Volume X — Curiosity

In 1954 a boy in Bombay asked his father why the sea is not sweet like rain. His father, who worked in a bank, did not know, and said so, and then did something better than knowing: he took the boy to a library. The answer turned out to involve rivers, rock, three billion years, and the fact that the sea is not getting saltier at any rate a human could notice.

That is the whole shape of this volume. A small question, honestly followed, opens onto something enormous.

The other nine volumes of this book are systems. Technology builds from a gate to a distributed system. Mathematics builds from counting to calculus. Each one has a spine, and reading it out of order costs you something.

This one has no spine, and that is the point. It is the shelf you go to when you have eleven minutes, or when somebody at a table says something you half know and you want to actually know it. Open it anywhere. Nothing here depends on anything before it.

What makes it different from a general-knowledge book

Almost every quiz book in the world is a list of facts with the reasons cut out. The Nobel Prize is not awarded in mathematics. True, and useless, and forgotten by Thursday.

Here every answer carries its origin. Not just what, but who first, why then, what problem they were actually trying to solve, and what it broke. The Nobel entry tells you that Alfred Nobel's will named five fields and mathematics was not among them, that the popular story about a mathematician stealing his wife is impossible because Nobel never married, and that the real reason is almost certainly duller and more human — he funded what he personally cared about, and he was a chemist and an inventor who had never cared much for pure mathematics.

One is a fact. The other is a story with a fact inside it, and a story is what a mind keeps.

You will notice a second habit throughout. Every entry that can be checked has been checked, and where the honest answer is nobody knows, it says nobody knows rather than repeating the tidy legend. A surprising number of famous origin stories — the QWERTY keyboard, the Great Wall from space, Napoleon's height, the goldfish memory — are wrong in ways that are more interesting than the legend.

The twelve parts

Things

1. How Everyday Things Work — the keyboard under your fingers, the collar on your shirt, the lock on your door, the numbers on your bank card, the code on a packet of biscuits. Objects you have touched ten thousand times without once asking why they are that shape.

Time

2. The Years That Changed Everything — the dates worth carrying, from the first cities to the year the web opened, each with what actually happened and why that year and not another. Ending with the calendar itself, which is stranger than the events it records.

People

3. Great Lives — the mathematicians, physicists, doctors, engineers, rulers and reformers whose names come up. Short, honest profiles: what they did, what it cost, and what they got wrong.

The world as it is

4. Science in Plain Sight — why the sky is blue and the sunset is not, why ice floats when almost nothing else does, what resonance is and how it brings a bridge down, and where the energy inside a sheet of paper comes from.
5. The World Mapped — countries and borders and flags, the superlatives, why places are called what they are, the borders that make no sense, India state by state, and how a map lies to you on purpose.

What people do for joy

6. Sport — cricket, football, the Olympics, athletics, chess, and the records, with the rules explained from the ground up rather than assumed.
7. Film, Television and Music — how cinema was invented by people who thought it was a fad, the studios, Indian cinema, the awards, and how music is actually built.
8. Art, Architecture and Wonders — the paintings everyone names, the buildings that changed what a building could be, and the wonders both ancient and current.
9. Words, Books and Languages — the books that get cited, the poets, where words come from, and the writing systems of the world.
10. Myth and Legend — Greek, Norse, Egyptian, Mesopotamian, Indian and the rest, told as the stories they are, with the family trees straightened out.

Thinking with it

11. How the World Adds Up — how to estimate anything to within a factor of ten, what fraction of humanity is asleep right now, the full scale of things from a quark to the observable universe, and why some things cost what they cost.
12. The Miscellany — food, festivals, animals, titles and degrees decoded, and the leftover marvels too good to leave out.

How to use it

Do not read it front to back. It will not reward that. Read the part that catches you, and follow the links out of it into the volumes that go deeper — a question about resonance here has a full derivation in Volume IV, a question about how a database saves a file has a whole Part in Volume I.

Read one page before a conversation you care about. Twenty answers, each with its origin, is a better hour than most.

And treat the questions as permission. Every entry in this volume began as somebody wondering something slightly embarrassing — why is that letter there, why do we do that, is that true. It is not embarrassing. It is the only mechanism by which anybody has ever learned anything.

Start with 1.1, which is about the six objects nearest to you right now.