How long would it take to bootstrap modern civilisation again from nothing?

[Lvl 2 Expert]

The population problem will go away relatively quickly. The knowledge brought should include fermentation, which gives alcohol. Alcohol gives us a disinfectant,

They will need a good distillery to get anywhere near disinfectant concentrations of alcohol. They won't need much of it, but it is another complex project which among other things will require a good way to regulate temperature.

I'll assume that about half of the C-sections can be handled normally via baby manipulation (turn the kid in the womb, a skill that some still have) but that 5% of pregnancies will have problems.

Stuff like turning the kid is not some arcane secret waiting to be rediscovered, in those cases where the position of the child is the problem they already try that first now. At least over here they do. When they can't do it at the hospital they even sent you home with some incense and the ridiculous idea planted in your head that this particular smell might make the baby turn on its own.

15 years of fertility on average (assuming our population is between 20 & 30 and stops having kids by 40)
1 baby every 2 years
7.5 pregnancies per woman.
x 1000 women
=7,500 kids in generation 2
Minus 10% (+-) for various bad things happening related to Labor & Delivery =
-100 from Generation 1
-750 kids
Net population growth from reproduction into Gen 2 6,650. Population when Gen2 hits adulthood = 8650.

These rates are reasonable and can certainly be exceeded. My father was one of 11 kids in a poor coal mining town in AR.

Poor maybe, but odds are they could still afford to have one parent be mostly just a parent, not a hunter/gatherer/fisher/metalworker/reinventor/writer-down-of-important-information. If you look at the demographic history of our planet there's certainly a big boom since around 1900 or so, but before that the growth is much more limited. Yeah, you can have some sort of hygiene and such in this setting, which would help, but stuff like modern vaccins and one income households would surely help too.

[Eldan]

The population problem will go away relatively quickly. The knowledge brought should include fermentation, which gives alcohol. Alcohol gives us a disinfectant, and we darn well know germ theory and handwashing. Lye soap is pretty easy, not requiring metal to make (wood buckets). Childbirth should end up being generally safe and sterile, without the major infection problems.

The WHO rate for C-sections, last I checked, was 11% (recommended/"normal"). Side note, there's a hospital in Las Colinas TX that had a ~51% C-section rate -- do your research! I'll assume that about half of the C-sections can be handled normally via baby manipulation (turn the kid in the womb, a skill that some still have) but that 5% of pregnancies will have problems.

I believe it to be a good assumption that someone who has successfully delivered a baby is less likely to have a problem on a future pregnancy (it's true with livestock, thus the term "proven," and a certain amount of the pregnancy problems are related to the mother's anatomy variations).

There's also a 25% miscarriage rate, much higher than many people realize... however, a miscarriage is typically recovered from quickly, so on average we can ignore it in our fertility calculations.

15 years of fertility on average (assuming our population is between 20 & 30 and stops having kids by 40)
1 baby every 2 years
7.5 pregnancies per woman.
x 1000 women
=7,500 kids in generation 2
Minus 10% (+-) for various bad things happening related to Labor & Delivery =
-100 from Generation 1
-750 kids
Net population growth from reproduction into Gen 2 6,650. Population when Gen2 hits adulthood = 8650.

These rates are reasonable and can certainly be exceeded. My father was one of 11 kids in a poor coal mining town in AR.

After 40 years you'll hit 32,000 adults, and then the generation after that gets you to around 120,000... or possibly more.

I don't know what the figure is to have a sustainable population to support all of the tech we are talking about, but I expect that 2,000-3,000 people devoted to it will cover most of it, leaving the other 5,000 handling food production and childcare.

I am expecting lots and lots of the diet will come from fishing, which at this point should be incredibly time-efficient versus hunting. Fish + salt + fruits/nuts (tree crops) + greens + whatever grains are found/made available.



I would also argue for an early (<10 year) split with a second colony/city in a different area to reduce vulnerability to drought, tornado, hurricane, wildfire, plague of locusts, Pompeii, or other natural disasters. This ideally would give access to different resources.

Yeah, no. So much wrong with that.

First of all, fermentation does not give you disinfectant. It gives you beer. Maybe wine if you're lucky and you figure the tech out. And while the Romans used wine as a disinfectant and it wasn't entirely useless, you need distillation to make anything really useful.

