Phyllotaxis
the spirals are counted, not admired
Concept

Out of sample — where it appears

A test of a rule on cases it was not read off. A rule scored on the rows that produced it can only lose to a worse description of them, so a perfect in-sample score is the state a rule most needs testing in rather than evidence that it is a law.

Named by 2 essays across 2 fields — each of them below, with the objects they name alongside it.

How far each rearrangement is from closing, against the lag it kept. One bar per excluded cut, its length the distance from the displacements summing to nothing, ordered smallest first, and each labelled with the lag the cut left standing. The seven shortest bars are the cuts that kept a lag of 7 or 8 and the six longest are the cuts that kept 4 or 5, with a gap of 6.3 degrees between the two groups and no row in it. The rule sorts every one of them.

The lag decides whether it closes

Seven of the thirteen excluded rows have displacements that cancel and six do not. Every row that closes kept a lag of seven or eight and every row that does not kept four or five, thirteen times out of thirteen — and then a lattice nobody had cut broke it.

mechanism · damage shape The hops the correction is fitted over, with the new one at the near end. Each cluster of rows placed by the lag it kept and the angle of the hop that lag keeps. The four the correction was fitted over run from 19.5 to 39.1 degrees; the new one sits at 12.78 degrees, a third smaller than any of them. A fifth point beyond the near end of a fitted range is a test of the fit, where a fifth point between two old ones would mostly have been a restatement.

A fifth cluster

A correction to the exchange's size was fitted over four hop clusters and its own file said so. A search turned up a fifth, at a hop smaller than any of the four, and the rule is right on it — which is what a prediction being confirmed looks like when the confirmation is worth having.

cylinder · ablation

Named alongside it

The objects these essays reach for when they reach for this one.

Claim testingContact familyExchangeFalsifiabilityHonest limitsSample sizeAblationConfoundingDamage profileDivergence stepExceptional chainFitted constant

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