High Altitude, Low Opening (H.A.L.O.)

High Altitude, Low Opening (H.A.L.O.)[1]

Three–dimensional warfare is said to have begun in China in the first years of the Common Era with the practice of manned flight on massive kites to reconnoiter enemy movements.[2] Perhaps more plausibly, kites were reportedly used by the Chinese as battlefield signaling systems, while the most vivid story of all recounts the use of an Aeolian kite designed to produce unearthly sounds when launched in the dead of night over the enemy camp during a famous battle of the early Han Dynasty, a gambit that successfully frightened the opposing army off.[3] It took nearly 2000 years from the dawn of the kite era until the physical and behavioral properties of gases were well enough noticed for the Montgolfier brothers to concoct the great “globes aerostatiques” that found experimental deployment in the Napoleonic Wars. Yet the first militarily effective use of balloons arrived only with the American Civil War although even here, as in the cases above, the airships in question remained tethered rather than released in free flight. Controlled aeronautics in fact makes its entrance in sky history only with the rise of machine aviation in the early 20th century—first with propeller aircraft, and later in the form of guided missiles of all kinds. Today, in yet a further phase in this indeterminate history, we see emerging the soon–to–be–ubiquitous phenomenon of the unmanned, remote– or automatically–piloted drone. And yet fully controlled flight is not the summit ambition of our modernity. Deeper still, and possessing an even greater magical hold on the imagination, has been the thermodynamic fantasy of achieving propulsive motion, or action of any kind, by agency of a ‘work–for–free’ mechanism.[4]

Entropy, it is true, never decreases, but this does not mean that the strategy of moving it around is either expensive (energetically or temporally) or does not itself constitute an engine of a peculiarly magical kind. In fact, it is the very nature and fact of entropy’s dynamism that affords a landscape of unfamiliar pathways and opportunities rarely grasped fully by the modern technological imagination trained and compelled to seek advantage only in ‘take–what–you–want–and–pay–for–it’ setups where the rule of the ledger sheet and the balance book holds sway. In other words, the simple fact that potential of one type (in this case, energy) endlessly and ineluctably decreases, migrates or transforms in any free environment does not mean new and different potentials are not continuously generated elsewhere as a direct result of these very developments. For the relentless cleaving and changing of the universe’s ‘matter flow’ establishes the rule of the differential in nature, and following from it the irrepressible reality of the gradient without which nothing would ever happen, and thanks to which so many great things not yet imagined, easily could.

Once, importantly, in the middle of the last century, the discrepant model of the clock was opposed to that of the cloud with a view to re-connecting thought to the empirical outcomes of actual nature, and away from the controlled and artificial conditions of the laboratory setting.[5] Today the logic most wondrously sensed and tapped by inventors, dreamers, scientists and makers of speculative—read plastic and sensuous—work, is that of weather, a system of unceasing innovation, in which nothing is wasted, in which no component fails to assert its influence, and in which, despite the abundance of behaviors and forms it throws up, no causes are dissociable from their effects. The attraction here, in the words that Karl Popper once used to describe something pretty close to it, resides in the idea of “plastic controls” that not only accept but actually celebrate indeterminacy in the temporal form world, that relinquish the hard control of our rationalist (read here ‘mechanist’) traditions. Today we are increasingly seeing the pervasive gradient/differential in nature as the wellspring of form and of the work equations that produce it.[6]

For all these reasons—indeed because of this overarching trend in historical ontology—sky has become a place, a plenum, a place to move and think differently, indeed it is becoming both a mode of thought itself and the foundation of an emerging ethos or system of ethoi.

Sky is an ocean (as Buckminster Fuller used to proselytize) only here it is one just as replete as the aqueous one around and below us that is awash with currents, strata, weather systems, differentials of density, temperature, direction, humidity, pressure and their shifting, always provisional and developing correlations. It is a system that generates singularities (points where qualitative changes occur) and tendencies at every moment and in every place. But here is the ironclad rule that governs: Nature always reduces the gradient (the inescapable Second Law applied now to every manifestation of form).

The simple process by which it works is no other than this: energy flows from higher, hotter, and denser to lower, cooler, and rarer. To sublimate the gradient nature sets into motion a flow. These flows, in sum, are today what matter more. One no longer concerns oneself solely with absolute values that represent averages of uneven distributions or conversely with isolated and discontinuous points. These flows and their reductions are becoming at once the stuff of science and of the ecological and artistic imagination alike.

The Aerocene, it might be said, is the name of a new ecological space that grasps into unity both the scientific and the artistic imagination and the neurological apparatus itself.  For it targets primarily an attitude of sensing energy, sensing potential, sensing in a vast and only apparent void what the ancient Chinese geomancers, ink wash painters and military strategists referred to as ‘shi’—the inbuilt propensity of any situation, position, or configuration to develop (flow) in a specific direction and in a certain way.[7]  Every moment flows into the next and every place abets or resists this flow in just the manner that is specific to it. When prehended together these variables form an ocean of particularities rife with harvestable action and energy.

A critical and moving component in the perception-confounding launch of a colossal airship like the Aerosolar is the assembly of a membrane from supermarket tote bags whose function is to establish the paltriest of separations between an inner and outer atmosphere. The fragility of the surrounding film is sufficient nonetheless to both delay and capture the impetus toward thermal equilibrium that no force or thing can forever escape, and in so doing to convert it for a time—perhaps for a very long time indeed—into manifest, even sublime semi-directed motion.  What is pitched into aesthetic relief here in a way that would be entirely familiar to late 19th century (embryological) biologists and 1980’s (nonlinear) mathematicians alike, is the salience of what is known as the separatrix, the marvelously subtle boundary point or line between two or more valleys and on which a process precariously hangs before it is forced to choose a direction of motion or fall. A ball for example can balance only for so long on a pinnacle or crest before it must yield to the infinitesimal atmospheric imbalances that set it fleeing to one of its several topographical destinies. But the ball can be said, in the moments before the system ‘breaks’ or launches, to be in a state of infinite sensitive search. Its job is to sense gradients. This is the physics and politics of the ‘aerocene’.

The bladder inflates slowly to claim a vast parcel of the air ocean. The solar stream courses onto and through it as the various component materials convert light energy into units of heat. The internal numbers build like steam in a locomotive chamber, but the expanses here are so vast that the tiniest differential in centigrade measures results in exponential expansion—so much less pressure than required by the iron horses of yesteryear yet in service of so much more startling effect. It is of course not the difference in temperature, but the consequent ones of dilation, displacement and relative weight that induce, at one threshold moment and no other, the liftoff and rise. The drama plays out at such gigantic scale all while connected to a variable so meager and demure that the spectacle simply fails to read as physics at all.

But then that is presumably why we have come: to bear witness to the singing of a new era in technics, sensation, and knowledge in the face of which the dogmas that for long subtended thought and behavior in a presumed universe of grave and fixed things, now fall or, shall we say, now melt into air.

— Sanford Kwinter


[1]  https://en.wikipedia.org/wiki/High-altitude_military_parachuting

[2] John Buckley, Air Power in the Age of Total War (London: University College London Press, 1999), 22-23.

[3] Berthold Laufer, “The Prehistory of Aviation,” Field Museum of Natural History, Vol. 18(1)(1928): 34.

[4] The concept of ‘work for free’ dates back to a thought experiment devised by James Clerk Maxwell in his 1872 Theory of Heat that Lord Kelvin later memorialized as “Maxwell’s Demon”.  In the experiment in question a sentient agent is posited who has the ability to control the passage of molecules from one chamber to the other simply by recognizing which are fast and which are slow and letting the slow pass into one chamber and the fast into the other. In this a way the warm are sequestered from the cool and without adding heat, energy or work their migrations will have brought about an increase in the temperature of one part of the system and a cooler one in the other—hence flagrantly contradicting the Second Law. The idea of work for free, despite the objections legitimately raised regarding the cost of the demon’s presence and labors, has been endlessly and equally legitimately hypothetically revived by practitioners such as Leo Szilard (Szilard engine) in physics, and Stuart Kaufmann (“order for free”) in biology. The Second Law may be globally inviolable but probing its many defects and open flanks at a variety of sub-global scales has proven consistently fruitful for both science and thought.

[5]  Karl Popper, “Of Clocks and Clouds: An Approach to the Problem of Rationality and the Freedom of Man” in Objective Knowledge: An Evolutionary Approach (Oxford: Oxford University Press, 1972) (original: 1965).

[6]  Eric Schneider and Dorion Sagan, Into the Cool: Energy Flow, Thermodynamics, and Life (Chicago: University of Chicago Press, 2005).

[7]  Francois Jullien, La Propension des Choses (1992) translated as On the Propensity of Things: Toward a History of Efficacy in China (New York: Zone Books, 1995).

Saraceno’s Model of Models: The Magnificence of Aerocene

Tomás Saraceno’s Aerocene is astonishing for many reasons. Foremost is the degree to which his experiment manifests the salient principle of thermodynamics as the motor of its operation: the universe abhors a gradient.[1] What is so cunning and breath-taking about this project, though, is how it deploys this principle. It projects the work of habitation and mobility aloft in the most abundant but lowest quality gradients on the planet: the dynamics of aero-solar exergy gradients in the atmosphere.[2]

The urbanization of this extremely low-quality but massively abundant gradient is a spectacular and mesmerizing basis for form; one that will likely take years to fully comprehend and realize. It is a stunning and ingenious model of formation, one whose thermodynamic depth is perhaps barely perceptible to most observers.[3] But this is exactly the munificent invitation of Aerocene: to peer into the sublimity of its formation and thusly envision an entirely different thermodynamic model for living in this century.[4]

To name but just one pertinent dimension of this model of formation, in a stunning inversion Saraceno grasps the prevailing problem of radiative forcing that today, we are told, otherwise threatens qualities of life on this planet.[5] He immediately and generously inverts that “problem” into the very gradient that will support many aspects of life in his aero-polis. The almost-nothing of our atmosphere that threatens everything today becomes, in his model, the everything that affords nothing other than a profoundly relevant political and thermodynamic model for life in this century.

In this way Saraceno’s model makes us think and think differently another basic principle of thermodynamics: the completely underestimated importance of system boundary selection.[6] All the key contemporary planetary dynamics—so often construed as “problems” of scarcity—such as climate change or climbing populations are in fact opportunities of abundance. The difference in this world-view is nothing other than a difference in system boundary characterization. Whereas scarcity-mongers live in constant fear of the isolated system boundaries they unwittingly select and accept to enact the terms of their perceived doomy scarcity, the reality is that humans utilize less than ten percent of incident available solar exergy for its operations.[7]

Saraceno takes the latter open system boundary characterization and its superabundance as his point of departure. Within this context of superabundance, Saraceno envisions a very powerful model of living based on cunning exergy matching of maximal work from his selected, deliriously low-quality gradient. As a formation of matter, energy, and movement, Aerocene should thus challenge many prevailing models for reasoning and imagining our world and how we might live with it today.[8]

In both emblematic and literal terms—and in formal, political and scientific terms—the dynamics of his formations are entirely reliant on a non-isolated conception of the world as a system.[9] Further, more immediately at a human scale, his formations of people, plastic, air and the sun serve as a constant reminder—an index—of the operative system boundaries of Aerocene. This amends the depravity of our pervasive, seemingly invisible metabolic rifts that are a primary enabling fiction of contemporary neoliberal life. To become Aerosolar, and to enter the age of Aerocene is to, finally, become astutely aware of one’s system boundaries as the basis of a novel polis. It is a consummate model of cosmopolitanism.

