At first Jason’s labors on this topic were not under the heaviest of classification restrictions, and Dyson presented a summary in the open scientific literature.13 An active optical system, he said, would consist of the following parts:
1. A primary light-collecting mirror (the main part of every telescope), the fixed surface that captures light from the celestial object;
2. A secondary mirror with segmented parts that could be steered independently so as to subtly alter the incoming light waves in order to undo atmospheric distortions;
3. A set of little motors that could quickly reposition the segmented mirrors with great precision;
4. A digital camera recording the light signals from the object;
5. A computer able to make use of the video signal, turning it into feedback commands that actuate the adjustment motors; and
6. Software that turns the video input into the proper feedback output.
In other words, the flexible mirrors were adroitly reconfigured to counteract the bad effects of the atmosphere. The whole process struck a balance between making the sampling time too long, in which case the overhead turbulence would blur the image, or too short, in which case the intermittant arrival of straggling photons from the distant object would render a dim image.14
Dyson, designer of nuclear spaceships and nuclear reactors, knew a promising technology when he saw it and urged astronomers to embrace the new “adaptive optics” method, as it would come to be called. This they failed to do, feeling, as Dyson supposed, that the military was going to be doing the hard work of perfecting the image-sharpening process. Indeed, they were right. Developmental work was just beginning.
The air force had produced prototype corrective systems that worked only for objects that were bright to start with. For fainter stars something else was needed. Another Jason, Princeton physicist William Happer, suggested shining a laser up into the sky in the direction of the target object and observe the light reflected from a thin layer of sodium atoms that hung at an altitude of 90–100 km.15 The sodium, debris from the breakup of past meteorites, resided above most of the atmosphere, and so laser light traveling up to the sodium layer and back would traverse the region of turbulent air twice, providing just what we needed to know about the turbulence above—a weather report for the next fraction of a second—in order to undo the distortion.
The government sponsors were now so keen for this kind of image sharpening that Jason devoted three separate reports to the subject over the period 1982–1984. The U.S. Air Force was so pleased with the results that the “laser guide star” concept and tests were placed under an especially tight security blanket. When President Ronald Reagan declared the start of his Strategic Defense Initiative, the system of space-based detectors and antimissile lasers commonly known as Star Wars, any hope of quickly transferring adaptive optics to the service of astronomers studying the cosmos was quashed. Only in 1992, through the efforts of astronomer (and first woman Jason) Claire Max, was the laser guide star concept made public.
Dyson considered his work on this turbulence-correcting technology to be his most valuable scientific contribution to Jason. Withholding knowledge from scientists, in Dyson’s opinion, delayed the use of adaptive optics in astronomy for a decade. He was appalled: “As often happens when secrecy is imposed on a government program, secrecy hides failure and exaggerates success.”16
MODELING CLIMATE
Jason was good at analyzing hypothetical threats, such as Soviet missiles hurtling across the Arctic Ocean. A fuzzier threat, at least as viewed in the 1970s, was the one posed by possible climate changes arising from the emission of sunlight-trapping carbon dioxide spewed by automobiles burning gasoline and power plants burning coal. Such combustion combines hydrocarbons with oxygen to make harmless water plus CO2, a molecule made of two oxygen atoms and one carbon atom. A blanket of atmospheric carbon dioxide mimics a greenhouse in that it lets sunlight in but reduces the amount of reflected sunlight returning to space. The result is a slow buildup of warmth.
