A cool flame: how Gaia theory was born out of a secret love affair

13 09 2024 | 07:34Jonathan Watts

Prof James Lovelock in 2004.Photograph: Tim Cuff/Alamy

Love rarely gets the credit it deserves for the advancement of science. Nor, for that matter, does hatred, greed, envy or any other emotion. Instead, this realm of knowledge tends to be idealised as something cold, hard, rational, neutral and objective, dictated by data rather than feelings. The life and work of James Lovelock is proof that this is neither possible nor desirable. In his work, he helped us understand that humans can never completely divorce ourselves from any living subject because we are interconnected and interdependent, all part of the same Earth system, which he called Gaia.

Our planet, he argued, behaves like a giant organism – regulating its temperature, discharging waste and cycling chemicals to maintain a healthy balance. Although highly controversial among scientists in the 1970s and 80s, this holistic view of the world had mass appeal, which stretched from New Age spiritual gurus to that stern advocate of free-market orthodoxy, Margaret Thatcher. Its insights into the link between nature and climate have since inspired many of the world’s most influential climate scientists, philosophers and environmental campaigners. The French philosopher Bruno Latour said the Gaia Theory has reshaped humanity’s understanding of our place in the universe as fundamentally as the ideas of Galileo Galilei. At its simplest, Gaia is about restoring an emotional connection with a living planet.

While the most prominent academics of the modern age made their names by delving ever deeper into narrow specialisms, Lovelock dismissed this as knowing “more and more about less and less” and worked instead on his own all-encompassing, and thus deeply unfashionable, theory of planetary life.

I first met Lovelock in the summer of 2020, during a break between pandemic lockdowns, when he was 101 years old. In person, he was utterly engrossing and kind. I had long wanted to interview the thinker who somehow managed to be both the inspiration for the green movement, and one of its fiercest critics. The account that follows, of the origins and development of Gaia theory, will probably surprise many of Lovelock’s followers, as it surprised me.

Knowing he did not have long to live, Lovelock told me: “I can tell you things now that I could not say before.” The true nature of the relationships that made the man and the hypothesis were hidden or downplayed for decades. Some were military (he worked for MI5 and MI6 for more than 50 years) or industrial secrets (he warned another employer, Shell, of the climate dangers of fossil fuels as early as 1966). Others were too painful to share with the public, his own family and, sometimes, himself. Even in his darkest moments, Lovelock tended not to dwell on the causes of his unhappiness. He preferred to move on. Everything was a problem to be solved.

What I discovered, and what has been lost in the years since Lovelock first formulated Gaia theory in the 1960s, is that the initial work was not his alone. Another thinker, and earlier collaborator, played a far more important conceptual role than has been acknowledged until now. It was a woman, Dian Hitchcock, whose name has largely been overlooked in accounts of the world-famous Gaia theory.


Lovelock told me his greatest discovery was the biotic link between the Earth’s life and its atmosphere. He envisaged it as a “cool flame” that has been burning off the planet’s excess heat for billions of years. From this emerged the Gaia theory and an obsession with the atmosphere’s relationship with life on Earth. But he could not have seen it alone. Lovelock was guided by a love affair with Hitchcock, an American philosopher and systems analyst, who he met at Nasa’s Jet Propulsion Laboratory (JPL) in California. Like most brilliant women in the male-dominated world of science in the 1960s, Hitchcock struggled to have her ideas heard, let alone acknowledged. But Lovelock listened. And, as he later acknowledged, without Hitchcock, the world’s understanding of itself may well have been very different.

Lovelock had arrived at JPL in 1961 at the invitation of Abe Silverstein, the director of Space Flight Programs at Nasa, who wanted an expert in chromatography to measure the chemical composition of the soil and air on other planets. For the science-fiction junkie Lovelock, it was “like a letter from a beloved. I was as excited and euphoric as if at the peak of passion.” He had been given a front-row seat to the reinvention of the modern world.

California felt like the future. Hollywood was in its pomp, Disneyland had opened six years earlier, Venice Beach was about to become a cradle of youth culture and Bell Labs, Fairchild and Hewlett-Packard were pioneering the computer-chip technology that was to lead to the creation of Silicon Valley. JPL led the fields of space exploration, robotics and rocket technology.

