Franklin D. Roosevelt, the President of the United States of America, received a letter on this day from Albert Einstein warning him of Germany’s plans for creating an atomic bomb.
In the letter, written in August but arriving in October, Einstein describes how he feels uranium may be used by the Germans as a source of power. Einstein explained in the letter how a chain reaction could be triggered in uranium which could unleash ‘vast amounts of power’ and this chain reaction could be used in by someone to create ‘extremely powerful bombs of a new type’ may thus be constructed’. He then continued by describing how such a bomb could be transported by ship into a port and detonated, leading to the destruction of the port and surrounding areas. Einstein felt an atomic bomb may be too heavy to carry on an aircraft.
Einstein offers some recommendations to the President, including assigning a person to inform the US Government of any further developments, highlight problems, source uranium for the United States, speed up US development of an atomic weapon and find funding for development.
Einstein finishes his letter by highlighting how Germany has stopped exports of uranium from Czechoslovakian mines, a sign he believes of Germany’s intentions to use the uranium it produces in its own atomic weapon development.
The letter would convince President Roosevelt to start the Manhattan Project, the US’s atomic weapon development programme.