Welcome to Atomic Week where we will investigate the intriguing case of the development of the atomic bomb. Naturally, we must start such a week with Albert Einstein. Einstein was not directly involved in the Manhattan Project, which developed the bomb, but his theoretical work helped to lay the groundwork for the development of the bomb.
In Einstein's work on his theory of relativity, he came up with the famous relationship of:
E = mc²
E is energy, m is the mass, and c is the speed of light. The equation shows that the total energy in any given object is the mass of the object multiplied by the speed of light squared. Light is very fast, so the speed of light is a very large number. This means the total energy in even a relatively small object is very large.
In fact, something as small as a grapefruit, if all the energy were released, would create an explosion that could level a city.
Enrico Fermi was one of the first to make this connection. He had successfully established sustained nuclear chain reactions, in which mass was being converted to energy. He speculated that such a reaction could be used to create incredible amounts of energy, or even bombs.
With World War II underway, Einstein realized that the technology existed to create a super weapon in which mass of radioactive material was converted to energy, creating an enormous explosion. He believed that Germany might be working on a super weapon, and that the US could be caught flat footed. Concerned about the matter, he wrote President Roosevelt the following letter. This letter then led to the development of the Manhattan Project to create the atom bomb.