Cunoașterea: cum poate fi reclădită civilizația după un cataclism

by Lewis Dartnell, Iulia Arsintescu (trad.)

Dacă societatea noastră tehnologică s-ar prăbuși mâine, supraviețuitorii unui astfel de cataclism vor trebui cel mai probabil să învețe din nou cum să supraviețuiască și cum să reclădească o nouă civilizație. Cartea lui Lewis Dartnell poate fi considerată un adevărat ghid de supraviețuire pe care orice nouă societate postapocaliptică ar trebui să-l folosească. Astfel, prin descrierea fundamentelor tehnologiilor pe care le folosim astăzi, Cunoașterea ne arată, de exemplu, cum să construim un radio și cum să generăm electricitate, cum să producem medicamente și cum să extragem metale și mai ales cum să redescoperim lumea înconjurătoare învățând să ne orientăm după stele. Însă Dartnell nu ne oferă doar informații de bază în vederea reclădirii civilizației, ci descifrează și explică cea mai mare invenție a omului: metoda științifică – fabulosul mecanism ce ne permite să cunoaștem alcătuirea universului și a omului.

Genres: Nonfiction, Science, Technology, History, Survival, Reference, Audiobook

328 pages, Paperback

First published April 1, 2014

About the author

Lewis Dartnell is an astrobiology researcher and professor at the University of Westminster. He has won several awards for his science writing, and contributes to the Guardian, The Times and New Scientist. He has also written for television and appeared on BBC Horizon, Sky News, and Wonders of the Universe, as well as National Geographic and History channels. A tireless populariser of science, his previous books include the bestselling The Knowledge: How to Rebuild Our World from Scratch.

Reviews

[Jengordon · Rating 2 out of 5]

I read a lot of "Prepper" books, and in general, a lot of apocalyptic literature. This one was a quick read, because it sucked. Dartnell had the kernel of a good idea, but then lost steam about 50 pages into the book, and what he filled the remaining 250 with was a stretch.

Good points: explaining how to get certain base-material chemicals from natural sources.

Bad points: he did not think deeply about what were the critical, enabling, technologies for "rebooting" (his term) life. He assumes that today's technology and standard of living is something we should strive to re-create, without asking about technical priorities, or indeed, about how to set up social structures to perpetuate a decent standard of living. What good does it do to tell me about what a proper harness for a horse looks like, if I haven't been told how to keep horses alive in the first place? It's great that hickory is a good wood for making gears and elm for making wagon wheels, but how many 21st century urbanites can tell hickory from elm from maple? Can you? And why tell me that forceps can be useful in delivery of a baby, without telling me anything about the basics of normal midwifery? Why try to tell me about electric cars (after society has fallen apart) being a more effective useable-energy-per-acre use of biofuels once you've told me that by the time we get to that point, the roads will be in a state of disrepair so as to make them useless?

I'm tempted to re-write his reboot. Start from a realistic assumption about what the world is like, and who my audience is. Are they living in a post-pandemic Boston in 2050? Great. What's the climate? What input materials are they likely to have? Can they really scavenge so much from grocery stores in this scenario, since pandemic (say, flu) isn't going to kill off everyone overnight? The moribund living will be eating the canned goods, leaving the survivors with nothing... OK, so I find myself in 2050 Boston, with a growing season that now runs from (date) to (date), annual rainfall of x, and the following animal/plant/insect hazards. I've gathered a commune full of survivors, and we've set up a social structure (which one? what has succeeded in the past for groups like this?) and found a way to defend ourselves against other groups. What are our scavenging priorities? (Hint: don't tell me how to make fertilizer. Tell me to locate and stockpile it so I have years of it to work with! Tell me what seeds to find and preserve -- and how to preserve them!) How do I manage birth control? What books from the library should I make it a priority to rescue before the building starts leaking and the rats start nesting in the books? What resources should I scavenge -- from what museums (what museums have working spinning wheels? looms?) -- and/or take over? What standard of living should I shoot for? What was available in 1400? 1600? 1800? And tell me what they knew at that time. Don't tell me how to build a radio. Tell me how to keep sheep alive.

This book has a tantalizing title but disappointing contents, because while it's clear the author knows a lot, he didn't think very much.

[Thomas Edmund · Rating 4 out of 5]

This book is going to need two reviews:

The first – would I want this book to be in my library should the world end? I’m afraid the answer is no. while certainly this book is cleverly researched, packed with information, and the subject matter carefully chosen (or at least with some sort of system, apparently there is a website.) Equally I realized that there was no well in hell I was going to be able to do any of this stuff. For example I have no doubt the chemistry has been meticulously researched, I just cannot fathom successfully conducting most if not all of the procedures listed in this book. I loved the way Dartnell offhandedly pointed out that some of the phosphorus reactions would in fact be poisonous (he did not however describe how to make a fume hub or gas-mask.)
In short if this was to be the book I was left with in the apocalypse I would desperately hope for a whole library of practical advice also, as at best I would use The Knowledge as a reference for what to start looking into.

The second (don’t worry this one is better)
As a book of general knowledge with an intriguing take, I actually enjoyed it. As long as I cast aside a nagging feeling that if the end of the world were to strike, I would be very doomed, I found trawling through The Knowledge to be a lot of fun. Part of the reason that I liked the book but wouldn’t want it as a doomsday guide, is that Dartnell couldn’t seem to resist delving into the history of technological development which while relevant from a general interest point of view, I wouldn’t be keen to trawl in the disaster scenario.

In summary I liked this book, just as a casual read, not as actual doom-preparation

[Beth · Rating 4 out of 5]

This book is absolutely hilarious. It’s not meant to be but it is. Published in 2015, it is a handbook for rebuilding civilization after, say, an asteroid strike, a solar flare, a nuclear war, or – let’s think – a catastrophic pandemic. In fact, Dartnell envisages a pandemic with a rapid-onset mortality of 80% such that survivors would have to leave urban areas to avoid the stench and contamination of all those dead bodies. Fortunately, we’re not quite at that stage in the current situation, so no need to hastily pack up the car just yet.

What was I expecting? Well, something about finding shelter, gathering and growing food, finding clean water, and generally battening down with a lot of tinned beans and the last of the world’s toilet rolls. And it’s in there but Dartnell is way ahead of this.

This is how to “reboot agriculture” by remaking 18th century farm equipment from the iron that you’ve just smelted from ore because there’s no more diesel for the combine harvesters. Instructions for making your own clothes include those for sheep-shearing and building a loom from the trees you’ve just chopped down. While you’re at it, build a water wheel to mill grain and generate electricity. There are diagrams of rudimentary foundries, metal lathes, the internal combustion engine and birthing forceps along with descriptions of fore-and-aft sails, hulls and keels. How to make paper from rags; how to remake a Guttenberg press; how to make crockery from clay and all sorts of useful chemicals from limestone. It is completely bonkers.

Frankly, most of us stripped of our central heating, supermarkets, cars, smart phones and high street fast fashion would be as helpless as kittens. I, for one, wouldn’t know lumps of iron-ore or limestone if they followed me round the garden. But if ‘all this’ gets this bad and we find ourselves heading for the hills, I might just stick this book in my pocket. Because, you know, just in case.

