A Sky Looming With Danger

Something’s in the air these days. Or so Steven tells me. He was recently back east from California — which was still smoldering from the wildfires — and we were talking about the dry weather. Abruptly, with deadpan seriousness, he said: “You know they’re putting stuff in the air, right?”

No, I told him. I didn’t know.

“That’s why the weather’s been so weird,” he said. “The government’s putting chemicals in the air. You should look it up later.”

I didn’t look it up later, or at least not in the sense that Steven wanted. Most people are familiar with this conspiracy theory. The idea that planes secretly spray the sky with chemicals has been around since the 1990s. It seems to be getting worse, causing threats of violence and reaching the highest levels of government, gaining momentum with every storm or climate-driven disaster. 

When Hurricanes Helene and then Milton hit in the autumn of 2024, pundits across social media began speculating that the storms were the product of climatic engineering. Meteorologists attempting to warn local residents even received death threats for supposedly obscuring the government’s role in weather manipulation. Last August, Robert F. Kennedy Jr. responded to a tweet about chemtrails, saying: “We are going to stop this crime.” This year, as the newly minted secretary of health and human services, he said that he suspects these chemicals are being infused into jet fuel by DARPA. Meanwhile, legislators in states like Florida and Alabama have attempted to ban nonexistent chemtrail geoengineering practices.

Attempts by mainstream commentators to make sense of these persistent conspiracies have tended to characterize them as either stubborn fantasy — “beyond ridiculous,” as Joe Biden put it in an address — or the product of a muddied and fractured media landscape. Yet the rampant misinformation, shameless politicians and profit-driven platforms amplifying these narratives fail to fully explain the allure of these conspiracies. 

Conflicting beliefs about the nature of the air predate digital echo chambers and modern environmental disasters. If we look further back, we can begin to develop a deeper understanding of what these aerial controversies really are: not mere delusions to be brushed off or misunderstandings to be fact-checked, not just dangerous misconceptions potentially leading to violent acts. Ultimately, they are the expression of a tension in how humans materialize the world itself.

The Conspiracy Of The Vacuum

The arc of the 17th century was marked by volatile change. The Treaty of Westphalia closed off the Thirty Years’ War and established the foundations for modern statehood. New perceptual technologies like the telescope challenged ideas of the cosmos that had been taken as fact for centuries. Civil war broke out in England, followed by a tenuous peace that threatened to topple over in the slightest breeze. 

At the eye of this storm was a now largely forgotten debate about the air, one revolving around a “conspiratorial” belief concerning what was (or, more accurately, wasn’t) in it. Eventually, this debate catalyzed an entirely new way of understanding the world.

The controversy began with a deceptively simple experiment conducted in the 1640s by Evangelista Torricelli. An Italian physicist, Torricelli took a tube full of liquid mercury that was closed on one end and open on the other and submerged the open end in a dish containing the same liquid. Instead of the mercury in the tube doing nothing, as people generally expected at the time, the mercury in the tube started to fall. But it didn’t completely evacuate the tube. Left behind was a suspended column of liquid with a seemingly empty space hovering above it. 

Torricelli had taken thorough precautions — no air bubbles in the tube beforehand, so trapped air in the mercury didn’t explain where the empty space in the tube had come from. Where there was once something, there now appeared to be nothing. A void had appeared from nowhere.

That void ignited a fierce debate among scientists and intellectuals. “Nature abhors a vacuum,” Aristotle had insisted almost 2,000 years before, a pronouncement that had held sway in the court of philosophical thought ever since. The idea of a nothing-something — a void — was considered a metaphysical impossibility. There was even a shorthand to refer to the idea: horror vacui — the horror of the vacuum. 

Natural philosophers across Europe struggled to reconcile this idea with the mystifying space that hovered above the mercury column in Torricelli’s tube. Some speculated that it must be a small pocket of expanded air, not a true vacuum; others, including René Descartes, predicted that it contained something called “subtle matter,” an infinitesimally minuscule substance thought to exist between observable bodies. Thomas Hobbes argued it was something similar, a pure ethereal fluid that made its way into the tube through the mercury, like smoke passing through water. Though the gap appeared empty, it was not, he argued, a true vacuum. In fact, as historians Simon Schaffer and Steven Shapin write in their book “Leviathan and the Air Pump,” Hobbes thought the idea of a vacuum itself wasn’t just “absurd and wrong … it was dangerous.”