Second, there's so many things that can go wrong with a birth other than just infections. Mortality rates are still non-neglible even with mordern techniques. Some mothers will just bleed out and there's nothing our stone age civilization can do.

Then, you're entirely neglecting childhood mortality. Diseases might interestingly be less of a problem, because the population is small and without humans existing previously, there won't be any viruses adapted to humans, but it will be far more than 10%.

Consider this: even in Europe, since the fifties, the child mortality rate went down by a factor of five. That's modern technology compared to the sixties.

Pneumonia is still the second-most common cause of infant deaths. A cause of death our population will be almost entirely helpless to.

Here's some of the highest infant mortality rates today:
Afghanistan: 121/1000, Mali and *****: 109/1000, Somalia 103/1000.
These are still countries where at least some have more modern medical technology than what our population will have. And those rates are just infants, not "surviving to reproductive age".

Many, many children will die.

[Chronos]

On an individual scale, a 1% (or 5% or 10%) child mortality rate is horribly tragic. But on a societal scale, it's a hiccup. If our growth rate is reduced to 90% or 99% of what it could be, that's barely noticeable.

As for flint, even if we do need to travel 100 miles to find flint, that's no problem. We're going to need to travel 100s of miles anyway, just to keep from depleting our food supplies, until we've got agriculture developed enough to settle down (which, again, will require long timescales that we can't significantly accelerate). The need for flint would just determine the direction of the initial movement. Besides which, where you find flint is mostly in river beds, and fresh water is going to be an immediate, first-priority need, plus all the other benefits of rivers (a power source, a travel route, etc.).

[Eldan]

Child Mortality rate might go well over 50%, though.

[jayem]

Child Mortality rate might go well over 50%, though.

I think the initial numbers have the grandparents still.sprogging.
However we know a reproductive replacement rate of comfortably over one at all points is poßible (we're not extinct), and we should do better.
and the 3ish given seems a good upper bound for when things are all good and we also took a field hospital.
Given everything, Im going to guess at at doubles (given the city sink effect and similar and that we have grown, and disasters, it's probably what we've actually been able to do in regions. And would be almost doable with a c Mort of 50% in the absence of anything else)

Without grandparents I think the first generation might want to take it slow though.

[J-H]

A quick search says that child mortality rates for the Yanomamo (mostly uncontacted Amazon tribes) are around 18%. I would assume that with better medical knowledge regarding diseases and infections, the Bootstrappers should be able to hit a lower %.

[Tvtyrant]

Have to factor the 1.5% of women who traditionally die per childbirth. Having a bunch of kids to even put child mortality is also going to kill our economically active adults.

Traditional childbirth is nearly as deadly per child as a Coronavirus infection is now.

[Kato]

A quick search says that child mortality rates for the Yanomamo (mostly uncontacted Amazon tribes) are around 18%. I would assume that with better medical knowledge regarding diseases and infections, the Bootstrappers should be able to hit a lower %.

I highly doubt that. Maybe birth / infant mortality, which is quite different. Child mortality in Europe 200 years ago was still close to 50% and no offense but I doubt an uncontacted tribe would be far better, even if 200 years ago was quite a while ago.

[Eldan]

A small isolated tribe might have some advantages over a large, crowded population, especially when it comes to infectious diseases. Typhoid and cholera were rampant in 19th century Europe. But the 19% figure does look a bit dubious.

[Grey_Wolf_c]

A small isolated tribe might have some advantages over a large, crowded population, especially when it comes to infectious diseases. Typhoid and cholera were rampant in 19th century Europe. But the 19% figure does look a bit dubious.

Agreed on the latter; the former I can see the logic for it, but since these tribes are, I'm guessing, smack-dab in the middle of malaria-carrying mosquito feeding grounds, I suspect that there is still a non-insignificant danger from that that is counted under "malaria deaths" rather than "birth deaths". Mind you, Europe had malaria 200 years ago too, so there still might be a difference.

And to drag my train of thought kicking and screaming back to the actual topic, no amount of home-made soap would protect these 20000 people from such things as malaria around the Mediterranean. Or any number of other quite nasty things we tend to clear with antibiotics these days, and that also needs to be taken into account. Malaria won't kill an adult, but it does knock you out of commission for a few weeks each year, and it does leave permanent damage besides.