[Tim Pendry · Rating 3 out of 5]

A rather disappointing book, 'The Knowledge' purports to give us the basics for the survival of civilisation in the wake of an apocalypse based on some slightly dubious assumptions about what actually survives of humanity and in what condition.

And that is the problem with the book - it is a thought experiment that is actually an excuse for a rather dull and worthy account of basic technologies with the standard proselytising for science which might be necessary for the darker reaches of America but is hackneyed elsewhere.

The book could be useful to survivors so long as they had sufficient understanding of many of the terms used to describe a technology. As it is, it falls between stools - insufficient to recreate very much quickly enough yet enough to remind us of the value of science and technology.

It is, in fact, a not-so-occult polemic. It contains absolutely nothing of the other half of what we would have to know to control our situation after the breakdown of our system - individual psychology, social psychology, the lessons of history, anthropology and 'organisation'.

From the beginning the post-apocalyptic world it presents is so bleak that, quite honestly, one questions whether why one would bother to rebuild a civilisation that might only repeat the same mistakes and so perhaps seek other more limited ways of survival with less technology.

One wonders if one of the influential texts driving this book (it is cited in the reading list) is Walter Miller's classic scifi novel 'A Canticle for Leibowitz' because at times it reads like a response to that book's thesis of science lost to faith. It is a quarrel started as a first strike on faith.

Going further, you look at the post-apocalyptic world and realise that Dartnell - as a good Enlightenment liberal - misses the key survival move on which everything else depends, including decisions on which of science or magical thinking are more going to help human survival.

And what is that key survival move? Simple. As soon as you can, grab the guns and organise in war bands to protect your own and control territory. Disturbingly, the progress implied in the book is also going to require cheap slave labour. There are no nice liberal solutions to apocalypse.

And what of the bunker people ... the government men and women holed up in survival mode with the organisational skills to enforce their authority once they emerge. They will incline to 'science' but they will also face resistance and that resistance may define humanity more than they do.

However, as far as it goes, Dartnell's message (though it should not need repeating) is a good one - the mastering of reality ultimately depends on scientific method because science and technology are intimately related. Faith can give you cohesion but not 'progress'.

Similarly, although a trifle dull except to techno-nerds, the run-through of all the basic technologies that underpin civilisation and which will require re-creation to rebuild it is informative and reasonable even if it is clear that we are talking about centuries of labour.

As a thought experiment it is worthwhile and educative but it is not really a useful guide for immediate post-apocalyptics other than in trying to hold the line against the loss of scientific methodology in very adverse conditions with something like 'hope'.

There is a book to be written not for the future (as this one purports to be) but for the present which describes exactly what would happen under various apocalyptic scenarios to the species using the insights of the social sciences and humanities alongside the history of technology.

The purpose should be to tell us that, most probably, the cost of apocalypse would be so high that we should work harder at averting it and, second, that there are thresholds of apocalypse where we can survive but at the cost of values that are implicit in this book and others.

Apocalypse is dark stuff. Some of the attention being paid to it now is frankly a little neurotic. There are people wasting their existences on worrying about it. However, greater awareness of the fragility of our condition might be useful to everyone.

The fashionable concentration of effort is on resource depletion. Dartnell makes a very good poont that a second civilisationary cycle would suffer from the fact that the first cycle had depleted much of the resource that the second might need in order to reach the same level of achievement.

This is good to understand as well aversion of threats but more attention should be paid to the disconnect between core humanity in crisis and the mountains of moral value that have been imposed on it as civilisation.

When civilisation goes completely (and we have seen this in the behaviour of men in war in our own and recent times) much of our moral framework collapses. The survivors will be those who know what to accept and reject in order to survive and remain 'decent' - and who have guns.

[Jason Pettus · Rating 5 out of 5]

I admit, I'm a junkie for those YouTube channels that examine the complex modern world by attempting to deconstruct modern products back to their humble beginnings; you know, like that dude who tried to make a business suit by breeding his own silk moths, shearing a sheep himself, and learning how to use a Victorian spinning wheel and a hand-powered loom. (Seriously, his channel is so interesting.)

Lewis Dartnell's The Knowledge: How to Rebuild Our World From Scratch fits exactly into this wheelhouse, premised around an intriguing question: Is it possible to write a single 300-page book that would let a post-apocalyptic society build itself back up into a modern state, including re-learning surgery, industrialized agriculture, the internal combustion engine, and a lot more? Although he doesn't quite succeed (he basically cheats by devoting the last chapter to the scientific method, as a catch-all for everything else he couldn't cover), the attempt itself is fascinating, a shrewd plain-language look at the absolute basic building blocks that have eventually led us humans to complex chemistry, vulcanized rubber, distributed electricity and more, along with guides to how people in Classical and Medieval societies first discovered how to create these things themselves out of such natural material as trees and rocks. Granted, it's not a book to rush through, or else it'll get tedious to the point of giving up before you reach the end; but it's a fantastic bathroom book to read for ten minutes at a stretch, a manuscript that will get you thinking deeply about so many of the consumer goods in our modern society we take for granted. It comes recommended to one and all in this inventive spirit.

UPDATE: After reading other people's reviews here, I'm dismayed at how many people gave this book a bad score based entirely on their opinion that "THIS PLAN WOULDN'T ACTUALLY WORK AT ALL!" or "WE SHOULDN'T REBUILD SOCIETY TO ITS FORMER STATE IN THE FIRST PLACE!" These people grossly misunderstood the entire point of this book, which is to take a fascinating look at how these scientific principles and industrial developments came about in the first place, how people like the Romans literally learned about complex chemistry using nothing but trees and rocks and ash, and why therefore it's entirely possible for humans to learn them again from the same material. What it's not is an actual realistic science-fiction step-by-step plan, and what it's also not is Dartnell's opinions about our modern world, and it's incredibly unfair that this book's score has been lowered by reviewers too narrow-minded to understand this. As a former publisher myself, it incenses me when a book gets an unfairly low score merely from readers who couldn't understand what the book's point was in the first place, much like if you gave Jane Eyre one star because it didn't have any zombies. ("I for one can't even see the point of reading Victorian literature if it doesn't contain supernatural battles! THUMBS DOWN!!!") Please, people, at least try to be a little smarter than this when it comes to reviewing books.

[Juliana · Rating 5 out of 5]

I picked this up after reading Station Eleven a fictional account of a group of global Pandemic survivors. It is essentially a how-to book on what you need to know in order to survive and reboot our world if that Pandemic or other event happens.

As a former editor for how-to technology books I give this five stars. It is practical and accessible. Reading it now--you learn alot of what makes our current world work.

[Charles Haywood · Rating 3 out of 5]

“The Knowledge” is meant as an assist to the human race. But to properly aid the human race, in a post-apocalypse future, two things are required. One is technical knowledge. The other is an understanding of the human race. Lewis Dartnell here offers technical knowledge, but he limits it to knowledge useful for “peaceful coexistence.” Given that violence is an inherent part of humans, which Dartnell seems to not understand, that limitation sharply diminishes the usefulness of his book.

