Freeman Dyson, one of the world’s most eminent theoretical physicists, recently celebrated his 90th birthday. Born in England on 15 December 1923, Freeman Dyson graduated from Cambridge University in 1945 with a BA in mathematics. In 1947, he moved to the USA where he went to work at Cornell University and, later, at the Institute for Advanced Study in Princeton. Professor Dyson is a member of the GWPF’s Academic Advisory Council. On the occasion of his 90th birthday, we republish an CCNet-interview he gave Benny Peiser in March 2007.
Freeman Dyson visits the GWPF, London 30 May 2012
Benny Peiser: Let me start with your essay, “Sir Phillip Robert’s Erolunar Collision,” that you wrote in 1933, aged 9. Your first ever piece of science fiction, a story about asteroid Eros, is very charming from a historical perspective. Eros plays a significant role in the history of modern astronomy. It was the first discovered near Earth asteroid and, with a size of circa 13 x 13 x 30 km, is the second largest known NEO. Evidently, your narrative about the asteroid’s close approach was written in the aftermath of the Eros fly by in 1930/31.
What I find intriguing in your account is the conspicuous cheerfulness of the astronomers. When the fictitious president of the astronomical society, Sir Phillip Roberts, announced that Eros may one day collide with the Earth, the reaction of his fellow astronomers is enthusiastic: “Three cheers for Eros!” and “Hip, Hip! Hurrah! They all shouted.” After more calculations revealed that Eros would collide with the Moon in as little as 11 years, the astronomical society decided to organise an expedition to the Moon so that they would witness the collision in situ, “instead of through a telescope.”
It would appear that the perception of a collision by a large asteroid with the Earth was still regarded as something of a challenge rather than a global catastrophe. Today, we know that the impact of an asteroid the size of Eros would wipe out more than 90% of all terrestrial forms of life. This, then, raises the following questions: Why was the potentially existential threat at the time of your writing greatly underestimated? Looking back at your own intellectual development, when did you yourself begin to realise the severity of the threat posed by asteroids and comets?
Freeman Dyson: Certainly as a nine-year-old I considered the Erolunar collision as a great lark and did not worry about the dangers. That is the normal reaction of nine-year-olds to adventures of all kinds. I remember an excellent film called Hope and Glory‘ portraying World War Two as seen through the eyes of a nine-year-old kid in England. For the kid, the war was a great lark. That was true. That film gave the most accurate picture of the war that I have seen.
To me it came as a complete and wonderful surprise when Luis Alvarez discovered the iridium layer that showed a connection between the dinosaur extinction and an extraterrestrial impact. There was no doubt that the two events occurred at the same time, and that many species of plankton in the ocean became extinct at the same time too. And still, I was always skeptical of Alvarez’s theory explaining how the impact caused the extinctions. And I am still skeptical. We now know that the other major extinctions do not have iridium layers associated with them, and we know that the dinosaur extinction has a major volcanic eruption (Deccan Traps) associated with it. So it is plausible that volcanic eruptions are the main cause of extinctions, with extraterrestrial impacts giving an additional push if they happen to occur at the same time.
After looking at the evidence, I do not agree with your statement, “we know that an impact of an asteroid the size of Eros would wipe out more than 90% of all terrestrial forms of life”. I would say that this statement is an exaggeration, similar to statements of the same kind that are made about global warming. Certainly the danger from asteroid impacts is real, and certainly it makes sense to study ways of deflecting asteroids when the opportunity arises. But I find much of the rhetoric about asteroid impacts to be exaggerated. It seems likely that the real dangers to the survival of the biosphere come more from inside the earth than from outside.
Benny Peiser: In your book Infinite in all Directions (1988) you discuss eschatological questions surrounding the theoretical issue of the end of the universe. As one of a very small number of optimistic cosmologists, you have developed a scientific theory of infinity. You write: “I have found a universe growing without limit in richness and complexity, a universe of life surviving forever and making itself known to its neighbors across unimaginable gulfs of space and time.” This hopeful cosmology contrast sharply with the apocalyptic Zeitgeist. What would you say are the most important intellectual principles and ideas that have sustained your unrelenting optimism?