If the Romans came closest to a fully thermodynamic model of telluric civilization, Saraceno has begun to devise an analogical Aerosolar model.  A deeply important dimension of the project is in the convergence of its physical and political realities as inextricably coupled systems. We too readily forget today that every political model is constitutively thermodynamic and that every thermodynamic model is deeply political.[10] In the case of Aerocene it is thoroughly provoking to imagine political systems based entirely on insolation-based intensive properties of the atmosphere such as temperature, pressure, and density; as manifests in varied jet streams, storms, or doldrums. Not since John Wellesley Powell vainly envisioned the political organization of the American West as a watershed model of the polis has such a convergent physical and political model of life emerged in modernity.

These thermodynamic, formal, and political models astutely merge in Saraceno’s project. In this way Saraceno offers us an ambitious model of contemporary formation, one far beyond timid and disabling models of isolating autonomy that stupidly constrict artistic, architectural, and urban praxis.[11]  Instead, Aerocene affords us a glimpse into a model—a different model of causality—for that which could afford and accommodate life today.[12] It is the only truly immanent, thermodynamic model of design in the domain of architecture and urbanization, driven as it is by the intensive properties of its formation. It eclipses—by orders of magnitude and significance—the bafflingly obdurate hylomorphic approaches to art, architecture, design, and urbanization that otherwise clog our current models.

The above is at most suggestive of the magnificence of Aerocene model and its thermodynamic depth. More than any other model for living and formation today, Saraceno challenges our current modes of imagination and reasoning and, in a gush of goodwill and optimism, offers a beguiling and ponderous alternative model for how we might best live today.

— Kiel Moe


[1] A gradient is an energetic difference. The universe tends to obliterate such difference, seeking an equilibrium it will never achieve. For all intents and purposes here, we live in constitutionally open and coupled systems. All forms in the universe can be understood as emerging from constitutionally open and coupled dynamics.

[2] Upon initial inspection, Aerocene seems to exploit the subtle thermal gradient on each side of Saraceno’s plastic bags. Further examination will reveal not only sensible heat gradients but latent heat gradients, boundary-layer fluid dynamics, and humidity all driving the pressure differences which produce the relevant buoyancy in this case.

[3] Thermodynamic depth refers to the degree of coupled subsystems in a thermodynamic system.

[4] It might well be that art and architecture finally come to learn the profound difference between form and formation in this century.

[5] Radiative forcing dynamics are what otherwise are characterized as climate change. The “climate change” characterization over-simplifies the topic and fetishizes carbon as the sole culprit. This occludes matters of theoretical, practical and political significance. The reality of radiative forcing dynamics provides a more varied and valid conception of how we might best design in this century.

[6] Every day, in every task, in every thought, the cosmopolitan twenty-first century citizen might well inquire, what is the appropriate system boundary at hand, and why?

[7] Humans collectively utilize about 16.5 terrawatts of exergy annually. The incoming exergy is on the order of magnitude of 165,000 terrawatts. It is difficult to construe an exergetic scarcity here, but rather only a scarcity of valid models, like Saraceno’s, for how to best squander this superabundance.

[8] A model is at once a unique object and an example of a world-view. Every physical object carries with it an entire view of the world. Ideally, an exemplary model would be both an exemplary object and afford an exemplary view of the world. Such models are rare. The Pantheon in Rome is one, Aerocene appears to be analogous.

[9] Any system will be open, closed, or isolated. The difference gauges the type of exchange, or lack of, amongst the system and its surroundings. Intimidated by vitality-inducing complexity, modernity tended to prefer the reassuring comforts of isolated models. Oops.

[10] In this sense, it would be suffice to discuss the state of any system or model.

[11] Above the cobblestones, the air!

[12] What causes something to appear the way it does?

Air Crafted Architecture

Museo Aero Solar, already presented in more than 20 locations worldwide since its start in spring 2007, is a global collective.  One of its initiators, Tomás Saraceno, defines it as “a solar balloon completely made up of reused plastic bags, with new sections being added each time it travels the world.”[1]

By making a speculative reversion of our impact on the earth, which is also denominated as a turn from Holocene to Anthropocene, Museo Aero Solar claims to “reduce and remove the imprint that humans leave.”[2]

[Neither] a brand, [nor] a copy-righted artwork […] neither a flying sculpture, nor a symbol or an aestheticization of some good, politically correct , eco-sustainable practice,Museo Aero Solar is firstly a community. What kind of future promise does it bear? Even if it does have an ecological claim, the general practice attaining more and more presence nowadays, it all stems from a contra-cultural and revolutionary movement: ggested change.e first of all ..ial, political and economical values, and… and thought like one of the famous “Stecca degli artigiani” squats in Milan (active 2001-2007)[3], which positioned itself against “eco-gentrification”[4] of urban space. The journey of the sculpture marks the clear political inclination, and a sensibility of the project: it has been assembled from Medellin to the Fustat district in Cairo, passing by Ein Hawd, the first Arab village recognized by The State of Israel, to the Biennial of Havana.

Utopia or reality?

Distinct in its optimism, the vision of the society that Saraceno has is as diverse, and colourful, as Museo Aero Solar’s sculptures. Becoming aerosolar, lifting our dwelling to the cloud level, would allow us to pacify cultural conflicts, to abolish national borders, and to solve geopolitical issues. In return it would bring socially distributed equality, thus freeing this aerosolar society from its common contingencies, and leave its further shape and structure for atmospheric elements. The common ‘ground’ in this case would be just an artistic experiment, floating us all together in the air. The principles that Saraceno relies on and articulates in his visions, such as participative actions, co-creation, and do-it-together practices, make this future society less apparent as a complex body of entangled social, political, and economic values, and more similar to a cyber-network, driven by an artistic aerosolar artifice.

Besides momentary workshops, and without the actual experience of living above the clouds, this community of aerosolar becoming virtually exists as an online social network. Saraceno says that his aim is “to build a city in the air, just as we’re building Linux or Wikipedia today.”[5] Thus, Museo Aero Solar is not only a sculpture, a museum made of reused plastic bags, but also a blog, a website, YouTube channel, Facebook community, Twitter hashtags, Instagram galleries, open Dropbox folders, wiki–tutorials, etc. To participate in Museo Aero Solar in one way or another is also to float in the blogosphere, a space that is extremely fluid and open. These features of communication channels reciprocate with the internal logic of the project. 

Tomás Saraceno sees the clear link between the three realities, or three types of networks: the ecosystem of digital media, the atmosphere of the globe with its co-dependant climate fluxes and flows, and the aerosolar society that inhabits it. The project of “Aerocene” seems to part from the roots, found in underground, counter–activism of the whole aerosolar initiative. Nevertheless, it goes forth with a de-policing of the world, and draws on a global and de-territorialised community living in the borderless sky. A social model as such proposes a new vision for humanity, where hierarchies, pre-defined identities, and organisational models are discarded in favour of horizontal, equal and immediate interactions between individuals within the aerosolar time–space.

Scarcity or abundance?

The intelligibility of Museo Aero Solar, Becoming Aerosolar, and Aerocene lies in the peculiar lightness of the way they translate, articulate (and highjack) the gravest problems of our times. The contemporary atmospheric condition is distinguished by violent meteorological phenomena, of the rising concentration of toxic gases and particles that constitute the most invisible pollution. Saraceno chooses to highjack global warming, and to treat its causality–the greenhouse effect–diametrically. He does not call for an immediate and definitive measure. Rather on the contrary, his vision employs the physical, thermodynamic process of warming, and makes it the main energy source–free and unlimited. This research, supported by collaborations with the scientific teams of NASA and CNES, thus materializes in the ultrathin membrane, a tiny wall between interior and exterior that enables the sculpture to harness the energies of the sun and the earth to go aloft.[6]

 The similar logic overruns the position taken towards the Anthropocene. The term comes from the new geological strata, the one mostly formed by the human activities of over–production and accumulation of artificial, synthetic, or composite materials, which are produced by transforming natural resources in an irreversible manner. Keeping this in consideration, aerosolar undertakings challenge traditional ecological positions by building its material base on plastic. Museo Aero Solar workshops bear the capacity to stitch more than 20.000 plastic bags together, and thus refuse becomes a resource. While downgrading, downsizing, and austerity have been eagerly adopted by the dominant discourse nowadays, Saraceno reveals, exploits (and denounces) this form of abundance that flows from an erroneous patterns and habits of production and consumption. Ambiguous, dynamic, less subversive than transgressive, his aerosolar can be seen as sublime parasites, or radical enterprises of diverting our inherited world.

Resistance or escapology?

Saraceno’s aerosolar undertakings, and namely, Aerocene, imply unrestricted movement across borders of art, architecture, and science. The ‘chimerical,’ highly prolific results of Saraceno’s research impair disciplinary boundaries by keeping political commitments and unbounded creative spirit. The highly advanced scientific knowledge that enters the project is met with the philosophy of low–tech, the methods of bricolage, decreased velocity, and collaborative work. Celebrated in the well-established scene of contemporary art, Saraceno’s works permanently urge to transgress and to escape the immune sphere that, according to Sloterdijk, symbolizes our over–developed world. Besides the playfulness of interactivity, his architectural artistic interventions bring sensations ranging from weightless levitation to vertigo, from disorientation to unique sensitivity to another being. Precisely these “anomalous” settings and feelings empower the aerosolar future projections and its ambitious initial realisations. 

In the current ecological discourse, science and technology are summoned together to curb climate change. As in “sustainable” architecture, the blind solutions go to the matter of isolation that is treated as a theoretical aim and a practical claim. Contrary to the repressive inclinations of the two, Saraceno does not resist the climate, the atmosphere, or the weather. He chooses to engage with its prodigious dynamics, and to rely on its thermodynamic fortune. “When Cloud Cities are in use, we will have learned to live on Spaceship Earth. To have the know–how to build a cloud city, you’ll need to know the wind, weather, and temperature,”[7]  he says. The first lesson to learn here, under Aerocene, is to hinder the accumulation of protective layers in which we tend to enclose ourselves: instead of producing artificial climates, we should learn to inhabit the one that (still) exists and surrounds us.

 — Pierre Chabard

A longer version of this essay has been published in French in Criticat, biannual architecture review, n°16, fall 2015, cf.


[1] “Museo Aero Solar,” last modified July 27, 2015, https://museoaerosolar.wordpress.com .