Dartnell covers every relevant general category of knowledge: agriculture, food/clothing; substances (lime, soap, etc.); materials (clay, glass, etc.); medicine; power; transport; communication; chemistry; and reckoning of time and place. Most of these are well covered, if necessarily only briefly. But Dartnell studiously ignores what’s first necessary to make any of these possible to obtain and maintain: weaponry. If history teaches us anything, it’s that substantial numbers of survivors would choose to prey on other survivors. How the non-prey would defend themselves would be the very first order of business—certainly long before, say, photography, a subject Dartnell covers in detail.

Dartnell has thought a great deal about the technical aspects of how humans might “reboot” society. Dartnell limits his apocalypse to catastrophic events that kill most people while leaving infrastructure intact, leaving a “grace period” in which survivors can loot the bones of the former civilization, and for a time even use dying technology like cars and solar panels. He explicitly believes that survivors will leave the cities and form wholly peaceful communities striving to recapture past knowledge, perhaps with an assist from his book. But again, the problem is that other than in technical application of scientific principles, Dartnell seems to be ignorant of how humans act in real life—how they’ve acted in history and how they will inevitably act in the future. Which is, by killing each other.

Why Dartnell does not cover weapons is fairly obvious. He omits any discussion of weapons, for any purpose at all, for ideological reasons—either because he thinks they’re icky or he believes we should give peace a chance. He even goes into great detail about crops as a food source, and omits any mention of hunting for food, except for an oblique mention of butchering (no details on that, of course). No guns, no spears, no bows and arrows, no traps. No stockades, no tiger pits, no abbatis. When the predators swarm into your camp, that’s the “Knowledge” that you’ll want, not how to use Barnard’s Star to calculate what year it is.

And it’s not like Dartnell ran out of space. He even discusses how to create gunpowder, but mandates it only be used for peaceful uses, and naturally declines any instructions on how to create new cartridges for the hundreds of millions of firearms that would survive his type of posited collapse. Dartnell admits, that “You might think that explosives are exactly the sort of technology you would want to leave out of a manual for rebooting civilization, to prolong peaceful coexistence as long as possible.” This is ludicrous. Peaceful coexistence will last in the apocalypse exactly zero seconds. When people aren’t busy trying to make explosives, they’re going to be busy making mustard gas.

But let’s say that Dartnell doesn’t want to turn this into a firearms manual like so much “prepper” literature. That’s understandable, and in any case Dartnell clearly envisions a time when former technology, whether cars or guns, no longer works. Or maybe this was a disarmed society lacking guns (though the UK, where Dartnell writes, has enormous amounts of guns, both illegal ones and ones in military hands, that would be immediately “redistributed” post-apocalypse). In that case, the use of basic metallurgy (which Dartnell covers) to create spears, arrowheads, daggers and swords would be critical to enable any community to defend itself. But Dartnell envisions peaceful souls all living in egalitarian harmony as they rebuild the world, so no mention of such unpleasant things sullies his book.

Also, these peaceful souls will spend their time loving animals, not hunting and eating them. In one place, Dartnell grudgingly admits that rebuilding medicine “may also call for disagreeable practices like animal testing.” I’m pretty sure the inhabitants of post-apocalyptic Earth won’t be much concerned with animal welfare, other than preparatory to their consumption.

Perhaps, one thinks, this is all a brain freeze by Dartnell, and he has subsequently realized that lack of discussion about weaponry creates a huge gap in his book. Nope. Since 2014, when this book was published, Dartnell has maintained a website, which has extensive discussion organized by month. Searching that entire website leads to exactly two results for “weapons”—one in a reference to “Doomsday Preppers,” without actual discussion of weapons, and the other in the famous (and dumb) quote by Einstein about World War IV. Searching for “firearm,” “gun,” “sword” or “spear”? Result: “Nothing Found.” I find it very hard to believe I am the first to point this omission out to Dartnell, so it must be a deliberate choice.

“The Knowledge” aims at an interesting goal—being a seed for a post-apocalyptic rebirth of society, containing key knowledge to restart society. By itself, it’s not much of a seed, since the actual how-to knowledge it contains is limited, and it assumes the ability to perform various scientific techniques that in reality might not be simple to perform. I don’t fault Dartnell for that. This book is certainly better than nothing as a manual for rebooting our society. However, Dartnell’s own criterion for inclusion of knowledge in this book is “I’ve tried to include as much as I think would be absolutely indispensable knowledge for rebooting.” Anyone who thinks weapons and defensive tools aren’t the most indispensable knowledge of all is a simpleton. Failure to include such knowledge, given Dartnell’s declared goals, is criminal negligence.

[Robert Day · Rating 3 out of 5]

Are you serious? Do you really think that this book will help you to rebuild civilisation? Before you bother reading this tome, think about what you can do on your own. Think about how motivated you feed when you're cold and hungry. Think about how dark it'll be when those nights are drawing in and you're burning books to keep warm. Think about how tempting it'll be to throw this one on the fire.

In a world where 99% of the world has succumbed to Coronavirus (or something like that) and you're in your house with only the corpses of your loved ones (and the odd neighbour) to keep your company, who're you going to call? Answer: no-body at all, because the battery's gone on your phone and (anyway) all the lines are permanently dead. Unless ... you fix 'em!

This book'll give you the knowledge to know the names of rocks that you'll need to fix stuff. But it won't tell you what that rock looks like. You'll need a geologist or a chemist or an archaeologist to tell you that. In other words, you'll need people. The author estimates that 10,000 people should be enough to get cracking on the task of rebuilding.

Thing is, if you've got 10,000 people then one or two of them are bound to know what's what. Some of them will know rocks, others will know electromagnetism and still others will know where to put their hands on a still. Because, yeah - alcohol is going to be important in the brave new world too. Oh, and explosives. You get to know how to build those too. My point is, if you have the accumulated wisdom of all these people, you're probably not going to need this book. However, you will need to keep warm, so keep it on hand - just in case you run out of trees.

My take away point is that I need to make some friends.

Read this book if you're interested in how things work, but not interested enough to want to do it yourself. Ignore it if you want to just relax with a big tray full of snacks and watch re-runs of House MD (and then hope that civilisation lasts a bit longer).

[Noel Coughlan · Rating 5 out of 5]

This is a very informative book with a lot of fascinating detail. It is basically a thought experiment. If most of humanity was wiped out in the morning and a handful of people remained, could they survive and rebuild modern technology? To determine this, Dartnell looks how these technologies were originally developed and any possible short cuts which the survivors could take.

The ‘apocalypse’ itself described in book was very clinical but this book is not meant to be a blow-by-blow instruction manual. I couldn’t see survivors sitting around it deciding what to do on Day 24. However, it does contain a lot of high level technological insight that a post-apocalyptic Edison or Pasteur might find useful and could spend years of their lives trying to leverage.

The book is apolitical. Its focus is the technology. If you need advice on how to hang on to your post-apocalyptic fiefdom, consult Machiavelli, Sun Tzu and other experts in such matters. Oh, it doesn’t cover killing zombies either.