CO2 has resided in the atmosphere for millions of years and has helped to keep the surface of Earth warmer than it would have been without it. That’s good; many species owe their existence to this greenhouse warming. Since the onset of industrial civilization, however, the levels of CO2 have risen greatly. After studying the matter in great earnestness, geoscientists, at least a large majority of those who publish their work in peer-reviewed journals, have concluded that on top of whatever natural climate fluctuations may occur, additional and deleterious climate changes owing to human activity are now under way. These changes include an accelerated rise in global temperature (many places are getting warmer, although a few places will be getting cooler), a rising of the sea level from the gradual melting of icecaps, and a strengthening of droughts in some places. The exact magnitude and timing of these changes is difficult to predict accurately, but a preponderance of climate scientists now believe the trends are ominous, and that society should act decisively in lowering the emission of greenhouse gases, especially CO2.17
One of the largest challenges in monitoring climate has been to separate human from natural effects. Even less was known about these issues in 1972 when Freeman Dyson began his work on climate change—another inspired summer project—working with Alvin Weinberg at Oak Ridge National Laboratory in Tennessee. Rising oceans, drought, wilder swings in weather: there were plenty of bad things that might result from too much CO2. Dyson tried to look for the good things.
He pointed to three examples of past or future environmental modification: a greener England, a wetter Sahara, and a warmer Siberia. First, England. This demi-paradise, Dyson’s homeland, with its gardens, farms, and pastures, was, he argued, utterly unnatural. The forests and swamps of primordial England had been made over into an artificial ecology to suit the needs of its human inhabitants.18 Dyson didn’t deny the possible dangers in fooling around with Mother Nature, but felt that we shouldn’t ignore the possible benefits of climate or habitat modification. We should weigh the good with the bad. The advantage of a wetter Sahara and a warmer Siberia, for example, would be a possible doubling of the arable land on Earth.
Genetic engineering and weather modification are two phrases likely nowadays to make us pause, and rightly so. But tinkering with nature is exactly what the human species has been doing since the advent of agriculture 12,000 years ago. Animal husbandry, the culling of grain species, in vitro fertilization, the damming of rivers, the burning of forests, are just a few of the large-scale human interventions in nature. First came Green England. Then, with the help of artificial fertilizer, came Green India. Fertilizer in excess can do harm, but in moderation it can and does feed millions. That’s why, when the subject of global climate change arose, Dyson could at least ponder welcoming it as a potentially good thing.
Oak Ridge’s Institute for Energy Analysis was hospitable. Dyson spent at least a few weeks there each summer over several years during the 1970s. In these years he participated in some of the first extensive computer simulations of climate change. Even then he began to have reservations about other people’s reservations about CO2. For one thing, the assumptions about climate and the data inserted into the computer simulations were poorly understood, circa 1975. The amount of carbon stored in the oceans and atmosphere were pretty well known, but the amounts stored in other reservoirs, such as topsoil or forests, were less well understood.*
Dyson was dissatisfied with this. The computer models, he thought, put too much emphasis on the atmosphere, not enough on soil. The scientists at Oak Ridge produced an official report on climate modeling. Dyson did not play a role in this report. And when shortly thereafter (1979) Jason prepared a climate report, Dyson was not a part of that either. He worked with colleagues, took part in the discussion, but did not sign as a coauthor.
Instead he prepared a report of his own, concentrating on what he felt the other reports had left out. He cited the fact, as an example of dramatic carbon upta
ke, that a field of corn will consume, in the course of ordinary photosynthesis, all of the CO2 within a few feet of the ground in about five minutes.19 Of course the circulation of air brings in fresh CO2, so photosynthesis never stops. But the uptake is impressive. Feed a plant more CO2 and it will grow bigger, he said. If the extra plant substance were in the form of stem and leaf, then indeed this form of CO2 storage would find its way back into the atmosphere since in the fall the plant would die or surrender its leaves. If, however, the CO2-enhanced growth (whether naturally or through genetic modification) can produce thicker roots, then the extra CO2 would effectively be locked up in subsurface storage.20
Dyson did not deny that a heightened CO2 fraction in the atmosphere could pose a threat through global warming. He only wished in his rebuttal—which he again referred to as a “manifesto”—to the Oak Ridge report to draw attention to the possible countervailing effect going on in the botanic world.21 He never fully concluded that enhanced CO2 led to a greater roots-to-shoots ratio. He couldn’t; the data wasn’t there. That was one of his main points: we needed more direct measurements; we needed to know more about what happens in the hidden realm of soil. Maybe that’s where the carbon was going. We needed a fuller exploration of dirt.
