The Record
The doubling years from 2511 to 2540, and the plan that carries the same pace to the first outbound seeds.
How does a one-tonne seed become a swarm?
By copying itself. Once the first minds arrived in 2511, the seed's fabricator and the machines it had built began to make more fabricators and more machines, each batch able to do the same fiction. Each doubling takes the Record's pace of 9.5 months. Over the 29 years from 2511 to 2540 that comes to 37 doublings, which turn a seed of about a tonne into 1.1 × 1014 kg of radiator material at the assumed film density challenge.
The film mass and replication target use the assumed 0.01 kg/m² cold-film density. This is an unsourced engineering target challenge; Cooling is the economy separates that assumption from the physical area law.
The matter comes from Kindling. The chapter runs the years as a time-lapse of the planet's surface being cut and lifted sunward as a swarm, with the night side staying black. At true brightness the swarm is too sparse to see in visible light in 2540, and the sim draws it brighter than it is so that the lift can be followed illustrative. Kindling holds 3.0 × 109 times the 2540 radiator-material target, so after 37 doublings the swarm is still a speck against the supply design challenge. Doubling is exponential growth, so most of the mass arrives late: the final doubling adds as much radiator material as everything before it. Building costs energy as well as mass: a fabricator spends 1 × 108 J for each kilogram it makes design.
The sim then goes down inside one fabricator. It passes an assembler cell and a manipulator tip, and ends on a single atom being placed, which is the atomic rung of Barrow's scale challenge. Then it climbs back out through the doublings to the swarm. Growth at this rate has to stop somewhere. The chapter says only that it keeps the pace until matter or heat sets a limit, and The Swarm is about the heat.
Everything after 2540 in this chapter is a projection, and the chapter labels it as one simulation. If the pace holds, the swarm reaches the plan's goal in 2553, and the first outbound seeds leave in 2610 for 12 nearby systems. The sim draws them as a wave map. Whether the pace holds is an assumption of the plan, and nothing in the Record confirms it.
Which numbers does this chapter rest on?
| What | Value | Basis |
|---|---|---|
| Doubling time in the Record | 9.5 months | physics |
| Doublings from 2511 to 2540 | 37 | physics |
| Years of doubling | 29 | physics |
| Radiator material target in 2540 | 1.1 × 1014 kg | challenge |
| Kindling's mass over that | 3.0 × 109 | challenge |
| Energy to build a kilogram | 1 × 108 J | design |
| Outbound seeds in 2610 | 12 systems | simulation |
Why exponential growth has a ceiling, and why it is heat before it is matter, is in Doubling and Cooling is the economy. The doublings are also the link between a power level and a civilization's rank on two scales at once, which Inward, not outward sets out. The Record's own events, from the first collector to the outbound seeds, are on the chronicle page.
Play it, or go there
Play this chapter 1:45, narrated, with the same numbers as this page.