Winston Churchill, British prime minister and one of history’s most influential statesmen, was undoubtedly a man with weighty questions on his mind. How best to save the British Empire? he must have mused. What will the postwar world look like? he surely wondered. But the legendary leader also focused his prodigious mind on less pragmatic questions. For instance: Is there life on other planets?
In fact, in 1939, Churchill penned a lengthy essay on this very topic, which was never published. Besides displaying a strong grasp of contemporary astrophysics and a scientific mind, he came to a breathtaking conclusion: We are probably not alone in the universe. The long-lost piece of Churchilliana has just floated up to the surface again, thanks to an article written by astrophysicist Mario Livio in this week's edition of the journal Nature analyzing Churchill's work.
“With hundreds of thousands of nebulae, each containing thousands of millions of suns, the odds are enormous that there must be immense numbers which possess planets whose circumstances would not render life impossible,” Churchill concluded in his essay. He wrote these words on the eve of World War II—more than half a century before exoplanets were discovered.
Until last year, Churchill's thoughts on the problem of alien life had been all but lost to history. The reason: His 11-page typed draft was never published. Sometime in the late 1950s, Churchill revised the essay while visiting the seaside villa of publisher Emery Reves, but the text still didn't see the light of day. It appears to have languished in the Reves house until Emery's wife Wendy gave it to the U.S. National Churchill Museum during the 1980s.
Last year, the museum’s new director, Timothy Riley, unearthed the essay in the museum's archives. When astrophysicist Mario Livio happened to visit the museum, Riley "thrust [the] typewritten essay" into his hands, Livio writes in Nature. Riley was eager to hear the perspective of an astrophysicist. And Livio, for his part, was floored. “Imagine my thrill that I may be the first scientist to examine this essay,” he writes in Nature.
Churchill did his homework, Livio reports. Though he probably didn't pore over peer-reviewed scientific literature, the statesman seems to have read enough, and spoke with enough top scientists—including the physicist Frederick Lindemann, his friend and later his official scientific adviser—to have had a strong grasp of the major theories and ideas of his time. But that wasn't what left the deepest impression on Livio.
“To me the most impressive part of the essay—other than the fact that he was interested in it at all, which is pretty remarkable—is really the way that he thinks,” Livio says. “He approached the problem just as a scientist today would. To answer his question 'Are we alone in the universe?' he started by defining life. Then he said, 'OK, what does life require? What are the necessary conditions for life to exist?'”
Churchill identified liquid water, for example, as a primary requirement. While he acknowledged the possibility that forms of life could exist dependent on some other liquid, he concluded that “nothing in our present knowledge entitles us to make such an assumption.”
"This is exactly what we still do today: Try to find life by following the water,” Livio says. “But next, Churchill asked 'What does it take for liquid water to be there?' And so he identified this thing that today we call the habitable zone.”
By breaking down the challenge into its component parts, Churchill ended up delving into the factors necessary to create what is now known as the “Goldilocks zone” around a star: that elusive region in which a life-sustaining planet could theoretically exist. In our own solar system, he concluded, only Mars and Venus could possibly harbor life outside of Earth. The other planets don't have the right temperatures, Churchill noted, while the Moon and asteroids lack sufficient gravity to trap gasses and sustain atmospheres.
Turning his gaze beyond our own solar system raised even more possibilities for life, at least in Churchill's mind. “The sun is merely one star in our galaxy, which contains several thousand millions of others,” he wrote. Planetary formation would be rather rare around those stars, he admitted, drawing on a then-popular theory of noted physicist and astronomer James Jeans. But what if that theory turned out to be incorrect? (In fact, it has now been disproven.)
“That's what I find really fascinating,” Livio notes. “The healthy skepticism that he displayed is remarkable.”
Churchill suggested that different planetary formation theories may mean that many such planets may exist which “will be the right size to keep on their surface water and possibly an atmosphere of some sort.” Of that group, some may also be “at the proper distance from their parent sun to maintain a suitable temperature.”
The statesman even expected that some day, “possibly even in the not very distant future,” visitors might see for themselves whether there is life on the moon, or even Mars.
