I am the author of 'The Knowledge: How to rebuild our world from scratch' about the science and technology you'd need to reboot civilisation as quickly as possible after an apocalypse. AMA!

Dr. Lewis Dartnell, in a recent article you wrote for the Telegraph titled "What would happen if satellites fell from the sky?" you mentioned a Google funded study that estimated driving times had been reduced worldwide due to GPS. Could you send me a link to that study? I'm looking to get a hold of that study in its entirety.

Sure! The most useful link I think is this one: http://www.oxera.com/Latest-Thinking/Publications/Reports/2013/What-is-the-economic-impact-of-Geo-services.aspx

Thanks much! Are you aware of any other studies that may measure economic impact of GPS or even satellites in general?

I've got a few other interesting references, yup, and would be happy to help. Could you give me a few hours to dig those refs out for you? Email me on [email protected] and I'll get back to you with my notes from that satellite article

1) In your view what would be the most serious threat to the survival of humanity if civilisation were ever to collapse?

2) Heard of the Human Interference Task Force? Thoughts?

From Wikipedia:

The field of nuclear semiotics arose in 1981 when a team of engineers, anthropologists, nuclear physicists, behavioral scientists and others was convened on behalf of the U.S. Department of Energy and Bechtel Corp. The goal of this "Human Interference Task Force" was to find a way to reduce the likelihood of future humans unintentionally intruding on radioactive waste isolation systems.

1) The worst way for civilisation to be toppled, in terms of how difficult it would be for survivors to recover again afterwards in the post-apocalyptic environment, would be something like an all-out global nuclear war, or a large asteroid strike. If you can't even reinstate successful agriculture because of a nuclear winter or the soil itself is poisoned and radioactive, there won't be much hope for a rapid reboot!

2) Yes, I've come across the Human Interference Task Force whilst researching. It's an intriguing idea! Closely related to the problem of how to communicate with intelligent alien civilisations (i.e. SETI), if they exist - how can you design a system for communication that is unambiguous and gets your meaning across, even if no common ground is shared...?

We considered ourselves a powerful culture.

I've always felt there's something almost Ozymandias-like in the message to the future proposed for the Yucca mountain & WIPP disposal sites.

Yes, definitely! That's in the British Museum now - it's absolutely awe-inspiring! I've written a feature article related to this, and 'ruin lust': http://the-knowledge.org/en-gb/2014/04/the-morning-news-demolish-me/

Should local and/or national governments subsidize resilience projects, for example, people working continuously with heirloom domesticated plants and animals, or 'library in the sky' satellites?

I think that would certainly be a very good idea. And there are some resilience study departments at universities and privately-funded projects talking about very similar themes, like the Long Now Foundation http://longnow.org . I've written a bit more about these projects here: http://the-knowledge.org/en-gb/2014/03/similar-projects/

What's a library in the sky though..? I've not come across that term before. Simply a digital library that can be commanded to transmit it's preserved information back down to the earth once prompted after the apocalypse?

The only time that I've heard a library in the sky referenced was by a sociology professor I had.

He talked about having a satellite in constant communication with some sort of ground control, constantly receiving the signal from earth saying "we're all still alive, the lights are on, we're ok." If the signal stopped, the satellite begins reentry at a certain point in its orbit with the intent of having it land in a predetermined location. He said it would be useful for it to have a variety of payload, from a literal library to seeds and water to bacteria.

That discussion was the result of a tangent from discussing societal collapse in...Egypt, maybe, in a lecture and it ended pretty quickly. I dunno if anyone has planned or is planning to have a satellite like this but it sure is a cool idea.

Ah, I see. Interesting idea. I wonder what advantages there would be to de-orbiting a satellite into a specific predetermined location, rather than simply building a secure facility in that same location. (satellites are necessarily small and limited in the mass of their cargo, and re-entry carries huge risks of failure!)

What are the avarage chances of survival if not prepared?

That would depend hugely on the nature of the disaster. If, say, the global power grids get knocked down by a coronal mass ejection (CME) from the sun and society collapses then you might find a horrific situation of competition for the rapidly dwindling resources. In which case, a hidden fortified compound with several years of stockpiled food would clearly help your chances. But with something like a pandemic that rapidly kills much of humanity (i.e. the opposite scenario), you might fair pretty well even without having prepared beforehand, by being able to scavenge what's been left behind.

For the record, I'm not a prepper myself, and have taught myself only a few basic skills, more out of interest than any belief that the world as we know it is genuinely about to end.

Something I muse myself with. Say, a few hundred years from now, seafood is basically wiped out, all the rainforests are nearly gone, every metropolitan dense as fuck and is about as polluted as Shanghai is now, etc, etc. What would be your recommendations, say, if humanity wasn't wiped out immediately by an asteroid or pandemic, but rather dies slowly due to infighting and civil unrest caused by diminishing resources and overpopulation?

If anything, that'd be the worst possible way for civilisation to collapse, at least from the point of view of being able to rebuild again afterwards. The survivors, knocked down to rudimentary means, would find the world impoverished of natural resources and they'd probably have a far, far harder time of rebooting them we did the first time round

I'm pretty sure the apocalypse is coming, but I'm time poor. What's the single most useful piece of technology I should bone up on?

Ps. Really enjoyed the astrobiology book btw, really good introduction to planetary science

Thanks very much! Single piece of technology - I suspect you won't go far wrong teaching yourself basic tool use: carpentry, a basic metal working, using a lathe, etc.

Is that for the purpose of making a living after the collapse of for the purpose of building useful structures?

Well, both on an individual level it'd be great to have some skills and expertise that will actually be useful after an apocalypse, and in the longer term it's tools like a lathe that will be critical for producing all the machinery civilisation will need to recover

In your book, you didn't discuss much mathematics (ordinary differential equations? design of experiments?) nor information about social structures (double-entry bookkeeping? joint-stock corporation?).

Was that because you think those ideas would be difficult to distill and relatively easy to rediscover? Or some more prosaic reason like "I only have so much time to research and write" or "I want to tell an entertaining story"?

No, you're absolutely right of course. I had a chapter on mathematics planned out, but ended up dropping it. For the simple reason that it just became impossible to handle it in the same way as all the other sections. You can tell someone in just a few pages something really fundamental and meaningful about the chemistry behind making soap or glass, or the key mechanism in a waterwheel, but not really with mathematics. That's not to say maths isn't crucial for running today's world, and has been throughout history, but it was an editorial decision made for what is at the end of the day a popular science book. Maybe for the next one..!

Fundamental and meaningful things about mathematics can easily be said in a few pages; unfortunately, it will take the student several days of study to understand each page, because there is still no royal road to geometry.

It's a really interesting question how important these social structures are for a materially prosperous society. I think the answer is "very, very important," but it's really tricky to put into a book.

I agree with you, but ultimately The Knowledge is a popular science book and not a maths textbook and so an editorial decision was made. And to be fair, looking at the vast majority of maths books published for a popular audience, they don't actually explain the deep workings of mathematics itself, but are concerned with puzzles and the stories of mathematicians.

Are there certain areas of the world you think would be better (or worse) to be living in during a collapse? For the sake of weather, or social mindset, or resources etc?

Also, if you could suggest one skill for someone to master (there will be no zombies, so it's probably not cardio), what would it be?

