World War II, like World War I, brought about scientific and technological developments that soon became matters of life and death. The nature of total war itself prompted a transformation in the relationship between states and scientists. Governments invested in the development of lethal and nonlethal technologies that ultimately became essential to the war and national security. In the fall of 1939, the British scientific community rapidly shifted its focus from matters of pure research to work aiding the war effort. Advances in the understanding of radio waves led to the development of radar, providing advance warning of enemy attacks. Other advances injected more and better electronics such as microwaves and early versions of digital computing devices into a wide range of military applications, laying the foundation for the commercial proliferation of electronics into everyday life after the war. Allied efforts to break the Nazi spy codes inspired the birth of the first rudimentary computers. The British mathematician Alan Turing and a team of scientists working for the British Secret Service set out to break the seemingly unbreakable Nazi Enigma code. In the process, they built an electromagnetic device that could cycle through hundreds of thousands of possible key/letter combinations in intercepted Nazi messages and eventually succeeded in breaking the code. Another breakthrough in computing was ENIAC, the Electronic Numerical Integrator and Computer, which was first developed to calculate artillery trajectories for the U.S Army and performed its calculations at electronic, not mechanical, speed. It is estimated that by 1955, ENIAC had completed more calculations than humans had ever solved to date. Link to Learning Long-term results of World War II include the beginning of computerization. Alan Turing predicted that someday machines would be able to pass the Turing test, which he called the imitation game. That is, machines would behave in ways that were indistinguishable from human actions. This video explains the Turing test in more detail. Presented in this video is an example of the logic of artificial intelligence as demonstrated in “Sophia answers the Trolley Problem.” Advances were made in life-saving scientific and medical techniques as well. A major medical development during the war improved the use and mass production of the antibiotic penicillin. Another life-saving advance was the achievement of Charles Drew, an African American physician who developed the process of rendering blood plasma, making it easier to store it for longer periods of time and offering an effective replacement for whole-blood transfusions. But racial bias entered the picture in 1941 when the American Red Cross agreed with a War Department decision to label blood and plasma as either “White” or “Negro.” Dr. Drew resigned from the National Blood Bank as a result of this racist and unscientific policy. Few developments were more dramatic than the massive mobilization of scientific and civilian resources for the building of the atomic bomb. In December 1938, German physicists Otto Hahn and Fritz Strassmann accidentally split atoms and discovered nuclear fission. A few months later, the Germans established a secret weapons program called the Uranium Club to create an atomic bomb. Seeing the implications of Hahn’s work, German-born physicist Albert Einstein, who had recently immigrated to the United States, sent a letter to President Roosevelt that had been written by physicist Leo Szilard, warning Roosevelt of this research and urging an increased U.S. commitment to conducting its own. By the late 1930s, British and other scientists became convinced that an atomic bomb was possible, and teams of physicists, some of them refugees from Nazi Germany, assembled and began experiments with nuclear chain reactions, the catalysts of an atomic explosion. In August 1942, the U.S. government boosted this effort with its top-secret Manhattan Project. At dozens of sites across the United States, from Los Alamos in New Mexico to Oak Ridge in Tennessee and Hanford in Washington State, 600,000 workers embarked on a frenetic race to build the world’s first atomic bomb. Meanwhile, Germany and Japan were also attempting to build their own. The German effort was hindered by technical and other problems. For example, top German scientists had fled Germany, and some were assisting the Manhattan Project. Further, Hitler preferred to support the development of V2 bombers for the air war with England rather than an atomic bomb. In 1941, the Japanese commissioned physicist Yoshio Nishina to begin working on an atomic bomb, calling the project Ni-Go. But lacking any information shared by the Germans and suffering under successful U.S. air raids, the project did not make much progress. Eventually, in July 1945, the Manhattan Project bore fruit, and a bomb was successfully detonated in the Trinity Test at Alamogordo, New Mexico. William L. Laurence, the official historian of the project, described this first successful trial of an atomic weapon: “On that moment hung eternity. Time stood still. Space contracted to a pinpoint. It was as though the earth had opened and the skies split. One felt as though they had been privileged to witness the Birth of the World—to be present at the moment of Creation when the Lord Said: Let there be light.” President Roosevelt had died suddenly in April 1945, succeeded by Vice President Harry S. Truman. It fell to Truman to decide whether to use the new weapon or not.