Some readers might find the advanced chemistry section a bit of a drudge, but I can’t see how Dartnell could avoid that, given leaving it out would undermine the book’s purpose. On the flip side, it provides useful context for any fledgling chemistry students.

The footnotes throughout the book are consistently very interesting. I think any writer interested in world building would find the book very useful.

One thing to note is that the book is shorter than it appears. About the last 20% is filled with references, including a useful list of relevant fiction.

One final word of advice. If you want to tuck this away for the apocalypse, so you can amaze the other survivors with your scientific knowhow, remember to buy the paperback, not the ebook. Unless you’re really sure you can get those generators up and running.

[Patrick · Rating 3 out of 5]

Having a quick look through the Goodreads review of this book, I couldn't help noticing that a fair part of the criticism reflected the fact that it might not actually be all that helpful in the event of the complete collapse of modern civilisation. Which I couldn't help thinking was rather missing the point. If modern civilisation breaks down completely, you will probably die. I certainly would - without complex modern pharmaceuticals, I wouldn't last long. Real life is not a young adult fantasy novel (although if you want to write one, this might not be a bad guide to lending it some realism).

Instead, the book is a thought experiment. Imagine that almost everyone died but, at least initially, the infrastructure of the modern world is not destroyed. It simply decays around you. What would you need to know in order to go about rebuilding something approximating a modern technologically advanced society? Except in reality, that's not the question it's answering. Instead it is looking, through a post-apocalyptic lens, at the question of what the technologies underlying the modern world are, and how they developed. From farming, through the making of clothes to navigation and time-keeping.

My problem with the book was probably just that I was too tired when I was reading it to follow a fair bit of the chemistry involved. Always one of my weakest subjects at school, and two decades later, I still struggle to keep in my head what exactly a salt is, or why the Alkali Act of 1863 was needed to control the burning of hydrogen chloride- which I thought was another name for hydrochloric acid? That and the fact that, for me at least, I didn't find the author's written style especially engaging. If time is short, and assuming that you're not living in a post-apocalyptic wasteland (and you're not, because, as I said, you'll most likely be dead) it might be better to listen to the author talking about the book here:http://www.littleatoms.com/lewisdartn...

[Robert Morris · Rating 5 out of 5]

This book was delightful. I am a big humanities history guy. Unfortunately I've got a bit of a mental block when it comes to science. The second somebody starts describing the details of chemistry or engineering I just kind of tune out. What Mr. Dartnell has achieved here is an excellent way to draw people like me into a broader understanding of our technological civilization.

The premise is simple. He doesn't spend too much time on the details, but he imagines a complete societal collapse. What would happen then? How would we rebuild? As a apocalypse nerd I found the premise irresistible enough to pick it up at an airport in Malta.

Dartnell then stealthily drew me into a detailed history of science and engineering, with a strong emphasis on the world's chemical underpinnings. I must confess that I didn't follow all of it, but when I took the time to walk through his explanations, I got a ton out of them.

The degree to which we are completely dependent on modern chemistry to sustain ourselves was something I was always aware of, but this book has done an excellent job of fleshing out that understanding. The central importance of certain fertilizers in carrying about a quarter of us was something that was made chillingly clear.

If the worst comes, who knows, this book could well be what's needed to re-start things. Regardless, I know I will benefit from a re-reading at some point. Most of my finished books get passed on, but I think I'll be holding on to this one for a while.

[Stephen · Rating 2 out of 5]

I have to admit that I struggled to read this book. It's not very engaging or well written. In many cases it reads like one of those science text books that I hated when I was at school. However, despite this, it does have an interesting premise, even though I consider it to be flawed. The premise is that the population of the United Kingdom (and elsewhere) is largely killed off by some unspecified catastrophe. Of the 65,000,000 inhabitants of the UK, only 10,000 remain. How do the survivors rebuild the UK to a standard of technology broadly similar to that of today? The book seeks to answer that question.

I think that I didn't really get past the objection of why one would want to rebuild the UK to a standard of technology broadly similar to that of today. Surely a catastrophe such as that would present an opportunity to make a fresh start? If we could rebuild our civilisation, would we want to reignite naked consumerism? Would we pass the chance of replacing maximisation with enoughness? Would we want to avoid the mistakes we made the first time around? I remain very unconvinced by the central premise that a recovering society would be foolish enough to follow the path that we have created for ourselves.

In considering this, I was impressed by the scale of the task. The task needs to be scaled in both time and space. The population density of the UK is currently about 0.0037 km2 per person. After the catastrophe described (but unspecified), the density would change to 24.3 km2 per person - roughly a box of 5 km by 5 km per person. There is a step whereby the survivors find each other and form a viable small community before a combination of hunger and thirst starts to impose themselves on the new death rate.

This is where it is vitally important to specify the nature of the catastrophe. Will all of the land be equally accessible and free from contamination? Will there be the remnants of a plague like event that keeps people apart? How much damage has been caused to our current infrastructure? What will continue to be usable? If we assume away these issues - as the book does - then we are overlooking a number of key factors that could affect our ability to rebuild our society, even if we wanted to.

This is where time comes into play. If we assume a population that doubles in each generation (each couple have four children who survive into child bearing age), then it will take 24 generations for the population to return to 65 million. That would be between 500 and 600 years, assuming no return of the events that caused the catastrophe. Is this credible? I don't think so. I believe that over the course of half a millennia society would develop in ways that we could not imagine from the perspective of today. The author assumes that society is a constant input factor, where experience suggests that it isn't.

Does this matter? Yes it does because certain technologies require a threshold population in order for them to be viable. For example, the book discusses the return of the Bessemer converter to manufacture steel. However, steel at that level will not be manufactured unless there is a demand for it, which requires a population of a certain size (possibly about 5 to 6 million). The technology cannot be considered in isolation from the society which it serves. If it is, it will tend to generate nonsensical results.

Despite all of the foregoing, I still believe that this book is a useful read. If one is constructing wild card scenarios or storylines, then it provides clues and inspiration about what may be feasible, given a certain population at a certain stage of development. It is also useful to know what knowledge might be lost and rediscovered, even if society is not looking to recreate the position we occupy today. From that perspective, it is worth persevering with the book, even though it is a difficult read.

[Pablo Bueno · Rating 3 out of 5]

Tengo que reconocer que empecé este libro por equivocación, pero, como sucede a veces, los errores se convirtieron en aciertos. Al menos en parte. Me explico: llegué a esta obra pensando que sería una especie de ensayo de género, un estudio sobre qué hacer si de pronto nos viéramos correteando alegremente en medio de algún tipo de apocalipsis propio de una novela de género.

No es así. Ni siquiera las posibilidades de la catástrofe de partida lo son: el autor postula que una buena pandemia, una guerra nuclear, un meteorito o, quizá, una crisis ecológica extrema, podrían arrojarnos de golpe a la edad media a poco que nos descuidáramos. Y, tal y como están las cosas, no parece algo demasiado inverosímil, si lo pensamos bien. Del mismo modo, la tremenda especialización que rige hoy en día nuestras vidas laborales hace que, incluso alguien con un conocimiento tecnológico profundo, sea casi ignorante en otras áreas de su disciplina y totalmente desconocedor de, por ejemplo, cómo sembrar cebollas.

