During the late 1930s, the field of nuclear science grew rapidly. Many advances in physics were made, culminating in the viability of nuclear fission. The beginning of the so-called nuclear age, though, really came from Einstein's 1905 papers. His development of the special theory of relativity was seminal in creating the ideas and science that would later lead to the invention of the atomic bomb. The equation E=mc2 indicated that a lot of energy could come from a relatively small amount of matter (see Chapter 7), and this was one of the founding principles behind the atomic bomb.
“Nuclear fission,” in this context, means that a uranium atom could be split into smaller elements. When this fission turned into a chain reaction, under a controlled environment, energy would be released. Controlled chain reactions became possible, meaning atomic power could be released gradually. Lots of atoms could potentially be split at once, leading to a huge explosion. These ideas struck physicists, and eventually would trickle down to the rest of the world–could this power be contained in the form of a nuclear weapon?
What is a chain reaction?
A chain reaction (as it relates to nuclear fission) is a technique whereby the end products from one reaction become the reactants in another reaction. For example, neutrons can initially be added to an unstable fuel. Fission occurs (producing more neutrons as well as other products), and these neutrons result in more fission of more of the fuel. This process continues until all the fuel is used up.
The Impact of Szilard
A Hungarian physicist by the name of Leo Szilard (1898—1964) played a major role, along with Einstein, in the militarization of the developing nuclear age. He was in tune with the European research community, and even more aware of the potential danger that advances in physics could have.
Leo Szilard, like Einstein, was Jewish. The son of a civil engineer, Szilard studied engineering at Budapest Technical University in 1916. He served in the Austro-Hungarian army starting in 1917, continuing his studies in 1919. In 1920 he moved to Berlin and began studies at the University of Berlin, and he took physics classes from none other than Albert Einstein.
Szilard and Einstein collaborated on scientific projects during this period, notably a design for a refrigerator pump. By the 1930s, however, Szilard found himself subject to the same terror from the Germans as Einstein. He would eventually leave Europe in 1933 for the same reasons as Einstein–mainly, to avoid the Nazi threat. He would work on chain reactions and nuclear fission throughout the 1930s.