NASA astronaut

"The Milieu Intérieur" Published in MIT Journal Thresholds #42: Human

  • 04.25.14
  • Matt Johnson's piece "The Milieu Intérieur," on the thermodynamics of bodies and buildings, was published in the Spring 2014 issue of the MIT architecture journal Thresholds.
  • earth from the moon
  • russian astronauts
  • johnson on the moon

"The cranium is a space-traveler's helmet. Stay inside or you perish." Vladimir Nabokov, Pnin.

Lunar Dust

In 1969, as a part of the Apollo 11 spaceflight, Neil Armstrong and Buzz Aldrin spent three hours as the first humans to literally touch the surface of another planet. This in itself is amazing, but their return to Earth was, in many ways, the most transformative part of the mission. The moment when their lunar module descended back to earth, to crash down in the Pacific Ocean, signaled the first time that alien dust had come into contact with our planet—a watershed in the history of our interaction with spaces. After spending nearly twenty-four hours on the surface of the moon, they re-launched the lunar module and began the return journey to Earth. Back inside the command module, with their helmets removed, they realized the extent to which this lunar dust could cloud a gravityless interior: it had been tracked in on their boots, their space-suits, their equipment. It was everywhere, coating every surface, floating in the air. According to differing accounts, the lunar dust smelled strongly like spent gunpowder or a desert rain. As Armstrong explained:

“we planned to sleep with our helmets and gloves on for a couple of reasons. One is that it's a lot quieter with your helmets and gloves on [and] we wouldn't be breathing all that dust. That was another concern. Our cockpit was so dirty with soot, that we thought the suit loop (the oxygen system in the suit) would be a lot cleaner."[1]

Because of the remote possibility that the astronauts would bring with them a space-pathogen on their return, within minutes of the door of the module opening after its splashdown, they were made to don Biological Isolation Garments (BIGs.) Once the astronauts had reached their command ship, they were placed in further isolation in a Mobile Quarrantine Facility for twenty-one days, during which they cleansed themselves with bleach and betadine, to remove any motes of space dust that may have attached to their skin. This quarantine had only days earlier been made mandatory by the US congress when it passed the Extra-Terrestrial Exposure Law.[2]

Until that moment, Earth had been regarded as an immunological bubble—a vast hermetic space enclosed in an atmospheric shell. But it had now been penetrated by an extraterrestrial artifact, the command module Columbia and its three astronauts. This minute vector of a potentially epidemic space-pathogen forced us suddenly to reckon with the idea of the Earth as nothing more than a membrane encasing a system in fragile equilibrium. It also indicates how nested the layers of this equilibrium are, with each successive layer attempting to achieve its own kind of homeostasis: from human body, to the glass astronaut’s helmet, to the command module, to the planet. Each of these layers wants to stabilize, to normalize its interior.

Homeostasis: the Environment Within

In the late 1860s, a French physiognomist named Claude Bernard developed a concept that eventually became fundamental to our understanding of how biological systems work. He called it le milieu intérieur, or the “environment within”, which indicated the human body’s ability to maintain equilibrium in spite of constantly fluctuating exterior temperature, humidity, pollution, and so on. In the late 19th Century, this was a radical concept, arising as it did in a period when physicians still believed in the ancient Hippocratic idea of “humors”—fluids such as bile, phlegm, and blood that regulate one’s health. Bernard said of his new concept of the milieu intérieur,

“all of the vital mechanisms, however varied they may be, always have one goal: to maintain the uniformity of the conditions of life in the internal environment. The stability of the internal environment is the condition for a free and independent life.”[3]

Bernard’s milieu intérieur was later elaborated into a more detailed concept that we now know as homeostasis, the ability for biological organisms to self-regulate. Imagine a person in a northern climate leaving a fire-warmed interior space and venturing out into a snowstorm. The body must self-regulate even against this sudden atmospheric shift: temperature changes, humidity changes, light changes, the concentration of oxygen in the air changes. Through an intricate series of calibrations, the body micro-adapts to its climate instantaneously. The physiologist Walter Cannon, writing in 1932, described even our voluntary behaviors as homeostatic—shivering, warming yourself with your hands, putting on or taking off clothing, wiping away sweat.[4] But we also subcontract out our homeostatic regulation to external technologies: fans, heaters, clothing, specific physical actions. Each of these is an externalized self-regulation system that allows the body to use less energy in its attempt to reach equilibrium.

