During the World War II a team of scientists was working on building the most powerful bomb of all time. It is known today as Project Manhattan, a secret programme then, which was realized in Los Alamos, New Mexico. Eventually, creating the bomb has become a reality and changed the world, especially influencing the image of potential next great war. It made us more careful about reasons of possible conflicts, but also more scared about their effects. On the other hand, it can be perceived as a guarantor of the peace on a global scale. Paradoxically, the fact of possesing such destructive weapons by possible opponents effectively stops superpowers from attacking each other. I want to touch on these two opposite points of view by outlining biographies of two Polish scientists who participated in the project.

Stan Ulam, a mathematician from Lwów (now Lviv, Ukraine), was engaged in Project Manhattan by John von Neumann. Due to his Jewish origin he was unable to being a scholar after getting doctorate, because of favorizing christian candidates by Polish universities. Forced to go abroad, he eventually found his place in United States, but turned back every summer to discuss mathematics with old colleagues. This decision saved his life, because the World War II broke out eleven days after the very last departure. After a few years of working as a lecturer and scholar in several places in America, he desired to do something that would be helpful to the Allies. It was the spring of 1943 when he joined the US Army Air Forces. Simultaneously he wrote a letter to John von Neumann expressing his eagerness to work in favour of the war. This way he got involved in a top secret government project in purpose of constructing an atomic bomb, when no one knew is it possible at all. His innovative mathematical methods of computing and estimating required parameters of the bomb caused a remarkable impact on pace of work in Los Alamos. It turned out that building such a bomb is possible and can be done by people of that time. Then, the whole team focused on turning the theory into reality. The goal was to possess this weapon before Germans. As we know, they succeeded... but there was also another aim on the horizon.

Joseph Rotblat was a physicist living and studying in Warsaw. He was of Jewish origin as well as Ulam. After getting a doctorate from the University of Warsaw he got a scholarship in Liverpool, Great Britain. He had to go there without his wife Tola Gryn, because of the financial reasons. When the value of his scholarship doubled, he came back to take her with him, but she had appendicitis and was unable to travel. She promised to join him as soon as she felt better. It was the 31th September when he lonely arrived there to continue assisting James Chadwick, two days before the war broke out. Tola was no more seen by him as she died in concentration camp. Through his entire lifetime it was too difficult for him to talk about her, thus he refused everytime when someone asked. Eventually, he got involved in the Manhattan Project as one of physicists. Even earlier he was examining collisions of elementar molecules, in both Warsaw and Liverpool. He claimed that (as a result of his research) it is possible to arrange a chain of nuclear reactions artificially, which would lead to an explosion of an unimaginable power. He said his first thought was to “put the whole thing out of my mind”. But danger of Nazi Germany changed his mind, causing him to join works on that bomb. His role in Los Alamos consisted of investigating if gamma rays affects the nuclear chain reaction and how does it happen. He met Stan Ulam there, with whom he was able to talk in Polish. He refused gaining US or British citizenship, because of the strong bond with Poland.

The other aforementioned aim was the hydrogen bomb. It was not preceded by pursuit of outrunning the war enemy. Many people ask whether it was necessary to build the next bomb, even mightier than the previous one. A lot of people who worked on that bomb and saw photos from Hiroshima and Nagasaki immediately stopped working for the government and turned back to their academic life. Stan Ulam saw the hope of building such a dreadful and powerful weapon as no one would start any war at all. That was his idea for ensuring the global peace. For this purpose he did his best to construct such a powerful bomb and now he is often called “mother of hydrogen bomb” (Edward Teller is “the father” and the construction - “Teller-Ulam configuration”). It is said that without his work it wouldn’t be possible to build it. By providing this kind of weapon he hoped that people will be too scared of its potential effects to start new wars. In the mid 1950s he started to consider nuclear propulsion for rockets and spacecrafts. He studied possibilities of such an approach with other scientists and engineers until USA signed a treaty in 1963 that precluded any tests in this direction. Eventually, he turned back to academic life and, as a proffesor of several universities, continued his mathematical career.

Joseph Rotblat had another conviction. Immediately after getting informed about the usage of the bomb, what stood in condradiction to his reasons of working on that project – defeating Germany, he declined further work for the US government and founded Pugwash. Rotblat’s foundation had a clear goal – to prevent the world from the nuclear doom. A lot of scientists started to co-operate with him to promote actions against the increasing amount of nuclear missils in the world. Pugwash remained a non-governmental organization despite of many opportunities to change it. In 1985 he found out, from secret recording, that the real aim of constructing nuclear weapons by USA in 1940s was getting the military superiority over USSR. It truly shocked him. He even proposed some ethic rules for scientists similarly to hippocrathic oath made by physicians. He claimed that scientists should reduce their scientific curiosity and restrict themselves in their work as the results could be devastating for the world. For his engagement in tendencies to demilitarise the world Joseph Rotblat and Pugwash were honoured with the Peace Nobel Prize in 1995. He researched for nuclear medicine, too. Especially, he examined the impact of radiation on formation of cancer cells.

These two significant scholars with totally opposite point of view on role of atomic bomb in today’s world are good represantions of what people can think of the problem. One side says that it guarantees the global peace, another one - that it should be limited to a safe extent or even abolish them. No matter what is the right statement, we should bear in mind that history often repeats itself. As we were frightened about Germans who can possess such a destructive weapon, there still might be someone inappropriate who will somehow get an access to it. And if it is the most powerful weapon of the human kind, what should we use instead to prevent him? On the other hand we don’t need endless amount of it just to use it against a person or country using it unproperly. There has to be a limit of reasonable amount of it. Perhaps such golden mean does exist.

Taking everything into account, one can spot that the problem of nuclear weapons is quite difficult to sort out. In each of these two attitudes there are rational arguments, but each of them excludes the other one.