The Structure of Vagueness

Abstract

Around the beginning of the 1990s, Frei Otto and his team at the Institute for Lightweight Structures in Stuttgart studied what they called “optimized path systems.” Previously, similar to the chain modeling technique Gaudi used for the Sagrada Familia, they had experimented with material systems for calculating form. Each of these material machines was devised so that, through numerous interactions among its elements over a certain time span, the machine restructures, or as Frei Otto says, “finds (a) form.” Most of them consist of materials that process forces by transformation, which is a special form of analog computing. Since the materials function as “agents,” it is essential that they have a certain flexibility, a certain amount of freedom to act. It is also essential however, that this freedom is limited to a certain degree set by the structure of the machine itself. In classic analog computing most of the movement is contained in gears, pistons or slots, or often in liquids held by rigid containers, but in the case of Frei Otto’s machines mostly all materials are mixtures of liquids and solids, or start out as liquid and end up as rigid. The material interactions frequently result in a geometry that is based on complex material behaviour of elasticity and variability. Sand, balloons, paper, soap film (including the famous minimal surfaces for the Munich Olympic Stadium), soap bubbles, glue, varnish, and the ones I will be referring to here: the wool-thread machines. This last technique was used to calculate the shape of two-dimensional city patterns, but also of three-dimensional cancellous bone structure or branching column systems. They are all similar vectorized systems that economize on the number of paths, meaning they share a geometry of merging and bifurcating.