Phyllotaxis
the spirals are counted, not admired
Generator

ring-field

The radius is the activator concentration and the dots are the 8 peaks a counter finds in it. The starting state was the uniform steady state plus 2% disorder; nothing in it favoured any position on the ring.
The activator around a ring of circumference 1.40The radius is the activator concentration and the dots are the 8 peaks a counter finds in it. The starting state was the uniform steady state plus 2% disorder; nothing in it favoured any position on the ring.8 peakscontrast 99% of the maximumpredicted 8, counted 8

Drawn at its defaults, in what a plant might be doing. It takes no options at all, so every essay calling it gets this exact drawing.

Called by 3 essays

the blast radius of changing it

What a plant might be doing

Turing's last problem

Turing's final work was on phyllotaxis and it was unpublished when he died. Its core is a ring of cells and two diffusing substances, and the thing it does is select a number of peaks — which can be predicted from the equations before anything is integrated, and then counted from what the integration produces.

 What a plant might be doing

A ring cannot make a spiral

The peaks on a Turing ring do not all appear at once — there is a first and a second. But which two lead is decided by the starting disorder, so the angle between them comes out at 177°, then 47°, then 109°, then 151°. A divergence angle is a relationship that repeats, and this one does not.

 What a plant might be doing

A growing organ is part of the rule

Every model on this site places primordia on a surface and then treats the surface as furniture. But the surface grows between one placement and the next, and that growth reaches the rule through the only channel it has — where the neighbours are. What looks like a boundary condition turns out to be a term in the model.

All 105 generators