Hobbes’ broader concern extended beyond scientific debate and is still familiar today: How can universal truths be established and defended in a competitive political landscape where control over a narrative comes with significant power? For Hobbes, there was no better model for realizing truth than geometry, which he referred to in “Leviathan” as “the only science that it hath pleased God hitherto to bestow on mankind.” The discipline showed how one could proceed from clearly defined principles and follow the chain of causes to their universal and necessary conclusions, thereby establishing stabilizing knowledge that compelled any rational person to agree. In contrast, experiments like Torricelli’s were too liable to individual interpretation and mistake to ground assent. It was rigorous rationalism alone that had the authority required to avoid the kind of conflicted concepts that gave rise to anarchy.

The political ramifications of such non-rational thought, like believing vacuums could exist, were clear to Hobbes: It threatened the unity of the state. Hobbes believed that dualist metaphysics, which allowed for non-material entities like vacuums and souls, gave interest groups like priests the leverage to establish themselves as alternative authorities to the civil sovereign. In this sense, belief in a vacuum was a political conspiracy: a deviant act that defied the authority of reason and undermined the unity of the state. As Shaffer and Shapin conclude, “for Hobbes, the rejection of vacuum was the elimination of a space within which dissension could take place.” At stake was nothing less than the thin barrier keeping order from chaos.

The Conspiracy That Became Science

While Hobbes was responding to uncertainty about both political unity and the nature of air by carefully constructing an epistemology based on first principles and rational law, one of his countrymen was leading the vanguard to develop an entirely alternative approach to truth. Along with other members of the Royal Society, Robert Boyle sought to establish “matters of fact” that could serve as the shared basis of inquiry. Though one might disagree on the interpretations and causes behind the facts, the facts themselves would be iron-clad, the testimony of nature itself. Critically, these facts wouldn’t be established through armchair theorizing, but experiments that would be observed by a credible audience and whose results would be circulated in a network of journals. It was, in short, the origin of modern science.

In “New Experiments Physico-Mechanical, Touching the Spring of the Air and its Effects,” Boyle demonstrated this system in practice. As its title suggests, air served as the central protagonist in the illustration of this new method. These experiments were made possible by the recently developed air pump, which allowed air to be pumped out of a glass container, removing it as a variable in a testing environment for the first time. Though it was an inordinately costly piece of technology and prone to breakdowns, the son of the Earl of Cork had money to spare, and the device became central to the nascent project of scientific experimentation. 

Famously, Boyle placed the Torricellian apparatus in this container and removed the air inside. As he did so, he observed the level of mercury in the column drop. But rather than seeking to support or refute the existence of a metaphysical vacuum as others had done, he sidestepped the question altogether. The problem with that line of thinking, he argued, was that the answer hinged on concepts that could never be truly defined. He proposed instead to identify operationally and experimentally what was happening in front of him. For Boyle, this experiment worked even if the vacuum wasn’t a space “wherein there is no Body at all,” but merely one that is “almost totally devoid of Air.” What mattered to him was that a phenomenon was testable and measurable, and a testable and measurable vacuum — “not in the strict and Philosophical sense, but in that more obvious and familiar one” — did indeed really exist inside that tube half full of mercury. 

It was a deceptively subtle maneuver with profound, revolutionary consequences. Boyle urged readers to bracket scientific reality to those entities that could be subject to experimental observation and debate. Anything that didn’t fit into this program (like Hobbes’ pure ethereal fluid or absolute vacuum) was rendered an inconsequential non-entity in this new ontology, outside the purview of physics proper. Knowledge about mysterious substances would be produced through controlled and mechanically enabled experiments, not rationalist analysis. This, too, came with political implications. If Hobbes’ philosophy was based on compulsion and unity — singular concepts, singular rulers, an epistemology oriented toward absolute certainty — then Boyle’s arose from a quasi-parliamentary process of experiment, consensus and revision.

