# The Why of Day and Night — v1

*What a component does by day and by night, and why. This document is the **why** the pseudocode
enacts and the biology implements: not the mechanism (that is the pseudocode) and not the general
nature of the model (that is logic_principles), but the concrete reasons the day/night behaviours are
as they are — why the loop has the shape it has, why the two scopes exist, and how they compose. It
is written at the level of a **general component**: every component runs the same shape, so the story
is told once. The organism is the integration of many such components, and the why does not change
with scale — what a component does for itself is, integrated, what the organism does. Along the way
the emergent objects appear — the synapse, the circuit, the assembly — which no component contains
but which the integration constitutes (see logic_of_aggregations for their ontology).*

*How this relates to the other documents. The pseudocode is the expression (the how, in algorithmic
grammar). logic_principles is the general why (why the model is a self-writing physics; the seven
categories; the four operations). logic_of_aggregations is the ontology (objects as names over cuts).
This document is the concrete why of day and night — the middle level: why these specific behaviours,
why two scopes, why they alternate. The biological how is deferred to a later companion.*

---

## The one shape, run in two scopes

A component does one thing, repeatedly: it acts, it recovers the ability to act, and — after a run of
acting and recovering — it prepares what comes next. Written as a rhythm:

> **(ACTION ⇄ RECOVERY) × many, then PREPARATION.**

This is the whole of a component's life, and it runs at both scopes. By **day** the shape turns
outward, against the world; by **night** it turns inward, against the component's own economy. The
categories keep their meaning across the turn — ACTION is always the defining deed, RECOVERY always
the fast alter-ego that restores the capacity to act, PREPARATION always the shaping of what is next —
but *what* is acted upon, recovered, and prepared differs between the scopes. The rest of this
document is why that shape, why twice, and how the two turns compose.

Why *this* shape at all, before either scope. A component that could only act would exhaust itself and
stop; so acting must be paired with restoring — ACTION ⇄ RECOVERY. But restoring the capacity to
repeat is not the same as improving what is repeated; a component that only acted and recovered would
run forever unchanged. So the alternation must be punctuated by a phase that reads what happened and
shapes what comes — PREPARATION. Three phases, because there is nothing else a repeating act can do:
perform it, restore it, or improve it. (This is the ring; see logic_principles §2.)

---

## The day loop — meet the world, gather evidence

**What the day is for.** By day the component meets the world. Its ACTION is its outward deed — the
release, the fire, the response, the propagation — performed in answer to what arrives. The day's
purpose is not to change the component (that waits for night) but to *act appropriately and to gather
evidence about what mattered*. The day writes claims; it does not yet pay them.

**Why ACTION ⇄ RECOVERY alternates, and × many.** The world does not present one event; it presents a
*stream* — a train of spikes, a barrage of input. Each act consumes something the next act needs:
vesicles emptied, ions displaced, budget spent. So each ACTION must be followed by a RECOVERY that
restores the capacity to act again, and the pair repeats as fast as the stream demands. The "× many"
is the stream: the component rides the train, acting and restoring, acting and restoring, meeting each
event in turn. RECOVERY is not rest — it is the fast alter-ego of the deed, the refill that keeps the
component in the fight. Its *speed* is the component's timing resolution: how fast it recovers is how
soon it can meet the next event.

**Why PREPARATION comes after the run, not during it.** Within the stream there is no time to reflect;
each act is answered by the next. But evidence about *what the stream meant* cannot be read from a
single act — it is a property of the run as a whole (how often, how strongly, in what coincidence).
That reading needs a stable average, which only exists once the burst has passed. So PREPARATION runs
in the quiet after the train: it distils the accumulated fast-traces into a slower evidence — the
**tag**, a provisional claim that *this* activity was worth consolidating — and it shapes what comes
next (occupancy, thresholds) so the following run is better tuned. PREPARATION is the day's
integration-and-provisioning phase: read the burst, stake a claim on the night, set up the next burst.

**The day's currency is information, and information is not scarce.** What the component gathers and
emits by day — signals, traces, evidence — is *non-rival*: one component reading a signal does not use
it up; many can read the same glutamate, the same retrograde, the same dopamine. Because the day's
currency cannot be depleted by sharing, the day's mode is **collaboration**: components act together,
read each other freely, and the more that participate the richer the evidence. Nothing is taken from
one component by another's acting. (This is scarcity deciding the mode; see logic_principles §5.)

