Somebody chose the order.
18 routes through the questions, each a handful of them in a sequence, and each with a sentence saying what that sequence is for. Nothing here is a prerequisite for anything else. Every question still stands on its own, and you can leave a route at any stop on it.
- From nothing to a bodyChemistry to a cell and a cell to a complex one, then sex, how one fertilised cell becomes a body, and why a body ages.6 stopsAll at deepBegins with: How did life begin?
- Counting what is aliveHow many kinds there are, why the counting is hard, and how fast they are going.5 stopsShallows to deepBegins with: How many living things have we never met?
- What you are not seeingPerception, attention, language, memory and choice: five places to ask how much of what the mind hands you it made itself.5 stopsSurface to abyssBegins with: How much of what you see is invented?
- The lights going outSleep, dreams, anaesthesia and a divided brain, four ways of asking what has to be present for anyone to be there, then why there is experience at all and whether a machine could have it.6 stopsDeep to abyssBegins with: Why do we sleep?
- OutwardStart where the Sun’s wind gives out and keep going until the question stops being about distance.6 stopsShallows to abyssBegins with: Where does the solar system end?
- The whole historyThe universe in order, from the first three minutes to whether there are last ones.6 stopsSurface to abyssBegins with: What happened in the first three minutes?
- Before anyone wrote anything downThe human past before writing, from a time when there were several kinds of human to the first farmers and the monuments built by people who did not yet farm.7 stopsShallows to deepBegins with: Who were we before anyone wrote it down?
- Things that endedPalaces that fell, cities that emptied, an island whose decline came from outside, and what any of it leaves behind.6 stopsShallows to deepBegins with: Why did the Bronze Age collapse?
- What a measurement isThe experiments first, and the interpretations last, once it is clear what any of them has to account for.5 stopsDeep to abyssBegins with: What actually happens when we look?
- The bottom of thingsEmpty space and information, then the smallest length, black holes and time, where quantum theory and gravity meet and no tested theory joins them, and last, why there is anything at all.6 stopsShallows to unknownBegins with: Is empty space empty?
- DownwardFrom the crust to the core, and the life that turns out to live kilometres into the crust and beneath the Antarctic ice.5 stopsShallows to deepBegins with: What is inside the Earth?
- The planet’s bad daysIce at the equator, a mass extinction, the rhythm of the ice ages, two thresholds that may already be behind us, and the layer we are leaving.6 stopsSurface to deepBegins with: Was the whole planet once frozen?
- What can be shownStart with the evidence and follow it until it runs out, which it does, in a specific place.10 stopsShallows to abyssBegins with: What did the ancient world write about Jesus?
- The man himselfWhat can be established about one first-century Galilean, and where the establishing stops.5 stopsShallows to abyssBegins with: What did the ancient world write about Jesus?
- Where the book came fromFour Gospels that never name their writers, a canon no single council chose, and a text you can check against a fourth-century page.8 stopsShallows to deepBegins with: Who wrote the Gospels?
- How it became an institutionFrom an illegal association in one province to an empire, a creed and, eventually, several churches.14 stopsSurface to deepBegins with: What did the earliest Christians actually do?
- What it didThe record of an institution with power, in the order the documents allow, including the parts it commissioned itself.7 stopsShallows to deepBegins with: What did Christianity do about slavery?
- The questions that do not closeWhere history stops being the right instrument, and says so rather than guessing.10 stopsShallows to unknownBegins with: What happened after the crucifixion?