Hobbes vociferously critiqued Boyle’s approach as non-philosophical. Of Boyle and the empiricists, Hobbes wrote that “they display new machines, to show their vacuum. … All of them are my enemies.” Yet Boyle’s empiricism eventually won out. Scientific reality became normalized as reality. From this point on, our understanding of the world was to be structured around experimental observability, and concepts like air and vacuum would be valid to the extent that they were observable through an experimental process, not to the extent that they could be “proven” by first principles. The vacuum, once seen as a conspiracy against authority by Hobbes, thus became a central component of the modern scientific era, familiar and self-evident.

Air, A Social Medium

Both now and then, the question of what is or isn’t in the air is under a spotlight amid political turmoil and social fracture. Air is a magnetic medium for people’s conflicted thoughts and suspicions to express themselves, a blank canvas upon which assumptions about the world and our role in it can be projected. 

Air is simultaneously everywhere and nowhere; though we’re constantly surrounded by it, we can’t observe it in the way we can a falling stone or a soaring arrow. In order for us to come to know air, we must first delimit and capture it — materialize it in some particular way. This process of materialization is always entangled in a meshwork of technologies, institutions, concepts and ideologies.

As Shaffer and Shapin put it, “Leviathan’s truth and the truth of the air-pump are products of different forms of social life.” It wasn’t a case of misinformation running rampant on one side or the other; it was a debate on the process and institutions and “forms of social life” that generated and legitimated information. For Hobbes, air emerged from the necessary maneuvers of the rational mind, yielding pure ether as ubiquitous and unassailable as the reign of the sovereign. In contrast, Boyle defined air as the subject of experimental inquiry, delimited by what could be observed and made real through shared witnessing. Boyle’s insistence on the reality of the vacuum was more than a minor shift in definition; it was a critique of the centralized and absolute “forms of social life” that constituted Hobbes’ approach to the world at large.

Today’s conspiracies about the air, if not conspiracies in general, are similarly products of the forms of social life that make up our technological and cultural relationship with the world. It’s not a coincidence that the conspiracies circulating about what’s in the air today emerge from a fear of atmospheric manipulation. It is the air’s capacity to be manipulated and instrumentalized that helps make sense of the subterranean concerns fueling these conspiracies.

Clouds That Kill

According to the philosopher Peter Sloterdijk, the 20th century’s form of life also began with the air. Sloterdijk puts the moment at 6 p.m. on April 22, 1915, near Ypres, when a German regiment under the command of Col. Max Peterson unleashed chlorine gas in warfare for the first time. Previously, violence in war had been directed at the human body; this attack targeted the “living organism’s immersion in a breathable milieu,” as Sloterdijk writes in “Terror From The Air.” “Instead of aiming at the soldiers … it targeted the air.” As troops were engulfed by this deadly atmosphere, they began to foam at the mouth, spit blood and die. What was once a background feature of the environment was thus “explicated,” transformed into a discrete resource that could be mobilized toward strategic ends.

Sloterdijk urges us to recognize how air is materialized as functional, extractable, manipulable, subject to human intervention. By situating the birth of the 20th century in this moment of terror, he suggests that we are not the inheritors of Boyle’s experimental worldview as much as Col. Peterson’s instrumentalized, manipulated, weaponized air.

Directly descended from the weaponization of the air during WWI, but more inclined toward planetary flourishing than death and destruction, is geoengineering. At their core, geoengineering proposals take the logic of aerial manipulation established at Ypres and direct it at the enemy of climate change — chemical interventions against atmospheric phenomena. As the science historian James Rodger Fleming puts it: “If something is wrong with the sky, shoot at it.” 

A few years ago, a startup called Make Sunsets launched three balloons full of helium and sulfur dioxide gas into the sky over Baja California. As the balloons reached a sufficient altitude, they popped, and the gas interacted with water vapor to turn into particles that deflected sunlight and heat away from Earth. 

In theory, these particles would offset a year’s worth of emissions from 175 gasoline-powered cars, at least according to Make Sunsets’ own estimates. Since then, they’ve gone on to release a total of 194 balloons (supposedly offsetting 175,162 metric tons of CO2). These unregulated stunts draw criticism from scientists and climate activists alike; the long-term effect of injecting sulfur dioxide into the atmosphere remains unknown. One initiative to ban solar geoengineering says such efforts are an “unacceptable risk if ever implemented as part of future climate policy.” 

