Freeman Dyson: Visionary physicist noted for unorthodox ideas about human destiny

He made great inroads into quantum electrodynamics, while his work designing neutron bombs led him to becoming an advocate of arms control

Big thinker: Dyson, pictured here in 2000, took inspiration from science fiction (NY Daily News/Getty)

The physicist Freeman Dyson, who has died aged 96, helped to crack the secrets of the subatomic world, tried to build a spaceship that could carry humans across the solar system, worked to dismantle nuclear arsenals and wrote elegantly about science and human destiny.

British-born Dyson spent most of his professional life as a kind of genius-in-residence at the Institute for Advanced Study in Princeton, overlapping in his early years with Albert Einstein.

In a career spent traversing fields as diverse as physics, biology, astronomy, nuclear energy, arms control, space travel and science ethics, Dyson was a purveyor of reliably unorthodox ideas. Perhaps most famous was that alien civilisations, seeking to maximise their supply of energy, would build elaborate megastructures around their parent stars to capture much of the solar radiation. (He freely admitted he lifted the idea from science-fiction writer Olaf Stapledon.)

Long before he became an oracle, he laboured in the trenches of mathematics and physics. He succeeded in the late 1940s in developing an early landmark synthesis of the latest thinking in the theory known as quantum electrodynamics. His resulting paper, “The Radiation Theories of Tomonaga, Schwinger and Feynman”, was regarded as an instant classic and gave Dyson lifelong credibility in the sciences even as he went on to tackle more speculative interests.

That included the interplanetary spaceship. Project Orion, initiated in the late 1950s, was an effort to design a spacecraft powered by nuclear explosions, rather than traditional fuels, and capable of carrying people throughout the solar system.

A 1 metre-tall model seemed to work fine, and the Orion team decided they could send humans to Mars by 1968 and to the moons of Jupiter and Saturn two years later. But the government was not keen on nuclear bombs as a form of propulsion and the project, taken over by the Air Force, was eventually terminated.

He contributed to the design of what became known as neutron bombs, work he later regretted bitterly, to the point of describing an article he had authored on tactical nuclear warfare as “a desperate attempt to salvage an untenable position with spurious emotional claptrap”. He became an advocate for arms control, and served as outside counsel to decision-makers in Washington.

In his mid-forties, in response to what he called “all these bright kids down the hall who are writing papers faster than you can read them”, he stepped back from the science front line and become more of a sage, writing books and magazine articles on science, technology and the future.

His primary job, it seemed, was to think big thoughts, such as this one, from his 1988 book Infinite In All Directions: “As a working hypothesis to explain the riddle of our existence, I propose that our universe is the most interesting of all possible universes, and our fate as human beings is to make it so.”

Freeman John Dyson was born in Crowthorne, Berkshire, in 1923, the son of George Dyson, a composer, and Mildred Atkey, a social worker. Small of stature, he endured bullying at boarding school, but found escape in science fiction, including the works of Stapledon, HG Wells and Jules Verne. Poring over an Encyclopaedia Britannica entry, he taught himself calculus by the time he was 15, knowledge that served him well in the Second World War when he became an analyst for the Royal Air Force Bomber Command.

In 1947 Dyson went to the US to study as a graduate student at Cornell University, studying under future Nobel laureate Hans Bethe and communing with the likes of Richard Feynman and J Robert Oppenheimer. Dyson had a knack for engaging them in long conversations, sometimes over weeks or months. One day in September 1948, while riding on a Greyhound bus across the plains of Nebraska and spending his vacation deep in thought about the various theories he had been busily absorbing, he had a revelation about how he could combine some of the ideas.

He arrived in Princeton and took up a position, working under Oppenheimer, at the Institute for Advanced Study, where Einstein had been spending his years in exile in vain pursuit of a grand unified theory. The first thing Dyson did was write down the conclusions he had reached on his bus ride, and those concepts evolved into his paper on quantum electrodynamics.

A raging intellectual battle took place amid Oppenheimer’s seminars regarding Dyson’s brainstorm. Until one day, he wrote: “I found in my mailbox Oppenheimer’s formal note of surrender, a small piece of paper with the words ‘Nolo contendere. R.O.’ scrawled on it in his handwriting.”

In 1960 he was elected to the council of the American Federation of Scientists, a leading voice for disarmament; he became chair in 1962 and wrote often for the Bulletin of the Atomic Scientists. In 1962 he also went to work for a new government department called the Arms Control and Disarmament Agency; he later testified in Senate hearings that led to the ratification of a treaty banning atmospheric tests of nuclear weapons. His book on the subject of nuclear war, Weapons and Hope, won a National Book Critics Circle Award in 1984.

The same innovations that made atomic bombs and long-range missiles could potentially open space to human exploration, and Dyson believed that humans would find their destiny in the stars. He believed that genetic engineering would make it easier. “Probably we’ll be a million species before long,” he said in 1998. “For example, if you want to run around naked on Mars you’d need a thick skin. I can imagine our descendants on Mars will be more like polar bears.”

In the early 2000s he drew criticism from other scientists and environmentalists for his views on climate change. Although he did not deny that the Earth was warming – he was not a global warming denier in the strictest sense – he thought that the environmental movement had overstated the threats to the planet, a view not shared by most scientists. Dyson’s fringe position reflected a deeper philosophy: that change is coming, inevitably, and we should embrace it and not fear it. His scenarios for the future always involved a completely different sort of human existence.

In Dyson’s expansive cosmos, our destiny is to spread intelligence everywhere. “The universe is like a fertile soil spread out all around us, ready for the seeds of mind to sprout and grow,” he wrote. “Ultimately, late or soon, mind will come into its heritage.”

Dyson’s first marriage, to mathematician Verena Huber, ended in divorce. He is survived by his second wife Imme Jung, whom he married in 1958, and six children.

Freeman Dyson, physicist, born 15 December 1923, died 28 February 2020

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