The idea of a body in homeostasis relies on a series of sophisticated biological feedback and control mechanisms not considerably different from a modern computer. Norbert Weiner would, in the 1950s, draw on Bernard’s idea of the milieu intérieur to create his theory of cybernetics, which attempted to explain how systems signal back and forth in order to maintain equilibrium. As Charles Gross writes, “today, cybernetics, a formalization of Bernard’s constancy hypothesis, is viewed as one of the critical antecedents of contemporary cognitive science.“[5] This idea of homeostasis can therefore be applied much more broadly to systems in general, as a way of measuring equilibrium in any context and for preserving the inner health and stability of any system, whether biological, organic, cybernetic, social, or architectural.

Buildings, too, can be read as a kind of externalized self-regulation system whose primary function is to assist the body in thermoregulation. In heat, we seek shade; in cold, interior warmth. We could even describe the history of architecture, from one perspective, as an attempt to achieve building homeostasis. Historically, architecture operated as a fairly “leaky” thermodynamic system, with an inefficient and at times utterly useless ability to thermoregulate. The earliest models of what might be called building homeostasis involved thick walls, thermal mass, and fires (in cold climates) or open walls, wind-scoops and brise soliels (in hot climates.) One thinks alternately of the adobe houses and the ramadas of the desert Southwest. Supplementary thermal technologies such as blankets, layered clothing, fans, iced drinks, and even water mist helped to alleviate extremes of climate. Siegfried Giedion put it more poetically: “the warm damp American climate, settled by northern peoples, stimulated from the first a desire for ice and cool drinks.”[6] But with the invention of air conditioning by Willis Carrier in 1902, our ability to regulate temperature and humidity in buildings increased dramatically. [7] We could now inoculate interior space.

Immunized Space

This idea of the inoculation of air and of interior space forms the central thesis for much of Peter Sloterdijk’s work, from his brief book Terror from the Air to his much more profound and far reaching three-volume study Spheres: Bubbles, Globes, and Foam. Sloterdijk’s Spheres project moves from the scale of the womb to the scale of the globe in explaining how humans build discrete, roughly spherical spaces in which to insulate themselves from their surroundings. He proposes an image of architecture as a kind of foam, in which individuals occupy contemporaneous, touching cells (or apartments) that nonetheless do not overlap.[8] Within these cells, everything, from temperature to air quality to airflow, can be regulated homeostatically. In that sense, buildings have long been one method for normalizing the highly variable exterior weather by creating a meteorological stasis.

In the 1930s, Le Corbusier determined an ideal interior temperature, somewhere around 18° C. Modern offices and households, at least in the US, are perpetually trying to balance temperatures at 72° F (though temperature is also a cultural construct, with Scandinavians preferring slightly colder temperatures, and Indians preferring warmer temperatures. Constance Classen speaks eloquently of these sensory cultural differences in her anthropological work.)[9] This condition of “normalizing” air temperature has meant sealing buildings up, creating an immunological space that is relatively pure and relatively stable. Even as buildings became more transparent, less physically substantial, their ability to isolate climate increased through new barriers such as curtain walls, gaskets, insulation, thermal breaks, and so on.[10] Drafty buildings were sealed, R-values went up. In the 20th century, this trend manifested as a concern for prismatic modernist forms and a glassy transparency, with the envelope as a mediator between the interior and exterior. Thus, influential works such as Mies Van Der Rohe’s Seagram Building or the Lever House by SOM were fundamentally about sealing spaces off almost hyperbarically. Huge HVAC systems regulated the interior environment. Air conditioning was piped in, the windows were siliconed shut, the inside ceased to interact with the outside. The messiness of systems, pipes, tubes had no place in a prismatic Modernist architecture. Mies Van Der Rohe’s concept of beinahe nichts (almost nothing) meant the necessary subversion of any overtly technical details within clean and barely-there spaces. Or, as Le Corbusier put it, “for Ledoux, it was easy—no pipes!”[11] (Certain exceptional buildings such as the Centre Pompidou wear their color-coded systems on the outside, like a body turned inside out, and serve as critical counterexamples to this pronounced trend.)

Within the profession, architectural offices began to separate into cadres of designers on the one hand, and technicians on the other. If buildings were reduced to a sequence of distinct systems to be hidden away in poché spaces, vaults and basements, then in an odd metaphorical similarity, building technicians frequently found themselves isolated from the actual architectural design. They were meant to address a narrowly prescribed domain of an architecture otherwise dominated by “style.” The artificial divide between the artistic and technological sides persists today, with many designers engaging technics either as a wholly separate discipline, as a set of hidden systems, or as an afterthought. (One of the strongest critiques of the LEED system, for instance, is that it simply grafts sustainable technology onto otherwise normative buildings.) This bipolar view of architecture—design versus technics—may have begun during the Enlightenment but became far more pronounced as modern innovations transformed building technologies. The new functionalist/formalist requirements of Modern architecture meant paring architecture down to essences, whether formal or functional.