[2] “Museo Aero Solar,” http://museoaerosolar.weebly.com.

[3] Félix Mulle, “Un ‘conflit créatif’ autour d‘un espace délaissé à Milan,” Criticat 2 (2008): 112-123.

[4] Mara Ferreri, Alberto Pesavento, Bert Theis, “ Isola: Arte e comunità contro l’Eco-gentrification a Milano,” European Institute for Progressive Cultural Policies, June 2009 (www.eipcp.net/ n/1244798405/).

[5] Inés Kazenstein,  “Tomás Saraceno : A View from Buenos Aires,” ed. Meredith Malone and Igor Marjanovic, in Tomás Saraceno : Cloud-Specific, (St. Louis: Mildred Lane Kemper Art Museum, 2014) 43.

[6] Tomás Saraceno and Bronislaw Szerszynski,  “Devenons solaires” , Anthropocène Monument symposium, 11th October 2014, Musée des Abattoirs, Toulouse, France.

[7] Kisa Lala, “Walking on air: Getting Cloud-Specific with Tomás Saraceno,” The Huffington Post, May 2012. (http://www.huffingtonpost.com/kisa-lala/walking-on-air_b_1556868.html)


As society struggles to come to terms with the implications of antropogenic climate change, it is becoming increasingly clear that any adequate response will require not just more efficient machines and renewable energy sources but an epochal shift in the energetic and material relationship between humans and their environment. Researchers in industrial and social ecology such as Rolf Sieferle and Marina Fischer-Kowalski, have carried out detailed analyses of the different ‘socio-metabolic regimes’ that have underlain different forms of human society, and these can help us understand the nature of the challenge facing humanity in the twenty-first century.  Two of the main kind of metabolic regimes seen thus far in human history have been solar-based. Low-density hunter-gatherer societies engaged in passive solar energy utilisation by utilising the resource density of lightly-managed existing ecosystems, whereas agrarian societies more actively maximised useful solar energy by clearing forests and raising high-utility organisms such as crops and livestock.[1] The spread of this agricultural form of society enabled societies to slowly increase their populations and to support non-agricultural economic and cultural activity. But it did so by increasingly monopolising the land surface and coastal waters of the Earth, creating ‘anthromes,’ where natural systems are embedded in and shaped by human systems.[2]

The third major regime was rather different.  This was the industrial metabolic regime that allowed the growth dynamic that had been made possible by the agrarian regime to continue and even accelerate, by shifting its main source of energy from the solar flux to geological stores of energy.  One way to describe this was as a move from surface to volume.[3]  For the first time, energy needs were more or less decoupled from territory, a point that Sieferle emphasises by calling fossil-fuel reserves a ‘subterranean forest.’[4]  Going down into the volume of the Earth—and thus into the deep time of the Earth’s past—became not just a minor additional activity but absolutely central to the logic of society.  But we have seen that this regime has been deeply perverse in its effects, especially in terms of climate change and ocean acidification, and cannot safely be sustained. So what could come next?  Here we need to be imaginative.

It seems likely that one way or another we need to shift to a new kind of solar regime – one that shares with the hunter-gatherer and agrarian regimes the utilisation of the massive constant flow of solar energy through the Earth system—rather than the mining of finite stocks of energy under the earth. Nevertheless a regime that can support the greatly enlarged human population that the fossil-fuel-based regime has produced.  The dominant emerging vision involves reducing energy needs through efficiency gains, and shifting from fossil-fuel use to the capturing of solar energy, either directly through photo-voltaic electricity or biofuels, or indirectly through harnessing the energy of the movement of air and water as the elemental media of the Earth dissipate the energy gradients created by the curvature of the Earth’s surface and the shifting relation between Earth and Moon.

Going up

Yet shifting from fossil fuels to solar energy in the dominant ways that are being envisaged would involve restoring the link between energy and territory.  There is thus a danger that the way that we reduce the pressure on the capacity of the atmosphere and ocean safely to absorb CO2 will simply redirect that pressure onto the surface area of the Earth, with even less room for non-human nature.  Given that the current socioeconomic system has a structural need for ever-growing energy consumption, simply shifting back to a territory-based socio-metabolic regime without otherwise radically altering the organisation of society is likely simply to displace, not overcome, the contradictions of our current way of life.

So maybe a return to the surface is not the way forward.  Maybe the fourth major socio-metabolic regime should continue the industrial regime’s volumetric approach, but intensify it and switch it around by going not downwards but upwards. For more than a decade now, Tomás Saraceno has been using his art to explore the idea of inhabiting the air. In series of works such as Air Port City, Cloud City, On Space Time Foam, Museo Aero Solar, Becoming Aerosolar and now Aerocene, Saraceno’s enduring themes have been going not down but up, not fossil fuels but light and air, and not the deep past but the deep future— a vision of living spaces lifted up into a light, airy, green future, floating and casting their diffuse shadows over a land liberated for non-human life to flourish.  At the moment, Saraceno’s vision of cumulus cities and cirrus cities convening and dispersing in the air remains just that—a fanciful vision.  But maybe its sheer apparent impossibility should prompt us to consider it as something to be actively explored—as exactly the sort of radical revisioning of how we inhabit the Earth that is needed at this time.

Opening up

Tomás Saraceno’s work can also help us envision another aspect of how we might need to alter the way we inhabit our planet. The historical disaplacements of one socio-metabolic regime by another have always been accompanied by dramatic shifts in ideas of the human, and of the human body’s relationship with its environment and the wider cosmos. Yet the contemporary politics of low-carbon living is still closely tied to the enclosed forms of embodiment associated with industrial society and its fossil-fuel excess.  Saraceno’s art offers clues as to how we might break that link and find new ways of enacting and experiencing our being-in-the-world.

Mikhael Bakhtin’s 1968 exploration of the ‘carnivalesque’ dimensions of medieval culture emphasised the openness of the medieval body to metabolic flows and enjoyments of matter and energy.[5] Teresa Brennan, in 2000, used Bakhtin’s analysis as the basis for a more general argument that people who lived under pre-modern socio-metabolic regimes typically conceived themselves not as closed off from the environment, but as opened to flows of energy, affect and mental content from their surroundings.  Yet with the Protestant reformation, which prepared the way for modern society, the body was progressively closed off.  Bodily engagement with the world, and with the divine, were increasingly devalued in favour of interior reflection, language and speech, and the close-contact senses of touch, taste and smell were de-emphasised in favour of those of vision and hearing.[6]

The transition to industrial modernity also involved developing very different ways of talking about energy and movement.  The word energy comes from the ancient Greek energos, meaning “being in action.”  This was a rich, qualitative concept that encompassed a broad range of different kinds of activity (poiesis and praxis), and relations between potentiality (dunamis) and actuality (energeia). The modern, quantitative concept of energy is very different.  It has made possible huge gains in human understanding of the universe, but has done so at the expense of an awareness of the qualitative dimensions of energy.[7] Defined as the capacity to do ‘useful work’, the modern idea of energy is very much a product of the industrial metabolic regime,[8] and has encouraged an alienation from the contingencies of creaturely existence. As Lewis Mumford put it, in the industrial system, “[p]ower was dissociated from its natural human and geographic limitations: from the caprices of the weather, from the irregularities that definitely restrict the output of men and animal.”[9]

Brennan also argued that the modern idea of psychic self-closure is inextricably linked with the technological domination of nature, and with the proliferation of commodities and characteristic of industrial, capitalist modernity.  In an echo of Latour’s 1993 argument that modernity’s attempt to separate and purify nature and culture has the counteracting effect of making hybrids proliferate,[10] she suggests that the notion of psychic closure from wider energetic flows has helped to drive the breathtaking energetic and material profligacy of modern society, and the incessant conversion of the energies of life into dead commodities.[11]

Yet the current way of thinking about low-carbon, sustainable living is still grounded in the modern, industrial ‘constitution’ of the body, one predicated on a minimisation of the material, energetic and symbolic exchange with the environment and the rational monitoring of behaviour.  A transition to a genuinely sustainable society might require not just a technological transition but also a more fundamental anthropic one, involving new ideas of what it is to be human, with very different understandings of energy and its relationship to life—and perhaps one that echoes those of pre-modern societies.

the aerocene vision

The Aerocene sculpture—along with all the wider social practices that convene around it—gestures towards such a new vision of the human.  The Aerocene vision is about going up, but also opening up.  The Aerocene sculptures gains its power to rise into and inhabit the atmosphere not merely from itself but from its openness to elemental media and cosmic forces.  They collect electro-magnetic energy from the sun and the Earth through its membrane; they use the weight of the atmosphere above it to rise, and pressure differentials in the atmosphere around them to move. They engage with the human bodies and collectivities that gather around them, becoming nodes in a network of bodies that make each other sensitive to the dynamics of the atmosphere. And the open body of Aerocene reminds us of the openness of our own bodies–that living things, like all dissipative systems,[12] depend on a constant flow of energy, matter and information across the boundary that at once divides and joins them and their environment. Aerocene points towards an anthropic transition that would open us up to the more-than-human world.

Inhabiting the air and opening up to the elements would also involve us recognising contingency and hazard as a necessary part of creaturely existence, rather than something that can ever be eradicated.  As Tim Ingold puts it, life (anima) is not something carried by the wind; it is being carried by the wind (anemos): “life is not in things; rather, things are in life, caught up in a current of continual generation.”[13] We need new forms of solidarity and security, predicated not on closure and independence but on the recognition of mutual vulnerability and interdependence.[14] The Aerocene provides a framework for that vision, a metaphorical—and maybe literal—lifting and opening up into the constant becoming of airy being.

Bronislaw Szerszynski


[1] Smith, Crosbie (1998) The Science of Energy: A Cultural History of Energy Physics in Victorian Britain, London: Athlone Press.

[2] Ellis, Erle C. (2011) ‘Anthropogenic transformation of the terrestrial biosphere,’ Philosophical Transactions of the Royal Society A 369 (1010-1035).

[3] Elden, Stuart (2013) ‘Secure the volume: vertical geopolitics and the depth of power,’ Political Geography, 34, pp. 35-51.

[4] Sieferle, Rolf Peter (2001) The Subterranean Forest: Energy Systems and the Industrial Revolution, Cambridge: The White Horse Press.

[5] Bakhtin, Mikhail Mikhailovich (1968) Rabelais and His World, tr. Helene Iswolsky, Cambridge, Massachusetts: MIT Press.

[6] Mellor, Philip A. and Chris Shilling (1997) Re-forming the Body: Religion, Community and Modernity, London: Sage/TCS.

[7] Illich, Ivan (2009) ‘The social construction of energy,’ in New Geographies, 2: Landscapes of Energy, ed. Rania Ghosn, Cambridge, MA: Harvard University Press, pp. 13-9.

[8] Smith, Crosbie (1998) The Science of Energy: A Cultural History of Energy Physics in Victorian Britain, London: Athlone Press.