Grey Wolf

[Xyril]

Why are we even talking about the time needed to learn to knap flint? The starting premise was that we'd have all the relevant experts we need in our first generation of colonists. Flint-knapping might be a fairly rare skill nowadays, but there are still experts in it.

You might be conflating two definitions of the word "learn." We wouldn't need to develop the technique from scratch the way our ancestors did, but we would probably need to spend a bit of time adapting what our expert learned in one set of circumstances to a different one. More importantly, if we want to manage our labor efficiently, we almost certainly want that expert to teach other people to help with the actual manufacturing--that takes a non-negligible amount of time, and we can't really ignore that aspect of things if we're trying to figure how best to allocate our limited resources and our limited pool of experts. Having a expert in physics means that we don't need to "learn" about gravity the way Isaac Newton did--however, if we want more than our original expert to apply that knowledge practically, then we still need people to "learn" about gravity the way primary school science students do.

Just as an example, if we're not the only group of rival humans on the planet, it would seemingly make sense to have a unarmed combat expert. After all, learning from somebody who has the benefit of centuries of trial-and-error would be a lot faster than having to watch mantises fight and adapt them into a martial art from scratch. However, the transfer of that knowledge to our group of potential defenders isn't instantaneous--to weight the true value of that knowledge, we also have to consider the fact that it'll take on average X hours of training to turn a botanical archaeologist into an effective fighter.

Depending on how prepared you need to be, those X hours per person might really add up, and that changes the relative value of different technologies. If we had perfect and instant knowledge transfer, then having one MMA champion or Marine close combat expert would give us 2000 expert fighters who could beat back untrained fighters armed with clubs and spears, all without the resource investment of making weapons or the opportunity cost of spending 2000X man-hours training instead of doing other useful work.

In practice, that non-negligible teaching/learning time matters. Weapons are not only a force multiplier, but also a work multiplier. Maybe an untrained guy with a spear can't beat the close-combat expert, but in only a fraction of X hours you can probably train spear-guy to be skilled enough beat expert-unarmed-combat guy. The cost is that you now need an expert spear-fighting guy, an expert spear-making guy, time to train spear-makers, and time to make spears, but if your goal is to have your 2000 guys beat back their 2000 guys, then it's quite possible the math works out.

Yeah, no. So much wrong with that.

First of all, fermentation does not give you disinfectant. It gives you beer. Maybe wine if you're lucky and you figure the tech out. And while the Romans used wine as a disinfectant and it wasn't entirely useless, you need distillation to make anything really useful.

Perhaps J-H forgot to explicitly mention an important step, but to be fair, distillation seems like the less tricky step, particularly if you come pre-equipped with modern knowledge of relative boiling points.

[Fat Rooster]

One thing that I think nobody has mentioned is that the mere notion that something is possible will make it's reimplementation/discovery much faster. Lasers, for example, require no more specialised tooling to create than for good glass. They were not created with a particular purpose in mind, but knowing that they are useful will make people seek them out. Likewise thermodynamics. Even if nobody can remember the exact formulations of them, knowing that heat can be made to do work makes trying to build an engine not crazy, and knowing that they are useful will make seeking out the exact formulations worthwhile. That's before we even consider the massive things that everybody knows about infection, or the potential of electricity (never mind that it is related to magnetism somehow), or the existence of a periodic table of elements, or even the existence of oxygen! Even if these things become fairy-tales in the new society they will vastly accelerate progress.

With regards to engine explosions being a problem, with modern knowledge it might be more sensible to go with a sterling engine to start. It is a much larger jump if you don't understand thermodynamics before good metallurgy, and if you are capable of good metallurgy then you might as well go with a high pressure engine, but if all you have is knowledge and unreliable materials then a sterling engine is the way to go. Building a functional 2hp tractor would make agriculture vastly more efficient (Don't start with draught animals), and a sterling engine can achieve that.

The other thing I think is worth mentioning is the sophistication of modern language. We are able to understand things because we are able to describe them, and we don't lose that. Basic mathematics will also help all over the place.

[halfeye]

Perhaps J-H forgot to explicitly mention an important step, but to be fair, distillation seems like the less tricky step, particularly if you come pre-equipped with modern knowledge of relative boiling points.