Freeman Dyson: My optimism about the long-term survival of life comes mainly from imagining what will happen when life escapes from this planet and becomes adapted to living in vacuum. There is then no real barrier to stop life from spreading through the universe. Hopping from one world to another will be about as easy as hopping from one island in the Pacific to another. And then life will diversify to fill the infinite variety of ecological niches in the universe, as it has done already on this planet. If you want an intellectual principle to give this picture a philosophical name, you can call it “The Principle of Maximum Diversity”. The principle of maximum diversity says that life evolves to make the universe as interesting as possible. A rain-forest contains a huge number of diverse species because specialization is cost-effective, just as Adam Smith observed in human societies. But I am impressed more by the visible examples of diversity in rain-forests and coral-reefs and human cultures than by any abstract philosophical principles.
Benny Peiser: In the first chapter of your new book, The Scientist as Rebel, you write that the common element of the scientific vision “is rebellion against the restrictions imposed by the locally prevailing culture,” and that scientists “should be artists and rebels, obeying their own instincts rather than social demands or philosophical principles.”
Contrary to this liberal if not libertarian concept of scientific open-mindedness, there has been growing pressure on scientists to tow the line and endorse what is nowadays called the ‘scientific consensus’ – on numerous contentious issues. Dissenting scientists frequently face ostracism and denunciation when they dare to go against the current. Has Western science become more authoritarian in recent years or have rebellious scientists always had to face similar condemnation and resentment? And how can young scientists develop intellectual independence and autonomy in a bureaucratic world of funding dependency?
Freeman Dyson: Certainly the growing rigidity of scientific organizations is a real and serious problem. I like to remind young scientists of examples in the recent past when people without paper qualifications made great contributions. Two of my favorites are: Milton Humason, who drove mules carrying material up the mountain trail to build the Mount Wilson Observatory, and then when the observatory was built got a job as a janitor, and ended up as a staff astronomer second-in-command to Hubble. Bernhardt Schmidt, the inventor of the Schmidt telescope which revolutionized optical astronomy, who worked independently as a lens-grinder and beat the big optical companies at their own game. I tell young people that the new technologies of computing, telecommunication, optical detection and microchemistry actually empower the amateur to do things that only professionals could do before.
Amateurs and small companies will have a growing role in the future of science. This will compensate for the increasing burocratization of the big organizations. Bright young people will start their own companies and do their own science.
Benny Peiser: In a Winter Commencement Address at the University of Michigan two years ago you called yourself a heretic on global warming, the most notorious dogma of modern science. You have described global warming anxiety as grossly exaggerated and have openly voiced your doubts about the reliability of climate models. These models, you argue, “do a very poor job of describing the clouds, the dust, the chemistry and the biology of fields, farms and forests. They do not begin to describe the real world that we live in.” There seems to be an almost complete endorsement of the world’s scientific organisations and elites of these models together with claims that they reliably epitomize reality and can consistently predict future climate change. How do you feel belonging to a tiny minority of scientists who dare to voice their doubts openly?
Freeman Dyson: I am always happy to be in the minority. Concerning the climate models, I know enough of the details to be sure that they are unreliable. They are full of fudge factors that are fitted to the existing climate, so the models more or less agree with the observed data. But there is no reason to believe that the same fudge factors would give the right behavior in a world with different chemistry, for example in a world with increased CO2 in the atmosphere.
Benny Peiser: In a chapter about the scientific revolutions in modern physics and mathematics, you describe the deep intellectual confusion in Weimar Germany in the aftermath of the First World War. You portray a society troubled by a mood of doom and gloom, a milieu that was conducive for scientific revolution as well as political upheaval. Unmistakably, the Great War set off a major shift in German thought, from the idea of progress and technological confidence to cultural pessimism and apocalypticism. As we know, the consequences of this mood of despair was calamitous. Do you see any comparison with the gloomy frame of mind that seems to be on the increase among many Western scientists today?
Freeman Dyson: Yes, the western academic world is very much like Weimar Germany, finding itself in a situation of losing power and influence. Fortunately, the countries that matter now are China and India, and the Chinese and Indian experts do not share the mood of doom and gloom. It is amusing to see China and India take on today the role that America took in the nineteen-thirties, still believing in technology as the key to a better life for everyone.