Clearly, trying to reboot civilisation (and the basis of that is of course going to be reliable agriculture) in freezing cold polar regions, or dry desert regions, or very small islands with limited range and volume of resources, is going to be very difficult. Much better to get yourself to a region with temperate climate, good fertile soil, with a near-by forest for providing firewood (and a whole bunch of other functions), and perhaps also by the coast for access to fishing as a great source of protein. Such a situation would definitely stack the odds more in your favour. But I don't think there's anywhere in the world that would be particularly good - Asia, Europa and the Americas have all sprouted numerous civilisations throughout history, and would be just as suitable after an apocalypse that collapses our current civilisation

I would also think though that places that are harder to live in now would have an easier time adapting to harsher living environments. If drought and famine are something that you have to plan for regularly you would be better equipped to deal in the case of a major problem.

Yes, of course. But in the long term, building a complex civilisation requires citizens to develop specific skills and crafts and that requires releasing them from working in the fields. Productive agriculture and providing a food surplus is a prerequisite for progression - where one person can feed ten others - and you've much more able to achieve this where farming isn't marginal. Giving the choice, I'd much prefer to restart in temperature conditions, rather than living in fear of drought

Dear Dr. Dartnell,

As someone who considered the possibility of some type of collapse, I plan on reading your book soon. However, I am convinced that if there is some type of cascading systems collapse (electric and water grid) WE WILL BE SCREWED! Big time. Have you seen this video about what will happen to all the nuclear power plants if electricity stopped :

http://www.youtube.com/watch?v=91JZCbGLCvk&feature=player_embedded

It seems that those that don't die off from the event, the rest will die from all the radiation leaked from the 400ish meltdowns that take place. Look at the maps of where nuke power plants exist. Especially in europe and USA. Seems like there needs to be a special group that is trained now that would somehow go to all the nuke power plants and keep the cooling pools going for eternity or until some type of technology was created to deal the the nuclear waste. I'm no fan of continued technological "progress" , but it seems like we have crossed a point of no return with nuclear energy. If the electrical grid collapses, all the those nuclear power plants will meltdown, and meltdown in ways unseen in the history of nuclear energy. Chernobyl and Fukashima are nothing compared to simultaneous full meltdowns at all nuclear power plants. Thus, even if some survive a collapse, it seems unlikely that there would be a future for most species (except those tolerant to high levels of radiation).

Hi, yes, the problem of the ~400 nuclear power stations (as well, of course, as all the naval ships with reactors on board for propulsion) is something I looked into for The Knowledge. My understanding was that a melt-down would be prevented by the fail-safe mechanism - i.e. control rods dropping down into the reactor purely by dumb gravity if the power fails, and not needed any human intervention. But in the longer term, with no humans to maintain or monitor the nuclear power stations, erosion and degradation would eventually start exposing the fuel rods to release radioactivity into the local environment - especially if the cooling pools for the spend rods dry-out and a fire starts. But I'll take a look at that youtube video now, thanks - I may well have misunderstood something!

Which post-apocalypse science fiction is most accurate?

My favourite post-apoc sci-fi includes The Death of Grass, Earth Abides, and A Canticle For Leibowitz - to pick only three! It's a very rich seam of thought-provoking literature. If you're interested, I've got a more compete list of my recommended favourites here: http://the-knowledge.org/en-gb/2013/12/novels/

Is there one basic technology everyone should master?

Hmmm. In general terms, I think all of us living in the modern world would feel a bit more satisfied if we had a go at *repairing things every now and then. This of course is getting harder and harder when automobile engines are computer controlled, and you can't even recognise the components in a modern phone or radio because it's all embedded in microchips. But tinkering with things, and the Hacker, Maker, Craft communities I think are all on to something really important.

What's the most annoying thing that post-apocalyptic TV shows miss/ignore (I'm looking at YOU, The Walking Dead)

Yeah, so don't mention the 'Z' word...! Zombies are a great fantasy horror, but scientifically impossible. But you can't fault sci-fi for its premise, I suppose. I guess the most obvious lapse, for clear stylistic reasons, is that everyone in a post-apocalyptic world often seems to healthy, with perfectly conditioned and moulded hair. But with a few tatters on their leather jacket and a brush of dust on their forehead... ;o)

Although large numbers of very hungry people (that's a euphamism for cannibals...) make a pretty good proxy. http://en.wikipedia.org/wiki/Nazino_affair (shudders)

True enough...! It's for that reason that the best scenario for an apocalypse would be something swift and clean, that wipes out 99.9999% of the people, but leaves all the _stuff left behind. So something like a viral pandemic could cause a severe population crash, and give the survivors an opportunity to recover without too much competition from each other

It's for that reason that the best scenario for an apocalypse would be something swift and clean, that wipes out 99.9999% of the people

7000 people left over, that's quite the apocalypse. That raises even more questions for me. With a mega-apocalypse, I feel like you'd have a hard time even FINDING another person.

You're right - I've been sloppy with my notation. I was intending to mean an 'arbitrarily large fraction of the current population'. The starting point that I picked was a surviving community of a few tens of thousand, able to work together and not slide back to a subsistence existence

Assuming that the complexity of our global civilization is based on fossil fuels, and further assuming that there's insufficient net energy left to implement a global alternative energy infrastructure, could civilization be re-built without easy-to-access fossil fuels?

That's the million-dollar question...! For the sake of the book, I focussed on the thought experiment about what are the fundamentals of civilisation and how did they develop over history (so it's actually more about how _our world works, and the apocalypse is only really a narrative conceit). But it did really niggle at me as to whether the civilisation that comes after us would really struggle to provide for its energetic requirements - particularly for the thermal energy needed for kilns and furnaces. Kevin Kelly has pondered whether a civilisation starting from scratch would be able to skip over a coal-fired Industrial Revolution straight to solar panel technology, but even that requires some pretty sophisticated techniques in purifying silicon wafers. The low-tech way for harnessing solar power is of course to crop biofuel crops, or at least biomass for burning in power stations - this is effective in Scandinavia with their sustainable forests. But coppicing fast-growing trees will only get you so far, and that's why 18th century Britain turned to coal in the first place...

Yeah, we've done biomass before, and it simply doesn't provide the massive net energy that industrialization requires. I'm haunted by the idea that if we fall apart because of our dependence on that cheap energy, there will never be another industrialized human society.

I think that's a very reasonable possibility! All the more reason to take care of things now...

All the more reason to take care of things now...

I'm also afraid that we have all the more reason to take care of things starting fifty years ago. We may have insufficient energy remaining to implement the necessary changes, and we sure don't have the political will and the infrastructure to effect the global co-ordination needed.

If only smart people were in charge...

And this is where the idea of the Long Descent http://georiot.co/kYC comes in. A lot of politicians are very smart, but I think the more general problem is the short-termism that a four-year voting cycle encourages

Thanks for the reference, I haven't read that one. Yours too looks very interesting. I was just musing this morning that probably no-one in my family or community knows anything about animal husbandry, and wondering where that knowledge would have to come from some day :)

Thank you! Certainly none of my friends or family know much about raising animals either. Not much cattle in London any more...

