In the last issue of LaLivella, we dealt with Enrico Fermi’s role in leading the word towards the atomic age [1]. We saw how, starting from very heavy atoms such as uranium and bombarding them with neutrons, it is possible to break their nucleus, thus creating two lighter nuclei and releasing an enormous amount of energy. Both nuclear power stations and atomic bombs are based on this principle. This phenomenon of fracturing atomic nuclei is called ‘nuclear fission’.
That being said, there is another nuclear process, which might be considered to mirror that of fission, which is known as ‘nuclear fusion’. This is based on the union of two or more atomic nuclei, resulting in a heavier nucleus and, again, releasing a large amount of energy. While fission uses very heavy and unstable atoms, such as uranium or plutonium, fusion uses extremely light atoms such as hydrogen. In nature, the process of fission is quite common; it is enough for an atom to be radioactive for it to decay naturally through nuclear fission. Fusion, on the other hand, is much rarer, at least for us inhabitants of planet Earth. Fusion requires extremely high temperature of tens of millions of degrees. This is why fusion only occurs in the cores of stars and other particularly violent sidereal locations. It is through fusion that the light elements present in the early universe came together to form the heavier elements that put us and most of what surrounds us together. On Earth, fusion occurs only artificially. It could represent the future of newly designed nuclear power plants in the coming decades.
Therefore, even at the juncture of terrestrial applications, fusion has followed the opposite path to fission. Thanks to Fermi, we have seen that fission was first used in power stations to produce energy and subsequently as an atomic bomb. Fusion, on the other hand, saw its first application in the hydrogen bomb or H-bomb, whose father in the Soviet Union was Andrei Sakharov.

At the end of his doctorate, Sakharov was introduced to a research team led by his professor, Igor Tamm, a high-ranking physicist who won the Nobel Prize for physics in 1958. The team’s objective was simple: to nuclear-arm the Soviet Union and catch up with the United States. Sakharov will live and work in a secret military site, controlled by the secret services, for about twenty years.
At the beginning of his career as a young scientist, Sakharov firmly believed in the importance of nuclear deterrence and the vital need to arm his country to balance the world’s military power. Hence, the first Soviet nuclear bomb was successfully tested just one year after Sakharov’s arrival. Later on, in his memoirs, he wrote about their succeeding by almost makeshift means due to the industrial state of the post-war Soviet Union. This was nothing compare to the means that the United States had provided for its Manhattan Project scientists. Nevertheless, for the next ten years, his work would focus on the creation and development of the even more sophisticated H-bomb.
To activate nuclear fusion – and thus the H-bomb – we have said that impressive temperatures are required. This is why nuclear fusion bombs are also called ‘thermonuclear’. So, how is it possible to reach such temperatures on Earth, with the means of the Soviet Union still weakened by the war against the Nazis?
By exploding a nuclear fission bomb. The H-bomb, in practice, is actually a double bomb, with two compartments: the first is a nuclear fission bomb which, when exploded raises the temperature to the extent of triggering the fusion inside the second compartment, thus creating even more deadly power.
The work of Sakharov and his team reached its highest point in the early 1960s. On 30th October 1961 at 11:32 a.m. the ‘Tsar bomb’, the most powerful bomb ever tested in history, was dropped on the island of Novaja Zemlja, north of the Arctic Circle. With three thousand times the energy of the bomb dropped by the Americans on Hiroshima, the explosion of the Tsar bomb produced a ‘mushroom cloud’ that reached a height of 64 kilometres and produced a flash visible from 1,000 kilometres away.
The following year a new phase of life began for Sakharov. He became aware that Soviet military power had become detached from the rest of the state apparatus. It had become an autonomous power, responding to logics disconnected from both science and the good of the country. In September of that year, two new nuclear tests were planned. Sakharov believed that radiation could seriously endanger the lives of thousands of civilians without any real scientific need. He tried to persuade the Soviet prime minister to abandon the project, but he was ignored. They went ahead with the test as planned. The two bombs were launched.
Something then changed in him profoundly: «A terrible crime had been committed, and I couldn’t prevent it! A feeling of impotence, unbearable bitterness, shame and humiliation overcame me. I dropped my face on the table and wept. This was probably the most terrible lesson of my life: you can’t sit on two chairs».

So, the conversion of the inventor of the H-bomb into the Soviet Union’s most famous dissident began. His struggle was courageous, painful and cost him seven years in exile. Even after his rehabilitation, he continued his political activism for peace and world cooperation until his death. Today, in addition to his example and writings, in the West, his name is connected to the award that the European Union gives to those who have distinguished themselves in the fight for human rights. While in Russia, ‘Memorial’, the human rights association he founded – the oldest in Russia – was closed down a few months ago by the Supreme Court.

His manifesto, published in the New York Times, earned him expulsion from the Soviet intelligentsia, begins with this timely warning: «The division of mankind threatens it with destruction. Civilization is imperilled by: a universal thermonuclear war, catastrophic hunger for most of mankind, stupefaction from the narcotic of “mass culture”, and bureaucratized dogmatism, a spreading of mass myths that put entire peoples and continents under the power of cruel and treacherous demagogues, and destruction or degeneration from the unforeseeable consequences of swift changes in the conditions of life on our planet.
In the face of these perils, any action increasing the division of mankind, any preaching of the incompatibility of world ideologies and nations is madness and a crime».