Clouds of Deceit (5 page)

But the story begins at the end of the nineteenth century. In
1895, Wilhelm Roentgen discovered X-rays in his laboratory in Bavaria. The rays were capable of penetrating opaque objects – a book of a thousand pages, for instance, or human flesh. Roentgen gave this form of radiation the name ‘X-rays' because he did not know their cause. Months later, in February 1896, Henri Becquerel found that uranium salts emitted radiation which would blacken a photographic plate. Becquerel's discovery of radioactivity in uranium was followed in 1898 by the identification, by Marie and Pierre Curie, of other elements which emitted radiation in this way, including radium.

These discoveries were not unaccompanied by warning signs. Pierre Curie discovered that a patch of his skin had become very red after he had carried a small phial of radium salt in his pocket for a few days - a clear sign that radiation could affect human tissue. In 1902, a factory worker employed on making and demonstrating X-ray tubes in Hamburg developed a tumour on his hand. A monument in that city to the so-called ‘radiation martyrs' records 169 deaths attributable to radiation among radiologists. Marie Curie herself died in 1934 of a blood complaint contracted through exposure to radiation; the same fate later befell her daughter, who carried on her mother's research.

In 1927, five employees of the Radium Luminous Material Company in New Jersey sued for damages after suffering rotting jaws and spines. The women were employed to paint the luminous dials of wrist watches, using radium paint. They used to lick their brushes to a fine point after dipping them into the paint; by 1924, nine of them were dead and many crippled. When the case came to court, Marie Curie was among the well-wishers who sent them messages of sympathy. They settled for lump sums of $10,000, and small pensions.

But the evidence of the horrifying effects of radiation on human beings did nothing to deter the quest for further knowledge. What the rays were composed of, and their relationship to the atom, exercised the minds of scientists throughout Europe, and beyond. The reason for this fascination was that the particles emitted by radioactive substances seemed to offer the first real hope of achieving the impossible - splitting the nucleus of the atom, and thereby liberating vast quantities of energy.

The word ‘atom' has a Greek root and means ‘indivisible'. Until the end of the nineteenth century, this is exactly what the atom was thought to be - an indestructible piece of matter resembling a golf ball. But the work of physicists was to change this picture irrevocably in the early years of the twentieth century. It was an unprecedented time for physics, with momentous discoveries coming thick and fast as scientists took up each other's exciting new ideas and developed them further. The devastating link between discoveries about the atom and the bomb was to be provided by Albert Einstein.

One of the key scientists in the field was Ernest Rutherford, who was born in New Zealand in 1871 but did his pioneering work in England in the first decades of the twentieth century. Rutherford examined the radiation given off by uranium, and gave the names alpha and beta rays to the two kinds he found. Meanwhile a French contemporary, Villard, discovered a third type, gamma rays.

The significance of this work on the nature of radiation is that it produced the revolutionary new idea that atoms are not indestructible. Radioactivity, it turned out, was the spontaneous disintegration of the nucleus of the atom, throwing out part of itself in the process. Rutherford and Niels Bohr, the Danish physicist who would later work on the Manhattan Project, produced a new theoretical model of the atom which was based on the solar system. In this model, the nucleus takes the place of the sun, and the electrons occupy the place of the planets.

The phenomenon of radioactivity raised the hypothesis that it might be possible to split the atom artificially, with the loss of a small amount of mass from the nucleus in the process. The implications of this possibility only became clear with the publication of a series of papers in 1905 by Albert Einstein.

Einstein said that mass and energy are equivalent - different sides of the same coin - and came up with a formula to measure the amount of energy which would be released by converting one into the other. Einstein's formula, E = mc
²
, demonstrates how much energy would be released by the conversion of even a small mass. E stands for energy, m for mass, and c for the speed of light. Since c is 186,000 miles per second, it is evident that
even if m is small, you will end up with a very large quantity of energy.

