Dreams of Earth and Sky

by Freeman Dyson

  The nuclear partnership began in 1943 and came to a sudden end with the passing of the McMahon Act by Congress in 1946. That year, the United States had bombs and the industrial equipment to make more bombs, and Britain was shut out. Britain had to decide whether to give up or go ahead with building an independent British bomb. Attlee had taken Churchill’s place as prime minister in 1945 and made the decision to go ahead with the British bomb. It was successfully tested in 1952, when Churchill was back in power. In that same year the Americans tested the first hydrogen bomb with a yield of ten megatons. Churchill quietly gave the order for a British hydrogen bomb, which was built and successfully tested in 1957. By that time Churchill had ended his second term as prime minister, but he achieved his goal of restoring the nuclear partnership and the sharing of secrets with America.

  Churchill, Lindemann, and Wells did not fundamentally disagree about nuclear strategy. They agreed that nuclear weapons were desirable as instruments of power, immensely dangerous, and historically decisive. Churchill and Lindemann saw the bomb as necessary to preserve the status of Britain as a great power. Wells saw it as necessary to establish the authority of a future world government.

  Only one voice spoke out in well-reasoned opposition to these views. The opposing voice belonged to Patrick Blackett, a physicist who had served as a naval officer in World War I, survived the Battle of Jutland in 1916, and led the team of scientists helping the Royal Navy to defeat German U-boats in World War II. He won a Nobel Prize in 1948 for discoveries in particle physics. Both as a scientist and as an expert in war-fighting, Blackett had far better credentials than Lindemann. But Blackett was a socialist and was active in left-wing politics. Lindemann hated him, and Churchill distrusted him. They made sure that Blackett was kept out of all high-level discussions of nuclear policy so long as Churchill was prime minister.

  As soon as Attlee became prime minister in 1945, he appointed Blackett to his Advisory Committee on Atomic Energy. The next year was the decisive turning point in the history of nuclear weapons. Several governments made serious proposals to put the newly created United Nations in charge of the nascent nuclear industries all over the world, with power to prevent any nation from building nuclear bombs. This was the last chance to avoid a large-scale nuclear arms race. Robert Oppenheimer in the United States and Niels Bohr in Denmark were the leaders of a worldwide campaign of scientists for international control of nuclear energy. The United Nations Atomic Energy Commission was created to exercise whatever form of international control the member nations could agree to establish. Everything depended on finding an international legal frame that the United States and the Soviet Union could both accept.

  The US proposal for international control was known as the Baruch plan because it was written by Bernard Baruch, a conservative banker and a friend of Churchill. The essential point that made it unacceptable to the Soviet Union was the enforcement clause, which gave the United Nations Security Council power to enforce the agreement by majority vote. In all other actions of the Security Council, each permanent member of the council had the right to veto majority decisions. In the Baruch plan the right to veto was abolished for decisions concerning nuclear weapons. In any dispute involving the Soviet Union, the Soviet Union was likely to be in the minority and the United States in the majority, so the Baruch plan was giving a permanent nuclear hegemony to the United States. Oppenheimer fought hard inside the American government for a plan that would recognize the Soviet need for equal treatment. Blackett fought hard inside the British government. Oppenheimer failed to convince Truman and Blackett failed to convince Attlee. American hegemony was what both Truman and Attlee wanted and hoped to make permanent.

  Stalin knew that the American hegemony would not last long. He said, “The atomic bomb is a good weapon for threatening people with weak nerves.” Stalin did not have weak nerves. He knew that his country had produced more tanks than Germany in wartime and could produce more atomic bombs than the United States in peacetime. In 1946 the Soviet Union proposed a simple prohibition of nuclear weapons, overseen by the United Nations but without any enforcement clause. After a year of argument about details, the negotiations ended and the nuclear arms race began. The American hegemony ended with the first Soviet bomb test in 1949.

  Blackett disagreed strongly with Attlee, not only about the Baruch plan but also about the decision to build a British bomb. Blackett believed that the military value of the bomb was illusory while the danger of possessing it was real. He argued that the bomb would be useless in any future wars that Britain might reasonably fight. Any war that was worth fighting could be won with nonnuclear weapons. And if there were ever a nuclear war involving the Soviet Union, the possession of nuclear weapons would make it sure that London and other British cities would be obliterated.

  After Blackett failed to find support for these views inside the government, he made them public in a book that was published in Britain with the title Military and Political Consequences of Atomic Energy and in America with the title Fear, War, and the Bomb. The book appeared in 1948 and became a best seller with translations published in eleven languages. Farmelo says rightly that the book had no influence on government policies or on majority opinions at the time. He says wrongly that the book is “so dense that much of it is barely readable.” In fact it is highly readable and widely read. It stands after sixty-five years as a classic statement of the case against the nuclear follies of our age. Some of Blackett’s predictions have been proved wrong and some of his arguments have become irrelevant, but the central theme of his book is still true. He is saying that the military utility of the bomb is small, that its political importance is exaggerated, and that only its danger as an instrument of mass murder is real.

