by Phillip F. Schewe

Freeman Dyson lived the life of ten men. By turns a mathematician, physicist, engineer, anti-nuke crusader, biologist, and writer, he considered himself a futurist. Dyson, who died 28 February 2020 at the age of 96, was especially drawn to the prospective human migration into space. His science background prepared him to weigh the aeronautics and biotech innovations needed; his intellectual curiosity led him to consider the likely ethical and economic implications.

Dyson’s ideas on humanity’s deep future made him a popular figure on college campuses and in magazines. What gave his vivid prognostications legitimacy was his proven scientific credibility. With the exception of the Nobel Prize, he won most of the great prizes for physics. A longtime professor at the Institute for Advanced Study in Princeton, NJ, his most important physics work was in consolidating the theory of quantum electrodynamics.

Among non-scientists, however, Dyson was better known for his opinions on climate change, rightly one of the most debated political and scientific issues of our time. Appearing on the cover the New York Times magazine in March 2009 in a picture that made him look like a war criminal, he was branded as a “global warming heretic.” Here was Dyson---Obama supporter, disarmament campaigner, nature-loving liberal---saying that leading climate scientists had gotten things wrong.

Here is a compact summary of Dyson’s views on climate. He didn’t deny that the amount of carbon dioxide in the atmosphere was increasing or that human technology was largely responsible, or that some of the global changes would not be deleterious. He believed, however, that the good might outweigh the bad. Having performed some of the first climate computer modeling in the 1970s, he wasn’t confident enough in current projections to justify the large expense needed to dispense quickly with fossil fuels. He felt that it was better to spend scarce resources on other pressing needs, such as improving education, hygiene, diet, and reducing the threat of future wars.

Dyson did not enjoy his participation in the climate debate. In the primary years of his research he had much preferred putting his mathematical abilities to practical use in a variety of other areas. For example, he designed the TRIGA nuclear reactor (used to this day) for training and for producing medical isotopes. Through his work with the Jason advisory group, he helped design a method for sharpening images of distant astronomical objects using a computer-controlled, frequently-adjusted set of mirror facets. This “adaptive optics” system is now employed by many of the largest optical telescopes in the world.

Dyson often claimed to have a short attention span, which obliged him to change research topics frequently. Often he was able to devote a career’s worth of inquiry into just a few numbers of years or even months. For example he helped introduce field theory into condensed matter physics; pioneered the use of random matrices, used in nuclear and solid-state physics; demonstrated mathematically the stability of solid matter; was one the early writers about the possibility that fundamental physical constants might change over time; and wrote the first detailed mathematical study of the very late universe.

He helped design a rocket ship, called Orion, whose propulsion would be supplied by exploding atom bombs and wrote a stirring manifesto about saving human society on earth by using atom bombs to hoist pioneers into space. Their motto was Saturn by 1970. Although Orion was never built, Stanley Kubrick borrowed some ideas (and filmed an interview with Dyson) as part of preparing for his movie 2001: A Space Odyssey. Dyson’s scientific and engineering knowhow allowed him to envision superior civilizations building immense solar-energy-collecting platforms for tapping stars’ energy. Around 1959 this “Dyson Sphere” idea helped launch the scientific search for extra-terrestrial intelligence and later figured in an episode of Star Trek.

August 2013, physics meeting in Singapore in honor of Freeman Dyson’s 90th birthday.
L to R: Lawrence Krauss, Freeman Dyson, Phillip Schewe

Visionary, yes, but Freeman Dyson always had his feet planted firmly on Earth. Another of his Jason projects was to prepare a 1966 report (long kept classified) which argued against the use of tactical nuclear weapons in the Vietnam war. In 1963, while working at the Arms Control and Disarmament Agency, he participated in crafting the limited nuclear test ban treaty, still in effect to this day, greatly reducing the threat of nuclear war and the amount of radioactive debris in the air. For many years he sought to curb the use of nuclear weapons by persuading (unsuccessfully) the U.S. government to adopt a no-first-use policy.

Notwithstanding this rich resume, Dyson’s legacy contribution to culture will, I believe, be his social writing in his later decades, conducted mostly in the New York Review of Books, where he confronted precisely those intractable issues---climate change, genetic engineering of humans, and planting colonies in space---that are so expensive to address and politically and technologically complicated to implement as to seem beyond the resources or consensus of any one generation. Dyson specialized in looking at topics about which even like-minded scientists could easily disagree. One prominent example was the subject of genetically modified food, where, he felt, the humanist view (feeding millions) could bump against the environmentalist view (insisting on “natural” ingredients).

Are we running out of time? Will humans migrate to a place like Jupiter’s moon Europa, with its apparently large volume of sub-surface liquid water? Not any time soon. For right now, Dyson felt, space travel was a joke. It’s too expensive and too bound up with mechanical engineering. True habituation to space would require plants, and then later humans, to adapt to a low-temperature, low-gravity, low-pressure environment. Long before we send humans out into the universe, Dyson argued, we should send small “cosmic eggs,” containing seedlings designed to weather some of those expected hazardous conditions around the solar system.

Dyson often compared the daunting prospective human migration across the cold emptiness of interplanetary space to the earlier Polynesian translocation into the vast Pacific Ocean. It was essential, he felt, for humans “to escape from their neighbors and from their governments, to go live as they pleased in the wilderness.” For this purpose, he figured, in the long run one world would not be enough.

Probably even one species won’t be enough. Like the finches on the Galapagos Islands, Homo sapiens will eventually come to occupy different niches, obliging its inhabitants to splinter into separate species. This, Dyson plainly admitted, was an exciting and scary prospect. The trouble with appraising this oversized vision of humans living on far moons or comets is that none of us now living will be around to see it happen.

The articles in this issue represent the views of their authors and are not necessarily those of the Forum or APS.