Book XV · opened 2026-10-16 · Logistics, transportation, airlines and trade
The Mathematics of Travel and Trade
Moving people and goods between places is a counting problem before it is anything else: how many routes, how much load on each, how often. This book works those counts out from first principles, one model at a time.
Each chapter states its model, its units and its limits, and prints every number from a script. No chapter uses airline, freight or launch-industry data unless that source is held and named on the page.
1 · Chapters
| ch | title | state |
|---|
| 1 | Hubs and Spokes — 50 cities need 1,225 direct routes or 49 spokes; the hub nearly doubles the passenger segments (4,802 against 2,450) and concentrates the load; in a toy flight model the hub wins at low demand and loses from 77 passengers per pair per day | live; ch01-verify.py passes (Lean not written) |
| 2 | What the Count Leaves Out — chapter 1 with a cost term C = αF + βS: the hub is cheaper only while β/α stays under a threshold (0.2396 at 4 passengers per pair per day, 0.0006 at 73, none from 74), and its flights land on one airport | live; ch02-verify.py passes (Lean not written) |
| 3 | Thirty Days — Brazil’s paid vacation as a counting problem: 106 legal ways to split 30 days (CLT art. 134 as a secondary source states it; statute not read), 16 for 24 days, 1 for 18 or 12; an even spread puts 30/365 = 8.2% of covered workers on vacation on any day | live; ch03-verify.py passes (Lean not written) |
2 · Scope named by the author
These are the subjects the author named for this book. None has a chapter, and nothing below is a result.
- Logistics and transportation networks: routes, load, frequency.
- Airlines: network shape, seats and flights.
- Trade: flows between places.
- Space tourism, Earth side only: the ground logistics of passengers and supplies are the same kind of network problem as airline and freight logistics.
Moon and Mars are not in scope yet
The author's point, recorded here: logistics to the Moon and Mars is a different problem from the Earth-side case. Chapter 1's assumptions (daily frequency, uniform demand, one hub) do not carry over, since transfer opportunities on those routes are set by launch windows and flight times, not by a daily schedule. The corpus withdrew earlier Moon and Mars claims for want of a derivation (see claude/STATUS-moonbase-mars-claims-cut in the project notes). A Moon or Mars chapter waits for a model built for it.
A record that needs the author's decision
The repository's docs (docs/part-ii-source-wants.md, CLAUDE.md) reserve Volume XV for the W-algebra route (Feigin–Frenkel) and say it is not opened. This folder takes the number for the topic above on the author's instruction of 2026-10-16. Those docs were not edited here, so they still say the old thing.
3 · What this volume will not claim
- That any real carrier, port or launch provider should use any network studied here.
- That a counting model prices anything: fares, fuel, aircraft, slots and connection time are outside it until a chapter adds them.
- That one shape of network describes travel, trade and space logistics alike. Shared functional form is not a shared invariant.