  Blackett said in 1948 that the Soviet proposal for abolishing nuclear weapons without enforcement should have been accepted. If his advice had been followed, we would have been in a situation like the one in 1972 when the United States, the United Kingdom, and the Soviet Union signed a treaty abolishing biological weapons. Before the treaty was signed, the large stockpiles of American and British biological weapons had been destroyed. After the treaty was signed, the Soviet Union cheated on a massive scale and continued to maintain a large clandestine stockpile. Today the biological weapons treaty is still in force and we still have reason to suspect that Russia may be cheating. The question now is whether we are better off with the treaty or without it. Is it better to have a world with biological weapons illegal and well hidden in clandestine facilities, or a world with large stockpiles of biological weapons openly deployed and vulnerable to theft?

  Opinions may be divided on the value of the treaty, but there is at least a reasonable argument to be made for keeping it in force. The same argument was made by Blackett for accepting the 1946 Soviet proposal for prohibiting nuclear weapons. If we had accepted the Soviet proposal, we would be living in a world with nuclear weapons legally prohibited but secretly manufactured and hidden away in various places around the world. Would that world be less dangerous than the world of huge stockpiles openly deployed in which we have lived for the last sixty years? Blackett answered yes to that question. It is time now for the world to ask the question again and decide whether Blackett was right.

  Looking back with seventy years of hindsight, we can see clearly that Churchill was deluded. Central to his vision of the world was the power and glory of the British Empire. He fought his wars for the preservation of the empire. The young people who fought for Britain in World War II were not fighting for the empire. They knew that the empire was crumbling and most of them were happy to see it swept away. That was why they voted in 1945 to sweep Churchill away. They knew that Churchill was living in the past, out of touch with the real world. I have a vivid memory of the British general election of 1950, when Attlee was running for reelection after five years of slow recovery from the war. Attlee came to Birmingham, where I was then living, to give a campaign speech to a large crowd. He spoke at leng
th about the social programs that the Labour Party had carried out during his tenure, the big improvements in public housing and public education, and the National Health Service. The crowd listened to this without much enthusiasm. Then at the end of his speech, Attlee said, “We gave freedom to India,” and the crowd responded with loud and long cheering. Giving freedom to India was the one thing that Churchill would never have done. Attlee won the election.

  When Churchill returned for his second term as prime minister, he recognized that the empire was fading and based his nuclear policy on another illusion, the special relationship between Britain and America. During World War II he had enjoyed a special relationship with Franklin Roosevelt, with frequent telephone calls and many personal meetings. His friendship with Roosevelt was a crucial part of his war strategy. It allowed him to think of himself as one of the Big Three, deciding the fate of the world in conferences with Roosevelt and Stalin. After returning to office in 1951, he tried to reestablish his special relationship with presidents Truman and Eisenhower. Truman and Eisenhower found his personal advances annoying and gently pushed him off. After the British hydrogen bomb was demonstrated in 1957, sharing of nuclear secrets was successfully reestablished, but Churchill’s belief that this would perpetuate Britain’s status as a Great Power remained an illusion.

  The big question that Farmelo does not try to answer is whether it makes sense for Britain to have nuclear weapons. Two famous scientists answered this question with a resounding no. One was Patrick Blackett. The other was Joseph Rotblat, a Polish nuclear physicist who went with the British contingent to Los Alamos. Rotblat was the only scientist who left the bomb project in 1944 as soon as he heard that the Germans were not working on a bomb. He served for most of a long life as leader of the Pugwash movement, an international alliance of scientists concerned about war and weapons. For his efforts as a peacemaker he won the Nobel Peace Prize in 1995.

  Just as Rotblat is unique as a Los Alamos scientist who walked out of the brotherhood of bomb-makers for reasons of conscience, the Republic of South Africa is unique as a country possessing nuclear weapons and unilaterally destroying them. The South Africans have set a splendid example for other countries possessing nuclear weapons to follow. Nobody gives South Africans diminished respect because they walked out of the nuclear club. The United Kingdom is now in an excellent position to gain respect and save money by following the South African example.

  *Graham Farmelo, Churchill’s Bomb: How the United States Overtook Britain in the First Nuclear Arms Race (Basic Books, 2013).

  21

  THE CASE FOR BLUNDERS

  SCIENCE CONSISTS OF facts and theories. Facts and theories are born in different ways and are judged by different standards. Facts are supposed to be true or false. They are discovered by observers or experimenters. A scientist who claims to have discovered a fact that turns out to be wrong is judged harshly. One wrong fact is enough to ruin a career.

  Theories have an entirely different status. They are free creations of the human mind, intended to describe our understanding of nature. Since our understanding is incomplete, theories are provisional. Theories are tools of understanding, and a tool does not need to be precisely true in order to be useful. Theories are supposed to be more or less true, with plenty of room for disagreement. A scientist who invents a theory that turns out to be wrong is judged leniently. Mistakes are tolerated, so long as the culprit is willing to correct them when nature proves them wrong.

