Two sources vibrating. Where their waves meet, particles settle on the nodal lines — the places where the vibrations cancel each other out. What remains visible is the geometry of interference: the pattern that emerges not from either voice alone, but from their meeting.
i. Two close sources, similar frequencies — strong interference, tight web.
ii. Sources farther apart, different frequencies — complex overlapping territories.
iii. Nearly identical frequencies — a beating pattern, slow moiré.
What happens when two vibrations find each other?