But what was Winston Churchill doing penning a lengthy essay on the probability of alien life in the first place? After all, it was the eve of a war that would decide the fate of the free world, and Churchill was about to become Prime Minister of the United Kingdom.
Such an undertaking was actually quite typical for Churchill, notes Andrew Nahum, Keeper Emeritus at the Science Museum, London, because it reflects both his scientific curiosity and his recurring need to write for money. It was skill with the pen that often supported Churchill and his family's lavish lifestyle (recall that he won the 1953 Nobel Prize for Literature, with a monetary award of 175,293 Swedish Kroner worth about $275,000 today).
“One recent biography is entitled No More Champagne: Churchill And His Money,” Nahum says. “That was a phrase he put into a note to his wife about austerity measures. But he didn't know much about austerity. He liked luxury so he wrote like crazy, both books and articles that his agent circulated widely.”
That’s not to say that Churchill was simply slinging copy about aliens for a paycheck. “He was profoundly interested in the sciences and he read very widely,” notes Nahum, who curated the 2015 Science Museum exhibition “Churchill's Scientists.” Nahum relates the tale of how as Chancellor of the Exchequer, Churchill was once sent a book on quantum physics, and later admitted that it had occupied him for the better part of a day that should have been spent balancing the British budget.
He not only read scientific content voraciously, but wrote on the topic as well. In a 1924 issue of Nash's Pall Mall Magazine, Churchill anticipated the power of atomic weapons. “Might not a bomb no bigger than an orange be found to possess secret power to destroy a whole block of buildings nay, to blast a township at a stroke?” he warned. In 1932, he anticipated the rise of test-tube meat in the magazine Popular Mechanics: “Fifty years hence, we shall escape the absurdity of growing a whole chicken in order to eat the breast or the wing, by growing these parts separately in a suitable medium,” he wrote.
In 1939 he authored three essays, tackling not just extraterrestrial life but the evolution of life on Earth and the popular biology of the human body. Two were published during 1942 by the Sunday Dispatch, Nahum discovered when reading Churchill's papers at the University of Cambridge. It remains a mystery why his thoughts on alien life went unpublished.
In the rediscovered essay, Churchill admits that, because of the great distances between us and other planet-harboring stars, we may never know if his hunch that life is scattered among the vastness of the cosmos is correct. Yet even without proof, Churchill seems to have convinced himself that such a possibility was likely—perhaps by swapping his scientific mind for one more finely attuned to the human condition during the troubled 20th century.
“I, for one, am not so immensely impressed by the success we are making of our civilization here that I am prepared to think we are the only spot in this immense universe which contains living, thinking creatures,” he wrote, “or that we are the highest type of mental and physical development which has ever appeared in the vast compass of space and time.”
Seventy-five years after Churchill's bold speculations, there's still no proof that life exists on other worlds. But, as was often the case, his analysis of our own still seems prescient.
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About Brian Handwerk
Winston Churchill is best known as a wartime leader, one of the most influential politicians of the twentieth century, a clear-eyed historian and an eloquent orator. He was also passionate about science and technology.
Aged 22, while stationed with the British Army in India in 1896, he read Darwin's On the Origin of Species and a primer on physics. In the 1920s and 1930s, he wrote popular-science essays on topics such as evolution and cells in newspapers and magazines. In a 1931 article in The Strand Magazine entitled 'Fifty Years Hence'1, he described fusion power: “If the hydrogen atoms in a pound of water could be prevailed upon to combine together and form helium, they would suffice to drive a thousand-horsepower engine for a whole year.” His writing was likely to have been informed by conversations with his friend and later adviser, the physicist Frederick Lindemann.
Noah Baker finds out about Winston Churchill’s close relationship with science.
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During the Second World War, Churchill supported the development of radar and Britain's nuclear programme. He met regularly with scientists such as Bernard Lovell, the father of radio astronomy. An exchange about the use of statistics to fight German U-boats captures his attitude. Air Chief Marshal Arthur 'Bomber' Harris complained, “Are we fighting this war with weapons or slide rules?” Churchill replied, “Let's try the slide rule.”2
He was the first prime minister to employ a science adviser, hiring Lindemann in the early 1940s. The science-friendly environment that Churchill created in the United Kingdom through government funding of laboratories, telescopes and technology development spawned post-war discoveries and inventions in fields from molecular genetics to X-ray crystallography.