  Brilliant Blunders, by Mario Livio,* is a lively account of five wrong theories proposed by five great scientists during the last two centuries. These examples give for nonexpert readers a good picture of the way science works. The inventor of a brilliant idea cannot tell whether it is right or wrong. Livio quotes the psychologist Daniel Kahneman describing how theories are born: “We can’t live in a state of perpetual doubt, so we make up the best story possible and we live as if the story were true.” A theory that began as a wild guess ends as a firm belief. Humans need beliefs in order to live, and great scientists are no exception. Great scientists produce right theories and wrong theories, and believe in them with equal conviction.

  The essential point of Livio’s book is to show the passionate pursuit of wrong theories as a part of the normal development of science. Science is not concerned only with things that we understand. The most exciting and creative parts of science are concerned with things that we are still struggling to understand. Wrong theories are not an impediment to the progress of science. They are a central part of the struggle.

  The five chief characters in Livio’s drama are Charles Darwin, William Thomson (Lord Kelvin), Linus Pauling, Fred Hoyle, and Albert Einstein. Each of them made major contributions to the understanding of nature, and each believed firmly in a theory that turned out to be wrong. Darwin explained the evolution of life with his theory of natural selection of inherited variations, but believed in a theory of blending inheritance that made the propagation of new variations impossible. Kelvin discovered basic laws of energy and heat, and then used these laws to calculate an estimate of the age of the earth that was too short by a factor of fifty. Pauling discovered the chemical structure of protein, the active component of all living tissues, and proposed a completely wrong structure for DNA, the passive component that carries hereditary information from parent to offspring.

  Hoyle discovered the process by which the heavier elements essential for life, such as carbon, nitrogen, oxygen, and iron, are created by nuclear reactions in the cores of massive stars. He then proposed a theory of the history of the universe known as steady-state cosmology, which has the universe existing forever without any big bang at the beginning, and stubbornly maintained his belief in the steady state long after observations proved that the big bang really happened.

  Finally, Einstein discovered the great theory of space and time and gravitation known as general relativity, and then added to the theory an additional component later known as dark energy. Einstein afterward withdrew his proposal of dark energy, believing that it was unnecessary. Long after Einstein’s death, observations have proved that dark energy really exists, so that Einstein’s addition to the theory was right and his withdrawal was wrong.

  Each of these examples shows in a different way how wrong ideas can be helpful or unhelpful to the search for truth. No matter whether wrong ideas are helpful or unhelpful, they are in any case unavoidable. Science is a risky enterprise, like other human enterprises such as business and politics and warfare and marriage. The more brilliant the enterprise, the greater the risks. Every scientific revolution requires a shift from one way of thinking to another. The pioneer who leads the shift has an imperfect grasp of the new way of thinking and cannot foresee its consequences. Wrong ideas and false trails are part of the landscape to be explored.

  Darwin’s wrong idea was the blending theory of inheritance, which supposed the qualities inherited by offspring to be a blend of the qualities of the parents. This was the theory of inheritance generally accepted by plant breeders and animal breeders in Darwin’s time. Darwin accepted it as a working hypothesis because it was the only theory available. He accepted it reluctantly because he knew that it was unsatisfactory in two ways. First, it failed to explain the frequent cases of hereditary throwback, when a striking hereditary feature such as red hair or musical talent skips a generation from grandparent to grandchild. Second, it failed to allow a rare advantageous variation to spread from a single individual to an entire population of animals, as required by his theory of the origin of species. With blending inheritance, any rare advantageous variation would be quickly diluted in later generations and would lose its selective advantage. For both of these reasons, Darwin knew that the theory of blending inheritance was inadequate, but he did not have any acceptable alternative when he published The Origin of Species in 1859.

  Nine years later, when Darwin published another book, The Variation of Animals and Plants Under Domestication, he had abandoned the blending
inheritance theory as inconsistent with the facts. He replaced it with another theory that he called pangenesis. Pangenesis said that the inheritance of qualities from parent to offspring was not carried in the seeds alone but in all the cells of the parent. Somehow the cells of the parent produced little granules that were collected by the seeds. The granules then instructed the seeds how to grow. For the rest of his life Darwin continued to believe in pangenesis, but it was another brilliant blunder, no better than blending inheritance and equally inconsistent with the facts.

  Like Darwin’s theories of blending heredity and pangenesis, Kelvin’s wrong calculation of the age of the earth and Pauling’s wrong structure for DNA were speculations requiring blindness to obvious facts. Kelvin based his calculation on his belief that the mantle of the earth was solid and could transfer heat from the interior to the surface only by conduction. We now know that the mantle is partially fluid and transfers most of the heat by the far more efficient process of convection, which carries heat by a massive circulation of hot rock moving upward and cooler rock moving downward. Kelvin lacked our modern knowledge of the structure and dynamics of the earth, but he could see with his own eyes the eruptions of volcanoes bringing hot liquid from deep underground to the surface. His skill as a calculator seems to have blinded him to messy processes such as volcanic eruptions that could not be calculated.

  Similarly, Pauling guessed a wrong structure for DNA because he assumed that a pattern that worked for protein would also work for DNA. He was blind to the gross chemical differences between protein and DNA. Francis Crick and James Watson, paying attention to the differences, found the correct structure for DNA one year after Pauling missed it.