Week 1 Session: Signs That Move — Framing the Question

What does a sign system need to represent change, not just categories?

22 February 2027

The question#

Most sign systems are good at naming things: a traffic light names three states, a musical note names a pitch and a duration. Few notations are built, from the ground up, to represent change itself — a state turning into another state, inside the notation, not just described around it. This week sets up that distinction before any course-specific content arrives.

What this builds on#

Nothing yet — this week is the frame the rest of the course hangs on.

Reading three sign systems for change, not just state#

A traffic light names three states clearly, but the rule that moves it from one to the next — red follows amber follows green — lives in the electronics behind the light, not in the light itself. Look only at the sign, and you cannot tell what comes next.

Musical notation does better: a note names a pitch and a duration, and a sequence of notes reads left to right as time passing. But most of what happens between notes — a crescendo, a rubato, a held breath before the next phrase — is written as an instruction to the performer, not as a state the notation itself transforms through.

Binary code comes closer again: a bit is a single two-valued unit, and a sequence of bits can represent anything discrete. But a bit flipping from 0 to 1 is an event that happens to the notation, from outside it — nothing in “0” or “1” alone tells you it is about to change, or into what.

This course studies a fourth case: a notation built from two-valued units (week 2), combined by a strict rule (weeks 3–4), where a specific structural mechanism — the changing line (week 8) — marks a state as about to transform inside the notation itself, not by external stage direction. That is the sense in which this system was built to represent change, and it is worth holding the other three systems in mind as the comparison case for why that is unusual.

What you should be able to do after this week#

Compare two or three sign systems (binary code, musical notation, traffic signals) on how well each one represents transition rather than category, and hold onto that question as the course introduces a system built specifically to answer it: yin/yang lines, trigrams, and hexagrams (week 2 begins the construction).