Do you think there's a possibility of a Last of Us sort of situation? Is it possible that a fungal parasite such as the Cordyceps could actually mutate in such a way to affect humans as it does in the game? Or for that matter, is it plausible for any parasite/virus to have that effect? Thank you for this AMA :)

Most human pathogens throughout history have actually been caught from the animals that we domesticated - dogs, cattle, sheep, etc. So the pathogen - whether that's a bacterium or virus - has to 'jump' species from the original host into the human population. This is achieved by mutation, and the concern is that certain strains of swine flu or avian flu will also acquire the necessary mutations to be transmitted effectively to a human, and then from person to person. HIV transferred into the human population relatively recently, whereas influenza has been with us for millennia.

What is the first thing you will be looking for if you survive apocalypse.

In the first few days of the aftermath, without a shadow of a doubt your priorities are going to be to ensure you have a reliable supply of uncontaminated drinking water. It'll stop flowing out of the faucets pretty soon, and from then you'll need to find sources of ground water - something none of us living in cities today (myself included!) probably would never have had to do before. You can filter water using layers of charcoal and sand, and then sterilise it by boiling. Or to save fuel, kitchen bleach or even swimming pool chlorine, DILUTED APPROPRIATELY, can safely disinfect water for you

Or to save fuel, kitchen bleach or even swimming pool chlorine, DILUTED APPROPRIATELY, can safely disinfect water for you

Instructions unclear; drank bleach. :(

Typing in agony...? ;o)

OK, to be precise: Just a few drops of a 5 per cent liquid bleach solution that has sodium hypochlorite listed as the main active ingredient (i.e. normal everyday kitchen bleach) will disinfect a litre of water in an hour.

What if apocalypse is caused by aliens. Can be the possibility. What is most powerful thing you can imagine or think of aliens would have?

So this links into my actual field of scientific research - astrobiology... It seems that even if life is common in the galaxy (i.e. plenty of wet rocks out there smeared with microbial lifeforms) that complex, animal, intelligent, technological life is rare. We may even be alone in the galaxy in that sense - no aliens that you could actually have a conversation with. But for the sake of the thought experiment, if an intelligent race of aliens has the technology to travel between the stars to come to the Earth picking a fight, they will almost certainly have the capability to wipe us out from orbit if they so chose. Even with weapons we understand ourselves, like hydrogen bombs (fusion weapons) it would't much to bombard us into oblivion

Is there a chance of using bioengineering and/or domesticated microbes to replace the Haber process for nitrogen fixation, something like the Clostrida-based acetone process?

Alternatives to the industrial chemistry of the Haber Process are being researched today, but I think you'd struggle to achieve this knocked-back to basics. But then, you can simply use nature's-own solution: planting leguminous plants like peas, clover, soy, etc.

You're like a real-life Hari Seldon, awesome!

One of my favourite books! Well, the first Foundation at least, the others got a bit funny...

What is your opinion on a Long Descent type scenario? No cataclysm, just the slow unwinding of civilization over the course of decades and centuries due to environmental degradation, resource depletion, political and economic crisis, etc? Death by a thousand cuts rather than apocalypse. Like how Rome and other great civilizations fell?

Yeah, I've read that. It makes for a less dramatic beginning for a thought experiment (like The Knowledge), but is perhaps a more likely scenario. The hope might be that civilisation can retract (ie. in terms of total population size and resource demands) gently enough that there isn't a great loss of life during the process

What would be the best government structure during the rebuilding process?

This is a really important point, and not something I talk about in much depth in The Knowledge (the book focusses on science and technology enabling a rapid reboot). One reason why I didn't include, for example, a 'Ten Step Guide to Creating the Perfect Democracy' is that at the end of the day its the guy with the biggest gun, or at least the most people in his gang (/army) that gets to decide how people are governed... There has been a long process of social reforms and revolutions from a medieval feudal society to the liberal democracies of today, and although certain shortcuts could be taken in science and technology, I wonder to what extent social development could be controlled. Probably not much is my hunch

Why should we want to reboot civilization?

Very fair question! I'm presupposing that post-apocalyptic survivors would want to work hard to rebooting civilisation. But I think it is fair to say that if you're struggling to feed yourself with ineffective agriculture, or your children are dying of infectious disease, or your day-to-day existence is laborious and punishing, you'd probably be interested in something that could alleviate that for you. That's what science and technology provides - over time it has created a world (at least in developed nations...) of abundant and varied food, effortless travel, astonishing effective medicines, and so on, and so on.

Unfortunately most of the people I know who are struggling to feed themselves with ineffective agriculture and whose children are vulnerable to dying of infectious disease don't have a lot of faith in this whole "civilization" thing, much less "science" and "technology" — they feel it's kind of failed them and is failing the world. Perhaps this is a sufficiently unusual self-selected group that their opinions wouldn't be the mainstream in the wake of a civilizational collapse, or perhaps not; do we have good records of public opinion after previous collapses?

I'm not saying that social injustice and wealth imbalance are good things in today's world, but if you don't have any science and technology then everyone is starving or dying of diseases. Who are you saying is the unusual self-selected group: the privileged or the disadvantaged? I'm not an historian of civilisational collapse so I don't really know about written records on that, to be honest, but it is an interesting thought

Maybe more a of a philosophical question, but an interesting one I think:

In the event of cataclysm and subsequent rebooting of civilization, do you think the resulting society would be on a path to a better place than where we are now? Would have a more global and necessarily self-reliant civilization, or are we now so detached from our more survivalist past that we'd have a hard time getting back on our feet at all?

That's a really good question, and something I thought a lot about but I'm not sure I ever really came to a proper answer. With hindsight, starting again from scratch a post-apocalyptic society could try to avoid making the same mistakes that we made, and would certainly be able to leap-frog over certain intermediate stages and bee-line investigation towards the most useful kinds of technology - that's the basis behind the possibility of an accelerated reboot. And whilst Industrial Revolution 2.0 would have access to a lot of coal still (as long as you're lucky to have open-cast mines nearby, or can successfully ventilate and drain deeper mines), we've already removed much of the readily-available crude oil. So a rebooting society would probably be forced down different routes than we had available to us. But I think you're right, as individuals (including myself!) most of our survival skills have atrophied to such an extent we'd struggle to support ourselves once civ collapsed. Far more so than a few hundred years ago

Thanks! In your research, have you come across any attempts to quantify just how much most people's survival skills have atrophied? Any kind of representative "survival skills survey" that would help reveal weak spots in our ability to survive?

Short answer, no. But I think it'd be a very interesting study. I think the trick would be in somehow quantifying the degree to which someone's survival skills have atrophied. And then being able to compare over time.

What do you think is the biggest threat to humanity right now?

If I were a betting man, I would say that the greatest threat to the continuation of civilisation as we know it might be a lethal pandemic or a coronal mass ejection, although it's also worth saying of course that there's no reason to expect either in our lifetimes, or indeed in the next hundred years

I am just curious , why coronal mass ejections, the way i understand it the amount of energy required to produce a coronal mass ejection that could actually damage the earth in a lasting fashion would not happen without outside influenze from our sun in its current state. The sun produces lots of coronal mass ejections all the time, averaging about 3 a day. Usually they represent themselves with disruptions to communications, increased magnetic activity and usally increases in Northern and Southern lights activity. I am genuinely interested in what might cause one that could kill most of us, i like learning new things!