Despite all this, it was a great surprise last year, while I was on a visit to the US National Churchill Museum in Fulton, Missouri, when the director Timothy Riley thrust a typewritten essay by Churchill into my hands. In the 11-page article, 'Are We Alone in the Universe?', he muses presciently about the search for extraterrestrial life.
He penned the first draft, perhaps for London's News of the World Sunday newspaper, in 1939 — when Europe was on the brink of war. He revised it lightly in the late 1950s while staying in the south of France at the villa of his publisher, Emery Reves. For example, he changed the title from 'Are We Alone in Space?' to 'Are We Alone in the Universe?' to reflect changes in scientific understanding and terminology. Wendy Reves, the publisher's wife, passed the manuscript to the US National Churchill Museum archives in the 1980s.
Riley, who became director of the museum in May 2016, has just rediscovered it. To the best of Riley's knowledge, the essay remained in the Reves's private collection and has never been published or subjected to scientific or academic scrutiny. Imagine my thrill that I may be the first scientist to examine this essay.
Here I outline Churchill's thinking. At a time when a number of today's politicians shun science, I find it moving to recall a leader who engaged with it so profoundly.
Churchill's reasoning mirrors many modern arguments in astrobiology. In essence, he builds on the framework of the 'Copernican Principle' — the idea that, given the vastness of the Universe, it is hard to believe that humans on Earth represent something unique. He starts by defining the most important characteristic of life — in his view, the ability to “breed and multiply”. After noting that some viruses can be crystallized, making them hard to categorize, he decides to concentrate on “comparatively highly-organised life”, presumably multicellular life.
His first point is that “all living things of the type we know require water”. Bodies and cells are largely composed of it, he notes. Other liquids cannot be ruled out but “nothing in our present knowledge entitles us to make such an assumption”. The presence of water in liquid form still guides our searches for extraterrestrial life: on Mars, on the moons of Saturn and Jupiter or on extrasolar planets (beyond our Solar System). As well as being essential for the emergence of life on Earth, water is abundant in the cosmos. This wonderfully universal solvent — almost every substance can dissolve in it — can transport such chemicals as phosphates into and out of cells.
Churchill then defines what is known today as the habitable zone — that narrow 'Goldilocks' region around a star that is neither too cold nor too hot, so that liquid water may exist on the surface of a rocky planet. He writes that life can survive only in regions “between a few degrees of frost and the boiling point of water”. He explains how Earth's temperature is fixed by its distance from the Sun. Churchill also considers the ability of a planet to retain its atmosphere, explaining that the hotter a gas is, the faster its molecules are moving and the more easily they can escape. Consequently, stronger gravity is necessary to trap gas on a planet in the long term.
Taking all these elements together, he concludes that Mars and Venus are the only places in the Solar System other than Earth that could harbour life. He eliminates the outer planets (too cold); Mercury (too hot on the sunny side and too cold on the other); and the Moon and asteroids (their gravities are too weak to trap atmospheres).
Churchill began his essay not long after the 1938 US broadcast of the radio drama The War of The Worlds (an adaptation of H. G. Wells's 1898 story) had generated 'Mars fever' in the media. Speculation over the existence of life on the red planet had been going on since the late nineteenth century. In 1877, Italian astronomer Giovanni Schiaparelli described seeing linear marks on Mars (canali; mistranslated as canals) that were thought to be constructed by some civilization. These turned out to be optical illusions but the idea of Martians stuck. Science-fiction stories abounded, culminating with Ray Bradbury's The Martian Chronicles (Doubleday, 1950), published in the United Kingdom as The Silver Locusts (Rupert Hart-Davis, 1951).
Churchill's essay next assesses the probability that other stars host planets. He reasons that “the sun is merely one star in our galaxy, which contains several thousand millions of others”. Churchill assumes that planets are formed from the gas that is torn off a star when another star passes close to it — a model suggested by astrophysicist James Jeans in 1917, which has since been ruled out. He infers that, because such close encounters are rare, “our sun may be indeed exceptional, and possibly unique”.