Most people don't have that knowledge. Most people seem to believe that alcohol is not entirely removed from a liquid by heating it to 70 degees celcius.

[Tvtyrant]

One thing that I think nobody has mentioned is that the mere notion that something is possible will make it's reimplementation/discovery much faster. Lasers, for example, require no more specialised tooling to create than for good glass. They were not created with a particular purpose in mind, but knowing that they are useful will make people seek them out. Likewise thermodynamics. Even if nobody can remember the exact formulations of them, knowing that heat can be made to do work makes trying to build an engine not crazy, and knowing that they are useful will make seeking out the exact formulations worthwhile. That's before we even consider the massive things that everybody knows about infection, or the potential of electricity (never mind that it is related to magnetism somehow), or the existence of a periodic table of elements, or even the existence of oxygen! Even if these things become fairy-tales in the new society they will vastly accelerate progress.

With regards to engine explosions being a problem, with modern knowledge it might be more sensible to go with a sterling engine to start. It is a much larger jump if you don't understand thermodynamics before good metallurgy, and if you are capable of good metallurgy then you might as well go with a high pressure engine, but if all you have is knowledge and unreliable materials then a sterling engine is the way to go. Building a functional 2hp tractor would make agriculture vastly more efficient (Don't start with draught animals), and a sterling engine can achieve that.

The other thing I think is worth mentioning is the sophistication of modern language. We are able to understand things because we are able to describe them, and we don't lose that. Basic mathematics will also help all over the place.

This is distinctly more damaging than the fall of Rome. In the fall of Rome the population fell 30% and infrastructure was mostly ripped up with some roads left. In this case all infrastructure and 99.9% of people are gone. People in places could literally see point perspective and concrete and they still couldn't figure out replication for a millennia, along with technology like water wheels and ball bearings.

[Marillion]

This is distinctly more damaging than the fall of Rome. In the fall of Rome the population fell 30% and infrastructure was mostly ripped up with some roads left. In this case all infrastructure and 99.9% of people are gone. People in places could literally see point perspective and concrete and they still couldn't figure out replication for a millennia, along with technology like water wheels and ball bearings.

The comment about the water wheels and ball bearings reminds me. I once read that ancient Greeks had built a toy-sized version of a steam engine, and it was considered by them to be a curiosity and a toy - nothing more - because metallurgy was, at the time, not advanced enough to create one that was large enough to do useful work. There's also the Baghdad Battery and other similar artifacts, which have been (somewhat shakily) hypothesized to be used in ancient electroplating procedures. Perhaps one or two of the original settlers would be best utilized as "toymakers", who spent their time creating small items as proof-of-concepts. They wouldn't spend too many resources on projects not related to their immediate survival, while still passing down knowledge with practical examples; That way, what knowledge is lost over the first few generations could potentially be recovered very quickly.

[Lvl 2 Expert]

Most people don't have that knowledge. Most people seem to believe that alcohol is not entirely removed from a liquid by heating it to 70 degees celcius.

Given that the boiling point of alcohol is a tad over 78 degrees, and in a mixture with water even getting it over 78 for a short time is more of a technical solution than one that works 100% in practice I hereby consider myself most people.

I once read that ancient Greeks had built a toy-sized version of a steam engine, and it was considered by them to be a curiosity and a toy - nothing more - because metallurgy was, at the time, not advanced enough to create one that was large enough to do useful work.

As far as I know they mostly had the wrong design. They used a metal chamber with some water in it mounted on a vertical axis with an outlet pointed such that creating enough steam by heating the chamber would make the chamber spin, a bit like a really weak rocket engine. Later designs use pistons, which let the steam build up pressure, which is much (, much) more efficient.

Edit: although now I think about it, I'm lying here, in the sense that there were multiple steam contraptions made by Greek inventors, and at least one concept for automatic doors (in front of a small temple statue, burn your offering and the god shows himself) did use pressure. Still no pistons or much efficiency though.

[Xyril]

Most people don't have that knowledge. Most people seem to believe that alcohol is not entirely removed from a liquid by heating it to 70 degees celcius.

That's an interesting non sequitur, but I thought the premise of this thought exercise was to contemplate how far we could get starting with a group of people curated for the knowledge they bring.

The knowledge brought should include fermentation, which gives alcohol.