You're right, a CME wouldn't damage the Earth itself or directly kill a human, but our modern civilisation is much more vulnerable than the planet itself. A sufficiently large CME would set the Earth's magnetic field ringing like a bell, which would in-turn induce huge currents in any long wires. So a CME isn't biological-hazardous, but it would hit our modern civilisation where it hurts - our electricity distribution grids and overloading the countless transformers. A very large CME occurred in the year 1859 (I'm currently modelling this for my academic research, as it happens), and is called the Carrington Event, after the astronomer who spotted it. The world was basically pre-electrical back then, but it still reportedly caused sparks from the few telegraph wires that started fires. Imagine what would happen if the same CME were to hit Earth today, with huge networks of metal wires, and more importantly, a society that is utterly reliant on electricity

I guess i didnt really think about it like that, even though i should have since i know it has very large electromagnetic impact when they occur. Now i guess my other question would be, is the current EMI shielding we have on newer structures and other important electronic equipment suffiecnt enough to cover them from most of the damage of such a large CME event. Also thanks for pointing out my lack of scope and the new info :)

Good question, don't know for sure! You can protect all of your appliances and gadgets at home, but when you're talking about the electricity distribution grid across an entire continent I think it's much harder to effectively shield every single one of the vulnerable parts. This would of course also be inordinately expensive, and so again economic factors come into play - why pay such a huge some of money to protect against something that might not happen this century..?

The odds of a Carrington-size event in the next decade are either something like 4%-6% or 12%, depending on which scientists you ask ( http://onlinelibrary.wiley.com/doi/10.1029/2011SW000734/pdf ; http://polaris.nipr.ac.jp/~ryuho/pub0/Kataoka2013SW_CarringtonStorm.pdf ). Either of these seems uncomfortably high to me, given that Oak Ridge has judged that even a storm of the size of the one we had in 1921 would probably be catastrophic for half of the U.S. ( http://web.ornl.gov/sci/ees/etsd/pes/pubs/ferc_Meta-R-319.pdf ). Furthermore, since the stats are pretty similar every decade, it seems pretty clear that one of these major storms will eventually hit us, hopefully later rather than sooner.

So I'm surprised to hear you say you don't think it's worth investing in shielding our major transformers. If one of these things is bound to hit us sooner or later, wouldn't we improve our odds if we erred on the side of trying to prepare the grid for it sooner?

It's not my opinion that it's not worth investing in shielding - I was just pointing out one possible economic argument as to why it's not already been done: in terms of the balance of risk and cost.

I am inclined to agree , thank you for your time and responses!

Cheers!

Thanks for the response!

You're welcome!

I'm an archaeologist and an anthropologist with many years of experience. Rate my ability to survive on a scale of "Wall-E style hover-chair" to "Almost Indigenous".

Can you create a bronze-age tool...?

Raw materials would be too hard to come by. Flints or nothing.

Are you familiar with the Foxfire series? https://www.foxfire.org/

How important is low-tech/no-tech in any sort of recovery?

I'm not sure I agree with you that raw materials would be too hard to come by. Which raw materials? (and bearing in mind that if our civilisation collapses all of the stuff doesn't disappear - you could simply scavenge iron from the dead cities and wouldn't need to smelt your own iron ore in the immediate aftermath). But yes, I've read all of the Foxfire series whilst researching for this book, and reference it in the bibliography http://the-knowledge.org/en-gb/bibliography/ - really eye-opening stuff! Another really interesting resource I came across were the low-tech website http://www.lowtechmagazine.com

There is a good chance that an apocalypse that requires rebuilding from scratch will be man made. Or it will be natural but we dismissed it. Either way we failed to take appropriate action to prevent or reduce the consequences. Besides all of the factors you promote to restart what would you suggest we do to mature our species to make sure we don't just repeat history with another apocalypse in a few thousand years that we could have acted on but didn't?

You know what, I'm not sure we necessarily could. Even if we inscribed some crucial lessons to avoid repeating the apocalypse again nice and clearly on the side of a mountain, would it have any effect? In that our civilisation did self-destruct (in this hypothetical situation), why would the society that comes after us necessarily want to take our advice...? I'd be a bit like a parent trying to tell his or her child: "Do as I say not as I do"...

What do you think about Open Source Ecology and the Global Village Construction Set?

Yep, the GVCS is an excellent attempt (and incidentally I've written about it here: http://the-knowledge.org/en-gb/2014/03/similar-projects/ ). They've made some good first steps in creating a mutually-self-supporting set of tools and machinery, and it would be awesome once they've created some of the more complex items in their set of 50

What do you think about my idea that the solution to fermi's paradox is that there is a convergent evolution whereby all lifeforms that achieve digital technology eventually achieve full conversion to near planck scale as possible computronium which explains all the dark matter in the universe. Dark matter is just computronium.

There's a common trope in sci-fi that advanced civilisations in the galaxy get bored with reality and upload themselves into computers, which can simulate reality in indistinguishably high fidelity and in fact run at a higher clock speed that reality (eternity in an instant...). Iain M. Banks plays with these ideas wonderfully, with his 'Minds' entertaining themselves by playing with alternative universe models, and 'Sublimed' races. This is all very feasible. But I'm not sure these computers need to be invoked to explain dark matter in the galaxy

In a post apocalyptic world, how much of the population would die from disease alone?

Good question. It would depend on the exact circumstances (are people still running around shooting each other for a can of beans...?) but a relatively peaceful post-apotcalpytic society knocked back to more rudimentary means would be in a similar situation to Europe or the US before the 'demographic transition', where the main cause of death was transmissible disease or injury (before the invention of effective medications, surgery, etc)

I'm really excited to see your book! I've spent a fair amount of time thinking about related issues (how to make a bicycle from raw materials, an unfinished design study for a durable computer time capsule to preserve The Knowledge for post-apocalypse generations, how to build digital computers with stone-age materials, maybe you can make a trackpad from garbage, how to bootstrap an electronics lab from e-waste, how to bootstrap post-apocalyptic telecommunications, microfilm preservation of information using laser printers (see this three-page 600dpi King James bible), using toner transfer to etch stone tablets, and perhaps most popularly, bootstrapping a usable software stack on a bare-metal computer, for which my best effort so far is a self-compiling compiler in two pages of code) but I have very little experience actually doing things like this in practice. (Vinay, /u/hexayurt, has a lot more experience with it.)

So what I want to know is this. How can we carry forward the project you've started by publishing your book? To take a minimal example, the book excerpt in Scientific American explains:

Sodium thiosulfate is the fixing agent still used today and is relatively easy to prepare. Bubble sulfur gas through a solution of soda or caustic soda, then boil with powdered sulfur and dry for crystals of “hypo”.

I think this should read "sulfur dioxide gas" rather than "sulfur gas", since sulfur doesn't boil until 444°, at which point you can't bubble it through an aqueous solution of anything, and also because sodium sulfite is what you get when you bubble sulfur dioxide through lye. By reflex I looked for the "Edit" tab, but Scientific American is not Wikipedia and therefore will probably remain in error; the same limitation applies to a paper book, or even a Kindle book. How can we import the knowledge from your book into some kind of platform that lets us extend it, refine it by correcting errors like this one, adding details like how much powdered sulfur and how long to boil, and contextualize it by linking to experiment reports by people who have actually tried following the recipes and have tips on how to get them to work? Hopefully we don't need to duplicate your book from scratch in order to do that!

Empire-derived video games like Civilization commonly have a feature called a "technology tree", where your civilization "develops" a series of "technologies" as it advances, each depending on some previous ones. Fictional works like Fire Upon the Deep have speculated about designing such a technology tree to help "backward" alien civilizations advance; yours is the first serious attempt I've seen to create a practical technology tree for real life.

