whatFilms under a single uniform tension, strung between pegs you can drag and add. The network obeys exactly one law: shrink total length. Junctions are not placed -- they sprout wherever a corner pinches too tight, and dissolve when their film runs out.

whyThe claim is Plateau's: films meet three at a time, at 120 degrees, always. Here it is measured, not asserted -- a live census over every junction reports the mean and worst deviation from 120, and it settles under a degree or two. The second number is sly: the network's total length as a fraction of the spanning tree between the same pegs. Below 1, the junctions are earning their keep; mathematics forbids it ever dipping below sqrt(3)/2, about 0.866. Drag a peg and the whole network reflows live, junctions gliding until the census reads 120 again. Drag far enough and the ratio can climb above 1: the network is holding a remembered topology, a local minimum -- exactly the metastability of a real film that nobody has popped.

howFree junctions feel one unit of pull per incident film and descend the length gradient; every few steps the topology heals -- a node whose tightest film pair pinches under 120 sprouts a new junction along the bisector, a junction-to-junction film shorter than a hair collapses, a degree-two junction dissolves. Pegs are fixed and films may end on them at any angle, as real films end on real pins.