This idea of a pipeless, homeostatic, sealed architecture gave rise in the 1960s both to massive geoengineering proposals and to tongue-in-cheek critiques of our newly isolated interior lives. One thinks of Buckminster Fuller’s proposal to seal central Manhattan in a vast geodesic dome: the temperature for a hundred blocks would be centrally controlled. Windows in buildings would remain open. The interior and exterior temperature would be identical, presumably around 72 °, and would never vary. Anyone inside this bubble could live unencumbered by extreme winter cold or extreme summer heat.

In the same period but at a smaller scale, the Austrian art group Haus-Rucker-Co. proposed a series of plastic, atmospherically isolated structures seeming to balloon from the windows of historic buildings. These projects, collectively called Oases, offered a means for viewing the city prismatically (and flanked by two small tropical palms) but without actually having to venture outside. The project acted as an interiorized exterior, one’s own private bubble-window from which to view the world. In another project titled Mind Expander Helmet, they suggested shrinking this “oasis” to the size of an individualized plastic helmet that could be worn around the city—your fully conditioned space travelling with you. Francois Dallegret and Reyner Banham’s Environment-Bubble also come to mind: “the standard-of-living package is apt to need some sort of an umbrella for emergencies, and it could well be a plastic dome inflated by conditioned air blown out by the package itself.”[12]


The profound dualism between design and technics did not originate in architecture, however. It were already a part of the larger cultural trend toward modernization, as Bruno Latour illustrates in his book We Have Never Been Modern. Latour argues that since the enlightenment we have tended to separate the worlds of the Humanities and social sciences (or what he calls the symbolic) from the world of the hard sciences (what he calls the material.)[13] In his view, these dualisms between the symbolic and material should disappear, to be replaced with what he calls the “non-separability of things and signs.”[14] The approach suggested by Latour is one in which scientific knowledge is hybridized and fully engaged with design. Applied to architecture, Latour’s theorization would result in a kind of seamlessness of the symbolic and the technological, a new cybernetic architecture.

The vague outlines of Norbert Weiner’s cybernetic organism can be seen within our current conception of architecture: an inhabitant who sees no real divide between digital control and phenomenal effect. When one can manipulate fluctuations of air, temperature, sound within a house instantaneously from a small touchscreen device, we have achieved a kind of cybernetic singularity. We are the feedback and control system that regulates building homeostasis. We seem to have achieved the role of Cybernetic human described by neurophysiologists Manfred Clynes and Nathan Kline as an “exogenously extended organizational complex functioning as an integrated homeostatic system, unconsciously,”[15] or what they called a Cyborg. Many of the architectural experiments of the 1960s, from Superstudio to Cedric Price, attempted early on to formalize this idea of a hybrid cybernetic condition where no artificial separation between the technical and the organic existed. But their experiments were still quasi-utopian, in the sense that technology could not realistically achieve the goals of much of the imagery being produced. But now, in the era of Lasik surgery, cochlear implants, pacemakers, prosthetics, genetic sequencing, multi-touch screens and so on, we might argue that the cybernetic human is fundamentally a reality, whether we are fully aware of it or not. As Antoine Picon has remarked, the image of our age is not the Renaissance’s humanist subject, nor even Le Corbusier’s Modulor, but the cyborg, which Picon says is “not a utopian figure, [nor, I would add, a dystopian one] but the result of the full use of existing technologies.”[16]

What Latour, Sloterdijk and others theorize is a shift in every discipline, including architecture, toward bio-hybridity. Bio-hybridity is a dissolving of the boundaries between hard sciences and soft, between technics and design. But this condition was already emerging almost a half century ago as part of a larger cultural turn from the physical sciences and toward the sciences of life (seen in our new era in which glowing rabbits, cloned sheep, and transgenic ears grown on the backs of mice do not seem to herald some vague Science Fictional futurism, but rather the outlines of an uneasy present.) Bio-hybridity arguably also owes its existence to the ecological reaction to a generalized climate crisis. If the climate crisis resulted from our uncritical embrace of resource-exploitative technologies in the 19th and 20th centuries, then ecology is now seen as a corrective realignment of our relationship to the environment from one of dominion to one of symbiosis. Thus politics becomes biopolitics, shifting from a concern for social constructs to how those social constructs are biologically formed, mediated and controlled[17]; engineering becomes bioengineering; technics becomes biotechnics (a transformation that Lewis Mumford had already forecast as early as 1970.)[18] Cybernetic mechanisms are now directly involved in our homeostasis, and extend well beyond the simple fire or fan, into a world of digital feedback and control systems. The primitive hearth fire has given way to the cybernetic LED display controlling a mechanical conditioning system: both warm you, but in different ways.

