Set-Point | The Shape of Things

Set-Point

The seed has never seen the sky.
Dark, damp, and no map but weight.
It cannot tell you where up is.
It can only turn from where it isn't.

Tip it left, the root bends right.
Tip it right, the root bends left.
Stand it true, and nothing bends.
The pull is the same all three times.
Only the angle has changed.

The farther from true, the harder the turn.
The nearer to true, the quieter.
Nothing is pushed.
Something is corrected.

No one sees the set-point.
It is not a place, and it is not a mark.
We learn it from which way the root turns.

A poem. It makes no claim. What it borrows is set out in the key below the poem, with its status.

Science and metaphor, kept apart

What the poem borrows

A root tilted from vertical turns back toward it, from either side, and a root stood true does not bend. This is ordinary textbook gravitropism. Status: well established as a description.

The turn follows the sine of the tilt angle, the sine law of gravitropism. That is the poem's "the farther from true, the harder the turn": the law gives a turn that grows with tilt up to a right angle. Status: a textbook law. One 2017 paper, on wheat coleoptiles (shoots, not roots), reports that its own data fit the law and that the response did not change at 2.5 times Earth's gravity: the plant reads the angle, not the strength of the pull. Roots were not checked here. The attribution of the law to a named author was not verified, so none is given.

What the poem does not claim

It does not say that acidic phytocannabinoids work this way. It borrows the geometry of one idea: a response set by distance from a baseline, whose sign reverses across a set-point, against a full agonist whose effect tracks dose. That idea is the prediction in section 3.4 of Preprint 5 (version 2), ledger L31. Status: hypothesis, untested. The paper says a size-of-effect gradient alone cannot tell it from a plain model in which more tone is simply worse. Only the reversal of direction can, and its proposed trial enrolls people on both sides of the set-point to look for it.

"No one sees the set-point" is the poem's line, not a method. Reading a subject's baseline off the response itself would make the prediction untestable, since the prediction is that the response depends on baseline. In the paper, classifying how far a subject sits from the set-point is held back until a criterion it names has been defined and validated.

The idea the poem borrows, drawn. Left: a full agonist's effect tracks dose and not the subject's baseline. Right: a normalizer's effect scales with distance from the set-point and reverses direction across it. A hypothesis, not a result. Figure by Jeffrey Benjamin, licensed CC BY.