In the 1950s, Wernher von Braun, the German scientist who designed the V-2 rockets that devastated London in the second world war, made JPL the base for the US’s first successful satellite programme. It was his technology that the White House was relying on to provide the thrust for missions to the moon, Mars and Venus. By 1961, the San Gabriel hillside headquarters of JPL had become a meeting place for many of the planet’s finest minds, drawing in Nobel winners, such as Joshua Lederberg, and emerging “pop scientists” like Carl Sagan. There was no more thrilling time to be in the space business.

Lovelock had a relatively minor role as a technical adviser, but he was, he told me, the first Englishman to join the US space programme: the most high-profile, and most lavishly funded, of cold war fronts. Everyone on Earth had a stake in the US-USSR rivalry, but most people felt distant and powerless. Three years earlier, Lovelock had listened on his homemade shortwave radio in Finchley to the “beep, beep, beep” transmission of the USSR’s Sputnik, the first satellite that humanity had put into orbit. Now he was playing with the super powers.


Dian Hitchcock had been hired by Nasa to keep tabs on the work being done at JPL to find life on Mars. The two organisations had been at loggerheads since 1958, when JPL had been placed under the jurisdiction of the newly created civilian space agency, Nasa, with day-to-day management carried out by the California Institute of Technology. JPL’s veteran scientists bristled at being told what to do by their counterparts in the younger but more powerful federal organisation. Nasa was determined to regain control. Hitchcock was both their spy and their battering ram. Lovelock became her besotted ally.

They had first met in the JPL canteen, where Hitchcock introduced herself to Lovelock with a joke: “Do you realise your surname is a polite version of mine?” The question delighted Lovelock. As they got to know one another, he also came to respect Hitchcock’s toughness in her dealings with her boss, her colleagues and the scientists. He later saw her yell furiously at a colleague in the street. “They were frightened of her. Nasa was very wise to send her down,” he recalled. They found much in common. Both had struggled to find intellectual peers throughout their lives.

Hitchcock had grown used to being overlooked or ignored. She struggled to find anyone who would take her seriously. That and her inability to find people she could talk to on the same intellectual level left her feeling lonely. Lovelock seemed different. He came across as something of an outsider, and was more attentive than other men. “I was initially invisible. I couldn’t find people who would listen to me. But Jim did want to talk to me and I ate it up,” she said. “When I find someone I can talk to in depth it’s a wonderful experience. It happens rarely.”

They became not just collaborators but conspirators. Hitchcock was sceptical about JPL’s approach to finding life on Mars, while Lovelock had complaints about the inadequacy of the equipment. This set them against powerful interests. At JPL, the most optimistic scientists were those with the biggest stake in the research. Vance Oyama, an effusively cheerful biochemist who had joined the JPL programme from the University of Houston the same year as Lovelock, put the prospects of life on Mars at 50%. He had a multimillion-dollar reason to be enthusiastic, as he was responsible for designing one of the life-detection experiments on the Mars lander: a small box containing water and a “chicken soup” of nutrients that were to be poured on to Martian soil.

Hitchcock suggested her employer, the Nasa contractor Hamilton Standard, hire Lovelock as a consultant, which meant she wrote the cheques for all his flights, hotel bills and other expenses during trips to JPL. As his former laboratory assistant Peter Simmonds put it, Lovelock was now “among the suits”.

On 31 March 1965, Hitchcock submitted a scathing initial report to Hamilton Standard and its client Nasa, describing the plans of JPL’s bioscience division as excessively costly and unlikely to yield useful data. She accused the biologists of “geocentrism” in their assumption that experiments to find life on Earth would be equally applicable to other planets. She felt that information about the presence of life could be found in signs of order – in homeostasis – not in one specific surface location, but at a wider level. As an example of how this might be achieved, she spoke highly of a method of atmospheric gas sampling that she had “initiated” with Lovelock. “I thought it obvious that the best experiment to begin with was composition of the atmosphere,” she recalled. This plan was brilliantly simple and thus a clear threat to the complicated, multimillion-dollar experiments that had been on the table up to that point.

