Universe 2

The world this project is running now: four founder populations on an archipelago, under a law set written from what the first universe taught.

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Identity

What is different about this world

Universe 2 is not a restart and not an improvement of Universe 1. It is a second world, founded to ask a question the first one could not: what happens to migration, isolation and contact when there are four landmasses rather than two, with open channels between them, two stepping-stone islets, and a refugium reachable only by building across deep water.

Its physics are Universe 1's, deliberately, with exactly two rules changed. Both changes come from things Universe 1 did rather than from anything anyone preferred.

• Excavation may no longer drown its own cell. In Universe 1, digging a cell below the waterline was irreversible: a submerged cell could never be dug again, so water was a one-way drain for ground. By the end, that world had less land than it was founded with. Here the last dig that would submerge a cell is refused, so an interior cannot sink itself.
• A dying carrier's last unit searches further for somewhere legal to land. Universe 1 grew a single column more than forty times its own legal ceiling in a sealed corner. The search radius here is eight cells rather than one, and the ceiling is now a gate every candidate world had to pass before this one was founded.

The map also gained the twelve-cell ocean margin Universe 1 had and the archipelago did not, and its massif's approach was deepened so the refugium is genuinely unreachable without building. What Universe 1 did, and why each of those followed from it.

How this world was chosen

The same discipline as Universe 1, which is the only reason its results will mean anything. The law set was frozen in writing before any candidate ran. Seeds came from a deterministic stream whose entire input is already public, taken strictly in the order it emits them. The first three passers of a registered screen were soaked blind for 172,800 ticks each and graded against six gates fixed in advance.

All three passed every gate. The launch seed is therefore the first of them in that order, not the best: two of the three were measurably better on things somebody might have been tempted by, and the record names them so nobody can later claim otherwise. Why choosing the most interesting world would have undone the whole method.

What permanence costs

This universe cannot be patched. A rule that turns out to be wrong stays wrong for the life of it, because any change that would make its state evolve differently is the seed of a different universe rather than a fix to this one. Universe 1 paid that price in public: it carries a thousand-unit column in one corner, a defect found early and never corrected, because correcting it would have ended the world it was found in.

Universe 1 is preserved in full rather than deleted. It ran for over a million ticks, closed a strait nobody designed, and stopped. Everything it recorded is still here.