(I spent quite a while reading through your web site editing this question.)

Hi, thanks ever so much for posting to this AMA, and especially all of those juicy links - I very much look forward to reading through them this weekend! Yes, Vinay has a huge amount of experience and expertise in this topic - and, indeed, I interviewed him a few times for the book.

You're right, that's an SO2 typo in the excerpt, although I'm relieved to confirm that it's correct in the actual text of the book - clearly a 'mutation' in the reproduction of the text onto the SciAm website.

But the far more important point you rise is about the continuation of this project, and from the outset I have always intended The Knowledge to be only the beginning - I'm very keen to extend this beyond the book and to create a more expansive resource. To a certain extent the Discussion page on the book's website the-knowledge.org was created to allow exactly this. But I think you're right - a community editable document like a 'wiki for rebooting' would probably be the best way forward. Please email me [email protected]

And yes, I'm a huge fan of Sid Meier's series of Civilisation games (Civ2 got me through school...) and the 'tech tree' was a mental touchstone while I was writing the book - I talk about it here: http://the-knowledge.org/en-gb/2014/01/games/

We've already used up the most accessible supplies of coal, oil, etc - if we have to redo the Industrial Revolution, how would we deal with that?

I've already answered something similar to this, about the remaining coal, but how Civilisation 2.0 would probably struggle to supply itself with crude oil: http://www.reddit.com/r/IAmA/comments/24jndm/i_am_the_author_of_the_knowledge_how_to_rebuild/ch7siet

For rebooting civilization process what kind of mentality you looking for in people. What is the best people can do to make the world best place for them.

Certain attributes I think would be really helpful, like resourcefulness, strength of mind (resilience), ingenuity, optimism...

I'm typing this on a tablet - which is resting a a copy of your book!

What do you think of the thesis that industrial civilisations are once only events per planet? That should there ever be a disaster that knocks us back to the Stone Age that it would then be impossible to booststrap ourselves through another industrial revolution because all of the fossil fuel and metal ores would haven been mined out already, and without them as an intermediate stage you cannot get to printed circuits, satellites or renewable energy?

Cheers! So I think there's two different points here - the remaining availability of metal ores, and the remaining availability of fossil fuels. If our civilisation collapses, the material we've created won't just disappear, and the surviving society would be able to scavenge the ready-smelted metals from the abandoned cites - even a long time into the future, an extremely rusty steel girder is essentially just a very rich iron ore, and can be smelted back to the native iron using the same basic techniques. But this isn't true of the fossil fuels that we've extracted thus far - we've mostly burned them and they aren't still around (apart from their warming legacy in the atmosphere...). While there's an awful lot of coal still in the ground (and accessible, provided you find yourself near an open cast mine, or can successful ventilate and drain deeper coal mines) we've already sucked up pretty much all of the easily accessible crude oil. So whilst I think a recoveringpost-apocalpytic society would probably be forced to make-do without oil (and I talk about alternatives for e.g. transport in the book), it would find metals easy pickings, and could probably also exploit coal again

Hmmm: very true.

My thought experiment was more along the lines of if we have a true Dark Age of a few centuries - long enough for most of the metal extant in our infrastructure to decay: given that - I cannot see anyone raising themselves much beyond "advanced agrarian" levels: Roman Empire kind of sophistication.

And without oil I would think any industrial ciivilization is doomed to be stillborn: it's energy density, portability and stability are unrivalled: if I remember correctly, England pretty much deforested itself at the start of the industrial revolution, trying to run a steam engine economy on wood alone.

The upshot of all this being: if we cock it up then that's it: no more industrial civilization for Earth.

Why not? Decayed metal is no different from metal ore in the first place, and the Romans were certainly able to smelt several metals. The industrial revolution didn't fuel itself on oil, but coal - and there's lots of that left. So there may be a chance for an Industrial Revolution 2.0

The prepared people who gather food and rebuild tech will probably lose it to thugs with guns. Then those thugs will use the resources and knowledge to become tyrants. It seems pretty pointless.

What seems pointless? Trying to continue? I think history has taught us time and time again the incredible resilience and resourcefulness of humanity. I'm not naive - there will clearly be a period of violence and turmoil once law and order disappears - but sooner or later an equilibrium will be reached again. And this is where The Knowledge picks up. What do you need to know to start rebuilding again...?

Two things: 1) From a personal standpoint, it seems like it's better not to invest the time and energy to prepare to re-establish civilization since, you'll be mass-mugged and probably murdered, anyway. More logical, if preparing at all, to arm yourself and those close to you and train. (I don't do this, b/c I don't think I'll see the end)

2)If we can't prevent our collapse the first time around, and end up having to go through all the brutality of the last few millennia up to and including the present, we really don't deserve a second chance. Regardless of disaster, there's going to be a giant culling of the human race; when the dust settles we'll be isolated tribes with each run, quite probably, by a local warlord/tyrant/chief. Then the whole empire building thing will start again.

I guess I just don't care enough about a human race that wouldn't prevent its own downfall after it's already acquired the requisite knowledge and skill to do so.

Yes, I agree with you absolutely that you'll need to defend yourself. But I don't think that everyone will give up hope and not try to make a living for themselves. And bearing in mind, the local chief is going to want to eat as well so will maintain order to the extent that crops can be grown. There's nothing novel about a post-apocalyptic scenario, and throughout history things have continued. I suspect the local chiefs giving way to another empire will happen again whether anyone thinks they deserve a second chance or not. People act in their own best interest, and civilisation is a consequence of that.

If we build things up again from scratch, any technologies that we should do differently? Like, should we go straight for fuel cells and not bother with internal combustion engines?

Yeah, this is a really interesting area to think about - and something I played with in The Knowledge. I did look into the question as to whether you'd be able to redevelop a transport system based on electric vehicles rather than the internal combustion engine - there was a period when electric, steam, and ICE vehicles were all being manufactured at the same time, and ICE vehicles won out based on a large part to do with their range. But starting from scratch again, without easy access to crude oil, development might go down a very different route.

Another thing I talk about in the book is to do with navigation, and the solution to the 'longitude problem'. In our history, John Harrison developed a sufficiently accurate and reliable clock for ships in the mid-1700s. But perhaps a rebooting civilisation might find electronic components (capacitor, electromagnet, diode, etc) to be easier to make than incredibly delicate clockwork. In which case you could determine your longitude based on the time at a base station (such as Greenwich, London) not by taking that time with you in an accurate clock, but by having that time transmitted to you by primitive radio...

No joke intended, did you get inspiration from the Foundation series, and should we attempt something similar?

Everything that we have learned is essentially irreplaceable in my eyes, it is a precious resource. Just look what happens in areas after the fall of great societies. Many times knowledge is lost and people regress, and it takes too long to recover. We are still figuring out how the Egyptians made the pyramids so well, and apparently without any of our modern tools.

The knowledge that I have learned to date, JIC something happens: i am a trained horticulturist; have a good understanding of chemistry, geology, and metallurgy; know how to work glass and form base glass from its raw constituents; can build kiln and furnace; know how to make concrete and clays; a passable knowledge of astronomy; the basic physics engines and some of the more complex; learned how to identify and culture penicillium; I am a decent shot with gun or bow; know how to create diesel on the go from crap restaurant oil; know how to make gunpowder;

I've read Foundation and it's mentioned in the book. But Asimov's principle of 'psychohistory' I thought was more about predicting the social development of a world than providing a seed of vital knowledge to allow it to reboot in the first place.