At a JPL strategy meeting, Lovelock weighed into the debate with a series of withering comments about using equipment developed in the Mojave Desert to find life on Mars. He instead proposed an analysis of gases to assess whether the planet was in equilibrium (lifelessly flatlining) or disequilibrium (vivaciously erratic) based on the assumption that life discharged waste (excess heat and gases) into space in order to maintain a habitable environment. It would be the basis for his theory of a self-regulating planet, which he would later call Gaia.


Lovelock’s first paper on detecting life on Mars was published in Nature in August 1965, under his name only. Hitchcock later complained that she deserved more credit, but she said nothing at the time.

The pair were not only working together by this stage, they were also having a love affair. “Our trysts were all in hotels in the US,” Lovelock remembered. “We carried on the affair for six months or more.” Sex and science were interwoven. Pillow talk involved imagining how a Martian scientist might find clues from the Earth’s atmosphere that our planet was full of life. This was essential for the Gaia hypothesis. Hitchcock said she had posed the key question: what made life possible here and, apparently, nowhere else? This set them thinking about the Earth as a self-regulating system in which the atmosphere was a product of life.

From this revolutionary perspective, the gases surrounding the Earth suddenly began to take on an air of vitality. They were not just life-enabling, they were suffused with life, like the exhalation of a planetary being – or what they called in their private correspondence, the “great animal”. Far more complex and irregular than the atmosphere of a dead planet like Mars, these gases burned with life.

They sounded out others. Sagan, who shared an office with Lovelock, provided a new dimension to their idea by asking how the Earth had remained relatively cool even though the sun had steadily grown hotter over the previous 8bn years. Lewis Kaplan at JPL and Peter Fellgett at Reading University were important early allies and listeners. (Later, the pioneering US biologist Lynn Margulis would make an essential contribution, providing an explanation of how Lovelock’s theory might work in practice at a microbial level.) The long-dead physicist Erwin Schrödinger also provided an important key, according to Lovelock: “I knew nothing about finding life or what life was. The first thing I read was Schrödinger’s What is Life? He said life chucked out high-entropy systems into the environment. That was the basis of Gaia; I realised planet Earth excretes heat.”

In the mid-60s, this was all still too new and unformed to be described as a hypothesis. But it was a whole new way of thinking about life on Earth. They were going further than Charles Darwin in arguing that life does not just adapt to the environment, it also shapes it. This meant evolution was far more of a two-way relationship than mainstream science had previously acknowledged. Life was no longer just a passive object of change; it was an agent. The couple were thrilled. They were pioneers making an intellectual journey nobody had made before.

It was to be the high point in their relationship.


The following two years were a bumpy return to Earth. Lovelock was uncomfortable with the management duties he had been given at JPL. The budget was an unwelcome responsibility for a man who had struggled with numbers since childhood, and he was worried he lacked the street smarts to sniff out the charlatans who were pitching bogus multimillion-dollar projects. Meanwhile, the biologists Oyama and Lederberg were going above his head and taking every opportunity to put him down. “Oyama would come up and say: ‘What are you doing there? You are wasting your time, Nasa’s time,’” Lovelock recalled. “He was one of the few unbearable persons I have known in my life.” In 1966, they had their way, and Lovelock and Hitchcock’s plans for an alternative Mars life-exploration operation using atmospheric analysis were dropped by the US space agency. “I am sorry to hear that politics has interfered with your chances of a subcontract from Nasa,” Fellgett commiserated.

Cracks started to appear in Lovelock’s relationship with Hitchcock. He had tried to keep the affair secret, but lying weighed heavily on him. They could never go to the theatre, concerts or parks in case they were spotted together, but close friends could see what was happening. “They naturally gravitated towards one another. It was obvious,” Simmonds said. When they corresponded, Lovelock insisted Hitchcock never discuss anything but work and science in her letters, which he knew would be opened by his wife, Helen, who also worked as his secretary. But intimacy and passion still came across in discussions of their theories.