Now Churchill shines. With the healthy scepticism of a scientist, he writes: “But this speculation depends upon the hypothesis that planets were formed in this way. Perhaps they were not. We know there are millions of double stars, and if they could be formed, why not planetary systems?”
Indeed, the present-day theory of planet formation — the build up of a rocky planet's core by the accretion of many small bodies — is very different from Jeans's. Churchill writes: “I am not sufficiently conceited to think that my sun is the only one with a family of planets.”
Thus, he concludes, a large fraction of extrasolar planets “will be the right size to keep on their surface water and possibly an atmosphere of some sort” and some will be “at the proper distance from their parent sun to maintain a suitable temperature”.
This was decades before the discoveries of thousands of extrasolar planets began in the 1990s, and years before astronomer Frank Drake presented his probabilistic argument for the rarity of communicating civilizations in the cosmos in 1961. Extrapolating data from the Kepler Space Observatory suggests that the Milky Way probably contains more than a billion Earth-size planets in the habitable zones of stars that are the size of the Sun or smaller3.
Reflecting on the enormous distances involved, Churchill concludes that we may never know whether such planets “house living creatures, or even plants”.
Churchill sees great opportunity for exploration in the Solar System. “One day, possibly even in the not very distant future, it may be possible to travel to the moon, or even to Venus or Mars,” he writes. By contrast, he notes, interstellar travel and communication are intrinsically difficult. He points out that it would take light some five years to travel even to the nearest star and back, adding that the nearest large spiral galaxy to the Milky Way (Andromeda — one of the “spiral nebulae”, as he calls them) is more than several hundred thousand times as far away as the nearest stars.
The essay finishes eagerly: “with hundreds of thousands of nebulae, each containing thousands of millions of suns, the odds are enormous that there must be immense numbers which possess planets whose circumstances would not render life impossible.” Here Churchill shows that he was familiar with the findings of astronomer Edwin Hubble in the late 1920s and early 1930s, who discovered that there are many galaxies beyond the Milky Way (about 2 trillion, according to a recent estimate4).
Taking a bleaker turn that reflects his times, Churchill adds: “I, for one, am not so immensely impressed by the success we are making of our civilization here that I am prepared to think we are the only spot in this immense universe which contains living, thinking creatures, or that we are the highest type of mental and physical development which has ever appeared in the vast compass of space and time.”
Almost 80 years later, the question that obsessed Churchill is one of the hottest topics of scientific research. Searches for signs of subsurface life on Mars are ongoing. Simulations of Venus's climate hint that it may once have been habitable5. Astronomers believe that, in a few decades, we will discover some biological signatures of present or past life in the atmospheres of extrasolar planets, or at least be able to constrain its rarity6.
Churchill's essay is testament to how he saw the fruits of science and technology as essential for society's development. When he helped to establish Churchill College at the University of Cambridge, UK, in 1958, he wrote7: “It is only by leading mankind in the discovery of new worlds of science and engineering that we shall hold our position and continue to earn our livelihood.”
Yet he was also concerned that without understanding the humanities, scientists might operate in a moral vacuum. “We need scientists in the world but not a world of scientists,” he said8. In order for science to be “the servant and not the master of man”, he felt that appropriate policies that drew on humanistic values must be in place. As he put it in a 1949 address to the Massachusetts Institute of Technology's convocation: “If, with all the resources of modern science, we find ourselves unable to avert world famine, we shall all be to blame.”
Churchill was a science enthusiast and advocate, but he also contemplated important scientific questions in the context of human values. Particularly given today's political landscape, elected leaders should heed Churchill's example: appoint permanent science advisers and make good use of them.
Kurt Hutton/Picture Post/Getty
Winston Churchill at his desk in 1939: a prolific writer, he covered scientific topics as diverse as evolution and fusion power.
An image taken by the Mars Reconnaissance Orbiter of the Martian surface, where the search for water is ongoing.
“Churchill sees great opportunity for exploration in the Solar System.”
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