Epistemic Spot Check: The Alchemy of Air (Thomas Hager)

[content warning: war, the Holocaust]


Fixed nitrogen is a startlingly important molecule, essential in both explosives and farming. Until the 1900s, turning atmospheric nitrogen (which is abundant) into fixed nitrogen was the purview of a handful of bacteria, and countries went to great length to get more.  Several wars were fought and decided over/by who had better access to nitrogen stores.

In the early 1900s, German scientist Fritz Haber invented (and engineer Carl Bosch industrialized) a process for producing fixed nitrogen.  This changed the world on a number of levels:

  • Removed the nitrogen-induced cap on the human population, which was ~4 billion people.  You know how people say it’s impossible for everyone to eat organic?  This is why.  There is not nearly enough natural fixed nitrogen to feed everyone.
  • Prolonged Germany’s involvement in World War 1 by one to two years, by both increasing the volume of explosives they had access to and by making it possible to feed people from relatively poor farmland.
  • Was part of a larger shift in Germany becoming an economic and scientific power.

The Alchemy of Air starts with a longer description of why fixed nitrogen is so important.  The meat of the book  is the invention of the Haber-Bosch process and the life stories of the two men responsible for it.  It touches on the chemistry of nitrogen, how a proof of concept becomes and industrial process at the age when those were beginning to separate.  At the end, it offers a glimpse into the rise of Hitler and the Nazi party as viewed by the scientific community.

Fact Checking

Claims: “Nitrogen is the most important element… for humans”, “more interesting than other elements.”  “Nitrogen is a/the rate limiting factor in life on Earth.  If you put more fixed nitrogen in a field, you can grow more.” (Prologue).

True-ish. I don’t know how to fact check which element is more interesting.  I went through 7 semesters of college chemistry without picking a favorite element.  But the more factual claim that nitrogen is a major limitation of growth on life on Earth checks out.  The other major elements we need- carbon, oxygen, and hydrogen- are relatively cheap to create from molecules found in the air (although oxygen is the limiting factor in certain aquatic ecosystems- and as you learn at the end of the book, fixed nitrogen abundance makes this worse).    Atmospheric nitrogen makes up 80% of the air, but it is incredibly energetically expensive to convert that into nitrogen useful to plants and animals (known as fixed nitrogen)

Claim: “N2 is [harder to break down because it is] held together with a triple bond, the strongest bond in nature.” (prologue)

True but incomplete. Nitrogen does use a triple bond.  On average, triple bonds will be more expensive to break or form than double or single bonds.  But carbon can form four bonds.  You can’t actually have a stable quadruple bonds because of complicated shape things, but they can triple bond with each other and each have a side chain.  It’s possible HCCH is just as expensive to break apart, but there’s enough carbon in easily accessible forms that it doesn’t matter.

Also, the fact that N2 (the kind of nitrogen found in the atmosphere) is expensive to break doesn’t explain why fixed nitrogen makes such an excellent explosive.  The fact that it is implies that fixed nitrogen is also energetically expensive to make.  The internet is rather lacking on this topic, but the fact that fixation is net negative on ATP (the energy currency of living things) suggests that I’m right.  “This bond stores a lot of energy” is not actually a good argument for why no one breaks it.

Claim: “Using [their complicated farming system involving three different animals and five different types of plants], the Chinese could feed as many as ten people per acre of farmland, a yield of food five to ten times greater than the European average of the 1800s” (p5)

True but misleading. Verifying this is surprisingly hard, but I do know that Chinese agriculture was incredibly labor intensive, much more so than European farming.  That’s why 1800s China has a bunch of proverbs about working hard and Europe had a bunch of proverbs about hoping it rained (source, although I’d like to do a fact check on this one).

Claim: Haber-Bosch uses 1% of the Earth’s energy (p271)

True, although this refers only to generated energy and not natural sources like the sun or underwater vents.

Claim: “Half the nitrogen in your blood, your skin and hair, your proteins and DNA, is synthetic” (p272)

False.  The atom was nitrogen when you found it and it’s nitrogen now.  The molecule that delivered it to the plant was synthetically produced, but the nitrogen has always been itself.  At a minimum, synthetic should mean you found different atoms and combined them into something new, but chemistry has an even stricter definition: elements that do not exist naturally and must be created in a lab.

Claim: “Nitrogen pollution in the water has been to linked to health problems like methemoglobinemia, or “blue baby syndrome”” (p274)

True.  The EPA supports this, although it appears there’s still some scientific controversy over exactly how large a role nitrogen plays.

Claim: Nitrogen run off causes algal blooms that devastate aquatic ecosystems (p274)


Claim: A long history of saltpeter I’m not going to transcribe fact-by-fact (chapter 1)

True.  I didn’t run down every fact but everything I could find checked out, and his conclusions (saltpeter was incredibly valuable) are supported by other information he didn’t mention.

Claim: Darwin was hired onto the Beagle as someone of suitable social stature for the captain to talk to so he didn’t go mad.


Claim: After saltpeter, bird shit became the coveted resource (chapter 3)

True. Again, I didn’t run down every single thing, but guano was the immediate catalyst for the South American colonies to revolt against the Spanish, the USA still has a law on the books allowing any citizen to claim guano rich islands for the country.

Other thoughts

Alchemy of Air is a weirdly uneven book.  I don’t think this is writing style, I think it’s just covering a lot of different material and what people find interesting varies a lot.  For example, I loved the sections on the history and economics of nitrogen, and how the Haber-Bosch industrial process for producing fixed nitrogen from the air affected World War 1.  The fourty three chapters on Bosch taking Haber’s proof of concept to a scalable industrial process?  Do not care.  Almost quit book until I remembered I could just skip them.

