Eight linked nodes firing left to right, each swelling as the pulse reaches it.

A single phase term sweeps zero to one over a fixed period and every node compares its own position along the chain against it, so the pulse is one number rather than a queue of timers and cannot drift out of step. A node's radius and glow both scale with how close the pulse currently is, falling off over roughly a sixth of the chain, which is what gives the travelling swell a soft leading and trailing edge rather than a hard switch. Nodes carry the secondary hue while lit and the primary while idle, and straight connectors run between them so the chain reads as linked even at rest.