Lovelock’s family noticed a change in his behaviour. The previous year, his mother had suspected he was unhappy in his marriage and struggling with a big decision. Helen openly ridiculed his newly acquired philosophical pretensions and way of talking – both no doubt influenced by Hitchcock. “Who does he think he is? A second Einstein?” she asked scornfully. Helen would refer to Hitchcock as “Madam” or “Fanny by Gaslight”, forbade her husband from introducing Hitchcock to other acquaintances, and insisted he spend less time in the US. But he could not stay away, and Helen could not help but fret: “Why do you keep asking me what I’m worried about? You know I don’t like (you) all those miles away. I’m only human, dear, and nervous. I can only sincerely hope by now you have been to JPL and found that you do not have to stay anything like a month. I had a night of nightmares … The bed is awfully big and cold without you.”

So, Lovelock visited JPL less frequently and for shorter periods. Hitchcock filled the physical void by throwing her energy into their shared intellectual work. Taking the lead, she began drafting a summary of their life-detection ideas for an ambitious series of journal papers about exobiology (the study of the possibility of life on other planets) that she hoped would persuade either the US Congress or the British parliament to fund a 100-inch infrared telescope to search planetary atmospheres for evidence of life.

But nothing seemed to be going their way. In successive weeks, their jointly authored paper on life detection was rejected by two major journals: the Proceedings of the Royal Society in the UK and then Science in the US. The partners agreed to swallow their pride and submit their work to the little-known journal Icarus. Hitchcock admitted to feeling downhearted in a handwritten note from 11 November 1966: Enclosed is a copy of our masterpiece, now doubly blessed since it has been rejected by Science. No explanation so I suppose it got turned down by all the reviewers … Feel rather badly about the rejection. Have you ever had trouble like this, publishing anything? … As for going for Icarus, I can’t find anybody who’s even heard of the journal.”

Hitchcock refused to give up. In late 1966 and early 1967, she sent a flurry of long, intellectually vivacious letters to Lovelock about the papers they were working on together. Her correspondence during this period was obsessive, hesitant, acerbic, considerate, critical, encouraging and among the most brilliant in the Lovelock archives. These missives can be read as foundation stones for the Gaia hypothesis or as thinly disguised love letters.

In one she lamented that they were unable to meet in person to discuss their work, but she enthused about how far their intellectual journey had taken them. “I’m getting rather impressed with us as I read Biology and the Exploration of Mars – with the fantastic importance of the topic. Wow, if this works and we do find life on Mars we will be in the limelight,” she wrote. Further on, she portrayed the two of them as explorers, whose advanced ideas put them up against the world, or at least against the senior members of the JPL biology team.

The most impressive of these letters is a screed in which Hitchcock wrote to Lovelock with an eloquent summary of “our reasoning” and how this shared approach went beyond mainstream science. “We want to see whether a biota exists – not whether single animals exist,” she said. “It is also the nature of single species to affect their living and non-living environments – to leave traces of themselves and their activity everywhere. Therefore we conclude that the biota must leave its characteristic signature on the ‘non-living’ portions of the environment.” Hitchcock then went on to describe how the couple had tried to identify life, in a letter dated 13 December 1966:

We started our search for the unmistakable physical signature of the terrestrial biota, believing that if we found it, it would – like all other effects of biological entities – be recognisable as such by virtue of the fact that it represents ‘information’ in the pure and simple sense of a state of affairs which is enormously improbable on non-biological grounds … We picked the atmosphere as the most likely residence of the signature, on the grounds that the chemical interactions with atmospheres are probably characteristic of all biotas. We then tried to find something in our atmosphere which would, for example, tell a good Martian chemist that life exists here. We made false starts because we foolishly looked for one giveaway component. There are none. Came the dawn and we saw that the total atmospheric mixture is a peculiar one, which is in fact so information-full that it is improbable. And so forth. And now we tend to view the atmosphere almost as something itself alive, because it is the product of the biota and an essential channel by which elements of the great living animal communicate – it is indeed the milieu internal which is maintained by the biota as a whole for the wellbeing of its components. This is getting too long. Hope it helps. Will write again soon.”