But it’d be a mistake to think that the Make Sunsets is and will be alone in planning and executing such an enterprise, nor is it the only case where those with the political weight and resources to achieve large-scale environmental modification do so on their own, without regard or input from those who might suffer deleterious effects downwind. There is a growing “pay to breathe” industry, for example, which transforms clean air into a luxury good to be enjoyed by a privileged few. Even ubiquitous technologies like the air conditioner take for granted the on-demand production of “cool” air in response to a growing heat crisis, eliding the ways in which these energy-intensive techniques contribute to the very condition they’re designed to alleviate.

Uniting these diverse technologies is an understanding of air as a resource that can be manipulated and utilized through human intervention — as another thing to be manufactured, manipulated, sold and deployed under our aegis. But treating the air like a malleable medium neglects all the ways that it eludes our control, exceeds us at every turn. In materializing air as an instrument that we presume to bend to our will, we set ourselves up for failure. The consequences for this mistake can be fatal.

Shortly after Col. Peterson’s first launch of chlorine gas at Ypres, the British deployed it at Loos. This time, however, the air didn’t cooperate. Wind blew the gas back at the British lines or stopped it short in no-man’s land. Chaos ensued. In a letter to his fiancée, one soldier recounted that “the gas hung in a thick pall over everything. … In vain I looked for my landmarks … but I could not see through.” By the end of the battle, British casualties were double the number of their German counterparts, and the commanding field marshal was forced to resign.

Rediscovering Air

The ecotheorist Donna Haraway once wrote that in matters of worldmaking, it matters “what thoughts think thoughts.” Concepts of the air arise through processes that are technological, political and historical. Conspiracy theorists, and some geoengineers, steeped in different pools of thought in a wider techno-culture, imagine quick-fix solutions to problems with the air, and they wage war on the sky. If we fear the air, then it is because we fear the culture that brings this air to life.

The reality of the air, and the world, is far more complex than the chemtrail conspiracists imagine. The cause of the world’s ills is not simple, discrete and contained; getting rid of nonexistent chemicals in jet fuel and the nonexistent shadowy government entity sponsoring them won’t stop the hurricanes or the floods or the pollution in our air.

In Ancient Greek, pneuma stood for both air and spirit; the Chinese qi was a life force that was also a moving air. In Sanskrit, ātman elides the self with breath. Across disparate cultures and epochs, air was considered akin to being itself. One couldn’t get far enough away from air to own and control it since one was constantly immersed in its movements. Discussing the teachings of Tibetan scholar Tarthang Tulku, the philosopher David M. Levin writes about the idea of a “body of breathing [extending] its awareness to the outermost atmosphere.” Air was and is a medium that binds people together with others — a force that helps us all recognize the dependencies we share and project our awareness to the scale of a world.

The funny thing is — there is something in the air. The chemtrail conspiracists are not wrong to sense encroaching asphyxiation, a sky looming with danger. The geoengineers are also not wrong to consider ways to use technology to address the rapid carbonization of the atmosphere. 

But this is not the first time we’ve been unsettled by the ghostly spectres haunting the air, and studying our past allows us to see how tensions emerge from the conceptual and social formations by which we make sense of the world. Centuries ago, Torricelli’s controversial experiment changed our understanding of the nature of air, and in so doing, opened us up to possibilities that were once unimaginable. It is thanks to his radical work that we now can talk of atmospheric pressure, forecast the weather and navigate the aircraft soaring on the “ocean of air” he envisioned around us. 

Weathering the storm ahead requires a similar revolution that recognizes the scale of the problem and the scale of the requisite response; nothing less will do. There are no silver bullet solutions, no chemtrails that, if ceased, would solve everything. What’s in the air is what humanity put there — not only pollutants and chemicals, but social narratives and systems of knowledge. As a result, we’ve destabilized the entire planet and its atmosphere — but also revealed how to reestablish balance, even if it’s an effort of monumental magnitude.