Substantial advances in building technology are often followed by a reduction of structural components. From the modernists’ exploration of transparency through the use of glass and of light, to the 2002 Blur Building by Diller Scofidio + Renfro; the aspiration to extend form, by blurring the border between the object and its environment has taken many shapes. The search for a building not confined by its walls was at its most creative and intense phase in the 1960s and 1970s, leaving traces of the exploration in design projects such as the tensile structures by engineer Frei Otto; Yves Klein and Claude Parent’s air-conditioned city (1961); the Pepsi Pavilion at EXPO ‘70 in Osaka; and the numerous radical architecture groups working with inflatable plastic structures.
 Rather than a utilization of mass, these projects are characterized by the expenditure of energy. However, the mentioned experimental projects—both built and imagined—all had a structure. There was something creating a tactile shape, some material borders allowing a form to become realized. At MoMA in 1971, in the run-up to the exhibition Italy: The New Domestic Landscape, curator Emilio Ambasz had been searching for a cutting-edge idea for the exhibition layout. The aim of the exhibition was to use Italy as a micromodel where a wide range of possibilities, limitations and critical issues of design were brought into sharp focus. As stated in the exhibition catalogue: “The purpose of this exhibition, therefore, is not only to report on the current developments in Italian design, but to use these as a concrete frame of reference for a number of issues of concern to designers all over the world.”  Ambasz wanted the exhibition layout itself to comment on current critical issues in the design discourse and decided early on to separate the exhibition into objects and environments. Exactly how this separation would take shape was up for discussion and the curator worked with several preliminary ideas, many of them involving the MoMA garden as a central component.
One possible solution was to enclose the environments with a vast inflatable plastic structure mounted over the garden [ill. 1], another one was to define the space by producing an artificial cloud that would hover above MoMA. Ambasz asked the experimental technology and design lab Ecology, Tool & Toy (founded by psychiatrist Warren M. Brodey and cybernetician Avery R. Johnson) to investigate the technical requirements needed to produce a real cloud that would have the capacity be suspended in a stable position regardless of weather conditions such as heavy rain and strong winds.
 A more feasible idea, however, was to produce plastic clouds to create the same effect [ill. 2]. Of the various project ideas for the garden venue, the plastic clouds came closest to realisation. The clouds—designed by architect Renzo Piano and planned to be made of Melinex (a thin polyester material)—were to be suspended between MoMA’s surrounding buildings by a network of cables, but the project came to a halt when none of MoMA’s neighbours gave their permissions to use the buildings to mount the fixing system. Yet, the most radical of all the air design ideas for the exhibition was Ambasz’s proposal of installing jet engines in the gallery space to separate the objects and the environments by a wall of air.
In the archives at MoMA there are few references to this project, which could indicate that this was a very short lived idea. The archival references to the idea include a copy of the article “Air-Curtain Walls and Roofs—‘Dynamic’ Structures” from 1971 by Canadian architect Peter Goering and aeronautical engineer Bernard Etkin. The two had collaborated on an experimental article for A discussion on Architectural Aerodynamics, a special issue of the journal Philosophical Transactions of the Royal Society of London. The article was given to Ambasz by his MoMA collegue Richard Palmer, as Ambasz apparently “had spoken about using ‘walls of air’ to define the upper tarrace space [of his] show.”
 [Ill. 3]
In the “Dynamic Structure”-article, Goering and Etkin published results from their technical research and scientific experiments on the future possibilities of air architecture. At the time of publication, the only successful air architecture projects in commercial production were air-curtain doors, mostly used in entrance areas of shopping centers in order to keep the cold outdoor air from mixing with the warm indoor air.
 The technical principle of an air-curtain door is rather uncomplicated; if the stream of air is powerful enough, the air stream will separate the outdoor and indoor climate and will prevent outdoor pollution such as insects, dust, and fumes to enter the indoor space while still allows pedestrians an almost unnoticeable entering. However, the authors claimed that air architecture was still in its infancy and that the complete utilization of air had yet to come.
Two streams of air will always coalesce if positioned with a specific width between them, creating an annular jet [ill. 4]. Goering and Etkin discovered that by directing an annular jet upwards, the air streams would form an “enclave R [see ill. 4] completely surrounded by the curtain.”
 If the jet engine could be designed as a continuous ring, this would “eliminate the static use of material entirely and expand only energy to provide a barrier against the environment.”  Air is a powerful element—not just in a metaphorical sense. By altering the density and velocity of an air stream, even rainfall and snowstorms will be prevented from entering the enclave. Experiments by Goering and Etkin conducted on a horizontal air stream established that a 0.3 m (1ft) thick stream, with an exit velocity of 10 m/s (100 ft/s) which corresponds to a jet power of 160kW (2.16 hp), would leave a dry span of 6 m (20 ft) beneath [ill. 5]. The experiments were carried out indoors, but the authors confirmed by calculations that even unstable and unpredictable weather could be controlled by “optimizing the jet thickness, its velocity profile, and its exit angle.”  The annular upward air jet would function in the same way as the horizontal jet stream: “We have found in some preliminary laboratory experiments that vertically falling rain will not penetrate into R provided that t/D and V exceed a critical pair of values that are mutually dependent”  [see ill. 4]. Further, the outcome of their experiments lead the two researchers to a rather bold conclusion: “It should be about the same weather D = 100 ft or 1000 ft (30 or 300 m). It appears indeed that a whole town might in theory be accommodated within R!”  [See ill. 4].
By utilizing the latest technology, the researchers envisioned that by designing an algorithm they could allow the enclosed air space to be responsive to the outer environment, the air would self-regulate the inner environment according to the outdoor conditions, and hence nature itself would design the immediate dynamic structures. Lastly, the authors held that developments in the field of aeronautics would eventually lead to the production of low-energy, mute jet engines, which would make the air structures completely convenient as a habitat to human beings: “[Imagine] to be able to walk in a pleasant downtown core and be free of inclement weather, yet be able to see the whole environment as if out of doors.”
 The air in Goering and Etkin’s dynamic structures conditions a place where the surroundings have no border. An uninterrupted space, an open expanse, a spatial extent of everything.
In the end, Ambasz’s never-realized wall of air did not separate the objects from environments, it equated them, it made them the same. They were both of air, in air. Air, this element that is almost nothing, yet it is everything.