**What the day produces.** Two things accumulate through the day and are handed to the night. First, a
field of **tags** — provisional claims, staked wherever activity coincided with reward, about what
should be consolidated. Second, **fatigue** — the metabolic debt of all this acting, reported upward.
The day does not consolidate and does not rest; it *acts and marks*, leaving tags to be paid and a
debt to be discharged. Both are the night's business.

---

## The night loop — consolidate the evidence, converge the structure

**What the night is for.** By night the component turns inward. The world is gone; there is nothing to
respond to. Now the component *changes itself* — builds the structure the day's tags called for, sheds
what went unused — and it does this by a self-contained loop that checks its own work. The night's
purpose is to **spend the day's evidence**: pay the tags, converge the structure, discharge the debt.

**The same three phases, turned inward.** ACTION at night is the defining deed of the night: change
the structure — build where night participation was high, release where it was low. RECOVERY at night is
the fast alter-ego of that: import the material and free the material that building and shedding
require (structural change costs matter, and matter must be moved). PREPARATION at night is the
**replay** — the component re-evokes the day's patterns as a probe and measures how well it
participated, which tells the next ACTION what to fix. So the night runs (build⇄release ⇄
import⇄free) × many, then replay — the same shape as the day, against the economy instead of the
world.

**Why the night's currency is material, and material is scarce.** What the night moves — the matter
and energy of structural change — is *rival and conserved*: what one component builds, another cannot;
the pool is finite. Because the night's currency is depleted by use, the night's mode is
**competition**: components contend for the shared material, and building here means not-building
there. The day's collaboration becomes the night's competition, and the reason is simply the currency:
information is non-rival, matter is conserved. (Same principle, opposite scarcity; logic_principles §5.)

**The self-contained loop: participation selects, restructuring consolidates.** This is the heart of
the night, and it closes on itself with no external driver. In RECOVERY each component is given a
limited **energy store** — all get a base, but those still carrying the day's tags get more, so past
participation (the day's evidence) buys present chance. Replay (the night's PREPARATION) then runs the
day's circuits, and a component participates in a circuit by igniting — which **spends its energy
store**. Because the store is limited, a component can take part only so long; as its energy drains it
can no longer sustain participation and **gives way**, letting other circuits — other components with
energy still to spend — recruit. So replay sweeps the repertoire, circuit by circuit, as stores
deplete, and each component's **participation is traced**. Restructuring (the night's ACTION⇄RECOVERY)
then **strengthens the participants**: the components whose participation trace is high, and which have
material, build up; those that did not take part drift down — while RECOVERY re-supplies energy and
material for the next round. Note what decides the outcome, and what does not: the **tag buys chances,
not prizes**. A high day-tag means a larger energy store, so a component gets to play the participation
lottery more often — but it wins a build only by *actually participating* in a recruited circuit. A
heavily-tagged component that plays often and never takes part in a winning circuit is not built; a
lightly-tagged one that does participate is. Participation is the arbiter of build-versus-release; the
tag only funds the attempt (and pays for the build, depleting as it does). Cycling many times, because
resolving who is potentiated and who is
depotentiated is a competition that takes many rounds. Around and around: **replay selects by
participation; restructuring consolidates the participants and re-supplies the energy; replay runs
again on the strengthened structure.** Each phase produces exactly the fuel the other consumes.

**Why participation, and not something a component cannot know.** A circuit is an emergent object — no
component contains it, and no component knows which circuit it is part of. Yet the night selects at the
circuit level. It can, because a component senses the circuit *arriving at itself*: the convergent
input a replay delivers is the circuit reaching this component, and igniting in response — spending its
own energy to take part — is its participation in that circuit. A component that never gets driven, or
that runs out of energy, simply does not take part and is not strengthened. So a purely local act —
spend energy to ignite when the circuit arrives — realises a circuit-level selection, without any
component reading beyond itself. What is consolidated is what participated; the circuit is selected
without anyone knowing the circuit.

**Why the night ends itself — two fuels running down.** The night is not clocked; it ends when its
work is done, and "done" has two meanings that run down together. First, **the tags deplete**: each
build spends tag, so as consolidation completes there are fewer claims left to fund participation and
strengthening, and the loop quietens. When the tags are exhausted there is nothing left to consolidate.
Second, **replay is expensive**: participation spends energy, and this cost — call it night fatigue —
accumulates as the night runs. Because replay *lengthens* across the night (early, on raw structure,
energy is spent fast on circuits that break; late, on consolidated structure, the same energy sustains
many completing circuits swept in turn), the cost accelerates toward the end. The night ends when
either fuel is spent: the tags exhausted (the work is done) or the energy spent (replay has cost too
much). The normal end is tag-exhaustion — the night finishes its job — with the energy cap a safeguard
against endless exploration.