We're not talking about a random segment of the population; we're doing a hypothetical where we curate a specific set of knowledge to help jump start civilization. J-H made a good point that with only a few important bits of modern knowledge--microbe theory of infection, basic protocols against contamination, the ability to make an effective disinfectant very early in our technological redevelopment--we could seriously reduce the mortality rate.

The response to his point strongly implied that failing to mention distillation was a serious flaw in the argument, one that undermined the larger point about infant mortality. The only reason I interjected was because I didn't think it was an oversight--if we're picking experts for our new civilization, I am almost certain that the guy who was selected for his knowledge of fermentation will also understand the basics of distillation. At the very minimum, he'd have enough implicit understanding of the scientific method to be able to figure it out quickly.

[veti]

As far as I know they mostly had the wrong design. They used a metal chamber with some water in it mounted on a vertical axis with an outlet pointed such that creating enough steam by heating the chamber would make the chamber spin, a bit like a really weak rocket engine. Later designs use pistons, which let the steam build up pressure, which is much (, much) more efficient.

Sounds like you could use that design to generate electricity, if you knew what you were doing... If you can get electricity with bronze-age level metallurgy, that would be a huge shortcut.

[Lvl 2 Expert]

The thing with distillation is not that it's hard to figure out, but it's had to do properly. Separating both a methanol (for throwing away or cleaning or such, less relevant if the thing you're fermenting is not fruit) and an ethanol fraction (for using) from a low alcoholic mixture is trickier to do than most people think, and definitely requires more gear than a single ceramic pot and a campfire. Some sort of thermometer would be nice, and the ability to create complex shapes from copper or glass would also be highly appreciated.

It's not impossible to make say a 70% alcohol solution under less than modern conditions, but it is going to be a pretty big project, quite possibly something you only want to start working on after you figured out where your next 100 meals are coming from.

[Lvl 2 Expert]

Sounds like you could use that design to generate electricity, if you knew what you were doing... If you can get electricity with bronze-age level metallurgy, that would be a huge shortcut.

Yeah, sure, you could probably run a dynamo against the vat and get enough power to run a small light, bicycle style. But the contraption isn't powerful enough to do much more than that. So if they have ideas for which it really helps to have small amounts of electricity they could go for it.

Or they could let a human or animal power the dynamo, or a water or wind mill. A good water mill in particular is vastly more powerful.




On another note: how long would it take these guys to start their first war?

And not the first large fight, or the first murder, a full on "adapting your technology for killing other people, then going at it for at least several days, impacting every life in the affected area and ending a significant amount of them" war.

They should get at least a few generations in before that happens right, given their small numbers?

[halfeye]

Given that the boiling point of alcohol is a tad over 78 degrees, and in a mixture with water even getting it over 78 for a short time is more of a technical solution than one that works 100% in practice I hereby consider myself most people.

I'm probably not going to remember to look things up before posting, but at this rate I really ought to. I thought it was 66 degrees celcius.

The number of people who think that the alcohol is necessarily still there so long as the *water* hasn't boiled is non-trivial.

That's an interesting non sequitur, but I thought the premise of this thought exercise was to contemplate how far we could get starting with a group of people curated for the knowledge they bring.

Sure, however, that means we have a lot of experts in a lot of fields, and the knowledge they have outside their own field of specialisation is likely to be the common background of our society, so e.g. physicists who also happen to be anti-vaxxers would probably be a thing.

[Fat Rooster]

This is distinctly more damaging than the fall of Rome. In the fall of Rome the population fell 30% and infrastructure was mostly ripped up with some roads left. In this case all infrastructure and 99.9% of people are gone. People in places could literally see point perspective and concrete and they still couldn't figure out replication for a millennia, along with technology like water wheels and ball bearings.

Roman concrete had a fairly advanced chemistry, that wasn't understood at the time (there are still many aspects of concrete chemistry that are areas of active research). It's advantages over stone construction can also be easily outweighed by the ease of moving it, if you don't already have good infrastructure set up and there is no good source nearby. Concrete simply isn't that useful a technology on it's own, because it can almost always be substituted by a technology that doesn't require the same trade infrastructure (wood or stone construction). Early on after a fall it is not a priority to be rediscovered, and if you do not understand that calcium oxide hydrolyses and then reacts with CO2 it is very hard to rediscover. I would call concrete one of those quirky things that is not discovered easily from theory, so not indicative of what could be achieved with a modern lay persons understanding. Like bronze, you can't discover it unless you are helped by geology.

