? What's the local geology, climate, and growing season? You cannot plan an intervention until you know what's missing, and much of what you assume is missing will already be there in a form you didn't recognize.

Offer useful work before sweeping advice. Being reliable and learning local constraints is how you earn the standing to be listened to later.

Weeks 3–8: Establish yourself as competent

You need a reputation before you need a workshop.

Pick one visible, small, immediately useful thing and do it well. Candidates that need almost nothing:

• Soap. Wood ash and waste fat can be locally available, and the result is visibly useful. Adoption still depends on cost, custom, and whether your batch is actually mild enough to use.
• Food preservation. A validated lacto-fermentation can use simple equipment, but it still needs a measured salt basis, suitable food and water, temperature and sanitation control, and a verified endpoint. It can visibly turn a glut into stores when those controls are available.
• Oral rehydration. Support local caregivers in using packaged ORS when available, or the precisely measured emergency household substitute when it is not. This is care, not a demonstration; severe dehydration and danger signs need urgent skilled treatment.
• Better rope and cordage.
• Sharpening. Most pre-modern tools are duller than they should be, and a properly sharpened edge is an instant, visible improvement. See woodworking.

Simultaneously: start the slow things now, because they take a year.

• Prepare a covered lime pit and identify a reliable limestone or shell source. Only obtain or burn quicklime and begin slaking once trained help, water, and splash protection are ready; fresh quicklime is severely caustic.
• A niter bed takes 1–2 years, but it is not a first-year default. Consider it only for a justified, non-food chemical program with protected groundwater, controlled waste, analytical capability, and the later equipment needed to handle strong acids safely.
• Age clay in a covered pit.
• Plant a legume somewhere you can point at it later. See agriculture.
• Start a vinegar mother.

The asymmetry here matters: some long-lead projects can be started with modest materials, but they still consume land, labor, supervision, and risk capacity. Budget those costs now; starting a suitable project late can cost a season or year.

Months 2–4: Build the base

This overlaps the previous phase deliberately. Begin it only once you have functional communication, protection or patronage, permission to use the site, and somewhere safe to work; that may take much longer than two months.

Priority 1 — Fire and charcoal. Furnace work depends on controlled fuel, airflow, insulation, and atmosphere. At a legally and environmentally suitable outdoor site, trained local operators can compare fuel preparation and bellows designs while enforcing the guide's carbon-monoxide, fire, and burn controls.

Priority 2 — Clay and pottery. Containers before contents. Fired vessels greatly expand controlled heating, fermentation, storage, and smelting, and suitable refractory clay can line a furnace; each use still needs a compatible body, firing, and contamination check.

Priority 3 — Lime. One kiln gives you mortar, plaster, limewash, tanning liquor, soap lye, glass stabilizer, sugar clarification, soil improvement, and nixtamalization. It's the single highest-fanout thing you can build.

Priority 4 — Writing and records. Start keeping a written notebook of everything: recipes, proportions, temperatures, outcomes, local plant and mineral names, prices, who's who. Even if nobody else can read it. This is your actual memory, and you will forget details you're certain you'll remember. See mathematics and record-keeping for what to record and how controls, replication, and uncertainty make comparisons useful.

Priority 5 — Water and latrines. This can be a very high-value program, but it is hydrogeology, source protection, drainage, operation, maintenance, and behavior—not merely digging. A properly sited and constructed well with an apron and protected lifting system, plus safely managed sanitation, can do more for the community than most workshop projects. Thirty metres is a useful rough screening distance, not a guarantee: groundwater flow, flood level, permeable or fractured ground, and the highest seasonal water table control the real separation.

Also: fuel. Before you scale any furnace, work out how much woodland it will use and whether harvest stays below measured regrowth. A locally suitable coppice cycle can create a renewable yield, but it still needs tenure, species selection, browsing/fire control, records, and periodic revision.

Alongside: soap at scale, and quietly get the household you live in to wash hands, manage water safely, and site sanitation using local groundwater flow, flood level, soil/rock permeability, and seasonal water table. "Downhill" on the surface is not a hydrogeological test.

Months 4–8: The first real technology

By now you should have fire, clay, lime, and standing. Pick your direction based on what the place actually has.

If there is an established metallurgical site, characterized ore, fuel, and engineered fume control: copper may be a more tractable teaching system than iron, but sulfide ores and toxic impurities can make it a hazardous industrial project. Build on local expertise; do not create an open smelter as a demonstration. See mining and prospecting.

If a surveyed stream has reliable seasonal flow and usable head: consider mechanical power, after checking water rights, flood behavior, millstones, materials, capital, and skilled labor. A successful grain mill can return many person-hours to the community and later drive bellows, hammers, or stamps.

If there's clean sand and you have a good furnace: glass, and then start grinding lenses. Spectacles can be valuable where you can produce clear glass, repeatable curves, durable frames, and individual fittings—and where a paying literate market does not already have them. None of those conditions is automatic.

If there are suitable fibers and enough clean water: paper can make records cheaper and support scalable printing. Woodblock and other printing methods may start on locally available surfaces before movable type or fine paper.

If there's an oilseed crop, or livestock being slaughtered: oils and fats and a press. Cheap to build, and it unlocks soap at scale, lamps, leather dressing, and eventually printing ink.

If it's a farming community: work on agriculture and animal husbandry instead of crafts. Locally tested soil correction, compatible legume rotations, suitable winter fodder, and site-designed erosion control can improve farm output substantially; food surplus is what funds everything else. Do not lime or reshape slopes before soil and water assessment.