Pero, tal y como dice Lewis Dartnell, sería imposible dejar todo el conocimiento recogido en un solo libro, por eso opta por las cuestiones fundamentales. Esa es, realmente, la idea sobre la que gira esta obra: darnos esos atajos científicos que, por falta de nociones periféricas, iluminación o simple casualidad, no permitieron que la tecnología y el saber avanzaran más rápido. También se tratan aquellos inventos que, por simple competencia comercial o circunstancias sociopolíticas, se perdieron. En este sentido, para alguien con un conocimiento tecnológico cercano a la nada, resulta sorprendente lo completo y variado que resulta el abanico de temas que se nos ofrece.

Para mí, el libro arroja una verdadera lluvia de datos que me ha hecho la lectura bastante espesa, aunque eso no es un problema del libro, sino mío porque, como he dicho, no era lo que buscaba. Una obra de este tipo, que además tiene un 15% de sus páginas dedicadas a bibliografía, sin duda no persigue lo que yo pensaba. Aun así, he echado en falta aportes enfocados a la propia supervivencia. Según la premisa del propio autor, nos encontraríamos en un entorno hostil en lo social, posiblemente con radiación, abocados sin duda a comer, beber y a movernos de un modo bien distinto a lo que solemos en esa primera fase de “reinicio de la civilización”. Puede que no sea el objeto en el que el autor quería poner el foco, pero esos datos me habrían alegrado mucho más la experiencia.

Dicho lo cual, tengo que reconocer también que, pese a que en ocasiones tenía que volver varios párrafos atrás para entender lo que estaba leyendo, algún tipo de curiosidad intelectual me impedía dejar de pasar páginas. Los mecanismos o el mero funcionamiento de la naturaleza que Dartnell describe resultan tan atractivos que a veces uno sigue leyendo por el placer del descubrimiento, de la maravilla ante lo desconocido.

Por otra parte, que a quien le toque se marque el título en rojo, porque es una mina para trabajar el trasfondo de una novela postapocalíptica. Las ideas que se pueden sacar de estas páginas pueden ser tremendas. Y, ya se me olvidaba, algo de utilidad tendrá también si alguna vez nos vemos en medio de las catástrofes que propone el libro. Eso si nos toca jugar el papel de esos pocos personajes que sobreviven y no el de la inmensa mayoría... O.o

[Realini Ionescu · Rating 3 out of 5]

The Knowledge: How to Rebuild Our World from Scratch by Lewis Dartnell - This book was awarded The Sunday Times "New Thinking" Book of the Year in 2014, and The Times Science Book of the Year the same year…It was also awarded Best Science Books of 2014 by io9 - The Times called the book "an extraordinary achievement", and "a great read even if civilization does not collapse" – you may wish to visit my bog or/and my YouTube channel where there are thousands of reviews on books like this, and magnum opera from The Greatest Books of All Time and other pages, plus notes on films from The New York Times’ Best 1,000 Movies Ever Made and other lists https://realinibarzoi.blogspot.com/20...



8 out of 10
The Knowledge: How to Rebuild Our World from Scratch reminds me of the apocalyptic scenarios from Planet of The Apes https://realinibarzoi.blogspot.com/20... and other science fiction works that predict Armageddon, extinction of human on earth, or a calamitous change

In Planet of The Apes, I mean the original, not the sequels, they might be five instalments by now, we have the protagonist on the beach, at the end, and he sees the Statue of Liberty fallen, and we realize that this Planet where the apes rule is in fact earth, humans have been so bad at managing it that they are now a dumb species
Alas, we see the things that have been happening and though we can only hope nothing like that happens for the next million years, or whenever the sun will eventually finish life here, climate change, the way people in charge behave give us reason to at least worry, and eventually buy this book about rebuilding

Then there is Dr. Strangelove or How I’ve Learned to Stop Worrying and Love The Bomb https://realinibarzoi.blogspot.com/20... a fabulous film one of the best ever actually, directed by the glorious Stanley Kubrick, with Peter Sellers in four roles, wherein a rogue American leader launches an attack on the then Soviet Union, with the ‘Doomsday Machine’ humans could be extinguished…
Or forced to live underground, in atomic bunkers, which brings me to a more recent formidable motion picture House of Dynamite, directed by Katherine Bigelow, in which we have the terrifying possibility of a missile being launched against the USA, most likely to hit Chicago, and the problem is they do not know who launched it

It is not the only challenge, indeed, that is the least worry – it reminds of The Buddha https://realinibarzoi.blogspot.com/20... and his retort when somebody insisted with questions about God: ‘you are like that fellow hit by a poisoned arrow who is foolish…
Instead of getting the poison out, he is looking for the responsible party, curious to know what village…’ in House of Dynamite, the prospect is of nuclear conflict, the missile will kill millions, so the response will get retaliation, and a spiral of nukes out of control will result, it is realistic in showing that different people will be unavailable

Some experts will be off duty, with patchy cellular access, and the rate of success for hitting such an incoming threat is low, although the Pentagon protested – remember, it is lead by an idiot, the administration there is the quintessential Ship of Fools – I see this as one of the best films of the year, better than Sinners, for this cinephile, and we get to learn such a paramount lesson from it https://realinibarzoi.blogspot.com/20... the West is not ready, and the one who has access to the codes is demented, he demonstrated again, and again, the latest is these days, with Venezuela, threats against Greenland, Mexico, Columbia, and let us not forget the 51st state…Canada

Now for my standard closing of the note with a question, and invitation – I am on Goodreads as Realini Ionescu, at least for the moment, if I keep on expressing my views on Orange Woland aka TACO, it may be a short-lived presence
Also, maybe you have a good idea on how we could make more than a million dollars with this https://realinibarzoi.blogspot.com/20... – as it is, this is a unique technique, which we could promote, sell, open the Oscars show with or something and then make lots of money together, if you have the how, I have the product, I just do not know how to get the benefits from it, other than the exercise per se

There is also the small matter of working for AT&T – this huge company asked me to be its Representative for Romania and Bulgaria, on the Calling Card side, which meant sailing into the Black Sea wo meet the US Navy ships, travelling to Sofia, a lot of activity, using my mother’s two bedrooms flat as office and warehouse, all for the grand total of $250, raised after a lot of persuasion to the staggering $400…with retirement ahead, there are no benefits, nothing…it is a longer story, but if you can help get the mastodont to pay some dues, or have an idea how it can happen, let me know

As for my role in the Revolution that killed Ceausescu, a smaller Mao, there it is http://realini.blogspot.com/2022/03/r...