[9] Mumford, Lewis (1934) Technics and Civilization, New York: Harcourt, Brace & Company. 196

[10] Latour, Bruno (1993) We Have Never Been Modern, tr. Catherine Porter, Hemel Hempstead: Harvester Wheatsheaf.

[11] Brennan, Teresa (2000) Exhausting Modernity: Grounds for a New Economy, London: Routledge.

[12] Prigogine, Ilya (1969) ‘Structure, dissipation and life,’ in Theoretical Physics and Biology, ed. MauriceMarois, Amsterdam: North-Holland PublishingCompany, pp. 23-52.

[13] Ingold, Tim (2007) ‘Earth, sky, wind, and weather,’ Journal of the Royal Anthropological Institute, 13(s1), pp. S19-S38.

[14] Szerszynski, Bronislaw (2010) ‘Reading and writing the weather: climate technics and the moment of responsibility,’ Theory, Culture & Society, 27(2-3), pp. 9-30.

The fixed and flowing air

500 years ago the people of Louth, a prosperous market town in east England, conquered the sky. At the west end of their church, St James’s, they built a tower and spire of phenomenal grace. Over ten years it rose from nothing to a pinnacled height of 90m: as high as the near slopes of the Lincolnshire Wolds, the low chalk hills below which Louth nestles; higher than the glaciers that shaped the flat plain on which it has sat since first settled sometime after the most recent ice age.

The spire was made from stone – sandstone quarried on the far side of the wolds. It was made from wool, trade in which was the source of the wealth with which the town paid the 305 pounds, seven shillings and sixpence that the spire cost. It was made from the food which that money bought for the builders and their families, and from their faith – faith both in the God that the spire glorified and in the masons whose knowledge ensured that its walls would not tumble, that its beams not buckle, and that its tower would not fall. It was made from sound; from the grunts of labour, the rhythm of chisel and song, the harmony of hymns, the whistling of the wind, the chimes of the bells that all of them knew — knew — would one day hang in their new-made heights.

And just as it was made of sound, it was made out of the air in which sound lives. The fibre-trapped insulating air that gave Louth’s wool the warmth men valued; the air from which the crops that fed the men took their carbon; the winds which, with the waves, had ground older rock to sand 200 million years before. The air they breathed, and into which the spire grew, and which it celebrated; the air of its inner spaces, bright lit through thin-columned high-arched windows; the air celebrated by its most spectacular features — the flying buttresses that spring from the pinnacles that top the tower to the mighty spire itself, not solid supports but open fretworks of stone, ideas built into and through the air.

All the air in the world has blown past Louth since then, and with the winds, change. The great spire of Lincoln Cathedral, across the wolds, which when Louth’s spire was built was the tallest man-made structure in the world, succumbed to lightning and fire, its height not to be matched again for centuries. Louth itself rose up in a rebellion savagely put down, its priest hanged at Tyburn. The wool trade faded, and new trades grew – a boy schooled in Louth, John Smith, sailed across the Atlantic to a new settlement in Virginia. The land was enclosed; the railway came; the railway went; small fields grew large again as machines replaced men in the land’s cultivation. On the flat fens between the wolds and the sea, where once a line of windmills ground flour and pumped water, the masts of wind turbines now rise white and thin almost to the height of the church; off the coast they rise higher still. And still the spire stands, a part of the air and a resistance to it, a solid spike in the changing sky, an anchor for a weathercock ever turning in the wind.

And yet now that change is no longer the sky’s only story.

As part of the celebrations of the spire’s 500th year, a local artist, Gary Woods, conceived of a work that would honour both the building and the change that it had seen. In 1844, when the spire was scaffolded for repair, another artist, William Brown, had climbed to the top, lashed himself in place and sketched a panorama of the town, the wolds, the flat fens leading to the North Sea, later turning the sketches into a celebrated panorama. Woods wanted to do something similar, but in the modern style. And so he commissioned video images of the spire from the point of view of a UAV hanging still and steady in the sky nearby. These video works, like Brown’s panorama, give wide views of Louth in its setting between fen and wold; indeed, as you watch, bits of Brown’s original panorama fade in and out, the old underlying the new. But these new panoramas differ from their predecessors in two crucial and interconnected ways. While their field of view is fixed, the images they represent move; a post van drives along Westgate, tennis players pace their court. And in the centre and foreground of the fixed field of view is the top of the spire itself. It is no longer a means by which such panoramas can be seen, but something which can be part of them — because to hang still in the sky is no longer something you need a connection to the Earth do.

The story of human flight has to date been almost entirely a story of movement — of racing the clouds, of outrunning the winds, of speed no grounded traveller can dream of. The age of the UAV hanging steady as a weathercock brings the world of flight new stillness. A UAV can stay on station where it chooses, held still not by stone or rope but by the energy that positions and powers its motors and the information sucked in by its sensors, the first varying constantly in response to the other. Transparent as the air is to light and radio, every point in the GPS-saturated atmosphere has access to the information needed to fix something there, as long as it can process information in the proper way. The historian Simon Schaffer reminds us that settlements are not settlements just because people settled there, but because the precise location has been settled by surveyors and their instruments, by sextants and telescopes. In this way all parts of the atmosphere can now instantly be settled. Airs flow as they have across the centuries, though some now trace out new Anthropocene patterns. But within that change there are not buttresses of idea and energy can hold any point of view fixed – not always, not under all circumstances, but in general principle. The air can be held in ecstatic stillness.

This new fixity where once all was fluid is an inversion of recent changes in the way we understand what goes on below. The once-solid-to-us Earth, we now see, is a nest of flows and currents, a slow, dense, opaque counterpart to the atmosphere circulating above. The folding of the crust brings up waves of rock such as the gentle-swelling wolds; the ebb and flow of ice shapes their sides and surfaces. The sinking of the planet’s crust into the mantle below pulls continents across the face of the Earth, buckling their borders, and creating new oceans between them. Beneath this cycling tumult, plumes of deeper warmth rise from the core through the lower mantle from like smoke in still air. In the core itself currents of liquid iron twist and turn above a seemingly solid kernel that is melting on one side as it crystallises on the other.

So: above a fixed but flowing Earth, a flowing air in which things can be fixed. There is a fear to be felt at this, fear that flight which once felt like the freedom of flow can now pinned to coordinates and thus controlled. A fear of drone eyes that hover forever with Hellfire at their command, of new lines of power cut across the sky. But there are surely possibilities both richer and lighter – more airy, if you will. A settlement is a choice, not a fate. Just as not all that is solid must melt into air, not all that flowed free must be fixed. To stand still where once one could but fly or fall is to have a new option. To stand, to fly; to fly, to stand. The flowing ground, the static air – what places and potentials for new masons, what sounding points for new bells, for sprites and spires reaching down towards change from stillness above, for diapirs and eleisons. New breaths; new sounds: new spaces; new glory.

— Oliver Morton

For Jane Burton, Nesta Roberts and Katharine Morton, nee Loft

On the Political Influence of the Sun

During the period of modernity we got accustomed to the understanding of the human beings as determined by the social milieu in which they live, as knots in the informational networks, as organisms depending on their environment. In the times of globalisation we learned that we are dependent on everything that happens around the globe – politically, economically, ecologically. But the Earth is not isolated in Cosmos. It depends on the processes that take place in the cosmic space – on black matter, waves and particles, star explosions and galactic collapses. And the fate of mankind also depends on these cosmic processes because all these cosmic waves and particles go through the human bodies. The positioning of the Earth in the cosmic whole determines the conditions under which the living organisms can survive on its surface.


This dependence of the mankind on the cosmic events that are uncontrollable and even unknown is the source of the specifically modern anxiety. One can say: Cosmic anxiety. The anxiety of being a part of Cosmos – and not able to control it. Not accidentally our contemporary mass culture is so much obsessed with the visions of asteroids coming form the black cosmic space and destroying the Earth. But this anxiety has also more subtle forms. As an example one can cite the theory of the ‘accursed share” that was developed by Georges Bataille. (1) According to this theory, the Sun always sends more energy to the Earth than the Earth, including the organisms living on its surface, can absorb. After all the efforts to use this energy for production of goods and raising the living standard of the population there also remains a non-absorbed, non-used rest of the solar energy. This rest of energy is necessarily destructive – it can be spent only through violence and war. Or, at least, through ecstatic festivals and sexual orgies that channel and absorb this rest of energy through the less dangerous activities. Thus, human culture and politics become also determined by the cosmic energies – forever shifting between order and disorder.


Now, Bataille’s solar myth reminds one strongly of the interpretation of the world history as defined by the activity of the Sun – interpretation that was formulated by Russian historian and biologist Alexander Chizhevsky in the 1920s and 1930s. During this period of time Chizhevsky’s ideas spread also to the West, especially to France and the USA, and some of his texts were published in French and English – so that his ideas could reach Bataille. (2) However, the main text written by Chizhevsky in which his theory is extensively formulated and proved by empirical data was published only relatively recently in Russian (3). Chizhevsky collected a huge empirical data – from the Roman and early Chinese sources up to the 1930 s – to show the close correlation between the periods of the higher activity of the Sun and mass revolutionary movements. It is, of course, the Russian revolution in 1917 that gave the decisive impulse to his research. Chizhevsky asks: why under similar social, economic and political constellations in some cases masses become mobilized and revolutionized but in other cases they remain passive and indifferent. The answer that Chizhevsky offers is this: to be able to start a revolutionary movement the human beings should be mobilized not only on the level of the spirit but also on the level of the body. The human spirit can be mobilized through an ideology but, according to Chizhevsky the degree of mobilization of the human body, like of all the organisms living on the Earth, is dependent on the cycles of solar activity. Chizhevsky collected an incredible amount of astronomical and historical data to show the correlation between activity of the Sun and activity of revolutionary movements. As he shows the greatest revolutions coincided with the greatest activity of the Sun – and the historical process is characterized by a succession of active and passive periods corresponding to the 11 years cycles of solar activity (the highest degree of activity follows the 22 years cycle). But it seems to me that for our time the most interesting part of his results concerns the relationship between activity of the Sun and English parliamentary election. These results show that the influence of the Sun dictates not only the choice between revolution and status quo but also between leftwing and rightwing politics in the framework of regular parliamentary processes. Thus, Chizhevsky shows that for the period between 1830 and 1924 the summary activity of Sun during the rule of liberal governments was 155,6% higher than during the rule of conservative governments. The conservative governments never had power when the number of sunspots was over 93. The moments of change in the solar activity are almost precisely correlated to the changes of the English governments.

At the end of his text Chizhevsky suggests that the knowledge of the correlation between activity of the Sun and political activity of the masses can prepare the political classes to the seemingly unexpected changes of the public mood. During the financial crisis in the year 2009 some specialist remembered the so-called Kondratiev waves – Nicolai Kondrtaieff, a student of Chizhevsky, applied his theory on the economic cycles and predicted all of them including the 2009 crisis. On the political level one is reminded of the years 1968, 1989 and, again, 2010-11. Here it is interesting to mention that the present time is the time of the weakest solar activity since the 20th century – the period of political indifference and passivity of the masses. However, the political effects of the bigger numbers of sunspots are often ambiguous. Chizhevsky specifically warns that the growth of solar activity can lead not only to the adoption of progressive agenda by the masses but also to the rise of irrational and reactionary populist movements.