Great, in which case you are definitely in my post-apocalyptic survival team..! Have you ever tried to extract penicillin from the mould, or used it therapeutically?

True, I mean it more in the sense of just gathering knowledge in a repository, but touche!

I have not but one of my friends did for an advanced mirco class. It is essentially just solvent extraction and purification. The difficult part would probably getting the necessary solvents. But assuming a collapse, I imagine solvents are not high on people's 'rush out and grab what you can' list.

I think that chemistry and physics are of the highest importance to not lose. So much of our current advancement came out of the understanding of those two disciplines.

Yeah, and there are other references to creating a repository of human knowledge to preserve it in case of catastrophe. I've written about a few of them here: http://the-knowledge.org/en-gb/2014/03/similar-projects/ 18th Century encyclopaedia compilers, like Diderot, also made a genuine attempt to catalogue the sum total of human knowledge at the time - I can recommend a book on this if you're interested.

From my own understanding, the solvents for extracting penicillin are ether and water, and I give instructions in The Knowledge. The wider problem I think is the extraordinary volume of 'mould juice' you need to process to get sufficient antibiotic to cure even a single patient. It wasn't until the bioindustrial might of the US came on-board during WWII that penicillin really became a useful drug

I have a family farm in rural North Dakota (I don't live on it, but hope to move back eventually). The nearest town is a mile away and has less than 100 people and Fargo is 45 minutes away. Do you think that being a farmer and having means of production, combined with the general lack of population in the area could ensure my safety? What things do you think someone in the position of an owner of fertile land could do to engage people and get them to cooperate?

You're certainly in a much better position than I am right in the middle of London...! But in the hypothetical scenario of a complete disintegration of law and order (the snapping of the social contract) I'm not sure that engaging people and talking will always be enough. I think it's a sad reality that weapons will be necessary to back up your words. And again, I think that's another interesting difference to London - here, (virtually) no-one has a gun and I wonder how that would play out in an apocalyptic scenario?

How would you account for the collapse of infrastructure in the long term? Particularly along the globalized network of food distribution that many take for granted, allowing us to eat tropical fruit in the dead of winter, fresh seafood in inland areas, etc.

Even if a group in a nutrient poor area was able to survive initially, how would they best address the long term deficiencies they would face?

Nutrient deficiencies? But people eat healthily before the modern phenomenon of flying food across the world - even bananas only really became common in the UK in the last few decades

Very true, and I certainly could have articulated better. I was thinking more along the lines of regional crop specialization and how the lack of availability of a specific food item could destroy certain areas that have become dependent on it and no longer maintain the capability to grow or have access to alternate crops.

Given how specialized certain regions have become in large scale agriculture, as opposed to the more subsistence level farming seen in earlier eras, how would we respond to something like a GMO crop collapse, a rapid adaptation to existing pest control methods, or the rapid introduction/adaptation of an invasive species/microbe/alien death fungus?

Hmmm. I guess my question has evolved beyond my initial speculation of what I would do without a banana to put on my oatmeal and more to what would happen if suddenly my oatmeal wasn't available anymore...better go stock up! Oh, and thank you for doing this and responding to my question!

Ah, I see, sorry. Yes, clearly that would be a huge problem. And more generally, most of the modern crop species, regardless of where in the world you are, are hybrid strains. These a phenomenally productive, and are crucial for feeding the world today, but they don't 'breed true'. Which means that if you collect the grain from a wheat field today, say, and then tried planting that, the plant that develops would be pretty poor. So instead, when rebooting agriculture you would really want to find seeds of 'heirloom crops' - traditional varieties. There are plenty of seed banks that store these for posterity (and preppers often stockpile them too), and perhaps the best in the world for protecting this genetic heritage through an apocalypse would be the Millennium Seed Bank in Svalbard.

The thing about hybrids not "breeding true" is not a big problem. Often the f2 and later progeny of F1 hybrids still have higher yields and disease resistance than heirlooms. There is much often parroted misunderstanding regarding this. It would be easy to take the segregates and just turn them into stabilized strains in a few growing seasons, creating new "heirlooms".

Thank you very much for correcting me on this. And is that true all the way down the lineage from an initial hybrid? If you keep replanting for 50 years, do you still have a healthy crop?

Well this depends on species. Crops are generally lumped in 2 categories basic inbreeders(ex..tomatoes) and basic outbreeders(ex..Maize) you can plant inbreeders save seed and rarely if ever have to worry about inbreeding depression. Basic outbreeders require outcrossing between a certain size population in order to avoid inbreeding depression. So as long as you maintain a high enough plant population yes the progeny of F1 hybrids will be a healthy crop for unlimited years. In fact because the progeny of hybrids will have more genetic diversity compared to stabilized strains you would have a better chance of avoiding inbreeding depression. There are of course exceptions to the rule such as if the hybrid was made with a parent having male cytoplasmic sterility, amongst others

Brilliant - thanks for that detail! If maize is a basic outbreeder, presumably that's also the case for other cereal crops: wheat, rice, barley, rye, oats..?

Hmm. I wonder how the strains preserved in Svalbard would survive in a large scale agricultural capacity, given that the current hybrid strains were developed to increase yield and hardiness. Although then again, that point may be moot depending on what type of apocalyptic scenario we're looking at.

Yes, absolutely, modern strains are higher yielding, pest resistant, etc. But they're also pretty reliant on modern agricultural practices - artificial fertilisers and pesticides. But assuming your society is knocked back to basics, and can't produce its own fertilisers and pesticides, I suspect you'd have more luck with traditional varieties, than the super-crops developed for the modern world

This discussion has definitely solidified my decisions on what I would attempt to be in a post-apocalyptic scenario. This farming stuff sounds like hard work! I think I'd be better off going to the gym now and learning how to use a sword....you know, for...umm....science.

I don't think anyone should be under any illusion that restarting from scratch will be anything but a long hard grind! Modern civilisation is so wonderful at providing for all of our needs that we take everything for granted now. They do like their swords in 'Revolution' don't they.... ;o)

How do you get from Leicester Square to Vauxhall Bridge, avoiding Pimlico?

;o)

To be fair, I was clenched for who would be the first one to go there. Congratulations...!

OK. Suppose there's some cataclysm that wipes out a lot of people. Society falls back to the dark ages. No electricity, no running water, no advanced medicine. Why, why WHY aren't we developing ways to do stuff like create medicines (antibiotics, aspirin), or create needed chemicals, or purify water, that could be done ad infinitum with just the tools that would be left to a collapsed society, instead of just stockpiling the stuff to high heaven? And why aren't we stockpiling THAT equipment?
Seems like most "preppers" think the disaster, whatever it is, will last years, not decades, and their supplies will last long enough. Might not be the case.
Thanks for doing this :).

Edit: Ehhh forget the "purify water" bit. Boiling and filtration work wonders. I got a little carried away :).

