Event 87

Beginning 1942 AD

Atomic Mushroom Cloud
Photo of a nuclear weapons test, nicknamed “Mike,” taken on November 1, 1952. The test was part of Operation Ivy. Mike was the first hydrogen bomb tested.
Credit: Photo from U.S. Department of Energy, courtesy of Wikipedia.

The atom (Greek for “uncuttable”) was a concept forwarded by the ancient Greek philosopher Democritus for the hypothetical smallest unit of matter. During the late 1800’s and 1900’s physicists explored deeper and deeper into the structure of matter. In the early 1900’s studies of radioactive materials like uranium, thorium, polonium, and radium by Madame Marie Curie and her husband Pierre (this research tragically caused her death from radiation poisoning) showed that these unstable materials gave off high-energy particles. Between 1910 and 1945 a tremendous amount of headway was made in modeling the nature and structure of atoms, in understanding processes such as radioactive decay that naturally transform certain atoms into other atoms, and, in deliberately manipulating atomic structure to produce other forms of atoms through bombardment with certain particles (such as alpha particles and neutrons). Eventually such manipulation resulted in control of nuclear fission, which not only produced new, smaller particles but also a tremendous amount of energy in the process. The meaning of Einstein’s equation E=mc2 had been truly revealed, and, with the construction of the first nuclear reactor in 1942 to contain and control nuclear chain reactions, the atomic age was born.

The first deliberate nuclear reaction was achieved by Ernest Rutherford (the ‘father of nuclear physics’) in Manchester, England in 1917, in an experiment in which he directed particles at nitrogen to transform it into oxygen (called ‘nuclear transmutation’). In the 1930’s a number of researchers, including John Cockcroft and Ernest Walton in Britain and Enrico Fermi in Italy, conducted experiments resulting in apparent ‘splitting of atoms’ by bombarding them with accelerated particles, producing nuclear reactions. The first nuclear fission (splitting uranium into barium) was then accomplished by 1938 by German researchers, chemists Otto Hahn and Fritz Strassman, working in Berlin, and physicist, Lise Meitner, who had to flee Germany during Hitler’s rise and worked in Scandinavia.

News spread quickly of this discovery, particularly with the visit of Danish physicist Neils Bohr to Princeton University, and by 1939 scientists at Columbia University were conducting their first fission experiment in the basement of the physics building. A letter on August 2, 1939 from Albert Einstein (drafted with Hungarian physicist, Leo Szilard, who had originated the concept of nuclear chain reactions in 1933) to Franklin Delano Roosevelt, alerted the U.S. administration that recent research was showing potential for uranium to “be turned into a new and important source of energy in the immediate future,” making it possible to “set up a nuclear chain reaction” that could produce “vast amounts of power.” Continuing to say that “extremely powerful bombs of a new type may thus be constructed,” he warned that Germany was currently taken over Czech uranium mines and may be repeating American work on uranium. Overall, the “Einstein letter” exhorted that the situation called for “watchfulness and, if necessary, quick action on the part of the administration.” U.S.-led Manhattan Project began, which during the ensuing years developed the atomic bomb. By October of 1939, uranium research was approved and the foundation laid for what ultimately came to be known as “The Manhattan Project,” a secret research program essentially working to develop a nuclear bomb before Hitler did.

 09 087 002chicagonuclearreactor
Drawing of the nuclear reactor built under the stands of an abandoned football stadium at the University of Chicago. The first nuclear chain reaction was conducted here in 1942 by Enrico Fermi and his team within this structure of graphite blocks containing lumps of uranium. This nuclear chain reaction, which sustained itself for 28 minutes before being shut down, produced a controlled release of nuclear energy, which has since been harnessed for bombs and weapons or as sources of energy for other purposes.
Credit: Illustration from Melvin A. Miller of the Argonne National Laboratory, Courtesy of Wikipedia

The first operational nuclear reactor (“Chicago Pile-1) was built under the Stagg Field Stadium at the University of Chicago as part of the Manhattan Project and under Enrico Fermi’s direction. In this reactor, the first self-sustaining nuclear chain reaction was set forth in 1942. The first experimental atomic weapon was detonated at Los Alamos, New Mexico in 1945, followed that same year by the atomic bombings of Hiroshima and Nagasaki in Japan near the end of World War II. During the Cold War that followed, the United States and the Soviet Union embarked on a nuclear arms race with the build-up of nuclear arsenals, and presently eight countries are known to have nuclear weaponry.

The first experimental energy-producing nuclear reactor was in 1951 in Idaho (and experienced a partial meltdown in 1955). Today there are over 430 nuclear power plants in over 30 countries, with more under construction and more planned. The nuclear reactors create high levels of heat, which in turn heats water to generate pressurized stream in order to run its turbines, producing electricity. They presently produce about 15% of the world’s electricity (the rest being produced by the burning of fossil fuels). Nuclear power plants can generate almost unlimited energy without the use of fossil fuels, but create radioactive waste (which is toxic for over 1,000 years) which must be disposed of. Events at Three-Mile Island in Pennsylvania, Chernobol in the Ukraine, and of course after the earthquake and tsunami in Japan on March 11, 2011, have shown the dangers of nuclear power plants if they malfunction due to human error, natural disasters, or, possibly, even terrorist acts.




The electricity you use has been partially produced by nuclear power plants. And the proliferation of nuclear weapons around the world and the fear of terrorists getting access to nuclear weapons or materials is something we should all take seriously.






This is an archive ofinformation about atomic history, including the Cold War, Manhattan Project, Hiroshima, the Trinity test, and others

This is a Wikipedia webpage about nuclear weapons.



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