With hindsight, these words are astonishingly prescient and poignant. Their view of the atmosphere “almost as something itself alive” was to become a pillar of Gaia theory. The connection between life and the atmosphere, which was only intuited here, would be firmly established by climatologists. It was not just the persuasiveness of the science that resonates in this letter, but the intellectual passion with which ideas are developed and given lyrical expression. The poetic conclusion – “came the dawn” – reads as a hopeful burst of illumination and a sad intimation that their night together may be drawing to a close.


Their joint paper, “Life detection by atmospheric analysis”, was submitted to Icarus in December 1966. Lovelock acknowledged it was superior to his earlier piece for Nature: “Anybody who was competent would see the difference, how the ideas had been cleared up and presented in a much more logical way.” He insisted Hitchcock be lead author. Although glad to have him on board because she had never before written a scientific paper and would have struggled to get the piece published if she had put it solely under her name, she told me she had no doubt she deserved most of the credit: “I remember when I wrote that paper, I hardly let him put a word in.”

The year 1967 was to prove horrendous for them both, professionally and personally. In fact, it was a dire moment for the entire US space programme. In January, three astronauts died in a flash fire during a test on an Apollo 204 spacecraft, prompting soul-searching and internal investigations. US politicians were no longer willing to write blank cheques for a race to Mars. Public priorities were shifting as the Vietnam war and the civil rights movement gained ground, and Congress slashed the Nasa budget.

The affair between Hitchcock and Lovelock was approaching an ugly end. Domestic pressures were becoming intense. Helen was increasingly prone to illness and resentment. On 15 March 1967, she wrote to Lovelock at JPL to say: “It seems as if you have been gone for ages,” and scornfully asked about Hitchcock: “Has Madam arrived yet?” Around this time, Lovelock’s colleague at JPL, Peter Simmonds, remembered things coming to a head. “He strayed from the fold. Helen told him to ‘get on a plane or you won’t have a marriage’ or some such ultimatum.”

Lovelock was forced into an agonising decision about Hitchcock. “We were in love with each other. It was very difficult. I think that was one of the worst times in my life. [Helen’s health] was getting much worse. She needed me. It was clear where duty led me and I had four kids. Had Helen been fit and well, despite the size of the family, it would have been easier to go off.” Instead, he decided to ditch Hitchcock. “I determined to break it off. It made me very miserable … I just couldn’t continue.”

The breakup, when it finally came, was brutal. Today, more than 50 years on, Hitchcock is still pained by the way things ended. “I think it was 1967. We were both checking into the Huntington and got rooms that were separated by a conference room. Just after I opened the door, a door on the opposite side was opened by Jim. We looked at each other and I said something like: ‘Look, Jim, this is really handy.’ Whereupon he closed the door and never spoke to me again. I was shattered. Probably ‘heartbroken’ is the appropriate term here. He didn’t give me any explanation. He didn’t say anything about Helen. He just dropped me. I was puzzled and deeply hurt. It had to end, but he could have said something … He could not possibly have been more miserable than I was.”

Hitchcock was reluctant to let go. That summer, she sent Lovelock a clipping of her interview with a newspaper in Connecticut, below the headline “A Telescopic Look at Life on Other Planets”, an article outlining the bid she and Lovelock were preparing in order to secure financial support for a telescope. In November, she wrote a memo for her company detailing the importance of her continued collaboration with Lovelock and stressing their work “must be published”.

But the flame had been extinguished. The last record of direct correspondence between the couple is an official invoice, dated 18 March 1968, and formally signed “consultant James E Lovelock”. Hitchcock was fired by Hamilton Standard soon after. “They were not pleased that I had anything at all to do with Mars,” she recalled. The same was probably also true for her relationship with Lovelock.

The doomed romance could not have been more symbolic. Hitchcock and Lovelock had transformed humanity’s view of its place in the universe. By revealing the interplay between life and the atmosphere, they had shown how fragile are the conditions for existence on this planet, and how unlikely are the prospects for life elsewhere in the solar system. They had brought romantic dreams of endless expansion back down to Earth with a bump.

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