Physicists began to cast around for ways of splitting the nucleus of the atom artificially. They tried alpha particles, but found they were usually repelled by the nucleus. In 1932, in England, James Chadwick discovered the neutron, thereby completing the model for the structure of the atom - it was now clear that it consisted of a nucleus made of protons and neutrons, and a number of electrons in its outer structure - and at the same time putting science firmly on the road to what would be known as nuclear fission.

While scientists began bombarding a variety of elements with neutrons, in the hope of splitting the nucleus of the atom in two, many people remained sceptical. In 1933, Rutherford, who had by then been made a peer, told the annual meeting of the British Association that anyone who predicted the release of atomic energy on a large scale was ‘talking moonshine'. But in 1935, Frédéric Joliot-Curie, son-in-law of Marie Curie, said that scientists who were able to construct and demolish elements ‘may also be capable of causing nuclear transformations of an explosive character… If the propagation of such transformations in matter can be brought about, in all probability vast quantities of useful energy will be released.'

In the end, scientists achieved the splitting of the atomic nucleus without realizing what they had done. In 1934, the Italian Enrico Fermi produced infinitesimal amounts of what he thought were completely new substances by bombarding uranium, the heaviest naturally occurring element, with neutrons. He believed he had produced new,
heavier
elements. It was not Fermi but the German chemist Ida Noddack, who suggested a different interpretation - that Fermi might have achieved a ‘new type of nuclear disintegration brought about by neutrons.' At the time, no one took the idea seriously.

Otto Hahn, a German chemist, working with Fritz Strassman, repeated the experiment and found barium among its products. Far from being a completely new,
heavier
element than uranium, barium is actually much
lighter.
Instead of turning into a heavier substance by absorbing a neutron, the uranium
appeared to have become much lighter. At Christmas, 1938, Hahn wrote to a former colleague, Lise Meitner, an Austrian physicist who had taken refuge in Sweden from the Nazi persecution of the Jews.

Meitner told her nephew, Otto Frisch, with whom she was spending Christmas, about the results outlined in Hahn's letter. Slowly, they realized the implication of Hahn's finding. They remembered Neils Bohr's description of the nucleus of the atom as similar to a drop of liquid. ‘It looked as if the absorption of the neutron had disturbed the delicate balance between the forces of attraction and the forces of repulsion inside the nucleus,' Frisch said later. ‘It was as if the nucleus had first become elongated and then developed a waist before dividing into two more or less equal parts in just the same way that a living cell divides.'

The most significant thing about fission, as Frisch decided to call the process, was that the combined weight of its products would be less than that of the original nucleus of uranium. The loss of mass would be only a fifth of a proton - but Einstein's equation had shown that this would be sufficient to produce a great deal of energy.

If Frisch and Meitner were right, it should be possible to detect the energy given off, in the form of a measurable electric pulse. They worked out that the amount of energy released, according to Einstein's equation, should be 200,000,000 electron volts. Frisch devised equipment capable of making an accurate measurement and repeated the experiment. It produced exactly the result they had predicted.

The news that the nucleus of the atom had been split galvanized other scientists. Niels Bohr read the paper written by Hahn and Strassman, explaining their findings, while he was attending a meeting of the American Physical Society in Washington. He told other scientists about it on 26 January 1939, adding details of Meitner and Frisch's theory about fission. Some physicists rushed from the room to repeat the experiment for themselves. Meitner and Frisch published their conclusions in a letter in
Nature,
the British scientific journal, on 11 February 1939.

In 1939, as the countries of Europe moved inexorably towards
the outbreak of the Second World War, the release of vast quantities of nucleur energy began, for the first time, to seem more than a fantasy. Meanwhile, as early as 1934, Leo Szilard, a Hungarian physicist, had come up with one of the key ideas for producing sufficient energy to make an atom bomb, that of the chain reaction - when the neutron hits the nucleus of the first atom and splits it, more neutrons are thrown out at the point of fission, which then split further atoms, and this process is then repeated.