— Boris Groys


1.     Georges Bataille, Accursed Share: An Essay on General Economy, vol. 1 (Zone Books, 1988).

2.     For example: A. L. Chizhevsky, les Épidémies et les perturbations electromagnettiques (Paris: Hippocrate, 1938).

3.     A. L. Chizhevsky, Zemlya v ob’yat’yakh solntsa, “The Earth in the Embrace of the Sun” in Chizhevsky, Kosmicheskiy pul’s zhizni (Moskva, 1995).

4.     See: Vincent Barnett, Kondratiev and the Dynamics of Economic Development (London: Macmillan, 1998).


Piloting the Aerocene

How to grasp, in feeling as much as in thought, the promise of new forms of life in the air? This question, and the promise that sustains it, runs through the work of Tomás Saraceno, and takes shape in the form of the sphere with which we are confronted at the Grand Palais. Prepared through careful arts of fabrication, through processes of inflation, this promise can only be realized, however, in the vital act of releasing something – and eventually many things – into the air. In Saraceno’s works, acts of release become ethical, aesthetic, and political occasions of profound importance and affective energy via which a cluster of possible futures for being and becoming airborne can be rendered explicit, foregrounded, made palpable. This cluster of possible futures take shape around the speculative form of what Saraceno calls the Aerocene, a concept-in-motion for imagining and devising new forms of life in the air that are sustained by little more than the elemental conditions in which they move.

In the acts of release through which the promise of the Aerocene emerges, Saraceno revives a form of aerostatic experimentalism. This is a form of experimentalism which, anticipated by earlier journeys and travels in the air, involves learning to sense, to feel, and to understand the condition of being airborne.[1] Whereas earlier vehicles for this kind of experimentalism were powered by hydrogen, helium, or hot air, Saraceno’s are solar-powered. And one of these works, the spherical envelope installed at the Grand Palais has the potential to become, through the act of release, a solar-powered vehicle for undertaking this kind of experimentalism.

While the success and achievement of this experimentalism depends on detailed scientific and technical knowledge, it goes well beyond these domains of expertise, drawing together and diagramming new formations of the technical, the aesthetic, and the ethico-political. Thus, central to this aerostatic experimentalism is the possibility of amplifying the feeling of being in the air, of making palpable variations in atmospheric worlds about which most of us have little awareness and of which we have an increasingly insulated experience. Saraceno is an activist and advocate for these atmospheric worlds, working to reveal them and to enhance our aesthetic awareness of their complexity because he knows that doing this is central to a renewal of ethical sensibilities across different spheres of life. He knows that the feeling of becoming airborne does not end with the brief acceleration of aerodynamic takeoff or the view from a passenger window. He knows that this feeling extends to experiences of aerostatic attunement in which craft, body, and atmosphere sometimes become co-extensive and co-intensive. And he wants to make this feeling more accessible by devising, for instance, tracking technologies that make it possible to generate distributed infrastructures of atmospheric awareness, allowing the movements of aerosolar sculptures to be sensed remotely, at a distance, and across different bodies. The promise here is of the generous elaboration of a mode of collective enquiry for sensing the conditions of being in the air.  

The importance of the act of release to Saraceno’s aerosolar work means that central to its ethical and political potential is the invitation it offers for a return to, and a renewal of, the figure of the pilot and of the skill of piloting.[2] These days the pilot has perhaps become a problematic, diminished figure. A figure encapsulated in an almost hermetically sealed cabin in which the elemental outside is only ever sensed fibre–optically, and for whom the force of flight control surfaces is dampened. A figure routinized into the background through checklists and automation, only becoming public through heroic or suicidal acts of control or through ghostly traces of voice recorders. A figure who, through the operation of remotely–controlled drones, performs their work at a clinical distance.

Saraceno’s work invites us to revisit and affirm different senses of the pilot and of the craft of piloting. On one hand, each of Saraceno’s works is a pilot project for aerosolar futures to come. Their ongoing, circumstance–specific experimentalism performs a tentative yet exuberant form of piloting that pulls together bodies, devices, infrastructures, and concepts into new situations of collective assembly. Indeed, this is the way Saraceno uses concepts like the ‘Aerocene’ or ‘Becoming aerosolar’. Rather than simply applying them, or employing them as frameworks, he pilots them by putting them to work to animate relations of co-fabrication and co-fabulation whose achievement is never guaranteed in advance. As a form of experimental empiricism, piloting is therefore critical to Saraceno’s mode of inventing and circulating objects, concepts, and affects. Seen in this light, the Aerocene does not therefore aim to represent the real conditions of the present as we find it. Rather, for all of us concerned about these conditions, the Aerocene performs a “piloting role” in that it “constructs a real that is yet to come, a new type of reality”.[3]

Then again, through the act of release, Saraceno asks us to think about piloting, rather pragmatically, as a responsive craft of becoming aerostatic and becoming aerosolar. Here the pilot is not so much in charge of a craft that travels despite the circumstances in which it finds itself. Rather, piloting becomes the very craft of sensing, feeling, and responding to the elemental variations of these circumstances. In the case of Saraceno’s aerosolar sculptures, piloting is an incremental tending of the trajectories of these works in response to variations in heat, light, cloud cover, and so forth. Understood thus, the pilot is akin to a choreographer in motion, whose works are composed not only of objects but also of the trajectories traced by these objects as they travel, always in material collaboration with the trajectories of their surroundings.[4] Indeed, the object, such as it is, is always an opening onto a possible way of moving, catalyzing a meticulously informed experimentalism in which deviations are joyous, dirigibility is only ever partial, and the envelope is always a shape of change that never fully closes in on itself. This is a craft of piloting which searches for opportunities for being led astray by eddies and up-draughts in sensory experience, and all in the hope that new inclinations in conceptual, ethical and political thought might emerge. A craft of piloting that is about acquiring enough technical expertise to facilitate experiments with the feeling of being in the air, with all the senses of stillness and motion this entails.

Crucially, Saraceno’s work elaborates a craft of piloting that performs and makes palpable a new kind of political physics of the air. Through the promise of the act of release, Saraceno asks us to re-imagine piloting as the crafting of modes of collective participation in the tending of forms of life in the air. This requires – indeed demands – ongoing commitment to speculative leaps. Imagine, for instance, as you look at this sphere, its release into the air. The mere fact of this body in the air will render it powerful as an affective attractor: an object of ethical and political attention. And left to its own devices, it might well circumnavigate the earth. But under certain circumstances imagine that the safety of this aerosolar body depends on being piloted and tended in relation to variations in heat from the sun, in infrared radiation from the earth, and in the thermodynamic winds of the atmosphere. And, further, now imagine that the responsibility for this piloting is distributed amongst an innumerable group of people, some on the ground, and some in the air. What would it mean, and what would it involve, for this group of people to take responsibility, collectively, for the altitude, direction, and speed of this aerosolar body? What would it mean to devise a way of responding to variations in the elements, to movements of the envelope in response to these variations, and to the responses of other people? And what if there were many of these aerosolar bodies in motion, all in the air at the same time? What new kinds of elemental intelligence would be required to sustain this experiment? What would it be like, in other words, to acquire the capacity to devise and choreograph political technologies for collectively piloting the Aerocene?

To consider these questions is to begin to appreciate something of the significance of Saraceno’s aerosolar works, and of the import of his ongoing collaborative experiments and speculations. It is to become open to the promise of these experiments in piloting the Aerocene: the promise of new senses of being and becoming atmospheric, new feelings for the air conditions that sustain worlds, and new shapes of thought for an aerosolar life we are only just beginning to grasp.  

— Derek McCormack


[1] See, for instance, Mason, Monck. Aeronautica; or, sketches illustrative of the theory and practice of aerostation: comprising an enlarged account of the late aerial expedition to Germany  (London, FC Westley, 1838); and McCormack, Derek, ‘Aerostatic spacing: On things becoming lighter than air’, Transactions of the Institute of British Geographers 34 1 (2009), 25-41.

[2] See also Michel Serres, Rameaux. (Paris: Editions Le Pommier, 2007)

[3] Deleuze, Gilles, and Guattari, Félix, A thousand plateaus: capitalism and schizophrenia. Trans Brian Massumi (London and Minneapolis: University of Minnesota Press, 1987), 142.

[4] On this understanding of choreography see Manning, Erin. Relationscapes: Movement, Art, Philosophy (Cambridge, MA: MIT Press, 2009).

I bind the Sun’s throne with a burning zone

* from a poem written by Percy Bysshe Shelley, ‘The Cloud’ (1820)

In 2014, on the occasion of the exhibition “The Anthropocene Monument”, initiated by Bruno Latour and Bronislaw Szerszynski at Abattoirs (the Museum of Modern and Contemporary Art, Toulouse), Tomás Saraceno presented an inflatable sculpture – a cloud made of plastic bags, titled Museo Aero Solar. Museo Aero Solar embodies a whole social movement and a collective, united under non-authorship and open source principles[1]. By the side of this installation, the artist also displayed his first sketches and attempts at a bigger undertaking – the project of Aerocene. It was a different cloud, shaped as a sphere with silver reflections that expanded, and occupied almost all the exhibition space. The work became a central axis around which texts, research material and technical drawings, displayed together with the sculpture, were assembled, articulating the new way of aerosolar travelling.

Aerocene is based on a technology that was originally invented by the French National Space Agency (Centre national des études spatiales – CNES) thirty years ago. MIR – the acronym of an infrared balloon – was an ‘autonomous’ balloon for meteorological researches. It was flying around the globe at a height varying between 18km and 32km. It had been heated by the sun during the daytime, and maintained its altitudes at night because of infrared emissions from the Earth’s surface. This journey of MIR could have lasted for months, and this was precisely one of his flaws. Lacking sufficient trajectory control and being submitted to strict aviation laws, MIR balloons are now deflated and their silver shine is locked in storage boxes. Saraceno wishes to relaunch them, and see them circumnavigating the sky again. He even speculates at the possibility of travelling with one, and maybe even living in there, uplifted by the sun.

