Why Is the Night Sky Dark? Olbers' Paradox, Explained
If the universe were endless and full of stars, every line of sight would end on one. Why the night is dark anyway, and what that reveals about time.
6 min read≈ 1,350 words3 questions
Field
How societies formed, changed and remembered.
2 Ideas · 5 Books · 31 questions
History studies how societies formed, changed and remembered their past. It works with sources such as written records, objects, buildings and numbers. Each source tells only part of the story, so historians compare them and ask who made each one and why.
The pieces here use history to explain things we still live with. Money, for example, is older than coins. For centuries, England kept records of debts on notched sticks of wood. Large books such as Yuval Noah Harari’s Sapiens try to tell the whole human story in a few hundred pages. The reviews say where such books are strong and where historians disagree with them.
Start with tally sticks, a short and concrete case of how a simple tool shaped a state’s finances. Then read the review of Sapiens for the big picture. Charles Mackay’s book on financial bubbles is a classic that people still quote, and the review shows which parts later research has corrected.
The best first reads in this field, in this order.
IdeaIntro
For more than seven hundred years, the English state kept many of its accounts on sticks of wood. You learn how a notched stick recorded a payment, why it was so hard to cheat and how a receipt could work like money. You also learn why the system ended in a fire that destroyed the old Houses of Parliament.
7 min read≈ 1,460 words3 questions
BookIntro
Sapiens has sold millions of copies, but many historians and anthropologists distrust it. You learn the main ideas of Harari's history of our species and how the book compares with similar books. You also learn which of its claims experts reject, and why.
9 min read≈ 1,960 words5 questions
BookIntro
Articles about stock market bubbles often quote one book from 1841. You learn what Charles Mackay actually wrote about money manias, false sciences, witch hunts and street fashions, and which of his famous stories modern historians no longer believe. At the end you know whether the book is worth your time and which parts to read.
10 min read≈ 2,170 words5 questions
BookIntro
A short Chinese text about war, more than two thousand years old, is still read by managers, coaches and generals. You learn the eight ideas that carry the book, what we know and do not know about its author, and where its advice stops working. You also learn which translation to choose.
11 min read≈ 2,490 words5 questions
If the universe were endless and full of stars, every line of sight would end on one. Why the night is dark anyway, and what that reveals about time.
6 min read≈ 1,350 words3 questions
Housel argues that you cannot predict events, but you can predict how people behave. The book's key ideas, its limits, and who should read it.
9 min read≈ 1,900 words5 questions
Harari's sequel to Sapiens asks what humans will want once famine, plague and war are under control. Its key ideas, weak points, and who should read it.
9 min read≈ 1,940 words5 questions