Phyllotaxis
the spirals are counted, not admired
Concept

Evidence — where it appears

3 essays name this object, across 2 fields. What follows is each of them, and the objects they name alongside it.
120° — a third of a turn3 and 6 — whorled137.51°2 and 3 — Fibonaccirise 0.055 in both panelsthe counts decide, not the eye

What a mechanism would have to show

This site says of every model it draws that reproducing a pattern is not explaining it. That is easy to repeat and hard to make precise. Here it is made precise — a list of what an account of phyllotaxis would have to establish, with each item marked according to whether the models on this site establish it.

mechanism · mechanism claims 00.2500.5000.750100200300internodes counted on one stemsmallest difference in correlation the count can resolvethe difference to resolve — 0.7656 internodesmatched at 0.75° of scatterone stem, counted once

The test a plant could settle

Every other open question in this collection is priced in tens of specimens, and one of them in a hundred and sixty. This one is priced in internodes on a single stem, and the number is fifty-six — because it is a statistic of one sequence rather than a share of a population.

wrong · sequence -0.20000.2000.4000.6000.5000.75011.251.50divergence scatter, in degrees — the one quantity a plant offerscorrelation between one divergence and the next4 runs per point · band ±0.13every point is a lattice

What a quiet plant is worth

Almost every measurement gets easier as the effect gets larger. This one gets harder — a stem's divergence sequence stops carrying information about its noise at precisely the scatter where the noise becomes obvious. The specimens worth measuring are the ones that look least interesting.

wrong · survey spec

Named alongside it

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

AutocorrelationDiscriminationDivergence angleFalsifiabilityIdentifiabilityMeasurementMeasurement errorNoiseSample sizeSpecimenSurveyAuxin

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