However, nobody is going to dwell there at the moment. The current shape of the global ecosystem makes Aerocene’s sculptures more similar to rescue boats than airy colonies of expansion. Diametrically opposite to Warhol’s silver clouds, presented in 1966[2], Saraceno’s work informs about the time of crisis and the deteriorating condition of the Earth. Visually resembling the droplets of mercury escaped from a thermometer, they call for the reparation of our common home Earth. Aerocene sculptures’ trajectory uses the numerous pathways and crossings of winds and jet streams. They do not care about (national) borders and call for a united global action. Consciously referring to the Anthropocene, Aerocene has its own ambiguities: its perspective can be seen as apocalyptic or dystopic, but it demonstrates the will to cope with deteriorating planetary shape with somehow joyous and merry means – collaboration and communitive actions. Aerocene as a multi-faceted project (assembling together different applications and modes of employment, solving technical obstacles that it passes with a soft, airy jump by its inventive spirit) could be seen as a geo-engineering undertaking. But in contrast to those technocratic projects that try to fill the atmosphere with micro-particles in order to reduce the global warming, Aerocene is a bold gesture of a sincere concern and social sensibility. Aerocene declares the stratosphere as a permanent autonomous zone (TAZ).[3] Its artistic imagination draws on camping in the air and floating ‘tree’-cabins.

To situate the artistic project within its background – cloud- and skyscapes, a retrospective look can be taken. Art historian Hubert Damisch in his book A Theory of /Cloud/: Toward a History of Painting examines the celestial domes of Correggio, a Renaissance painter. Two cycles depicting breakings and collisions of an illusionary sea of clouds, created in Parma at the first quarter of the 16th century, were already speaking and showing the epistemological change that was still yet to come with the Copernican revolution. Furthermore, baroque and its shapes of clouds takes the society from the closed world to the infinite universe. During the first quarter of 21st century, Aerocene is a contemporary of the Anthropocene. It makes the limits of life on the planet tangible and comprehensive, on the contrary to the harsh-real utopian ideas of the techno-science. Floating in the levels of stratosphere, Tomás Saraceno’s sculptures draw the line of a certain demarcation. Similar to the yellow buoys in the water, separating safe waters from dangerous ones, Aerocene bears a paradoxical message: up from the sky it calls the necessity to be on the earth, well-grounded.

Within the celestial domes of Correggio and the ones of 17th century baroque, Hubert Damisch pays a special attention to the detail of “nuvola” (it. a cloud) that appears at the theatrical scenography from the Middle Ages. This essential element has made Christ, Virgin Mary and saints to fly, camouflaged by fake mechanical clouds in mystery plays of quattrocento. Mantegna and other painters used the “nuvola” in their sacred depiction. According to Vasari, we owe the clouds and their representations in art to Brunelleschi, one of the inventors and developers of the perspective in painting. “We notice how many painters have re-appropriated the different elements of theatre, depicted its scenography in the least problematic fashion” – notes Damisch. “Rocks that hide the dragon of Uccello [Saint George and the Dragon painting by Uccello] are made of carton, the clouds of Mantegna appear as wooden model covered by a painted canvas that was used to make scenography the most realistic. Mantegna does not seek to simulate or repeat the nature. The contrasting difference between atmospheric clouds and the mechanical-theatrical ones is a conscious gesture, referring not to the natural phenomena but to its cultural value.”[4] The installations and actions of Tomás Saraceno are close to being a set of such a scenography. Illusions are visible, but the cultural or social values prevail over them. The art of Tomás Saraceno is not one of engineering, design or architecture. His genius lies in his capacity to construct technological objects that make the division between natural phenomena and a human individual disappear.

Jacques Roubaud in his short text Sky and earth and sky and earth, written 1987, speaks about the “permanent condition” of skies of John Constable. “The clouds [in his paintings] are paradoxical visualisations of perpetually changing traces of a fixed skyscape. These fixed representations bring some sort of permanence to us – the fixed moment of memory.  The ever-changing sky has a permanence of that sort, since “cloud castles”, once destructed, are then again rebuilt, reassembled and reshaped by the wind. This type of transformation is much more sustainable than the one of earthly objects. Decomposition of vegetation, collapse of buildings and built structures, death of living beings – all designate the irretrievable past. On the contrary, constantly forming without ever attaining a fixed form, the vapor of the sky seems to be much more long-lasting.” [5] Saraceno’s project Aerocene aims to provoke, to bring to us similar feelings. Two centuries after the start of industrial revolution, the ever-changing but ever-lasting sky and the air has too become a subject of crumbling and decomposition. Aerocene thus is a signal at the border of the modern world, a world where humankind will consume the sky after it has already devoured the earth and the ocean.

— Olivier Michelon


[1] “Museo Aero Solar,” www.museoaerosolar.wordpress.com [accessed July 27, 2015]

[2][2] Silver Clouds is an installation, made by Andy Warhol and engineer Billy Klüver, exhibited in 1966 at the Leo Castelli Gallery.

[3] The concept of “permanent autonomous zones” is informed by the acclaimed text of critical cybernetic theory by Hakim Bey T.A.Z.: The Temporary Autonomous Zone (1991), and its later discussions as Permanent TAZs (by H. Bey 1994). PAZ defines more-or-less permanent counter-culture movements and communities, that share “the same ways of making” and same lifestyles, defined in opposition to cultural and political normativity.

[4] Damisch, H. (1972) Théorie du nuage. Pour une histoire de la peinture. Paris: Éditions du Seuil. 103.

[5] Roubaud, J. (1997) Ciel et terre et ciel et terre et ciel. Paris: Editions Argol. 81

Tianhe 天河区: Parables of the Celestial River

‘Nothing distinguishes me ontologically from a crystal, a plant, an animal, or the order of the world; we are drifting together toward the noise and the black depths of the universe, and our diverse systemic complexions are flowing up the entropic stream, toward the solar origin, itself adrift. Knowledge is at most the reversal of drifting, that strange conversion of times, always paid for by additional drift; but this is complexity itself, which was once called being. Virtually stable turbulence within the flow.’ 

— Michel Serres[1]

Tianhe-2 is a 33.86 petaflop supercomputer, the fastest on the planet, located in southern China in the sub-provincial city of Guangzhou in the eponymous district: Tianhe.  Tianhe, however, is not merely a region within a Chinese province housing the world’s fastest supercomputer of the same name.  Tianhe is also the region where every star we can see with our naked eyes dances in its galactic choreography—it is where we all reside.  Tianhe translates to English as celestial river, and is the Chinese equivalent for ‘Milky Way’.

In the center of Tianhe, our vortical, starry-river home, is what cosmologists call an Active Galactic Nuclei (AGN): a luminous and spectrally saturated accretion of matter amplified by a supermassive black hole.  AGNs are the largest and most persistently radiant objects in the entire cosmos and represent an active area of research in physical cosmology, not least because they are known to emanate extremely energetic particles into the domains of interstellar space.

In the core of Tianhe-2, are over one hundred thousand microprocessors, each a complex silicate lattice with billions of transistors.  Since computation occurs via charged particles within semiconductive microprocessors, any interference by forces, or other charged particles, can cause failures in long-term strings of the computer’s modelling operations, ruining weeks or months of computations.  As processors become smaller and computation becomes more omniscient and ambient, industries have begun to apply ECCs, or Error Correction Code, to deal with the constant environmental bombardment of charged particles, the atmospheric noise that interferes with the circuitous processes of microprocessors.  Given Moore’s Law,[2] the importance of ECCs to the smooth functioning of the computational future should not be underestimated.


In August 1912, the Austrian-American physicist Victor Francis Hess was lured by unexplainable phenomena into the troposphere with a series of six balloon flights.  Hess studied the conductivity of air and the amount of ionization above the Earth’s surface.  His discoveries would win him the Nobel Prize twenty-four years later.  But what he measured still mystifies physicists and astronomers alike, and is the locus of millions of dollars in research and collaboration around the globe.

Reaching an altitude of 5500 metres between Vienna and Germany, Hess discovered an increase in radiation as he ascended past 2km into the troposphere.  This ionizing radiation was soon shown (to great scepticism) to be neither terrestrial (since it increased as one ascended away from the ground) nor solar in origin (as it was shown to radiate at night and during solar eclipses). This unknown radiation—at the dawn of human understanding of radioactivity—was posited to be Galactic in origin, meriting the name cosmic rays.  Decades of subsequent balloon experiments revealed an ionization maximum between 20 and 25 kilometres above Earth’s surface: the Pfotzer Curve.

Cosmic rays and other astrophysical phenomena would also seduce the French space agency, Centre Nationale des Études Spatiales (CNES), into the realm of the Pfotzer Curve: more specifically a threshold spanning the upper troposphere and lower stratosphere, between 20km and 32km high.[3] From the 1970s CNES’ long-duration, stratospheric missions employed the Montgolfiere Infrarouge (MIR) balloon.  The MIR, a solar relative of the Aerocene, dwells in this airy milieu above the paths of airplanes both day and night by exploiting cascades of energy from our nearest star, Sol, as well as the infrared radiation emitted by the Earth – its uses no other gases than air.  MIR and Aerocene freely ride the isopycnal surfaces of this atmospheric ‘critical zone’[4], resonating with exotic perturbations from far beyond the Solar System’s heliospheric reach, eddying in the galactic tide-pools of Tianhe.

A “cosmic dancer on history’s stage,”[5] the Aerocene is part of a legacy of experiments,  initially led by mere noise, lured by specific conditions of the upper troposphere and lower stratosphere.  This unique atmospheric zone is the most critical for analyzing Earth’s radiative budget, for measuring turbulence and atmospheric pollution, and for detecting high-energy cosmic rays.  It is also precisely at 20 km that Google is now deploying Project Loon: a fleet of balloons that will beam LTE Internet to Earthbound smartphone users.  Sri Lanka will be the first country to be “covered” by March 2016.[6] Indeed the Earth may soon be veiled by another lattice of processing power, borne by the very thermodynamic infrastructure that has always insulated us and our machines from the cold, dark, deep waves beyond.

The Catatumbo is a river in Venezuela where vast amounts of Ozone is regenerated on a near-nightly basis by the planet’s most consistent lightning storms, storms named after the river over which they emerge an average of 300 times a year.  Earth itself is wondrously illuminated by around 3 million lightning flashes per day (or 40 per second, 1.4 billion a year).  Contrary to common understanding, the ground itself produces upward flowing “positive streamers:” invitations to down-flowing plasmas. [7]  A bolt of lightning is: “a stuttering chatter between the ground and the sky,” during which these fields of virtual potential actualize and equalize for a radiative moment. [8] These electromagnetic surges generate not only atmospheric plasma and Ozone, but also the atmosphere’s extremely low radio frequency of 7.83 Hz: Schumann Resonance.  This means that every atom, molecule, or crystal—the DNA in our mitochondria, the information in fibre-optic cables and the silicate bodies of computer chips—are alive with persistent, electrochemical fields of resonance.  Somewhere, between ground and sky, lightning events, like every beat in a drum roll, continually accentuate and inflect the planet’s elemental vibratory dances.

Such reciprocal, pulsating choreographies light up the bifurcating path of the Aerocene, and other high-altitude objects.  In Floating to Space: The Airship to Orbital Program, John Powell (by no accident a close friend of Tomás Saraceno) describes a ‘Zoo of Lightning.’[9] Such spectacles include “Blue jets,” or azure cones that project from the top of cumulonimbus clouds; “Elves,” or extremely dim discs of light that occur with fiery red “Sprites”; as well as “Gnomes,” “Trolls” and “Pixies.”  All of these high-altitude Transient Luminous Events (TLEs) will in 2017, for the first time, be methodically investigated by CNES’ new Satellite TARANIS, aptly named after the Celtic God of Thunder.