The parts on the personal lives of Bosch and Haber were very mixed bag.  Mostly boring, but intricately involved with the extremely interesting things that were happening at the time (~1900 to the rise of the Nazis).  Fritz Haber was a German Jew who merged love of science with love of country in his mind, and converted to Christianity in part so he could be viewed as more fully German.  The Haber-Bosch process probably bought Germany another year in World War 1, probably two.  He played a major role in inventing chemical warfare (Alchemy would have you believe he invented it, but is prone to exaggeration).  You can guess how this ends.  In 1934 he flees the country, made more difficult by the fact that the rest of the world still considers him a German war criminal.  The chemical he invented for use on Allied soldiers in WW1 is adapted for use in the concentration gas chambers in WW2.

Bosch’s life is also complicated.  Between the wars he dedicated everything he had and then some to inventing a way to synthesize gasoline.  This included collaborating with the early Nazi party for funding.  They were happy to do so because they, correctly, anticipated that an internal source of gas would be necessary in the upcoming war.  At some point Bosch realized what he’d done, made a bunch of symbolic gestures against the Nazis, and died in disgrace.  It’s weird because those symbolic gestures probably cost him a lot and accomplished nothing, whereas there’s some chance he could have prevented WW2 and the entire Holocaust by not working quite so hard to create synthetic gasoline.  By the time the Nazis were in power it might have bankrupted his company to stop, but it was still doable.  Maybe someone else would have invented synthetic gas… but Bosch’s company was uniquely well positioned to do so, and he basically willed it into existence by convincing an increasingly large collection of people to toss money at the process.  He didn’t even have to give up, he just had to try less hard on fundraising.

And of course both men have saved/enabled billions of lives by creating the process that feeds them.

I don’t know what to do with this information.  The world is complicated and I want the right thing to be obvious.


Generally reliable, moderately stylized.  I trust the author for broad strokes but not to give me non-nitrogen related nuance.

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Epistemic Spot Check: A Brief History of the Human Race (Michael Cook)

I was worried my epistemic spot checking project was doomed before it began.  The well regarded Sapiens dismissed a link between cultural and genetic evolution, and Last Ape Standing made two explosively wrong errors in the first chapter.  Neither related to human evolution (one was about modern extreme poverty and the other about cetacean evolution), but I just couldn’t let them go.  I worried that every book was terrible if you actually fact checked it, or maybe just every book on the emergence of homonids?

And then I started A Brief History of the Human Race.  Two chapters in, I cannot find a flaw in it.  There are a few simplifications, and some broad statements he later walks back, but nothing I can point to and say “that is miseducating people.”  Meanwhile there are a lot of things I can point to and say “that is right”, even things I initially thought were wrong.  So I think A Brief History… might be the one.

Here’s a list of statements I checked and their results.  Normally I sort claims into true and untrue sections, but that proved unnecessary in this case because it is a beautiful rigorous snowflake of a book.

Claim: The holocene era has had unusual climactic stability, and is warmer than typical for the planet (page 6).
This checks out, but it’s a little weird that his graph doesn’t label the temperature axes, and it’s a graph of oxygen ratios from a single glacier rather than the wider variety of evidence available.
Cook further claims that this warmth and stability is what let farming, and thus history, start.   There’s some counter evidence to the claim of the holocene as the absolute start of agriculture. but it certainly seems legitimate to say that’s when it really took off.
Claim: there exists art “well over 20,000 years old” (page 9)
I was very surprised by this but if anything he’s underselling it; there’s claims of 50,000 year old art 
Claim: most human DNA is junk DNA that serves no purpose, and mutations have no effect (page 11):
He’s a little behind the times on junk DNA. Even when A Brief History… was published (2003) we knew it that while lots of DNA didn’t encode any proteins, much of it does seem to serve some purpose and mutations in it are significant.  At a minimum noncoding DNA definitely plays a role in the regulation of DNA transcription, the structural cohesion of the chromosome, and protecting coding DNA from degradation.  This is the closest thing to a falsehood I found in the first two chapters.  At the level of genetics this book is discussing I think it’s a forgivable simplification, although an addendum noting the real world was more complicated would have been appreciated.
Claim: humans are inbred (page 12)
Very true.
Page 13: AFAIK this explanation of multiorigin vs out of Africa human evolution hypotheses is correct, and he’s picked the correct winner.
Claim: evidence of human tool use half a million years ago (page 16)
me: there is no way there were tools that long ago.
internet: yes there is.
Claim: early hominid and chimp tool use are both culturally transmitted (page 17)
I’m pretty sure this is correct, and I appreciate the distinction he is making
Claim: it was hard for nomadic hominids to combine their tools in novel ways, because they had so little room. There are exceptions, but they might have been better off sticking with lower technology (page 20).
I am extremely happy to see this guy acknowledge that hunter gatherers had a pretty kick ass life and farming sucked.
Claim: iron is more abundant than copper because of something about supernovas (page 29).
Claim: cattle domesticated multiple times (page 30).
Claim: humans adapt to domesticated animals culturally but not genetically (page 32).
This ignores the co-domestication of humans and wolves but is basically true for everything else.
Claim: humans did not genetically adapt to farming (page 33).
me: ehhhhh….lactose tolerance was a pretty big deal.
p34: exceptions: lactose tolerance and disease resistance.
me: I accept your apology.
Claim: Maori had and then lost the technique for pottery (p36).
Not only is A Brief History… not saying wrong things, it is throwing out tangential facts at about the right rate.  I was never going to look up which molecules supernovas produced.  But now I have a general idea of the concept of “primary elements” and how this affected human history, which makes me happy.
Verdict: A Brief History of the Human Race has passed the epistemic spot check with flying colors, and is enjoyable to read.
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