Benny Peiser: One of your most influential lectures is re-published in your new book. I am talking about your Bernal Lecture which you delivered in London in 1972, one year after Desmond Bernal’s death. As you point out, the lecture provided the foundation for much of your writing in later years. What strikes me about your remarkably optimistic lecture is its almost religious tone. It was delivered at a time, similar to the period after World War I, when a new age of techno-pessimism came to the fore, reinforced by Hiroshima and Vietnam.
It is in this atmosphere of entrenched techno-scepticism and environmental anxiety that you advanced biological, genetic and geo-engineering as industrial trappings of social progress and environmental protection. At the height of ecological anxiety, in the same year as the Club of Rome proclaimed the “Limits to Growth,” you envisaged endless technological advancement, terrestrial progress and the greening of the galaxy, famously predicting that “we shall learn to grow trees on comets.”
At one point towards the end of your lecture, you christen your speech a “sermon.” Indeed, your entire lecture reads as if it was written for a tormented audience searching for a glimmer of hope. In his book The Religion of Technology, David Noble claims that the whole history of technological innovation and advancement has been primarily a religious endeavour. Noble claims that even today your ideas of technological solutions to terrestrial problems constitute in essence a religious conviction. How much of your cosmological view of the world has indeed been shaped by Judeo-Christian traditions? And do you see that there is an inherent link between your religious and your philosophical optimism?
Freeman Dyson: It is true that the tradition of Judeo-Christian religion is strongly coupled with philosophical optimism. Hope is high on the list of virtues. God did not put us here on earth to moan and groan. As my mother used to say, “God helps those who help themselves”.
I am generally optimistic because our human heritage seems to have equipped us very well for dealing with challenges, from ice-ages and cave-bears to diseases and over-population. The whole species did cooperate to eliminate small-pox, and the women of Mexico did reduce their average family size from seven to two and a half in fifty years. Science has helped us to understand challenges and also to defeat them.
I am especially optimistic just now because of a seminal discovery that was made recently by comparing genomes of different species. David Haussler and his colleagues at UC Santa Cruz discovered a small patch of DNA which they call HAR1, short for Human Accelerated Region 1. This patch appears to be strictly conserved in the genomes of mouse, rat, chicken and chimpanzee, which means that it must have been performing an essential function that was unchanged for about three hundred million years from the last common ancestor of birds and mammals until today.
But the same patch appears grossly modified with eighteen mutations in the human genome, which means that it must have changed its function in the last six million years from the common ancestor of chimps and humans to modern humans. Somehow, that little patch of DNA expresses an essential difference between humans and other mammals. We know two other significant facts about HAR1. First, it does not code for a protein but codes for RNA. Second, the RNA for which it codes is active in the cortex of the human embryonic brain during the second trimester of pregnancy. It is likely that the rapid evolution of HAR1 has something to do with the rapid evolution of the human brain during the last six million years.
I am optimistic because I see the discovery of HAR1 as a seminal event in the history of science, marking the beginning of a new understanding of human evolution and human nature. I see it as a big step toward the fulfilment of the dream described in 1929 by Desmond Bernal, one of the pioneers of molecular biology, in his little book, The World, the Flesh and the Devil: An Enquiry into the Future of the Three Enemies of the Rational Soul. Bernal saw science as our best tool for defeating the three enemies. The World means floods and famines and climate changes. The Flesh means diseases and senile infirmities. The Devil means the dark irrational passions that lead otherwise rational beings into strife and destruction. I am optimistic because I see HAR1 as a new tool leading us toward a deep understanding of human nature and toward the ultimate defeat of our last enemy.
Benny Peiser: Britain’s leading cosmologists seem to be particularly gloomy about the future of civilisation and humankind. The so-called Doomsday Argument seems to have had a significant influence on many Cambridge-based scientists. It has induced among them a conviction that global catastrophe is almost imminent. Martin Rees, for instance, estimates that there is a 50% chance of human extinction during the next 100 years. How do you explain this apocalyptic mood among leading cosmologists in Britain and the almost desperate tone of their pronouncements?