**Why the night changes character as it runs.** Early night has many unpaid tags, so much to build —
but on raw structure the circuits break fast, so energy is spent quickly and replay is short while
restructuring is long. Late night has few tags left, most structure built — so circuits complete, the
same energy sustains participation across many circuits swept in turn, and replay is long while
restructuring is short. So the night shifts from restructuring-heavy to replay-heavy as consolidation
progresses. This is not
imposed; it falls out of the tags depleting. The shape of the night *is* the progress of consolidation
made visible.

---

## The relation between day and night — a two-stroke engine

Day and night are not two separate regimes; they are the two strokes of one engine, and each produces
exactly what the other consumes.

- The **day produces tags** (evidence of what to consolidate) and **fatigue** (metabolic debt). It
  cannot consolidate — the world is present, the component is busy acting, and consolidation needs the
  component offline.
- The **night consumes tags** (pays them into structure) and **discharges fatigue** (the restructuring
  and its metabolic settling repay the debt). It cannot gather evidence — the world is absent, there
  is nothing to act on.

So neither scope is primary; they are locked in a cycle where the day writes claims the night pays,
and the night rebuilds the structure the day will next act on. The day fills the tag-field and raises
the debt; the night empties the tag-field and discharges the debt. A rested, consolidated system's
scope flips back to day (waking); an overloaded one carries unspent tags forward.

**Collaboration by day, competition by night — one principle, opposite scarcity.** The mode flips
between the strokes because the currency flips. By day the currency is information (non-rival), so
components collaborate. By night the currency is material (conserved), so components compete. The same
components, the same shape, but sharing where the resource is free and contending where it is scarce.
And the competition is *adjudicated by* the collaboration: what a component built in the night is
proportioned to how it participated in the replayed patterns — so the night's contest over scarce
matter is settled by the collaborative replay of the day's evidence.

**The switch is earned, never clocked.** Nothing schedules the turn from day to night or back. Day
accumulates fatigue until it dominates rest and the scope is forced to night; night spends tags and
discharges fatigue until the work is done and the scope is permitted back to day. Both transitions are
the earned outcome of an accumulation reaching a threshold — the same logic, at the top, as the tag
that is earned by a day's coincidences or the structure that is earned by a night's replays. The whole
system, from the single synapse to the day/night cycle, is built of accumulations that cross thresholds
and are read from above. (Time is suffered, not counted; logic_principles §7.)

---

## From the component to the organism — the same why, integrated

Everything above is told of a general component, and nothing changes when we integrate. The organism
is not a different kind of thing with a different why; it is what many components become when coupled.
Its day is the collaboration of their days; its night is the competition and replay of their nights;
its sleep need is the sum of their tags and fatigue; its consolidation is the convergence of their
structures. The two-stroke engine at the top — gather by day, consolidate by night — is the same
two-stroke engine at each component, integrated. The why does not gain a new term at the larger scale;
it is the component's why, multiplied and coupled.

What *does* appear at the larger scale is the **emergent objects** — the ones no component contains but
the coupling constitutes. The **synapse** is the alignment three components sustain by day and
re-verify by night. The **circuit** is the coincidence of many components' primed thresholds, replayed
and converged upon at night. The **assembly** is the largest of these — the set of circuits that
recruit together, swept and stabilised across the night's replays. These are the objects the day/night
loops are *for*: the day gathers the evidence that says which alignments and circuits matter, the night
builds and converges them. But they are never expressed in any component — they are what the
integration verifies, and what we, as observers, name (see logic_of_aggregations). The organism's why
is the component's why; the organism's *objects* are what that why builds when components are many.

---

## In one view

The day meets the world and gathers evidence, acting and recovering through the world's streams and
preparing tags in the quiet — collaboratively, in the non-rival currency of information. The night
turns inward and consolidates that evidence, building and releasing structure and importing and
freeing material through many rounds, then replaying so that components participate — spending a
limited energy store — and the participants are strengthened — competitively, in the
conserved currency of material, in a self-contained loop that ends when its two fuels (the day's tags,
the night's replay energy) run down. Day produces what night consumes and night rebuilds what day will
act on; the switch between them is earned, never clocked. And all of this is one shape — act, recover,
prepare — run outward by day and inward by night, in a single component and, integrated, in the whole
organism, building the emergent objects that no component contains.