Why are “Trolls” and “Elves” the object of a new satellite mission?  The past 15 years has witnessed the stunning discovery that lightning is a catalyst for Earth’s own emissions of cosmic and gamma radiation,[10]as well as annihilations of antimatter.  In 2009, the Fermi Gamma-ray Space Telescope in Earth orbit observed an intense burst of gamma rays and positrons (antimatter) coming out of a thunderstorm over Namibia.  Scientists would not have been surprised to see a few positrons, but the flash detected by Fermi produced about 100 trillion positrons, a phenomenon never previously observed.[11] Our hydrogen-blue Earth creates interference-patterns in celestial tributaries not so unlike those rippling out from Tianhe’s AGN.


What do such parables tell us?  Just as Earth’s electrically charged surface reaches up to the clouds to co-produce lightning (a meeting in mid-air!) so too does the Earth extend its reach, sending its own streamers of ionized and electromagnetic invitation to the corners of the cosmos.  The Earth (and those reading this essay) are not passive to such phenomena.  We are writ into fields of energy and force that are patterned in specific currents.  These are fields that extend from ions to photons to electron cascades, from storms to balloons to microprocessors, from silicates to scripts to cells, and through the genetic codes and enzymes of all Earthly species.

Tomás Saraceno’s Aerocene is alive to cosmic energies in the way that the molecules of Earth’s crust are alive to the charge in atmospheric storm-systems, and in the way that the Earth itself is alive to the AGN in the far-off turbulence of the celestial river.  The Aerocene is a cascade experiment with force-fields and phenomena that are far more cosmic, far more promiscuous, than most individuals of our species realize.  Like “Sprites,” “Blue Jets,” and “Elves,” like Victor Hess himself, the Aerocene prehends the charged matter of Earth, the atmosphere, Sol, and Tianhe’s Active Galactic Nuclei, finding, like so many other phenomena, a path to weave between and within.

The genealogy of the Aerocene is composed of the buoyant search for answers to seemingly simple questions, questions that upon investigation become cosmo-logical in scope.  This fact should not be underestimated.  Like the atmospheric noise that confused and drove Hess to the sky, the clapping noise of lightning on distant horizons, the quasi-noise of spacetimematter(s) patternings—these ancient and primordial static-interferences, floating or spinning now, charged and cascading, reaching and joining—these have been great lures for thought, exploration and invention, for physical and epistemological risk and renewal.  Such noisy, wandering potentials are a reminder that terrestrial life is not now, nor has ever been, insulated from the vast astronomical plenum.  And it is thus that we find ourselves, led by an indistinct babel, to detect the whisper of a blackhole-Shiva[12] hinting that yes, indeed, we probably do reside within the luminous logic of a holographic supercomputer of the same name . . . [13]


Dr. James Gates: What I’ve come to understand is that there are these incredible pictures that contain all the information of a set of equations that are related to String Theory.  And what’s even more bizarre then is when you try to understand these pictures, you find out that buried in them are computer codes just like the type that you find in a browser when you surf the web.  And so I’m left with the puzzle of trying to figure out whether I live in the Matrix or not.

Niel deGrasse Tyson: You’re blowing my mind at this moment. So you’re saying, are you saying your attempt to understand the fundamental operations of Nature leads you to a set of equations that are indistinguishable from the equations that drive search engines and browsers on our computers?

JG: Yes that is correct.

NT: Wait, wait I’m still—I have to just be silent for a minute here… So you’re saying as you dig deeper and deeper [bending over and miming a digging motion] you find computer code writ in the fabric of the cosmos?

JG: Into the equations that we want to use to describe the cosmos, yes.

NT: Computer code.

JG: Computer code.  Strings and bits of ones and zeros.

NT: And it’s not just that it resembles computer code, you’re saying it IS COMPUTER CODE?

JG: … and it’s a special kind of computer code that was invented by a scientist named Claude Shannon in the 1940s. That’s what we find very deeply inside the equations that occur in String Theory and in general in systems that we say are Supersymmetric.[14]


—Jol Thomson and Sasha Engelmann

[1] Michel Serres. Hermes: Literature, Science, Philosophy. (Baltimore: The Johns Hopkins University Press, 1982), 83.

[2] Moore’s Law is the observation that approximately every two years since 1975 computational power has doubled (and we could add, miniaturized by a similar factor).  It is suspected that the inherent limit to this doubling is the width of the atom itself, a limit we are already rubbing up against. See: Gibbs, S.  “At the limit of Moore’s law: scientists develop molecule-sized transistors”, The Guardian, July 21, 2015.

[3] I. Sadourny. “The French balloon programme: capabilities and scientific programmes,” Advances in Space Research, 30(5) (2002): 1105-1110.

[4] Bruno Latour. “Some advantages of the notion of “Critical Zone” for geopolitics,” Procedia Earth and Planetary Science, 10 (2014): 3-6.

[5] Mike Davis. “Cosmic Dancers On History’s Stage? The Permanent Revolution in the Earth Sciences.” New Left Review I/217 (1996).

[6] <http://www.theverge.com/2015/7/29/9069961/google-project-loon-internet-sri-lanka>

[7] D.R., MacGorman, et al. The electrical nature of storms. (Oxford: Oxford University Press, 1998)

[8]  Vicky Kirby. Quantum anthropologies: Life at large. (Durham: Duke University Press, 2011), 10. 

[9] La Frenais, R., Saraceno, T., & Powell, J. “Floating into Deep Space,” European Planetary Science Congress 2014, EPSC Abstracts, Vol. 9, (2014), 843.

[10] Gamma rays are a class of high frequency electromagnetic radiation composed of high energy photons.  Gamma rays are produced when charged cosmic rays interact with atomic nuclei as they escape the vortices of gravitational fields.  As such they serve as beacons for the presence of cosmic rays. 

[11] “Thunderstorms shoot antimatter beams into space” National Geographic News (2011) <http://news.nationalgeographic.com/news/2011/01/110111-thunderstorms-antimatter-beams-fermi-radiation-science-space/>

[12] “Shiva” is the name given by Stephen Jay Gould to the pattern or “cycle of impacts [of objects on Earth] driven by a galactic tide, probably the Sun’s vertical oscillation in the plane of the Milky Way Galaxy.” Shiva-shakti is also the processual Hindu god of destruction and transformation.

[13] Nick Bostrom.”Are we living in a computer simulation?” The Philosophical Quarterly 53.211 (2003) 243-255. See also, Beane, S.R., et al. “Constraints on the Universe as a Numerical Simulation,” arXiv preprint arXiv:1210.1847 (2012).

[14] “The Theory of Everything”, hosted by Neil deGrasse Tyson (2011) <https://www.youtube.com/watch?v=-sMBCTpsvH0>

Aerocene: Becoming Aerosolar — A collaboration between Tomás Saraceno and MIT

Aerocene: Becoming Aerosolar
A collaboration between Tomás Saraceno, Visiting Artist MIT

Leila Kinney, MIT Center for Art, Science & Technology (CAST)
Lodovica Illari and Bill McKenna, MIT Department of Earth, Air and Planetary Sciences



One of the oddest sensations of hot air balloon flight is the feeling of absolute stillness and extreme quiet.  A paradox:  moving with the wind eliminates the feeling of wind and thus a feeling of movement. Tomás Saraceno is fascinated by – or, more accurately, creatively obsessed by – airborne movement of all kinds, from the astonishing phenomenon of “kiting” spiders that create parachutes of gossamer silk, catch updrafts and drift through the jet stream to propel themselves hundreds of miles from land, to the ongoing series of prototypes for floating biospheres fueled by wind and solar power that he has created for more than fifteen years, Air-Port /Cloud-Cities. They are speculative models for alternate ways of living – and alternate ways of flying. Saraceno would like to propose zero-carbon emission flight; make your reservations now for Aerosolar Airlines, as he has been known to say!

As the inaugural Visiting Artist for MIT’s Center for Art, Science & Technology (CAST), beginning in Fall 2012, Saraceno brought these multifaceted interests into creative dialogue with multiple departments across the Institute.  Moving among practical, theoretical and hypothetical considerations, Saraceno discussed everything from nanoengineered materials to solar energy to weather patterns to the origins of the universe, asking architects, engineers and scientists in diverse fields to imagine with him what a different reality might look like.  A wide-ranging foray into disparate areas of expertise led Saraceno to develop a productive collaboration with Lodovica Illari, a climatologist whose specialty is large scale atmospheric dynamics, and Bill McKenna, whose architectural training led him to her EAPS (Earth, Atmospheric and Planetary Sciences) lab to work on visualizations of geophysical fluid dynamics.  Sharing a mission “to make people understand what is not intuitive” (her words), they began with “Weather in a Tank,”[1] a series of rotating fluid laboratory experiments created by Illari and Professor John Marshall.   

Aerocene is the latest node in Tomás Saraceno’s continuous experimentation with solar balloons, which include his own do-it-yourself versions, (e.g., 59 steps to be on air by sun power, 2003), crowd-sourced variations made with plastic shopping bags (Museo Aero Solar, ongoing since 2007,) and a residency at CNES (Centre Nationale d’Études Spatiales), spent immersed in studying their MIR (Montgolfière Infrarouge) solar balloon flights.  Now Illari and McKenna have used the MIR flight data to visualize the possibilities for a new series of solar balloons that could monitor the chemical components of the stratosphere and measure their effect on climate change.  But there is more than a gathering scientific data in the offing.  In keeping with his capacity to work at multiple scales, modes of expression and registers of engagement, Saraceno also sees these balloons as “lighter-than-air sculptures” and as an opportunity for a highly distributed network of participants to monitor their progress, predict the weather collectively, and raise awareness of our technological disruptions of planet Earth.  The scenarios outlined below link technical expertise to visionary thinking and material realities to a future “jet stream art research center” – “Cloud Cities” in the making.


An example from the past

Montgolfiere InfraRouge (MIR)

Tomás Saraceno is a visionary artist who is constantly pushing the boundaries of our imagination. He has been fascinated by clouds and lighter-than-air balloons for many years – see his Cloud City exhibition [2]. Recently he has fallen in love with infrared/solar balloon technology which he has dubbed ‘aerosolar’; a balloon with zero energy consumption that can fly using radiation from the sun during the day and radiation from earth during the night. This technology, originally developed by CNES (the Centre National d’Etudes Spatiales) [3] in the 1970’s, can be used as an inspiration, Saraceno believes, for how mankind could begin to live in symbiosis with the earth, sparking the imagination and inspiring the public think about conservation at a time when the earth is at risk from overpopulation and climate change.

