# 23. Rhythm and Entrainment

## Central question

How does periodic behavior, synchrony, phase drift, and the limits of resonance metaphors.

## Why it belongs here

This module extends the Core Workbook's Five-Foci grammar into a concrete domain while preserving observation, provenance, uncertainty, and proportionate action.

## Outline

1. **Define the domain and its scale**.
2. **Map the relevant actors, signals, and conditions**.
3. **Distinguish direct observation from interpretation**.
4. **Trace feedback, thresholds, and failure modes**.
5. **Compare competing explanations**.
6. **Design a reversible exercise or study**.
7. **Name authorization, consent, and safety boundaries**.
8. **Return to the operating loop** — define, observe, trace, label, act, and observe again.

## Evidence boundary

Use the domain's strongest available evidence. Do not convert metaphor, subjective experience, or correlation into mechanism without an appropriate test.

## Deliverable

A one-page field map with a question, scale, observations, hypotheses, evidence status, next action, and review date.