Months 8–12: Consolidate, and teach

Teach someone. This is the transition from "useful stranger" to something durable. A single apprentice who can make soap, fire a kiln, or burn lime without you means the knowledge no longer dies with you — and you are, as established, medically fragile.

Write it down properly. See writing and literacy and mathematics and record-keeping. Adapted to local materials and local language. Multiple copies, in different places.

Set up the compounding things:

• Selective breeding of crops and animals, with written records, maintained genetic diversity, and local welfare/agronomic goals. It takes land, labor, time, and careful selection across generations.
• A movable-frame beehive.
• A second and third batch of everything slow, so you're never waiting.

Reassess. You now know the place. What you thought was the bottleneck in month one probably wasn't.

Years 2–5: Where it actually goes

• Printing, if the writing system, suitable surfaces, ink, press, proofing, and demand justify it. It can greatly improve replication, but editions still contain errors and physical copies need preservation and distribution.
• Water power applied to a second and third process — bellows, hammers, fulling, sawing, ore stamps.
• Public health at settlement scale — wells, latrines, drainage. Unglamorous, and it will save more lives than every other thing you do put together.
• Smallpox control, if it is present: isolate suspected cases and contacts. Vaccination is an option only with a verified vaccine source, experienced practitioners, consent, and containment; cattle alone do not supply cowpox.
• Trade goods for actual money: spectacles, dyes, spirits, soap, paper, salt.

What not to do

Some hard-won conclusions from the rest of this repo, collected.

• Don't start with an unsupported iron, steel, or steam program. Ironmaking predates mechanical power, but all three demand mature combinations of fuel, refractories, tools, measurement, skilled labor, and—especially for steam— precision engineering. Inventory the local capability before choosing one.
• Don't try to melt pure sand in an ordinary furnace. Read glass. A controlled silica–flux–stabilizer batch and sustained heat are both required.
• Don't skip the boring prerequisites. Nobody dreams of burning lime. Lime is the gate on a quarter of this repository.
• Don't announce the future. Demonstrate carefully, seek consent, record results, and adapt to local institutions; evidence alone does not guarantee adoption.
• Don't assume you're smarter than the locals. You have different knowledge, not a better mind. Their practices are usually well-adapted to constraints you haven't noticed yet, and the fastest way to be wrong is to assume otherwise.
• Don't drink from a lead vessel, cook in a lead-glazed pot, or sweeten anything with lead. See silver. This one killed a great many people who thought they were being sophisticated.
• Don't seal low-acid food in a jar and call it preserved. See food preservation. Botulism is invisible.
• Don't inject or drink crude mold preparations. See penicillin.
• Don't scale alcohol production without public-health and fire controls. Distillation adds flammable vapor, pressure, toxic-contaminant, and social harms; cuts based on smell or taste do not certify methanol safety.
• Don't build a technology you can't maintain. A machine nobody but you can repair is a machine with a one-lifetime warranty.

If you have one week and nothing else

Strip everything away and these are high-value ideas that avoid new industrial infrastructure. They still need ordinary vessels, fuel, ingredients, land, measures, writing materials, or trained help.

1. Boil drinking water. Wash hands with soap. Protect the water source. Use 30 metres between a pit latrine and a well only as a rough minimum, keep the pit bottom at least 1.5–2 m above the highest groundwater, and allow much more distance in sand, gravel, fractured rock, karst, or flood-prone ground.
2. Oral rehydration for diarrheal illness: when packaged ORS is unavailable, mix six level teaspoons of sugar and half a level teaspoon of salt into one litre of safe water. Give frequent small sips and discard leftovers after 24 hours. Lethargy, confusion, inability to drink, persistent vomiting, or severe watery or bloody diarrhea needs urgent skilled care; severe dehydration often requires intravenous fluid.
3. Isolate suspected smallpox and seek an established vaccination practice. Do not improvise cowpox identification or variolation: either can spread infection, and variolation can cause fatal smallpox. See medicine.
4. Compatible legumes and rhizobia can fix nitrogen. Test a locally suitable rotation, verify root nodules, account for harvested nitrogen, and return residues where appropriate; do not prescribe one crop to every field.
5. Protect the milk chain and use a validated heat process. Prefer milk from controlled herds, prevent recontamination, and use a verified pasteurization time and temperature before children drink it; see animal husbandry.
6. If untreated maize dominates the diet and other niacin- and protein-rich foods are scarce, use an established nixtamalization practice. This needs food-grade alkali, heat, water, and controlled proportions; see lime.
7. For small swings, pendulum period is governed mainly by effective length and local gravity. About 0.994 m gives a one-second half-swing at standard gravity, but calibrate locally and control amplitude and temperature.
8. Write things down, including units, conditions, failures, and uncertainty. One-variable-at-a-time trials can help diagnose a simple change, but use replication, controls, randomization or blocking, and interaction-aware designs when decisions matter.

Five of those eight are medical or agricultural, and several begin with ordinary household or farm capabilities rather than a new furnace. Their value depends on careful execution, measurement, consent, local conditions, and escalation to skilled care or engineering where indicated.

A closing honesty

You are one person with general knowledge and no tools, arriving in a society that has spent centuries optimizing itself against constraints you don't yet understand. You will not industrialize anything single-handedly. The realistic best case is that you introduce a handful of specific, high-value ideas, teach them to people who will still be alive after you aren't, and write them down so they survive the teaching.

That's a smaller ambition than the fantasy, but a few locally validated changes that other people can maintain may still have durable value.

Start with clean water.