As far as I am aware, water wheels were never lost. People stopped building them, but that probably had more to do with the cease of food exports than losing the understanding. Why transport your grain to a centralised site to be milled when it is just going to come back to you? Why not have a smaller animal driven mill closer. We are aware of water mills that were not closed at the fall of rome being maintained and run for centuries. It was past 1000AD before the large settlements started exceeding the population they were at the fall of the roman empire, and at the point where the construction of new mills was required. Almost instantly we see the technology "rediscovered", and water mill construction resumes. Likewise with ball bearings; the lack of them appearing anywhere is probably more due to the lack of a good use case than people not being able to come up with them. DeVinche types who design and study machines without a specific use case are outnumbered 1000/1 by people who design to solve a specific problem. If DeVinche presented his designs for ball bearings to a cart maker the response would probably be "why? That looks 100x harder to build, and 100x more likely to fail than using a lubricated bearing surface". You only need good bearings for high efficiency low torque setups, and they don't actually occur until you get quite high tech.

Another apocryphal tail I heard is with regard to whether the Aztecs discovered the wheel. They were aware of it, but given how mountainous and rough their terrain was it simply didn't make sense to use them. What they could not manufacture was the disc brakes required to operate carts safely!

This illustrates how technology might progress. Progress will be slow where either a solution already exists, or you need an advanced state of technology for any improvement. The lack of draught animals will make the construction of a basic engine occur extremely fast, if a use exists for it. Even a 1/2 horse power engine is an improvement if it is not competing with a horse! Once you have a basic engine you start down the industrial revolution gradient. Good bearings would get created fast because there is a use case for them, and from there anything that needs bearings is easier.

Going back to sterling engines, another good reason for building one is that they can be operated in reverse, and operate a refrigeration setup. For food security that would be huge. Refrigeration is one of those things that we didn't know would be useful until we were able to do it easily, and is actually not that hard.


Distillation is not that complicated, provided we have clay. Setting up a basic ceramic column isn't that hard and the only real issue from that point is throwing away any methanol (not critical for disinfectant, and also not that hard as long as you are reasonably conservative about it. You can smell when the distillate changes, and if your column is half decent there should be relatively little overlap. The methanol can be used for cleaning anyway, so doesn't even have to be wasted). Depending on where we get our initial alcohol this might not even be a problem, and distillation is so useful that even more advanced distillation setups are well worth constructing. Steam distillation of wild garlic (or any similar plant) is a route to a powerful insecticide, for example, that may also treat parasites (no conclusive proof to modern standards, but certainly used historically and probably better than nothing. Parasites are going to be a problem). If you can produce sulphuric acid somehow, and are able to distil it to a reasonable strength, then ethanol can be reacted into ether, permitting relatively advanced surgery (C-sections being the big one). You can do reasonably advanced medicine with even a half decent still, and that can be made from the same materials as you make your pots from (yes you want pots; cooking food vastly increases the available nutrients, and boiling water is by far the easiest way to make it safe, so you want pots ASAP).

A good glass still would be ideal, but making glass that will not shatter under heating is non trivial, and a 'phase 2' objective. Finding a good source of boron might not be easy. Getting basic glassware definitely is an achievable phase 1 goal, but many of the things you need it for are better done with ceramics at this point. You are certainly more likely to have access to clay than either copper or boron.

Electricity will be the first big milestone that may need travel, as it almost strictly requires copper. The metallurgy required is actually pre-bronze! If you have access to that it is pretty uncomplicated, and once you have it bootstrapped you can switch to aluminium, so even limited quantities are good enough. For bootstrapping though the copper is probably going to be vastly harder to get than the energy, so I don't think we can say whether the energy is likely to come from a water wheel, wind mill, or engine.

[Xyril]

Sure, however, that means we have a lot of experts in a lot of fields, and the knowledge they have outside their own field of specialisation is likely to be the common background of our society, so e.g. physicists who also happen to be anti-vaxxers would probably be a thing.

