The six active sectors of M∞, the particles that live in each, and the inactive band that the chain skips. Click a sector — in the panel or the scene.
Each sector is an infinite, flat, macroscopic space; the geometry label (CP¹, S³, …) names the local symmetry of that sector's potential minimum, not a compact shape. The tower orders them by sector dimension d. The greyed rungs are d=7,8,9 — supercritical but unreached by the coupling chain, so no active geometry forms there.