This cybernetic revolution has prompted much discussion of a “human 2.0.”[19] But if we are willing to restructure our understanding of what it means to be human in the midst of this cybernetic moment, should we not also be willing to reformulate the rules of architecture, in order to create an architecture 2.0? Insofar as architecture has co-evolved alongside humanity (and with the help of technology) our current transformation implies a major co-evolutionary shift that might result in a much more integrated sense of architecture vis-à-vis its human users. We already see the outlines of this shift in the work of Phillipe Rahm, François Roche, Jürgen Mayer, Diller and Scofidio, Sean Lally, and others who engage with the somatic and the sensory. For instance, in their proposal for a Phase Shift Park in Taichung, Rahm and landscape architect Catherine Mosbach create a park not so much of surfaces as of atmospheres and physical states, meant to transform the body through heat, humidity, and pollution. The park will “micro-adjust” its climate and atmospheres over time, learning genetically from its users. This is a new type of architectural diagram, taking into account not only the broad mappings of surfaces and objects within the landscape, but also the ways in which these surfaces might directly affect the park’s users metabolically. The subject of this architecture is no longer the Modulor—a fundamentally geometrical construct delineated from Da Vinci’s Vitruvian Man. Instead, it is a cybernetic being whose body is in equilibrium ever while the external environment is in perpetual flux.

The difficulty for architecture, illustrated in Phase Shift Park, is move beyond a condition of being merely sensory, or merely formal, or merely tectonic. It can be all of these things at once, which is why the old bipolar debates regarding form versus function (or any other dualism) so frequently appear as artifacts of a now-ancient high modernism. An ecological sensibility extends beyond simple buzzwords to become a habit of thought, as Gregory Bateson has said.[20] The theories required for such a shift are inherently unstable, relying on terms that seem to have no fixed meaning—thermodynamic, cybernetic, energetic, ecological—or rather meanings so broad and radically interdisciplinary that they almost dissipate completely. This may be why, despite the urgency with which Sanford Kwinter and others promote a new energetic architecture, its true outlines are hard to discern.[21] The certainties of Modernism, in its reliance on compositional technique and tectonic purity, are hard to reconcile with a new conception of architecture based on atmospheres and effects. Bateson, in his schismatic essay “From Versailles to Cybernetics,” raises a pertinent disciplinary question that we now face, namely, how to not merely work within the rules as they are at the moment to create the best possible outcome, but how to change the rules. What is important in history, he says, is the moment at which “the bias of the thermostat is changed.”[22] Seen in this light, many of signature movements in architecture in the latter years of the 20th century (Postmodernism, Deconstructivism, et al.) appear largely stylistic—not reworkings of the totality of rules bounding architecture, à la Bateson, but rather rearrangements of the operations within a set of rules already given at the outset of Modernism. Yet below the surface of architecture’s disciplinary arguments, a less-noticed conceptual fault line appears; it marks the increasing non-separability of culture and nature and the integration of the biological with the technological.

To bring the argument full circle, the Apollo 11 astronauts were arguably the first fully cybernetic humans: a non-separable matrix of the biological and the technological. What they undertook when they broke through the Earth’s membrane, twice, was not simply an exploration of near-outer space. It was a philosophical engagement with our concept of interiority as well. What did it mean to dwell inside of a system? What did it mean to cross the threshold between a system’s inside and its exterior surroundings? We had always lived in the open, subject to the fluctuations of weather and climate. For millennia, our architecture was porous, unstable, incomplete. But now, in the age of space suits and air conditioning, we would be able to live hyperbarically. The Apollo 11 mission indicated a possibility for dwelling completely inoculated from the outside, regardless of atmosphere or external effects. If our living systems are now able to mimic our metabolic systems, then buildings might cease to be machines for living in and would be more like homeostatic bodies nearing a permanent equilibrium. But the inherent irony is that even as our theories about architecture become more ecological, more hybrid, more porous, the architectural membranes within which we inoculate ourselves become thicker. They become more resistant to external atmospheric effects. Interior air is increasingly separated from outside air—pure, stable, clean. The building is a kind of space-traveler’s helmet…but should it be?