Some favorite quotes from To The Hermitage and other works

‘Fiction is infinitely preferable to real life...As long as you avoid the books of Kafka or Beckett, the everlasting plot of fiction has fewer futile experiences than the careless plot of reality...Fiction's people are fuller, deeper, cleverer, more moving than those in real life…Its actions are more intricate, illuminating, noble, profound…There are many more dramas, climaxes, romantic fulfillment, twists, turns, gratified resolutions…Unlike reality, all of this you can experience without leaving the house or even getting out of bed…What's more, books are a form of intelligent human greatness, as stories are a higher order of sense…As random life is to destiny, so stories are to great authors, who provided us with some of the highest pleasures and the most wonderful mystifications we can find…Few stories are greater than Anna Karenina, that wise epic by an often foolish author…’

[Michael · Rating 3 out of 5]

On the one hand, Dartnell gives us a concise history of technology; on the other hand, no one should buy this book expecting to revive civilization - that level of detail is just not there. Instead, use this book to ransack a large university library after the apocalypse.

[hien · Rating 1 out of 5]

TL;DR... THIS BOOK IS A LITTLE 'TL;' SO MAYBE 'DR' IT! :(
i wouldn't call myself a "Prepper" in any sense: i don't really stockpile canned goods for anything longer than a potentially bad winter, i don't have hidden tip sheets on how to make our most common tools and materials, i don't go camping and test my survival skills.
i do, however, have nightmares of apocalypse scenarios that end up subtly changing how i address filling my knowledge bank and my appreciation for my current lifestyle.
a couple months ago, i had a dream about the end of the world as we knew it via the Sun's abrupt star death, billions of years before it was meant to happen, and as dreams go it was standard (which means it was totally not standard at all). there were plenty of logical fallacies and plot holes and what i focused on in the dream was building a damn radio so that i could broadcast an SOS and see if there were any other survivors. so of course, when i woke up, i started following along with a mechanical engineering course load at my alma mater and watching plenty of videos about amateur welding and scrap metal scavenging.
what i mean to say is: you don't realize how good you've got it until it's gone, which is an age old lesson humanity learns over and over again. Dartnell's book suffers from being writ in the good before the gone, which means the content regularly and sometimes laughably fails its premise.
i rated this from multiple perspectives: 1) what if i was actually an apocalypse survivor and only had this on hand? 2) is this an enjoyable read in a non-apocalyptic world? 3) if i forget about the title, could i get through this and feel like it was a worthwhile read?
unfortunately, this book fails for me on all those points of view. i found it lacking in essential information that ends up glossed over, whether because Dartnell may think it common knowledge or even sometimes because he just... doesn't want to include it? in the agriculture chapter, he spends time talking about farming tools like a scythe, a seed drill, plows, but doesn't ever say "most crops grow in certain seasons." it's a no-brainer for most, but as we get more technologically advanced as a society there are plenty of teenagers and kids these days that wouldn't know that at all--and preserving precious vegetable spores and fruit seeds in the apocalypse by not planting them out-of-season seems kind of like an important factor of agriculture to me. further on in the book, he acknowledges that aspirin is "the most widely used drug in history," and mentions that it comes from a "simple chemical modification to... salicylic acid," then just stops there and doesn't explain anything else. i just don't think it's as effective as just quickly laying out what is done to get aspirin, which would be useful once society and science have redeveloped enough to put it into action, versus just laying a mention of aspirin out as a tidbit to taunt a survivor with.
Dartnell also spends so much time on preposition: who invented what and when in our world, which can be entertaining but feels like unnecessary fluff for the potential apocalypse-goer needing to learn how to make a damn magnet. it was hard for me to be entertained by these additions knowing that the book is "meant" to be helping apocalypse survivors since i would start thinking about how they would be wasting time reading through this all to try and get to important information. i suppose it would be fun to learn little facts about invention throughout human history if you were just reading this with no apocalyptic strings attached, though. just wasn't the book for me!!!

[Ellie · Rating 4 out of 5]

The introduction does speculate a little about different types of apocalypse, but settles on a viral pandemic as our final foe. This would leave survivors the advantage of a fairly intact infrastructure whilst they find their feet as well as little competition for resources.

The book is split into sections dealing with aspects such as agriculture, medicine, power, construction and more advance scientific methods. It’s not just a survival guide but a reminder of how much we take for granted. Josh had recently shown me the TED Talk for the guy who tried to build a toaster from scratch. Just knowing how it works is not enough but you need to know how to mine and extract the base materials required first. This book is very much on that premise, how even simple things will be much more difficult.

The earlier chapters do deal with scavenging and making the most of what’s been left behind. It also points out these things won’t last forever and why the country is a better bet than urban areas in the long term. With easy access to forests and the sea, where I live right now isn’t too bad a location if the worst happens!

Speaking of forests, trees are amazing. Their potential for fuel is not simply just by burning, you can even rig up a car to run on wood gas. Then there’s charcoal, crucial for filtering water and making compounds essential for further technological advancement. There’s creosote (the thing that makes smoked food taste so good as well as being a fine ting to paint your fence with), sticky pitch, acetic acid (think vinegar) and acetone (think nail varnish remover). Plus you can build shelter with it.

I found the agricultural, medical and chemistry bits the most fascinating and accessible, based on my previous knowledge. We’ve already got some sourdough starter and homemade cider in the corner of the room, so we’re ahead in our preparations, at least when it comes to yeast. Some of the engineering bits went a bit over my head. In practical terms, it gives only a brief overview of what you’d need to know, if you have no prior knowledge you would struggle to do all the things in the book.

However it is thought-provoking and full of facts if you like stuffing your head with facts. There are some things that seem easier than I would have expected once they’ve been explained, which can only give us all hope for the apocalypse.

[Thomas · Rating 4 out of 5]

So, if the apocalypse does come, I really hope I'm not here to deal with it. Maybe I'll be off traveling while it happens or something. Yeah, that sounds good.

The thing is, the one thing Dartnell convinced me of, above all else, is that it's going to be a really hard road for civilization to crawl back out of that pit. Granted, there are a ton of shortcuts available -- for everything except maybe the organic chemistry that, as it turns out, plays a far greater role in our daily existence than most likely realize. But those even with those shortcuts, it's going to be a hard road forward. Forget what the preppers might tell you -- just packing a few years supply of canned goods and stockpile of guns and ammo isn't going to help much.

That being said, this book is a pretty great exploration of the landscape if you really want to understand what it will take to climb back up. If you read sci-fi or any of the post-apocalypse literature that's out there (and there is a log of it), this book is going to change the way you view it. Having recently read Lucifer's Hammer, I realize just how much most of these books miss. It's good to recognize that a book like this isn't going to be a cookbook for bringing society back, but it outlines the range of concerns and developments that will need to happen.

I was honestly tempted to give this one five stars, but I think it would have had to cover a bit more detail, provided about twenty times more illustrations, and likely been about ten times as long to fully satisfy my desire to understand what this book was trying to cover. Of course, I'll need about 5-10 years to give a thorough study if/when that book finally comes to be. ;~)

[Aaron Hook · Rating 2 out of 5]

The two-stars is deceptive. Not really sure how to rate this. I'm very much opposed to the basic premise of the book. The book is meant to be a guide for quickly rebooting our civilization after a catastrophic collapse. Dartnell acknowledges that the most likely scenarios for such a collapse are due to civilization itself. But he never really addresses the elephant of a question in the room: SHOULD we try to rebuild?

