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Essays arrive in groups rather than one at a time. The most recent group is below in full, and every earlier one after it, newest first.

Essays arrive in groups rather than one at a time, and a group usually opens up a subject not covered before. Between one group and the next nothing changes, so a reader who has seen the most recent group has seen everything.

28 September 2026

5 essays on the pattern itself, shells and growth, branching and transport and packing and tiling

A seed head with half its rim missing, and three places its centre could be put. A 900-organ golden head, every organ displaced by 0.1 of a spacing, with the organs beyond seven tenths of the radius removed over half the head. The centroid of what is left lies 3.099 spacings from the centre the head grew about; the centre about which the inner annulus's two counted families are most coherent lies 0.0132 spacings from it. The inset magnifies half a spacing around the true centre. The pattern itself

The centre the spirals give

Reading a seed head's divergence from its organs' positions needs the head's centre, and a photograph does not give it. A misplaced centre turns every organ's angle by an amount that varies round the head and grows toward the middle, so it could read as a twist. It does not, until it is large: a 900-organ head tolerates a centre a sixth of a spacing off, a 2,400-organ head a quarter. The centroid of the organs finds a whole head's centre to a hundredth of a spacing, and read about it the positions separate every twist shape exactly as well as with the centre given. The radius law, which looks like the natural fit, does not find it at all. And when half the rim is missing the centroid moves three to five spacings and turns an untwisted head into a twisted one, while the centre about which the counted spirals are most coherent still lands within a hundredth of a spacing.

6 figures
One cut along a shell's axis read back for all three of Raup's numbers, the axis found from the cut itself. The seven whorl sections a high spire at W = 2, D = 0.2 and T = 2 shows over three turns on a plane through its axis, alternately right and left of it, each drawn at 48 points moved by noise of 0.003 of the rim. Told only the points and which section each lies on, and started from an axis laid a quarter of the innermost radius off and two degrees out, the fit finds the axis 0.0055 innermost radii and 0.0053 degrees from the true one — the inset magnifies the axis at the apex — and reads W = 2.0000, D = 0.2004 and T = 1.9994: out by 0.002%, 0.205% and -0.029%. The circles are redrawn from those numbers. Held at the laid axis, the same cut reads T = 2.084 and D = 0.1746. Shells and growth

The cut along the axis

A median section cannot see how far a shell travels along its axis, so the third of Raup's numbers seemed to need a second cut. It does not need the first. One cut through the axis shows every whorl twice a turn as a whole circle, and fitted with the axis free it returns W, D and T together — to 0.023, 0.085 and 0.031 per cent on a high spire drawn to a thousandth of its rim, from an axis laid a quarter of a radius off and two degrees out. On the shell the median section was read on, it reads the expansion twice as well over a turn and the distance from the axis as well. Laid by eye and left there, the axis costs T four per cent and a high spire's D thirteen, and the residual says so. What it does not always say is that the saw missed the axis: on a low spire a cut a fifth of the innermost radius off moves W by two and a half times its own noise error with the residual at the noise.

7 figures
A crown sized against buckling on clamped bases, coloured by the share of that load each branch keeps on the base its parent really gives. A symmetric crown 9 generations deep, every branch 2^(−1/2) of its parent's length, turned 20° at every fork, with equal loads on the tips, sized against buckling as if every branch were clamped. Each branch is coloured by the share of its clamped buckling load it keeps once its base is the tip of a parent that bends, the parent alone: from 0.296 to 0.795 outside the trunk. A daughter turning back toward vertical off a steep parent keeps least, one turning outward most. Branches pointing level or down carry no compression and are drawn faint. Branching and transport

A base that gives

Every branch sized against buckling was a column clamped to a parent that does not move. A parent bends, and a column on a base that turns keeps only a share of its clamped load — the root of φ·tan φ = kL/EI — which no stiffening of the column itself lifts past the load at which a rigid rod on that base would tip. On the crown sized as if clamped, that share is 0.561 at every branch when the loads run along them, falls from the ground to 0.447 when the whole path is counted, and under gravity is a closed form in the turn from a parent's tilt to its daughter's: 0.795 for a daughter turning outward, 0.296 for one turning back upright off a steep parent. Resized for the bases they really have, the crown's junctions alternate about two from generation to generation, 226 branches of a thirteen-generation crown have no radius that holds them, and the cone of directions that divided buckling from bending no longer divides them.

7 figures
A window of a golden head's tiling after a share of its cells have divided, five-sided cells joined to the sevens they touch. A window ten wall spacings square, a little under halfway out on the 900-organ golden head's tiling, after 61 divisions — 10 per cent of the head's 607 measured cells — by a random cell by its shortest wall, seed one. Cells are filled by side count and every five-sided cell is joined to each seven it touches. Over ten seeds the tissue at this stage has a side-count variance of 0.57, Aboav's a of 1.20, a Lewis slope of 0.164 and 94 per cent of its fives touching a seven. Packing and tiling

A tissue that was never shaken

Every tissue whose laws have been read here was disordered by moving its points. A growing tissue also disorders itself by dividing, and a division is a wall no set of points generates. Held as a map and divided cell by cell by three rules, a golden head's tiling switches Lewis's law on once a tenth of its cells have divided, at a variance of side counts lower than any moved tissue reaches the law at, because the commonest single division makes two half-sized fives and two full-sized sevens at once. Dividing the largest cell first reaches the corner of the plane no moved tissue reached — Lewis's law on and Aboav's a above its band, at 1.67 — because the largest cells of a golden head are its sevens. And the two numbers that placed every moved tissue on Lewis's law to one and a half times the noise misplace a divided one by fifteen times it: they were a calibration of how the tissue was disordered, not of tissue.