I guess it comes down to the balance of risks. The powers-that-be deem it more valuable to spend resources running society today, rather than preparing for an eventuality that might never happen. The consequence of something is always a combination of both the likely outcome and the probability of it ever occurring in the first place. An apocalypse would clearly be very detrimental, but is improbably (compared to, say, needing to invest in more schools and hospitals today)

Yeah but the thing is, if we developed those techniques, they wouldn't just be useful in an apocalypse. They'd be useful in places like third-world countries. Places that don't have electricity, or medicine, today. And on top of that there's the fact we'd unhook all those processes from dependency on things like electricity, which I think would only be beneficial, especially in regards to the amount of pollution we produce and the amount of resources we consume to power stuff. Aaargh...it's frustrating :(.

Well, this is being done to a certain extent - aid agencies are working with 'appropriate' or 'intermediate' technologies for people in the developing world. There's also an element of technological leapfrogging happening in the developing world - villages disconnected from any national grid, but jumping straight to electrification by solar panels, or using mobile phones without first having landline telephones installed

What steps have utilities taken so far to prepare against CMEs?

To my knowledge, not much at all. It would be an enormously expensive undertaking to protect every single transformer in the power distribution grids across entire continents

Hey Lewis. In your opinion which will happen first: self-sustaining colonies on other planets in the solar system, or the collapse of civilisation on Earth?

Hi! I'm a space scientist, so I'm optimistic about our growing capabilities and basic drive to explore outwards. I think humanity is more likely to found a colony on Mars before civilisation collapses here on Earth. We certainly do face some serious challenges in the coming years, but I don't think we're facing endtimes

I've heard many times, that humans are so resilient in the face of adversity. An apocalyptic scenario would be certainly be overwhelming for survivors to handle (physically, emotionally, etc.)

How likely do you think it would be, that survivors would have the 'will' to carry on? Personally, I think i'd be looking for a cliff to jump off of, if I survived.

I think there will be a few people that may think they can't carry on and will commit suicide (there's a very powerful theme of this in The Road). But I think the majority of people would carry on and try to thrive. After all, people have survived in the Andes after a plane crash and got themselves through the ordeal, or being marooned on a deserted island (such as Alexander Selkirk, the inspiration for Robinson Crusoe). I think that, on the whole, people are surprisingly resilient and hardy, and you simply adapt to your new circumstances

Do you think that the very notion of "being always ready" which exists in some survivalists either brings or emanates from serious psychological issues? I'm often worried that "apocalyptic thought" has some connection with forms of sociopathy.

I think that striving to learn new skills and self-improve are admirable qualities, and that stockpiling a reserve of canned food and bottled water is a very sensible precautionary step to take, particularly in parts of the world where natural disasters are common. But as with anything in life, I suspect that some people take a hobby to the extreme. I think it's fair to say that resilience and trying to preserve society shouldn't necessarily mean disconnecting yourself from society today.

Post apocalypse if you along with 2 to 3 others survive which is the one thing you would change on earth apart from growing more trees

Can I have a few more buddies than just 2 or 3 please...?

But as for what I'd change... hmmm... I live in London (and would probably find it hard to travel very far from England if civilisation were ever to collapse) so if I could, I'd change it so that the coffee plant could be grown in our climate here ;o)

OK some more buddies added for you to enjoy coffee with them :)

Ta!

This is something I walways wondered, what would be good to change after starting fro scratch? I'm talking about wether one should be Metric or imperial, celcius or fahrenheit, the calendar, language, etc.

So I would argue that something like the metric system of units would be a very helpful thing to reinstate. And you need _a calendar in order to predict the seasons and so farm successfully and not starve to death. The 365 (and a quarter...) days in a year is a physical parameter of the earth, but you don't need to split this into 12 months with 31,28,31,30, and so on days. Not trying to plug the book, but this is treated in two chapters in a load of depth. Including, how can you tell what day of the year it is, and how can you reconstruct the metric system from scratch...

What is expected within first few weeks after a catastrophe? I would expect in cities to be wide shortages of everything, so having any kind of a weapon, and willing to use it liberally is going to be an advantage. Perhaps form a group of others and take over control over some area with enough food/water - eliminate everyone you do not need to preserve supplies for as long as possible.

This is a pretty grim outlook, is there another option?

So, depending on the exact nature of the event that collapses civilisation, I think several outcomes are possible. If law and order disappears but lots of people are still alive, there will clearly be a very brutal period of turmoil where it's every man and woman for themselves, and survival of the fittest. You're going to need weapons to protect yourself, and be looking for safety in numbers. This is exactly the sort of scenario that's been explored so well in apocalyptic films and books. But my biggest interest is in what comes _after that. Once some semblance of order is restored (as happens time and time again in history), how do you start rebuilding...?

Which is, in your opinion, the most likely apocalyptic scenario?

Hi, I've answered something very similar to your question here: http://www.reddit.com/r/IAmA/comments/24jndm/i_am_the_author_of_the_knowledge_how_to_rebuild/ch7sxg9 Does that answer what you meant?

Sorry, I thought that question was about the most dangerous, not the most likely. But yes, it does. Thanks.

Ah ok, I see. Most dangerous (i.e. the one you'd really struggle to recover from afterwards): large asteroid/comet strike or global nuclear war Most likely: probably something like a global pandemic

What is the smallest catastrophe that is likely to completely wipe out humanity? (even if some survivors are left initially, they wouldn't be able to reproduce enough to ensure human survival)

Perhaps something like widespread infertility - people aren't killed, but for some reason humanity becomes unable to reproduce. I'm not sure how likely this is, but the effects are explored brilliantly in P.D. James' book 'The Children of Men', and the film adaptation (which I heartily recommend btw!)

Perhaps something like infertility? People don't die, but for some reason humanity stops being able to reproduce. I'm not sure how likely this is, but the consequences are explored brilliantly in P.D. James' book 'Children of Men', and the film adaptation

Assuming access to a large heavily fortified deep underground complex with chemical oxygen generators, CO2 scrubbers, geothermal electric power, stockpiled food and water (ie completely no need to surface), what is the longest possible/probable duration you foresee having to inhabit it?

Depends on the nature of the apocalypse, I guess. An all-out global nuclear war...? You'd probably want to lie low for decades for the atmospheric dust to begin settling again and allowing conditions for agriculture. But you'd still need to find a patch of ground that isn't hopefully radioactive. If the vast majority of humanity perishes from an aggressive pathogen, you could probably re-emerge after just months. But be careful that you don't then catch it from survivors who were exposed

How long would it take for human civilization to disappear? 1000 years, 2000 years before no trace is left?

Brilliant question, and I'd point you to two brilliant books that address exactly that:

• Alan Weisman, The World Without Us
• Jan Zalasiewicz, The Earth After Us: What Legacy Will Humans Leave in the Rocks?

But to answer you in general terms: roads and carparks etc would become buried with vegetation in decades, buildings (including skyscrapers) in most parts of the world would collapse over centuries, but it would take millions of years for the surface traces of human civilisation to be scoured from the face of the Earth

What do you mean by surface traces? Collapsed structure remains like rebar and the sort, or chemical remnants?

Both. Physical traces like steel girders, pure aluminium (never encountered naturally), concrete. Chemical traces like plastics, nitrates (from artificial fertilisers). It's obviously a very complex question, depending on exactly what sort of trace of civilisation you're talking about, and where in the world. But the bottom line from those two books is that alien archaeologists would know about our technological civilisation an awfully long time into the future

Do the Boy Scouts ever work with you?

What are the most important languages to know?

