atomic bombs dropped on Hiroshima and Nagasaki rise in public television broadcasting transistor developed by Bell Labs as the first alternative to the vacuum tube Wiesner with Dr. Y.W. Lee invents auto-correlator, a device used to decrease radar and radio noise Soviets test an atomic bomb North Korea invades South Korea UNIVAC I, the first commercial computer, is delivered to the U.S. Bureau of the Census 1945 1946 1947 1948 1949 1950 1951 Franklin D. Roosevelt dies Harry S Truman becomes President of the U.S. Germany and Japan surrender United Nations founded beginning of the Cold War McCarthy steps up investigations against 'communists' in the U.S.