The aerosolar balloon is ‘zero-energy’ and yet can circumnavigate the globe much like the albatross of the southern oceans, but flying much higher, even up in to the stratosphere. One could imagine using such balloons to monitor the ozone and other chemicals in the troposphere and stratosphere with nearly zero energy cost – except for the helium or hot air needed to lift the balloon in to its initial orbit.

In collaboration with Saraceno, our group at MIT has studied the data from past balloon flights carried out by CNES, and begun planning future flights of smaller balloons that are being developed with Saraceno and his group.

Since 1971 CNES has been supporting a program of long-duration scientific flights using hot air balloons, MIR (Montgolfiere InfraRouge). The MIR is a very light hot-air balloon, which is heated by direct and reflected solar fluxes during the day and upwelling infrared fluxes from the Earth at night (see Fig1).

Fig.1 MIR radiative budget (left), MIR flight profile (right)
Letrenne et al (1999): French Long Duration Balloon Activity: The InfraredMontgolfiere (MIR), Proceedings AIAA International Balloon Technology Conference,  28 June – 1 July, 1999, Norfolk, VA.

Fig.1 (left) shows the MIR radiative budget. The balloon is heated by upwelling infrared fluxes from the earth during night–time and direct and reflected solar fluxes during day-time. The first ascent from the ground is made possible using helium gas. After 2 or 3 days the helium is completely evacuated and the MIR then flies only using hot air –see Fig.1 (right).

The MIR balloons have been used to perform tropical and trans-polar stratospheric flights. As an example we describe a flight in 2004, when the balloon travelled from Brazil to Australia rising and falling in the stratosphere over the diurnal cycle, whilst being carried along by the prevailing winds.


MIR flight from Brazil to Australia (February, 2004)

As shown in Fig.2 and 3, the balloon cycles up and down in the stratosphere following the sun’s diurnal cycle, as it is carried by the winds from Brazil to Australia. During the day it rises and it sinks at night.

Fig 2: The path of the solar balloon between February 2nd to 14th 2004 as it flies from Brazil to Australia. Colors along the track represent the altitude of the balloon: orange/red = high altitude, purple/blue = low altitude.
Also shown is a meridional (S-N) section of the zonal-average zonal wind (flow from the west is in cyan/blue and flow from the east in pink/gold). Following the flow from the east, typical of the tropical lower stratosphere at this time of the year, the balloon moves up and down between the heights of 30 km at day and 20 km at night.

Fig 3:  Map of the zonal wind at 30 mb on Feb 14, 2004. The balloon can be seen to be drifting from east to west, following the prevailing tropical flow in the southern hemisphere: blue indicates a wind from the west to east, pink and yellow from the east to west.


Trajectories for February 2004

Using NCEP reanalysis data from February 2004, MIR virtual flight trajectories have been computed beginning from lots of initial launch points over all of S. America. Most of the trajectories reveal a flow from east to west over the central Pacific. These are the winds that the actual balloon was embedded in, as can be seen from the balloon track on the left of Fig. 4.

Fig. 4 (left) – Observed path of the balloon from February 2nd to 14th 2004, as it flies from Brazil to Australia – daytime is marked orange, nighttime is marked violet.
(right) 30 mb trajectories in February 2004 (10 days travel) at the same time as the MIR flight. Trajectories are colored with the direction of the wind: blue from the west to east, pink and yellow from the east to west, as in Fig.2.
Initial launch positions for the trajectories are over South America.

MIR flight and ozone (February, 2004)

The MIR balloon could be a great tool to monitor the ozone distribution in the stratosphere if it were instrumented with an appropriate measuring devise. The following images show the track of the 2004 balloon flight together with the observed ozone distribution at that time. In Fig.4 we see it sampling high ozone concentration in the stratosphere along the equator. See Marshall et al. (below, under References 2) for the impact of the ozone on climate.

Fig. 5 (top) Section is showing vertical distribution of ozone during the flight period – purple/white indicates high ozone concentrations.  Ozone has a minimum concentration in the troposphere and a maximum in the tropical lower stratosphere at a height of around 30km.  (bottom) During the day the balloon flies just below the region of maximum ozone concentration, moving from east to west, as seen in Fig 3.

The CNES explored conditions during the year when it was best to fly a hot air balloon.
The period of the flight was carefully chosen to maximize solar and infrared radiation thus prolonging the duration of the flight, as shown in Fig.6.

Fig. 6 A statistical analysis of upward IR fluxes from SCARAB satellite during 5 years (1994-1999) compared to the computed IR flux curve sufficient to stabilize the MIR at low level for the season and latitude given.

Fig.6 shows that the least favorable conditions are encountered primarily in the middle and higher latitudes, due to the combined occurrence of dense cloud formation in the troposphere at these latitudes and relatively high temperature in the lower stratosphere. Clouds act to shield the balloon from upwelling infrared radiation resulting in the air temperature inside the balloon falling during the night, and reducing the necessary buoyancy needed to keep it afloat. The most favorable period and ideal latitudinal zone is found 25 degrees in Austral summer and 15 in Austral winter. It is for this reason that CNES chose to launch the balloon in February at the latitude of 25S.

Looking to the future

When and where would it be best to launch a balloon?  How do we choose?

To get a better idea it is important to check the climatological distribution of the wind throughout the year. Fig.7 shows isosurfaces of the zonal wind in January (left) and July (right): inside this surface the wind speed is greater than 25 m/s. It is clear that in the Northern hemisphere flow tends to be strong and mostly toward the east in winter. A band of flow from east to west tends to dominate the tropical atmosphere, but its location shifts with the seasons as the Hadley Cell migrates.

Fig. 7 (top) Isosurface ofwind speed (u >25 m/s) during January, showing a prevalent flow from west to east (blue) in the northern hemisphere, while flow is from the east to west (pink) (u <-25 m/s) in the southern hemisphere. (bottom) ) as above but for July, showing that at this time of the year the flow from the east is strong close to the equator, while in the southern hemisphere the flow tends to be from the west (NCEP Climatology).

Fig. 8 Hovmoller diagram of the zonal wind as a function of time – months of the year. Flow from west to east is marked in cyan/blue, flow from east to west is marked in pink/orange.  (left) flow in thestratosphere at 30 mb and (right) flow in thetroposphere at 250mb.

Hovmoller diagrams at various pressure levels, as in Fig.8, can help us choose the appropriate time of the year to launch a balloon along specific tracks. If we want to fly a balloon from Brazil to Australia in the stratosphere, we should choose a month such as January or February. In fact several MIR flights in the tropical stratosphere were launched from Brazil or Ecuador in February (Fig. 2).

Similarly let’s suppose we want to fly a balloon from Boston to Paris: when would a launch lead to the fastest travel time? We find that it is also best to launch in January or February, when the flow from west to east at the jet level (250 mb) is very strong, as can be seen in Fig.8 (right).

Trajectories from current forecast data for the stratosphere

Ifwe were planning to launch a balloon in to [AA1] the stratosphere from South America now, in October 2015, as we write this article, where might it be carried by the prevailing winds? We can use the NCEP global model (GFS) forecast data[5] to figure this out.

Fig.9 shows typical trajectories at 30 mb starting from different locations over South America. It is clear a track from east to west is dominant at low latitudes, whereas at high latitudes and close to the equator it is from west to east.

Fig. 9 Trajectories at 30mb in October 2015. They show 10 days travel, starting from grid point locations over South America – see upper corner map for initial locations. Trajectories are computed using the GFS forecast data (GFS model run from October 12th, 2015) – cyan/blue = flow from the west, pink/orange = flow from the east.


Trajectories from forecast data in the troposhere – for Paris

What about launching a balloon in the troposphere at the jet level to try to reach Paris from the US at this time of year (October)? Where would it likely go?

To estimate where we might launch the balloon, we have computed backward trajectory for 5 days starting at locations near Paris in western Europe – see Fig.10.

Fig. 10 Trajectories at 250 mb in October 2015 (October 20, 2015). Left imageshows travel aftter 1day, centerafter3 days, right after 5 days.  Flow from the west is marked in cyan/blue, flow from the east is marked in pink/orange. Backward trajectories have been computed using forecast data (GFS model) from locations over western Europe.

In October the flow is typically not very zonal, and therefore, it is not surprising that we might reach Paris in 5 days starting from very different locations over the US, for example, Texas, the East Coast or even the Caribbean Islands.



Tomás Saraceno’s vision of flying solar balloons between cities might be too futuristic, but this technology could be used to sense the lower stratosphere at zero energy cost, although some helium might be used at the launch time. The lower stratosphere is a critical layer where the chemistry of ozone, methane and other chemicals has a fundamental impact on our climate. Concentrations of these chemicals are not well known and there is a clear need to better monitor these constituents.

To summarize our view into the future, we have computed trajectories at two levels, 30 mb and 300 mb, starting from all world airports – Fig11.

Fig. 11 Horizontal trajectories at two levels and at two time periods. Trajectories are seeded from all world airports. One single path shows travel time of 12 hours, snapshots are 6 days apart. (Integration begins on February 4th, 2004). Top panel: trajectories at 30 mb. Bottom panel: trajectories at 200 mb. (Trajectory calculations by Prof. Glenn Flierl, MIT [6])

It is evident from Fig.11 that at 30 mb, in the lower troposphere, after 6 days of travel, the balloons would have sampled most of the continental area over the earth, but with gaps over the ocean. On the other hand, because the balloons need IR radiation at night, there are only limited regions on the earth where the balloons can stay up for a long period – see Fig.6 – these are mainly the regions of sinking of the Hadley cell where there are no clouds.  This is a big limitation at the moment but we feel that it is worth revisiting the possibilities of flying some solar balloons again to measure the stratosphere more accurately than has been done in the past.

The IR/solar balloons could be the answer. With their low energy consumption they are the best example of green technology for atmospheric sensing! 

Note: Integrated Data Viewer4 (Unidata) [7] was used for most of the plots.


Lodovica Illari acknowledges support from the Frontiers in Earth Science Dynamics (FESD) ‘Ozone and Climate Project’ of the National Science Foundation (US).
Bill McKenna acknowledges support from MIT Center for Art, Science & Technology (CAST) and Prof. Glenn Flierl (EAPS).  Tomás Saraceno has been a Visiting Artist with CAST since 2012.


(1) CNES (MIR)

[1] Montgolfiere InfraRouge:  https://cnes.fr/fr/web/CNES-fr/9276-mir-principes-du-vehicule.php
Letrenne, et al. (1999): French Long Duration Balloon Activity: The Infrared Montgolfiere (MIR), Proceedings AIAA International Balloon Technology Conference, 28 June – 1 July, 1999, Norfolk, VA.

(2) MIT (EAPS)

John Marshall, Susan Solomon, Lodovica Illari. Frontiers in Earth System Dynamics: NSF-funded project on the climate implications of the ozone hole: : http://ozoneandclimate.squarespace.com/

(3) NCEP (Global Forecast System)

GFS: http://www.emc.ncep.noaa.gov/

(4) UCAR (Unidata)

Integrated Data Viewer (IDV): http://www.unidata.ucar.edu/software/idv/