In the late 1930s, Szilard became obsessed with the idea that Nazi Germany might be able to solve the problems still standing in the way of the bomb. In 1939, as the achievement of Hahn and Strassman became known and the political situation worsened, Szilard's obsessive quest to persuade the British and American governments to make the bomb took on greater urgency.

He hit on the idea of involving Albert Einstein, then living in the US. He persuaded Einstein to send President Roosevelt a letter, dated 2 August 1939, which predicted that uranium would soon be turned into ‘a new and important source of energy'. It said that an atom bomb, exploded in a port, might well destroy all of it, along with some of the surrounding territory. The letter, whether written by Einstein or just signed by him at Szilard's prompting, urged Roosevelt to consider making the atom bomb. It succeeded in persuading Roosevelt to take action - he set up a Uranium Committee which, although it moved cautiously, started looking at the possibility.

What was probably the most vital piece of work at this stage was actually done in England. When war broke out, the German scientist Rudolf Peierls happened to be out of Germany on a visit and he refused to go back. He moved to Birmingham University, where he worked with Otto Frisch, by now also a refugee from the Nazis. In March 1940, the two scientists produced a three-page memorandum for the British government. Margaret Gowing, official historian of atomic energy in Britain, describes it as ‘a remarkable example of scientific breadth and insight'. It was, she says, ‘the first memorandum in any country which foretold with scientific conviction the practical possibility of making a bomb and the horrors it would bring.'

September 1939 put a stop to the free exchange of ideas between scientists which had made the atom bomb a possibility. Frisch and Peierls were doing their work at the very time when the veil of secrecy was falling on science. Although, to the horror of people like Szilard, papers on nuclear fission were published in 1939, the outbreak of the war brought with it a reversal of the tradition of openness between scientists.

That such a change was inevitable in the circumstances did not prevent it bringing with it far-reaching and baleful effects. The US government developed a proprietorial attitude to anything associated with nuclear energy both during and after the war, an effect which led directly to the arms race which continues today. At the beginning of the war, the US overestimated Germany's capacity to work out how to make the atom bomb; by the end of it, the American government clung obstinately to the illusion that the US was decades ahead of the USSR in nuclear technology and should hang on to that advantage, come what may. Scientists in Britain and the US pleaded with their governments to dispel Russia's suspicions about the West's intentions by sharing nuclear secrets: a course, they thought, which offered the best chance of controlling the terrifying weapons demonstrated at Hiroshima and Nagasaki.

But the US government remained obdurate, and tried to maintain its pre-eminence in the field by closing the doors even to its close ally, Britain. America's illusion of superiority was shattered only four years after the nuclear attack on Japan: the USSR exploded its first bomb in Soviet central Asia in August 1949. But by then the damage had been done and the arms race was already well under way.

Towards the end of the war, it became clear from intelligence reports that Hitler's Germany was a long way from making an atom bomb - its efforts had been hampered both by the exodus of scientists from Germany and by a decision to use a technical process which required a substance called heavy water, the greatest supply of which had been successfully removed from France just before the German invasion. The US government's motives in going on with the Manhattan Project, after the removal of the threat which gave birth to it, are a matter of conjecture.
On the one hand, work was stepped up so that the bomb would be ready to drop on the Japanese before the end of the war. At the same time, General Leslie Groves, the army engineer in charge of the project, told scientists in 1944: ‘You realize that all our work is against the Russians?' One scientist who had gone to work on the project from a British university, Polish-born Joseph Rotblat, remembers to this day the effect this revelation had on him. ‘To me, this came as a terrible shock. The Russians were our allies. Thousands were dying every day stemming the advance of the Germans. I never really got over that.'

Nevertheless, at the outbreak of the war, the scientists who pushed their governments to make the atom bomb did so out of fear and loathing for Hitler. In Birmingham, Otto Frisch and Rudolf Peierls worked on their famous memorandum, which was to offer striking new solutions to a number of the technical problems involved in making the bomb.