Discipline
Physics
Lessons across the journey that lean on physics, in the order they appear in the story.
- 1.1 Was the Big Bang an explosion?Draft
The Big Bang was not a blast at a point in empty space. It was the whole universe, everywhere at once, hot and dense and beginning to expand.
- 1.2 The first three minutesDraft
How quarks became protons and neutrons, and how the first nuclei formed before the universe was twenty minutes old.
- 1.3 Why is the night sky dark?Draft
A dark night sky is evidence that the universe has a finite age and is expanding.
- 1.4 The afterglowDraft
The cosmic microwave background, the oldest light there is, and what its faint ripples tell us.
- 1.5 How we knowDraft
The three pillars of evidence for the Big Bang, and how each one could have proved it wrong.
- 1.6 The Dark Ages and the first lightDraft
A hundred million years of darkness, and then the first stars switch on.
- 1.7 Open questionsDraft
Dark matter, dark energy and inflation: what the standard model of cosmology cannot yet explain.
- 2.1 Gravity versus pressureDraft
How a cloud of gas collapses, heats and ignites.
- 2.2 What a star isDraft
Fusion in the core balanced against gravity: the equilibrium that lets a star shine for billions of years.
- 2.3 The lives of stars, sorted by massDraft
Why a star's mass decides everything: how long it lives, how it dies and what it leaves behind.
- 2.4 GalaxiesDraft
Cities of stars, dark matter and the cosmic web.
- 2.5 Reading starlightDraft
Spectra, distances and the cosmic distance ladder: how we measure things we can never visit.
- 2.6 The Sun, a typical starDraft
Our own star as an ordinary star, with Aditya-L1 as India's eye on it.
- 2.7 One chart for every starDraft
The Hertzsprung–Russell diagram, which organises every star by brightness and temperature.
- 3.1 Where the elements come fromDraft
Stellar nucleosynthesis: how stars build carbon, oxygen and iron.
- 3.2 Making goldDraft
Supernovae and neutron-star mergers, the violent events that make the heaviest elements.
- 3.3 The periodic table as a history bookDraft
Every element has an origin story; the periodic table arranged by where each one was made.
- 3.4 Why carbon?Draft
Bonding, chains and rings: why carbon chemistry is the chemistry of complexity.
- 3.6 From quarks to the HiggsDraft
The fundamental particles and the four forces that shape matter.
- 3.7 Are you really made of stardust?Draft
The famous claim, tested element by element.
- 4.1 From nebula to planetsDraft
How the solar system assembled from a disc of gas and dust.
- 4.2 Earth's violent birthDraft
The Moon-forming impact and the magma ocean.
- 4.3 Core, mantle, crustDraft
Differentiation: how the Earth sorted itself into layers.
- 4.6 Deep timeDraft
Radiometric dating: how we know the age of a rock.
- 8.2 The Scientific RevolutionDraft
Not a discovery but a method, and not invented anywhere in particular.
- 8.3 Fossil Fuels and IndustryDraft
Digging up three hundred million years of sunlight, and what it did to everyone who did not.
- 8.4 The Great AccelerationDraft
Twenty-four graphs that all bend at the same moment, and what that moment cost.
- 8.5 The AnthropoceneDraft
A proposed geological epoch that was formally rejected in 2024, and why that rejection changes nothing about the evidence.
- 9.1 The next century: climateDraft
The range of plausible futures narrowed at both ends, and almost nobody noticed.
- 9.2 Energy after fossil fuelsDraft
The transition is probably cheaper than not doing it, and that is the least interesting thing about it.
- 9.3 Machines that learnDraft
Chapter 6 said collective learning made us. This lesson asks, carefully, whether this counts.
- 9.5 Leaving EarthDraft
Space is one of the most valuable things we do, and almost all of its value points back at Earth.
- 9.6 The deep futureDraft
Earth has about a billion years of biosphere left, not five, and that is only the first paragraph.