7 figures
A gap in the disorder staircase read at a hundredth of its grid. μ₂ on a head of 3,690 organs from 137.1975° to 137.2725°, a gap in which the staircase counts no step, read every 0.00005° — 1500 samples — against the staircase's median; the open circles are the staircase's own samples every 0.005°, which the fine sweep passes through exactly. No change between two fine samples reaches a fifth of the median. The curve is a sawtooth: 13 falls of ten cells or more, 19 at 137.2004°, 21 at 137.2009°, 18 at 137.2054°, 21 at 137.2058°, 14 at 137.2111°, 18 at 137.2115° and more, against 0 climbs that large; climbs average 2.4 cells and falls 4.0. Packing and tiling

What lies between the steps

The disorder staircase — the spread of a head's side counts against its divergence angle — gained steps with every larger head, forty at 3,690 organs, and nothing said whether it had steps at every scale. Read again at a hundredth of its grid inside its two widest gaps, it has none: no change there reaches the size it counts as a step, and no dip hides between two of its samples. The steps stop. What the gaps hold instead is a sawtooth — μ₂ climbing a cell or two at a time and falling in teeth of ten to thirty-two cells, five of them exactly twenty-one — and a step, read at the same resolution, is not one event but two runs of flips of fifty-five cells each. How many steps a head has is a statement about where the line is drawn; the steps themselves are finite.

7 figures

Before that

Everything published earlier, newest first. Titles only — the cards are on the full listing.

27 September 2026

5 essays on the pattern itself, shells and growth, branching and transport, packing and tiling and the claims, measured

26 September 2026

6 essays on the pattern itself, shells and growth, branching and transport, packing and tiling and the claims, measured

24 September 2026

7 essays on the pattern itself, shells and growth, branching and transport, packing and tiling and the claims, measured

23 September 2026

7 essays on the pattern itself, shells and growth, the claims, measured and packing and tiling

21 September 2026

3 essays on shells and growth and packing and tiling

17 September 2026

8 essays on the pattern itself, the claims, measured and branching and transport

16 September 2026

6 essays on shells and growth

14 September 2026

8 essays on shells and growth, the pattern itself and branching and transport

12 September 2026

10 essays on branching and transport, the pattern itself and packing and tiling

11 September 2026

13 essays on shells and growth, branching and transport and packing and tiling

7 September 2026

50 essays on shells and growth, branching and transport, the pattern itself, packing and tiling, what a plant might be doing and stems and cones

2 September 2026

20 essays on what a plant might be doing, stems and cones and where the angle comes from

31 August 2026

20 essays on what a plant might be doing, stems and cones and where the angle comes from

30 August 2026

20 essays on what a plant might be doing, stems and cones and where the angle comes from

29 August 2026

20 essays on what a plant might be doing, stems and cones and where the angle comes from

28 August 2026

12 essays on the pattern itself, what a plant might be doing, stems and cones and where the angle comes from

27 August 2026

12 essays on where the angle comes from

26 August 2026

12 essays on where the angle comes from, the pattern itself, what a plant might be doing and stems and cones

23 August 2026

12 essays on the pattern itself, what a plant might be doing, stems and cones and where the angle comes from

22 August 2026

12 essays on what a plant might be doing, packing and tiling, the claims, measured, stems and cones and where the angle comes from

21 August 2026

12 essays on what a plant might be doing, packing and tiling, the claims, measured, stems and cones and where the angle comes from

20 August 2026

12 essays on what a plant might be doing, packing and tiling, the claims, measured, stems and cones and where the angle comes from

18 August 2026

12 essays on what a plant might be doing, packing and tiling, the pattern itself, the claims, measured, stems and cones and where the angle comes from

17 August 2026

12 essays on branching and transport, what a plant might be doing, packing and tiling, the pattern itself, the claims, measured, stems and cones and where the angle comes from

15 August 2026

12 essays on branching and transport, packing and tiling, the pattern itself, the claims, measured, stems and cones, what a plant might be doing and where the angle comes from

14 August 2026

12 essays on what a plant might be doing, the claims, measured, stems and cones and where the angle comes from

12 August 2026

12 essays on the claims, measured, stems and cones and where the angle comes from

10 August 2026

12 essays on the claims, measured, the pattern itself, stems and cones and where the angle comes from

6–8 August 2026

34 essays on the pattern itself, stems and cones, the claims, measured, shells and growth, where the angle comes from, branching and transport, what a plant might be doing and packing and tiling

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