That said, the information in the book is great and I enjoyed learning about how so many things we take for granted are produced and how they work. I'd actually highly recommend it from this perspective. But the blind and inconsiderate adoption of technological advances (which will likely plunge us headlong into our own collapse) is probably not the best thing to champion for a potential reboot.

[Lukas Lovas · Rating 4 out of 5]

Yes. I am getting a paper copy or two. This book won't help you survive the apocalypse. But just in case you do...This book will help you keep on surviving, living and even (dare I hope?) prosper. Imagine that everything fails. How long would it take for society to revert to dark-ages state of things? I don't think it would be long....It would actually be a bit worse...For how many of you know anything about farming? Smelting iron? Raising crops? Making soap? ...this book however gives all this basic information. It's not a manual...but it'll give you the ideas and concepts, so that you can figure it out from the scratch. This book might very well save our civilization, if a cataclysm ever comes.
Worth reading, and worth keeping somewhere safe, where the looters (suvivors) might find it :)

[Scottsdale Public Library]

As a dedicated reader of disaster stories both real and imagined, I’ve often wondered how a modern society could rebuild itself in the wake of a true apocalypse. This book attempts to answer that question with solid information on the science and practice of remaking the basics of civilization – from agriculture to medicine, chemistry to energy generation. It also ponders what steps of our historical technological progression could be skipped or avoided entirely; after all, we’re not restarting society from the mindset of cave-men. For a single book, it packs a lot of actionable information, but of course it can’t hold everything. Ultimately it serves as a great jumping-off point for further investigation: not the only resource you’d need, but a good guide for finding more. Well recommended for anyone interested in tech history or disaster preparation.
-- Hillary D.

[Thomas Ray · Rating 1 out of 5]

The premise is blithering. Most of us simply won't survive the collapse of civil society--the collapse of the systems that bring food and water to the almost-all of us who have no way of providing it for ourselves--and the resulting violence. It won't be a lack of knowledge that will limit post-apocalypse survivors: it'll be a lack of order, of resources, of ability to rebuild the systems the knowledge will still abundantly exist to show the theory of.

[Kieran · Rating 1 out of 5]

The final sentence of this book reads “The keys to rebooting civilization may well be within this book.”

They aren’t.

Long winded and impractical, this book is a waste of time.

Dartnell is enthusiastic about the subjects covered here, but he does not cover them deeply enough for the reader to fully understand them, much less reboot civilization.

[Nabila · Rating 2 out of 5]

Interesting, but very dry. So dry, in fact, that it wouldn't surprise me if half of the survivors of the apocalypse would rather die than having to finish this book.

[Javier Calle · Rating 3 out of 5]

Una oportunidad perdida. El autor plantea dudas muy interesantes que nos hacen pensar sobre lo poco preparados que estamos para un escenario apocalíptico de cualquier tipo y cómo profesiones y conocimientos ahora denostados serían los reyes en esa situación. Por ese lado está bien. Lo malo es que el libro está demasiado literado y no acaba ahondando en cuestiones importantes. Habría sido mucho mejor y más práctico si se acercase más al formato manual que quería ser y menos a lo que ha acabado siendo.
Para este tipo de libros, uno lo que quieres son instrucciones claras y concisas, sin tanta paja alrededor.

[whoknowswhynot · Rating 2 out of 5]

I wanted to love this book but just could not get into it. As someone who has read their fair share of post apocalyptic fiction, I feel I have deep understanding of the ‘knowledge’ that would be required to rebuild civilization and while this book laid it out, it either went weirdly deep into some areas (describing in detail how forceps could be used to deliver a baby) but breezing over the science of other things (distilling, filtering, etc.). As a high level look at things it does a good job but it’s a dense read. “How To Invent Everything” by Ryan North does a much better job of tackling the same topic.

[Gendou · Rating 1 out of 5]

This book is no more interesting than clicking around on Wikipedia to find out how stuff works. Really a high school education should teach you everything in this book. Oh, you can make clothes with a loom. Also, lathes are a thing. To make steel, you start with high-carbon pig iron burn the carbon off then add back in the right amount. Cool...

What I was hoping for, and what was promised by the title, was a guide that short-cuts certain steps in technological development. Instead, he tells us how to make do with the junk left over from an apocalypse. I mean, if you're writing a zombie novel, that's cool. But I want to understand which steps are arbitrary in human technological history, and which are necessary. I don't think anyone really knows that, so I'm not surprised. Just disappointed.

The book isn't even very well edited or organized, either. Real sloppy.

[Eugenio Gomez-acebo · Rating 4 out of 5]

Me ha divertido este libro en tiempos de cuarentena por el COVID-19, y coincide bastante con la apreciación de que en las sociedades modernas hemos perdido mucho del conocimiento básico que nos ayudaría a iniciar una civilización desde cero.

El ejercicio mental parte de la premisa de que quedamos unas 10.000 personas vivas tras una pandemia, con el planeta básicamente como está ahora, tipo "Soy Leyenda". La catástrofe nuclear no nos permite arrancar de nuevo. Como se ve en tiempos de cuarentena, lo primero que llama la atención es cómo la naturaleza reclama su sitio y se abre camino. Habría muchos incendios, especialmente en ciudades. A medio plazo habrá que huir de ellas, no serán seguras. Demasiado gas almacenado, explosiones. Hay que ir al campo, y mejor hacia la costa.

¿Qué pasaría en los primeros meses? ¿Qué hay que hacer? Lo primero, buscar cobijo, alimentos y agua. Necesitaremos 3 litros de agua por día. Nos explica cómo filtrar el agua con carbón vegetal y arena. También las botellas de agua servirán, y mejor al sol para esterilizarlas. El pegamento nos servirá para cerrar heridas. En cuanto a comida, un super nos durará 55 años, con las latas y conservas. La gasolina no durará tanto, 10 años máximo. También explica que hay que ir a un campo de golf para buscar las baterías de los cochecitos, alternadores de coches para disponer de generadores eléctricos. Los plásticos, mejor PET.

A medida que vamos repasando disciplinas la cosa se complica y el poder replicar lo que explica el autor resulta más complejo. Empezamos con la agricultura, una práctica tremendamente artificial y hambrienta de nitrógeno, fósforo y potasio, así como pesticidas. Hay que volver a la agricultura tradicional. Nos explica la composición del suelo: arena, limo y arcilla en proporciones ideales 40/40/20. Habrá que reinventar el arado, una máquina para dar la vuelta al suelo; la grada, para aplanar; la sembradora. Plantar las tres principales: maíz, arroz y trigo. Y ya después cebada, sorgo, mijo, avena y centeno. Para evitar el barbecho, plantar leguminosas: guisantes, alubias, trébol, alfalfa, lentejas, soja y cacahuetes. Es lo que se llama el sistema Norfolk: Leguminosas, trigo, tubérculos y cebada. Los tubérculos nos ayudarán a alimentar el ganado, que nos dará estiércol y carne. El estiércol humano hay que pasteurizarlo a más de 65 grados. Y para obtener fosfatos: harina de huesos y ácido sulfúrico para dar fosfatos.

