history+of+radiation

The following is a brief timeline outlining some of the major events concerning radiation. It is by no means comprehensive.

1895 - Rontgen uses a CRT to generate X-Ray radiation; leads to its use in X-ray machines for the medical field.



1896 - Becquerel discovers radioactive properties of uranium by accidentally irradiating and exposing photographic plates.



1898 - Marie Curie discovers new radioactive elements - polonium and radium - and finds that thorium is radioactive as well. She and her husband Pierre coin the term "radioactivity" to describe the phenomenon of radiation.



1902 - Ernest Rutherford discovers the fact that some types of radioactive decay create different elements from their original sources.

1911 - Frederick Soddy found that radioactive decay of both thorium and radium created lead, but in two distinct masses - lead-208 and lead-206, respectively, and called these "isotopes" of lead.



1913 - Thomson identifies two isotopes of neon (20, 22) using a CRT to separate charged neon gas into two streams.



1919 - Ernest Rutherford is the first to transmutate one element into another (N to O), a feat unsuccessfully attempted since the days of alchemy.



1932 - James Chadwick discovers the neutron, a key particle in the nucleus and important in nuclear transformations.

1939 - Otto Hahn is the first to discover nuclear fission of uranium in Nazi Germany as the second World War is about to begin. Lise Meitner and Otto Frisch determine that the energy released during nuclear fission confirms Einstein's famous E = MC 2 theory he wrote of in 1905.

1939 - US President Roosevelt begins the Manhattan Project after a letter from Einstein encourages him to develop atomic weapons before the Nazis do.

1941 - Glenn Seaborg discovers plutonium.

1945 - On July 16, the first atomic bomb was tested (code-named [|Trinity]); it was a plutonium implosion bomb with a 20 kiloton explosive yield.



1945 - On August 6, the [|"Little Boy"] uranium bomb was dropped on Hiroshima - the first time an atomic bomb was used in war.



1945 - On August 9, the [|"Fat Man"] plutonium bomb was dropped on Nagasaki - the second and last atomic bomb used in war.



1949 - The Soviet Union enters the nuclear era with its first atomic bomb test. Thus begins the arms race and the Cold War.

1945 - The US government and armed forces begin a wide array of human radiation experiments. Many are deemed unethical and were exposed by the Advisory Committee on Human Radiation Experiments under President Clinton in the mid-1990's.

1951 - The [|first hydrogen bombs] are tested in the US, with yields in the megaton range.

1951 - The first [|nuclear-powered] electricity-generating power plant begins operation.

1953 - The Soviet Union tests its [|first hydrogen bomb].

1954 - The [|first commercial nuclear power plant] begins operation in the Soviet Union. US President Eisenhower commissions his "Atoms for Peace" program, aimed at developing nuclear power plants.

1957 - The first commercial nuclear power plant in the US begins operations at Shippingport, Pennsylvania.

1964 - China successfully detonates its first nuclear device.

1979 - The first major commercial nuclear power plant accident occurs on March 29 in Harrisburg, PA, at the [|Three Mile Island] facility.

1986 - The [|Chernobyl nuclear disaster] occurs on April 26 near Pripyat, in the Soviet Union (now Ukraine).



2011 - A massive earthquake and resulting tsunami severely damages the Fukushima Daiichi nuclear power plant in Japan, causing a nuclear disaster.



Nuclear power plant construction was essentially halted worldwide due to the threat of major accidents similar to Chernobyl and the decline of oil prices. Recent spikes in oil prices, along with growing concern over greenhouse gas emissions from coal-fired power plants, have led to discussion of new nuclear power plant construction. China plans on ramping up nuclear power plant construction to meet its energy demands.