Dyson held what could be called politely by his scientific colleagues a minority opinion. This wasn’t unusual for him. He had held minority views before: he had promoted nuclear spaceships; he had opposed (at least at first) the test ban treaty. Dyson rather liked having a minority view, and this didn’t seem to lessen his friends’ regard for him. Henry Abarbanel, a physicist at the University of California, San Diego, joined Jason in the 1970s and was a member of the Jason climate group. He disagreed with Dyson’s climate views but was thrilled to argue with him. Being at the Jason summer study meeting allowed one to exchange ideas with many of the world’s top scientists; it was like attending the famous 1927 Solvay conference. “Inside there is an equality at play among the best thinkers,” Abarbanel said, “and the reward of arguing with a Dyson or a Garwin is a supreme scientific experience. And they feel the same way.”22
Dyson’s interest in the climate debate would come and go over the years. As we shall see, the research devoted to the subject, the worldwide average surface temperature, and the notoriety of Dyson’s views were all going to rise over the coming decades. His continued questionings of climate modeling assumptions, his critiques of research funding patterns, and his dismissal of apocalyptic projections for future climate were to become ever more grating on a lot of scientists. To this Dyson could only respond: that can’t be helped.
12. Success in Life
Dyson as Astronomer
(MID 1960s TO MID 1970s)
Did he win the Nobel? When measuring a scientist’s success, this is what they ask. When weighing the relative importance of things, a scientist will say that the work itself is its own reward, not the early-morning October call from Stockholm.
In practice, though, getting or not getting that prize does matter, both to you and to the people you pass in the hall. They know whether you have it. In the faculty roster or on those long lists of notable signatories on petitions sent to newspapers you get an asterisk next to your name. True, you never have peace again. Everyone wants your opinion or recommendation. They want to borrow that asterisk. It becomes hard to do research at the old pace. Noblesse oblige comes with the asterisk. Committees, statements, good causes, moral weight.
In October 1965 at last the Swedish call went out to three men for their work on quantum electrodynamics. Nobody disputed the importance of QED. It provided the full quantum explanation of how atoms and light interact, how particles can be created or annihilated, how lasers work. It made possible advances in a variety of practical fields like optics, chemistry, and electronics. The awkwardness lay in the fact that the Nobel Prize can be given to a maximum of three people. As the fourth man, Dyson had to be left out.
Shin’ichiro Tomonaga, Julian Schwinger, and Richard Feynman won the physics Nobel that year, and it fell to Freeman Dyson to write about it in Science rather than to receive it. Graciously leaving his own efforts out of the account, Dyson said that QED was still essential in explaining high-precision atomic experiments. For example, Dyson pointed to a recent measurement of the inherent magnetism of the electron. The experimental and calculated values agreed to better than 1 part in 10 million.1
When asked whether he felt bad about not getting the prize Dyson invariably relegated his historical role in forging QED to that of a mediator among the approaches taken by the three others. Decades later, as he was asked about this repeatedly, Dyson developed an even more sophisticated riposte: it was better to be asked why you didn’t win the Nobel than to be asked why you did win.