[1]NASA. Apollo 11 Technical Crew Debriefing. July 31st, 1969. p. 81.

[2] This law, passed in July of 1969, just days before the Apollo 11 mission, applied “to all NASA manned and unmanned space missions which land or come within the atmospheric envelope of a celestial body and return to the Earth. The law made it illegal for Americans to contact or engage with extra-terrestrials, their equipment, or their belongings. It also implemented a mandatory quarantine period for any person who may have come into contact with extra-terrestrials. 14 CFR Part 1211 of the Code of Federal Regulations

[3] Bernard, C. (1974) Lectures on the phenomena common to animals and plants. Trans Hoff HE, Guillemin R, Guillemin L, Springfield (IL): Charles C Thomas

[4] Gross. p. 384.

[5] Gross, Charles. “Claude Bernard and the Constancy of the Internal Environment.” Neuroscientist 98. p. 382.

[6] Giedion, Siegfried. Mechanization Takes Command. New York: Oxford University Press, 1948. p. 596.

[7] See Margaret Ingels’ biography of Carrier for an interesting history of the invention of the air conditioner. Ingels, Margaret. Willis Haviland Carrier: Father of Air Conditioning. Garden City: Country Life Press, 1952.

[8] Sloterdijk, Peter. “Sphere Theory: Talking to Myself About the Poetics of Space.” Harvard Design Journal. 30. Spring/summer 2009. P. 134.

[9] For an articulation of this idea, see Classen, Constance. “Foundations for an Anthropology of the Senses.” International Social Science Journal. 153 (1997).

[10] For an historical account of how architecture was transformed by mechanical systems in the modern period, see Banham. 1969.

[11] “Pour Ledoux, c'était facile - pas de tubes!” This phrase was inverted by Reyner Banham to describe how modern buildings had somehow become all tubes, all pipes. See Banham, Reyner. “A Home Is Not A House” Art in America #2. April 1965.

[12] Banham, Reyner. Quoted in Dessauce, Marc. The Inflatable Moment: Pneumatics and Protest in 1968. New York: Princeton Architectural Press, 1999. p. 133

[13] Latour, Bruno. We Have Never Been Modern. Cambridge: Harvard University Press, 1993.

[14] Latour. We Have Never Been Modern. p. 135.

[15] Manfred E. Clynes, and Nathan S. Kline, (1960) "Cyborgs and space," Astronautics, September, pp. 26–27 and 74–75; reprinted in Gray, Mentor, and Figueroa-Sarriera, eds., The Cyborg Handbook, New York: Routledge, 1995, pp. 29–34.

[16] Picon, Antoine. “Architecture, Science, Technology and the Virtual Realm.” In Picon, Antoine and Alessandra Ponte, eds. Architecture and the Sciences. Princeton, NJ: Princeton Architectural Press, 2003. p. 310.

[17] For more on biopolitics, see Foucault, Michel (1997). The Birth of Biopolitics: Lectures at the Collège de France, 1975-1976. New York, NY: St. Martin's Press. Agamben, Giorgio. Homo Sacer: Sovereign Power and Bare Life. Stanford: Stanford University Press, 1998. And Hardt, Michael and Antonio Negri. Multitude: War and Democracy in the Age of Empire. New York: Penguin Books, 2005.

[18] See Mumford, Lewis. The Pentagon of Power: The Myth of the Machine Volume 2. New York: Harvest Books, 1974.

[19] See, for instance, Fuller, Steven. Humanity 2.0: What It Means To Be Human Past, Present, and Future. London: Palgrave Macmillen, 2011. And Ray Kurzweil. “Human Body Version 2.0,” Presented at the Future of Life Conference, 2003 and published on his website.

[20] Yet even Bateson admitted that he had difficulty thinking in this new, ecological mode that he’d identified. “The most important task today, perhaps, is to learn to think in the new way. Let me say that I don’t know how to think that way.” In Bateson, Gregory. Steps to an Ecology of Mind. Chicago: The University of Chicago Press, 2000. p. 468.

[21] See Kwinter’s essays in Kwinter, Sanford. Far From Equilibrium: Essays on Technology and Design Culture. Barcelona: Actar, 2008.

[22] Bateson. “From Versailles to Cybernetics.” In Steps to an Ecology of Mind. p. 484.