Freeman Dyson: My view of the prevalence of doom-and-gloom in Cambridge is that it is a result of the English class system. In England there were always two sharply opposed middle classes, the academic middle class and the commercial middle class. In the nineteenth century, the academic middle class won the battle for power and status. As a child of the academic middle class, I learned to look on the commercial middle class with loathing and contempt. Then came the triumph of Margaret Thatcher, which was also the revenge of the commercial middle class. The academics lost their power and prestige and the business people took over. The academics never forgave Thatcher and have been gloomy ever since.
Benny Peiser: Your sociological reading raises the question whether the current fashion of issuing doomsday predictions could be interpreted as the revenge by leading academics against the business community? After all, their very activities, success and societal role are blamed for impending catastrophe. Could it be that the scientific prophets of doom are trying to regain some of their lost influence by portraying themselves as saviours who, at the same time, provide governments with strong incentives for increased state power and intervention?
Freeman Dyson: I agree with your diagnosis of the academic disease. The academics are suffering from business envy, in the USA as well as inBritain. And of course there are companies like Halliburton that it is reasonable to hate, enjoying political power in the Bush government and profiteering from the war that they encouraged Bush to start. Opposition to the war is mixed up with opposition to the business community. But I agree with you that there is a longer-lasting envy of the business community that has nothing to do with the war. The academics preaching doom and gloom are indeed hoping to take their revenge on the business community by capturing the government.
Benny Peiser: There has been an apparent shift among the political left and liberals from what used to be called progressive ideas to more dystopian anxieties. What are the reasons that you have not been carried away by this tide of cultural and technological pessimism. And why have so few academics and authors of popular science been able to resist this shift towards unhappiness and desperation? In other words, how much of our optimism is shaped by people around us and positive experiences, and how much is due to rational thought, I wonder?
Freeman Dyson: I do not agree that there has been a recent shift from progressive ideas to dystopian anxieties. The best writers have always been dystopian. In the 1890s we had Wells’s Time Machine and The Island of Doctor Moreau‘. In the 1930s Huxley’s Brave New World. These were the classics that I grew up with seventy years ago. Nothing that has been written recently is gloomier than Wells and Huxley. And in spite of that, there have always been optimists like me and Amory Lovins. I recommend Amory Lovins as an antidote to gloom and doom.
Benny Peiser: Finally, let me ask you about your thoughts regarding Britain, the country of your birth, the USA, the country of your choice, and the future of the Western democracies. At the end of your new book you write that “without religion, the life of a country would be greatly impoverished.” Perhaps nothing symbolises the glaring differences between Britain and the USA more than the gradual fading of religion in the cultural life of the UK and the profound permeation of religion on public life in the US. Sometimes I wonder whether both extremes may be detrimental to a stable, liberal and open-minded society. In a world of mounting intellectual dogmatism, is there, in your view, a middle way between the Scylla of nihilist despair and the Charybdis of fundamentalist unreasonableness?
Freeman Dyson: I do not agree with your assessment of religion in Britain and the USA. The extremes of religious dogmatism in the USA and of atheistic dogmatism in Britain are greatly exaggerated by the media. In both countries, the average atheist and the average Christian are not dogmatic or unreasonable. So far as I can see, there is about the same variety of beliefs on both sides of the ocean. Certainly we do not need any accurate navigation to find a middle way between the two extremes. Probably ninety percent of the population are somewhere in the middle.
It is also interesting in this connection to observe the similarity, in optimistic mood and rapid material progress, between China and India. Although China is traditionally non-religious and India is traditionally permeated with religion, this does not seem to make much difference. In both countries, rapidly growing wealth and technological progress create a mood of optimism, with or without religion.
That’s all for today. Thank you for posing a good set of questions.
Thanks also for CCNet which I enjoy reading.
P.S. One more thing. I met your father’s cousin Ernst Straus once when he came to a conference in Princeton. He gave an interesting talk about the frustrations of being Einstein’s assistant. He said Einstein treated his assistants as slaves, in the tradition of the German Geheimrat. It was a thankless job with very little joy, and he escaped as soon as he could.
Benny Peiser: Thank you for the interview, Professor Dyson!
14 March 2007