Over the years, others have taken up Dyson’s cause. Here are the opinions of some Nobelists: Steven Weinberg, who received the prize for uniting the weak nuclear force and the electromagnetic force into a single theory, thought that Dyson should have the prize. If the three-person rule kept him out that year, he should have gotten it another year. Chen Ning Yang, who won for his theory about why nature is not mirror symmetric, felt that Dyson should have gotten a Nobel because he had done something that the other three hadn’t: proven that each of the many component terms in the calculations were finite.2 Frank Wilczek, whose Nobel came for his work developing a quantum theory of the strong nuclear force, holds that Dyson deserves the prize, and since he couldn’t receive it at the same time as the other three, then it was appropriate to have given it to him in 1999 along with Martinus Veltman and Gerardus ’t Hooft for their work on field theories.3 And dissenting opinions? Murray Gell-Mann argued that Dyson contributed to the formal look of QED by harmonizing the work of Tomonaga, Schwinger, and Feynman, but that this wasn’t enough to win him the Nobel.4
FAMILY FIRST
When pressed further about the Nobel Prize, Dyson’s answer, polite but with an edge of exasperation, was to say, Look, I’ve had a great life. As a young man on the eve of the Second World War I fully expected to die. But I came out of it alive. I’ve got a great job. Do whatever I like. Study fascinating problems. Keep up ties with learned colleagues around the world.
And family. He hadn’t won the Nobel but he had plenty else to be happy about. In the hierarchy of important things, Dyson’s ranking of things that made for a good life was as follows: (1) family, (2) friends, (3) work.5 His family life in the home on Battle Road Circle was indeed full. In addition to Esther (born 1951) and George (1953) by his first wife, he and Imme Jung were to have four daughters: Dorothy (1959), Emily (1961), Miriam (1963, often called Mia), and Rebecca (1967). Although the parents spoke mainly English to each other, the young mother spoke mainly German to her babies.6
Dyson’s parents had also lived full lives. His father, Sir George Dyson, had a prolific musical career as a conductor, administrator, and popular composer of oratorios. He died in 1964. Freeman’s mother, Mildred Dyson, a lawyer and prominent crusader for women’s issues, would die at the age of ninety-four. Alice, Freeman’s sister, still lived in Winchester, England. She remained unmarried. She did social work, taught French, and converted to Catholicism. In 2011 she turned ninety.
Esther and George lived with their father for much of the year and with their mother during summers and at Christmas. Their half-sister, Katarina, remained with Verena Huber-Dyson. Katarina was serious about ballet. Esther and George both went off to college at the age of sixteen, Esther to Harvard (Radcliffe, to be exact) and George to the University of California (San Diego and then Berkeley). Esther was a good girl and George a bad boy. Before going to college, Esther spent the academic year in London with friends of Freeman’s, establishing for her what would become a lifelong habit of travel. At Harvard she was an economics major, worked on the school newspaper, and then went to work for Forbes magazine.
George Dyson, by contrast with well-behaved Esther, was a handful. He was given to brooding and was not a good student. He was brilli
ant but didn’t want to do the assigned work. He frequently cut class and would read books at the nearby library at Princeton University. Starting at the age of twelve he built a kayak in his bedroom and then in the garage.
In 1968, at the age of fourteen, he was arrested for possessing drug paraphernalia, for which he spent a week in jail. His father at first declined to bail George out since he wanted to teach him a lesson. Several days along and still in jail, George called his mother, who was then teaching in Chicago. George was soon released. Divorced now for ten years, Verena and Freeman found one more thing to argue about. Verena was outraged by Freeman having left George in jail, while Freeman blamed George’s familiarity with drugs on Verena’s Berkeley friends.7
George did well in his college classes but he was restless and didn’t remain long at the university. In 1971 he attended Katarina’s wedding in Vancouver and decided to stay on there. For three years he lived in a treehouse, ninety-five feet off the ground. There he read about exploration, such as the journals of Captain James Cook and histories of the Pacific Northwest, especially those about the native peoples and Russian hunters of sea otters.8
As the 1960s and 1970s wore on George and Esther became less of a presence at the home in Princeton. Instead things revolved around the four little girls—Dorothy, Emily, Mia, and Becca. What was life like in the Dyson household? The family culture was mostly in the European style, tending toward strictness. If you acted up at the dinner table you were sent to eat in the kitchen. There was little TV or candy. An au pair, usually a young woman from Europe, was always around, and one of these brought television into the home. All the kids went to public school in Princeton. Freeman insisted on this.9
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