Science
by Bill Bryson
How do we know any of this?
Bill Bryson realised on a long flight that he knew almost nothing about the planet under him. He spent years reading and pestering scientists to find out how anyone worked out things like the age of the Earth or what's inside an atom.
Hear a sample · read by Laura
Bryson keeps returning to how lucky we are to exist. Earth sits at the right distance from a steady star, and its large Moon keeps the planet's tilt stable. And every one of your ancestors, back to the first life, survived long enough to have children.
Bryson loves the people behind the science, and many were very odd. Henry Cavendish was so shy that even his housekeeper dealt with him by letter. Yet an experiment at his home gave a remarkably accurate measure of how much the Earth weighs.
Ernest Rutherford's team fired tiny particles at thin gold foil, and a few bounced almost straight back. He realised nearly all an atom's mass sits in a minute nucleus at its centre. Bryson quotes the image of a fly in a cathedral, but a fly far heavier than the building.
Bryson points out that bacteria were here billions of years before us and would carry on fine without us. We couldn't manage without them. Microbes break down dead plants and animals, and they help digest the food in your gut.
The question
Bryson set out to learn how scientists worked out things like the age of the Earth.
Your atoms
The atoms in you are billions of years old and have been part of many other things.
Scale
Space is far bigger and emptier than any school chart can show.
The scientists
Many great discoveries came from odd, stubborn people, and some went unnoticed for years.
Tiny rulers
Bacteria run the planet. We couldn't live a day without them.
A story from the book
Clair Patterson set out to date the Earth from lead in ancient meteorites. His samples kept being spoiled by lead from the modern world. He got his answer, about 4.55 billion years, then spent decades campaigning against leaded petrol, which was spreading lead everywhere.
Hot take · true or myth?
Edmond Halley paid to print Newton's great book on gravity.
True. Halley asked Newton about planetary orbits and pushed him to write up his answer. The Royal Society had spent its money on a book about fish, so Halley paid for the Principia himself.
One thing to try
This week, when a news story gives a science figure, like a fossil's age or a star's distance, look up how it was measured. Bryson's whole book grew from wanting to know how scientists know.
Knotd has the key ideas from 250+ non-fiction books, each in a few minutes, in plain words. A Short History of Nearly Everything comes with a Hot Take round to make it stick.
Get the whole book on KnotdOpen in the appHow do we know any of this? Bill Bryson realised on a long flight that he knew almost nothing about the planet under him. He spent years reading and pestering scientists to find out how anyone worked out things like the age of the Earth or what's inside an atom.
You are very unlikely; Odd people, big discoveries; The nucleus is tiny; The planet belongs to microbes.
This week, when a news story gives a science figure, like a fossil's age or a star's distance, look up how it was measured. Bryson's whole book grew from wanting to know how scientists know.
Yes. Knotd has the key ideas from A Short History of Nearly Everything in a few minutes, in plain words, plus a Hot Take round to test them. It's one of 250+ non-fiction books in the app.