El siguiente capítulo nos cuenta la historia del alimento, y la invención de la cocción como herramienta digestiva fundamental. Explica las técnicas de conservación de alimentos (desecación, sal, vinagre, ahumado). Luego explica cómo hacer pan con la harina que surge de pulverizar el grano. También señala la importancia de la levadura, sobre todo para hacer cerveza. Y muestra cómo hacer una nevera sin electricidad ni compresor, un refrigerante de absorción. De la historia de la ropa, me quedo con lo complicado que es esta industria hoy. habrá que aprender a tejer lana. Y como curiosidad, el botón se inventó en el año 1300.

Lo siguiente es hablar de sustancias. Hay que rescatar el carbón vegetal como combustible, ya que pesa poco y tiene un gran poder calorífico. Se hace quemando madera sin oxígeno. Aprendemos a hacer velas de cera animal. Cal viva, se hace con carbonato calcio a 900 grados. Jabón, a partir de grasas animales con potasa que se obtiene de la ceniza de madera. Arcilla, a base de cocer barro. Mortero de cal y cemento, presente en época de los romanos (el Panteón). El cemento hidráulico, hormigón armado, metales (acero). Y por último el vidrio, que no es más que arena fundida con sosa.

El siguiente capítulo es sobre medicina. El peligro más relevante en un mundo postapocalíptico es la infección, por lo que seguirá siendo importante lavarse las manos. Para el cólera, el tratamiento es evitar la deshidratación, por lo que hay que beber mucha agua. Habrá que inventar el forceps, para ayudar a dar a luz. El estetoscopio, y ya para nota los rayos x. Si hay que hacer cirugía, las tres As: anatomía, asepsia, anestesia. Por último explica como hacer penicilina. No sabía que era tan laborioso.

Sigue con la energía. 14000 kWh son 3000 kg de madera seca, es decir 0,25 ha de bosque. La hidroeléctrica deber ser la primera: los romanos inventaron la rueda hidráulica vertical. Hasta la Edad Media no surge la rueda hidráulica de corriente alta. El molino de viento es más sofisticado, ya que requiere de elementos de frenado y orientación. Nos anima a reinventar la máquina de vapor vertical con presión atmosférica. Las turbinas Kaplan y Pelton. Nos explica la ley de Ohm, y aunque está mal formulada, se argumenta bien porqué es mejor llevar corriente alterna que continua. Explica qué son y como funcionan los transformadores (inducción electromagnética). Lo que está claro es que todo tendría que ser un poco prueba y error.

En el apartado de transporte, la cosa es un poco ciencia ficción cuando anima a construir un motor de explosión o incluso una máquina de vapor . Habrá que reinventar el yugo para el transporte con animales.

En la sección de comunicaciones, se explica cómo hacer papel con celulosa: está muy metida dentro del tronco del árbol. Hay que usar un proceso que se llama hidrólisis. Es el mismo proceso que se usa para que el jabón y para ello se usan los mismos álcalis: potasa, sosa o cal. Para hacer tinta podemos usar cualquier cosa que manche. Añadir sal para que sea conservante. La tinta para que no se vaya con el sol se llama tinta ferrogálica. Nos invita a descubrir el morse. Luego nos anima a inventar la imprenta, y la radio; es fascinante cómo se hicieron radios rudimentarias durante la II Guerra Mundial.

La química avanzada tendrá que ser pilar fundamental para avanzar como sociedad. Aquí nos explican varios procesos básicos (y creo que imposibles de reproducir en una isla desierta). La electrólisis, la fabricación de explosivos, basada en el ácido nítrico como poderoso agente oxidante, la pólvora (con partes iguales de salitre y azufre con seis partes de combustible de carbón), la nitroglicerina, muy inestable y para lo cual se añade un material absorbente para hacer cartuchos de dinamita, invención de Nobel; la fotografía. La química industrial basada en hacer dos componentes básicos: sosa y nitratos. La sosa se necesita para fabricar vidrio, jabón y papel, y se hace con un proceso muy ingenioso a partir de sal común llamado proceso de Solvay. Los nitratos se obtienen si somos capaces de sintetizar amoníaco. Es un descubrimiento clave en la historia de la humanidad. Si el guano y estiércol se acaban y el nitrógeno de la atmósfera es muy abundante, pero poco reactivo, debemos acudir al proceso de Haber Bosch. Básicamente es mezclar hidrógeno y nitrógeno 400 grados y 200 atmósferas para obtener nitrato de amonio.

El libro termina con la reflexión de cómo medir el tiempo (el reloj de arena, de sol y mecánico) y como conocer dónde estamos (latitud por estrellas y longitud con un buen reloj). Finalmente, apunta que lo fundamental es obviamente el método científico, la prueba y error. Resultaría descorazonador volver a quemar a gente en la hoguera.

[Kate · Rating 4 out of 5]

Full disclosure, I received an advance copy of this book through a GoodReads contest.

That said, I can honestly say I enjoyed this book very much. Dartnell does a very good job setting up the parameters for his thought experiment about exactly what knowledge survivors of an apocalypse would need in order to rebuild society. Because he sets up early on just exactly what type of apocalypse he's using (pandemic infection that leaves man-made structures intact) and about how many survivors he's working with, I found his conclusions exceptionally plausible.

I am a sucker for dystopic books and survival stories, and I would recommend this to my friends who share those likes. Dartnell does go into very technical details in some sections (especially the Substances chapter on chemicals and such) which is definitely not my strong suit. Although I didn't understand that section completely, I got the gist, and believe that despite being very elevated in the concepts and academic in the descriptions, the content is still accessible to laypersons (which, when you think about the goal of the book, is exactly what he was going for). One of my favorite examples of this is his line "So the next time you're warmly tipsy, remember that your brain has been mildly poisoned and impaired by the excrement of a single-celled fungus. Cheers!" (p. 84 on my advanced copy)

[Fernando del Alamo · Rating 5 out of 5]

Imagina que desapareciera de golpe gran parte de la sociedad que te rodea, o que hubiera una guerra y te vieras solo... ¿serías capaz de sobrevivir? Al principio tendrías los supermercados llenos (ojo, sin electricidad) y farmacias a tu disposición pero, ¿sabrías qué alimentos o medicinas consumir?

Este libro intenta ser un manual de lo que el autor considera conocimientos mínimos que deberíamos tener para poder intentar hacer una sociedad nueva. Tendríamos que volver a cultivar nuestras plantas para procurarnos alimentos, conseguir materias primas, tener unos pocos conocimientos mínimos, máquinas de vapor, etc. Por supuesto, olvidad el petróleo que casi está agotado.

Es una guía interesante que habla desde el método científico, de algo de biología, medicina, sociología, economia e ingeniería, así como de procesos industriales como el proceso Faber-Bosch para obtener nitrógeno.

Piensa que debes fabricarte todas las cosas de primera necesidad, como ropa, jabón para lavarte, etc. Un libro muy curioso que no te deja indiferente. A mí me ha dado pie a pensar que hay cosas que explica que deberían estar en el sistema educativo. Después de todo he concluido que yo no sobreviviría.