Honestly, I thought this was outside the scope of our thought exercise--which was no more complicated than "bring modern knowledge, how can well can we rebuild"--but you do raise an interesting point about the logistics of squeezing that knowledge into however many people we have.

That said, if we're going to assume that we bring people with severe knowledge deficits, I feel like at this point you're presenting an unreasonable extreme as a given purely for the sake of bolstering an untenable position. Given the size and diversity of the population--and how many fantastical leaps we're already taking since we're moving to a duplicate Earth that exists as if humans had never been around--I think it's reasonable to assume that somewhere on this Earth, we'll be able to find a physicist, a carpenter, a survivalist, and anyone else we need without also picking up someone who is anti-vaxx, flat-earth, or anything else that's misguided to the degree that it would adversely impact their ability to be useful to society. Actually, it's not even that big of an assumption--I personally know at least one theoretical physicist and one carpenter, neither of whom believe that vaccines cause autism or that the Earth is flat and 5000 years old.

Also, I think it's unreasonable to assume that the "common background" of knowledge will dominate the new society, if only because doing so would possibly immediately doom our colonists. While this very forum probably demonstrates that a lot of knowledgeable people tend to drastically overestimate their capability and knowledge outside their field of specialization, for our bootstrapped society to work we must have people with enough self-awareness and humility to recognize the limits of their knowledge, especially in that crucial first generation who retain direct Old Earth knowledge. If one of our survival experts is someone with a lot of practical knowledge of primitive hunting and trapping techniques, and he never actually gets to teach or apply his knowledge because all the physicists and engineers outvote him because they decided that their advanced degrees and theoretical knowledge coupled with "common background" knowledge of how hunting should probably work, then what's the point of even bringing the knowledge? If our architect,carpenter, and structural engineer only get a partial say in how to design and build the bridge because the botanists, geographers, and metallurgists all vaguely remember building a bridge in middle school and think it should be a big collaborative effort, how good do you think that bridge will turn out?

[halfeye]

Honestly, I thought this was outside the scope of our thought exercise--which was no more complicated than "bring modern knowledge, how can well can we rebuild"--but you do raise an interesting point about the logistics of squeezing that knowledge into however many people we have.

...

If our architect,carpenter, and structural engineer only get a partial say in how to design and build the bridge because the botanists, geographers, and metallurgists all vaguely remember building a bridge in middle school and think it should be a big collaborative effort, how good do you think that bridge will turn out?

It's a worry. I was thinking of this exercise as a bit like the game Alpha Centauri, with some experts dumped on a fresh planet with almost nothing. How much intellectual baggage people will bring is a question, they could all be selected for knowing everything, but where do you find people like that?

[Bohandas]

Does anyone have an idea of how long it takes to domesticate animals?

That depends on if you know what you're doing and how much resources you have. If you've got a lot of both there's precedent for doing in under a century

https://en.wikipedia.org/wiki/Domesticated_red_fox

[Xyril]

It's a worry. I was thinking of this exercise as a bit like the game Alpha Centauri, with some experts dumped on a fresh planet with almost nothing. How much intellectual baggage people will bring is a question, they could all be selected for knowing everything, but where do you find people like that?

Well, we couldn't find a Renaissance man like we could back when the sum of human knowledge was magnitudes of order smaller, but finding a fairly comprehensive number of experts who recognize the limits of their knowledge isn't exactly hard. I've worked with a lot of them.

It also helps to remember that we're not looking to push the boundaries of science and technology, just to reestablish as much as we can, as quickly as we can. We don't need the guy who could plausibly conceive of a new theory that explains the underpinnings of the physical--we just want a physicist who, for example, understands quantum mechanics well enough so that so that we have a theoretical structure to fall back on when we're working on semiconductors and the engineer needs some help figuring out why things don't seem to be working like they're supposed to. Ideally, he'd be the same guy we have to provide an understanding of optics, and maybe know enough about fluid dynamics to help the aerospace and mechanical engineers. It's a rare individual who can really expand the boundaries of human knowledge, but smart people who have developed a comprehensive understanding of the discoveries of others well enough to teach or to apply it are actually a lot more common--certainly common enough that we can probably avoid the flat earthers and the violent sociopaths.

If you're really worried about that last bit, maybe we can double or even triple up on psychologists and criminologists.