I was leader of Red Six when I was a scout! (although saying that now, it does sound exactly like an X-wing squadron...) But no, I've not done any direct work with Boy Scouts or Cub Scouts on this topic

Languages - this would depend entirely on who else is around and what they speak. But given that Mandarin and Spanish are the most common first-languages in the world today, and English used for international interactions (trade, ATC, science, etc), probably one of those three

Do you think Global Warming will eventually end the world?

Global warming wouldn't 'end the world' but it will certainly present some very serious hazards for agriculture around the world and those living in low-lying areas.

Are you a particularist or universalist in the philosophical sense and why?

I'll be totally honest, I'm not a philosopher and I'm not sure what either of those terms mean specifically?

Well in the context of an apocalypse i would use those two terms in conjunction with ethical reasoning. A universalist would believe and argue for ethical principles that can only be maximized on a global basis, achievable by everyone. A particularist accepts that there are vast cultural differences from place to place and therefor it is impossible to force upon 1 central ethical aim. I personally wonder in an apocalypse whether cultural barriers break down and we all acknowledge our similarities as a species or if an apocalypse further divides the human race into tiny extremist pockets of survivors with a relative understanding of laws, morals and ethics. I would love your thoughts please.

Ah, I see, moral relativism (if I've used the right word here). While I do agree that there is diversity in the accepted norm of morality and ethics amongst different cultures, I do think that certain actions are deemed wrong pretty much by everybody: murder, rape, theft, and so on. My hunch is that, after an apocalypse, people will be initially pre-occupied with survival and looking after their own family, and may be driven to actions they would otherwise be shocked at. But over time, law and order will return and ethical codes become established. I guess that whatever mix of people are involved in that process would decide amongst themselves what they deem to be right and wrong. This is one of the main reasons I didn't really touch upon topics like ethics, governance, and so on in the book

Perhaps this is outside your field, but do you think that, were there a "hard reset" on human civilization through nuclear war, a natural disaster, or something else, humanity would have the opportunity at a "second go"? Would having lost access to all the low hanging fruit of fossil fuels make a second industrial revolution or even global civilization an impossibility?

Do you think such a apocalyptic event would condemn mankind to near the same level of development from then, onward (or at least as long as we can reckon) ?

I think it would depend on what catastrophe caused the collapse of civ in the first place. Global nuclear war; you might really struggle to reboot quickly. Viral pandemic; would leave the infrastructure of the world un-devastated and the survivors might have a much better opportunity to start again. But, without wanting to plug, that's exactly what The Knowledge is about. In particular, although there's a lot of coal left in the ground, we've pretty much sucked-up all the easily-accessible crude oil already. So a rebooting society would have to find alternatives to gasoline-powered transport, for example. It's not impossible, but it would definitely force a different developmental pathway to the easy ride we lot had first time round...

Hey Doc! In your opinion which areas of the globe are better suited for long term survival, and which would become all out chaos/ruin?

I've yet to read your book, but I may have to bump it up on my list to get! Cheers!

Hello! I've answered a similar question here: http://www.reddit.com/r/IAmA/comments/24jndm/i_am_the_author_of_the_knowledge_how_to_rebuild/ch7s985 ...but of course the exact details will be pretty dependent on the precise nature of the catastrophe that topples civilisation and how many people survive the initial event.

If hope you enjoy The Knowledge if you do read it - I've found it absolutely fascinating to research for!

The world would be like Walking Dead minus the zombies for the first fifty years

Walking Dead without the zombies. So, empty then..?

How many people would it take to get back to early 20th century technology within 100 years? Where would they have to be?

Great question, and something I'd love to be able to give a definitive answer to! It of course depends on how far back society regresses before it can catch the decline and then start pulling itself back up by its own bootstraps, and that will largely depend on exactly what it was that toppled our civilisation in the first place - after a global nuclear war, for example, you might find an accelerated reboot to be extremely difficult. I think another important factor is how quickly your post-apocalyptic population can grow - and this will depend on how effectively you can maintain agriculture, control diseases and rediscover essential medicine and surgical techniques. If you have too few survivors humanity could regress all the way back to a subsistence existence, or even hunter-gatherer lifestyle, but with too many then the initial survivors might be forced to compete with each other too much for the remaining resources. The starting point for the thought experiment in The Knowledge is a surviving community of a few tens of thousand, but you might fare better with more.

This question isn't related to an apocalypse scenarion, but you may be able to give an interesting answer based on your reasearch. If our civilisation never had fossil fuels (particularly oil) in abundant quantities available, how far behind todays technology level would we be now, if at all?

That's a great question, but hard to give a specific answer. Firstly, 'today's technology level' is quite a generic term - different areas of technology would have been affected to different extents. Transport would of course be unrecognisable today without fossil fuels, whereas perhaps communication technologies could have found alternatives, and there would be other (perhaps unexpected) consequences in areas like agriculture - artificial fertiliser is created using fossil fuel energy and pesticides and herbicides are synthesised from chemical feedstocks deriving from crude oil. 18th century Britain progressed through the Industrial Revolution fired by coal, and it might be hard to argue that a similar transformative process would have happened at all without this readily-accessible energy reserve. I've answered another similar question that might also be of interest to you: http://www.reddit.com/r/IAmA/comments/24jndm/i_am_the_author_of_the_knowledge_how_to_rebuild/ch7xni1

I was telling my lawyer brother about the show "Revolution" and he seemed to think that the government would not fail so completely or so quickly as portrayed in that show. Do you think our government would be able to maintain any semblance of order if communications were knocked out on a global scale for an extended period of time?

I'm not sure, to be honest. The premise behind 'Revolution' is that all modern electrical technology suddenly ceases to work (impossible, of course, but a thought-provoking premise), and I think that that would certainly pose a serious threat to the status quo. The government is only effectual through the forces it controls, and if the members of the police and army panic along with everyone else in an apocalyptic event (we're all only human at the end of the day) then a few elected individuals in Westminster or the White House or Wherever would have little control over how things pan out from that point on.

Does your book, The Knowledge, give specifics on how-to do the things needed, or is it a guide of things we should learn how to do? Meaning, is it a practical guide or a theoretical one?

As far as possible, I try to balance between the two. There are a lot of direct, practical directions given at the beginning of each chapter, and then they move on into grander, larger-scale concepts which would be impossible to actually explain in full detail (in a single book). At the end of the day, the book's not a survivalist guide or an engineer's handbook; it's a thought experiment on the science and technology that forms the foundation of all that we take for granted in everyday life today, and how you could recreate it all from scratch if you ever needed to

Very good, thank you for the reply. Would you, or have you, ever considered putting out a multi-volume set of books to act as a sort of engineer's handbook or post-collapse primer of technology? Volumes on water, steam engines, water wheels, etc.. I think it would go very well in today's prepper market!

A lot of great material does already exist out there - if you're interested, take a look through the reading lists that I referred to when researching: http://the-knowledge.org/en-gb/further-reading-by-chapter/ or as the full bibliography: http://the-knowledge.org/en-gb/bibliography/ . I genuinely think The Knowledge would be an interesting and useful resource for Preppers, but it was primarily written as a science book examining the very fundamentals of how our modern civilisation works, and how it progressed over history

P.S. - You would be a remarkable contestant on this television show - http://www.fox.com/utopia/#

Grand - I'd not come across that before! I'll really look forward to watching that, but definitely, definitely not putting myself up for actually doing it...