[Excession]

Electricity will be the first big milestone that may need travel, as it almost strictly requires copper. The metallurgy required is actually pre-bronze! If you have access to that it is pretty uncomplicated, and once you have it bootstrapped you can switch to aluminium, so even limited quantities are good enough. For bootstrapping though the copper is probably going to be vastly harder to get than the energy, so I don't think we can say whether the energy is likely to come from a water wheel, wind mill, or engine.

Pretty sure you're also going to need a permanent magnet to build a generator. Will a loadstone do or are you going to need iron for that?

Not that iron is that hard to make if you know what you're doing and have the ore.

[Eldan]

That depends on if you know what you're doing and how much resources you have. If you've got a lot of both there's precedent for doing in under a century

https://en.wikipedia.org/wiki/Domesticated_red_fox

The Wikipedia article doesn't go into that, but there's serious doubt by experts that any actual domestication has happened in that experiment, beyond just, well, traumatizing a population of foxes.

[Fat Rooster]

Pretty sure you're also going to need a permanent magnet to build a generator. Will a loadstone do or are you going to need iron for that?

Not that iron is that hard to make if you know what you're doing and have the ore.

Yeah, but assuming similar geological history you would expect something similar to banded iron formations to be pretty ubiquitous*. Iron ores are much more common than good copper deposits. This is a reflection of their abundance in the wider universe, so will probably be true even given a very different geological history. Historically we worked with copper first because it was so much easier to discover how to work it that it was possible to discover it by chance, if you were in the right place. Given that we already know how to produce iron, it is likely that we will be using it before a good copper supply is established.


*I suppose if the planet developed an oxygen atmosphere despite very little water, you wouldn't get such deposits, but such a planet would need to have precisely enough water for it not to all be tied up in minerals but not so much that oceans can exist. If Oxygen does not exist our settlers die. If free water does not exist our settlers almost certainly die (hard mode++). If we have chosen a planet to be survivable there are probably widespread iron ores.

The biggest immediate problem with livestock might not actually be domestication, but fencing. Keeping livestock from wandering off is a fairly substantial infrastructure project early on. Hunting 'dogs' (nearest equivalent. Velociraptors if you were dropped on earth 75million years ago) might come about more accidentally than deliberately, if we are producing waste that they can scavenge. While domestication will take a long time, animals being familiar enough with people to be able to be worked with might happen much faster. Pack animals that are kept roped might be the closest thing to livestock for a while, but will probably need to be caught quite young, and not be useful for months to years. It is worth mentioning that there have been occasions where non domesticated animals have been successfully put to work, and been considered tame (and given a rank in the polish army).

[Xyril]

*I suppose if the planet developed an oxygen atmosphere despite very little water, you wouldn't get such deposits, but such a planet would need to have precisely enough water for it not to all be tied up in minerals but not so much that oceans can exist. If Oxygen does not exist our settlers die. If free water does not exist our settlers almost certainly die (hard mode++). If we have chosen a planet to be survivable there are probably widespread iron ores.

This was from the original post in this thread:

Now, let's drop them in an uninhabited replica of Earth, around the Mediterranean area. This is a planet that has no resources depleted by humans, and all the creatures that were driven off or hunted to extinction roam freely. The new arrivals have nothing but their bodies and their brains: no clothes, no technology. For the sake of fairness, nobody in our small army has any condition that will render them helpless or dead if deprived of modern medicine.

So we're basically setting up shop on Earth, before humans ruined everything. From a biological perspective, that probably simplifies things, although it is an interesting thought exercise to consider whether there's different, plausibly-naturally occurring planetary configuration that might be even more optimal for us, assuming we could speed run through some earlier levels of technology.

Something like a fish-world with larger, more productive oceans might let us put off serious developments in agriculture to the point that we can skip developing some intermediate technologies (e.g., mules and plows) or avoid having to temporarily rely on less sustainable practices with long-term consequences (e.g., the sort of slash-and-burn practices that exhaust the soil and require yearly expansion into the rain forest to be economically sustainable.)

It is worth mentioning that there have been occasions where non domesticated animals have been successfully put to work, and been considered tame (and given a rank in the polish army).

This has been left out of historical books because ammo-fetching bear is obviously far more wholesome, but that bear had 96 confirmed kills--most of whom were enemy soldiers.