In the first days of 1934, Frederic and Irene Joliot-Curie announced in a note to the Academie des Sciences that they had created a radioactive atom which did not exist in nature.
The discovery of artificial radioactivity was of vital importance,. It means that the property of radioactivity is not limited to the handful of radioelements found in nature. Radioactivity is, in fact, a fundamental property of matter. At the time of the creation of the Universe, all the radioactive isotopes were produced. Most of them with short half-lives have gradually disappear. Others, whose half-lives were sufficiently long, can still be found today. Producing radioisotopes via nuclear reactions is equivalent to recreating those short-lived radioactive isotopes that have since disappeared.
Man is now able of obtaining radioisotopes needed as tracers and markers. This allows scientists, engeneers and doctors to follow the evolution of any marked substance.
The applications are numerous and, for the most part, have been mastered. A great deal of caution is nonetheless required: the large-scale production of isotopes can be dangerous, and a certain amount of protection is needed.
Discoveries made in the exact sciences always lead to advances in the others. Nuclear physics is no exception, as the discovery of artificial radioactivity allowed for impressive advances in a wide range of other fields.
The most spectacular, perhaps, are those advances in the field of biology, where radioactive tracers have allowed for an explosion in the information available on the functioning of living organisms.
A French pioneer in nuclear medicine, Maurice Tubiana has said: "It is often said that the first half of the 20th Century was dominated by advances in physics and the second half dominated by advances in biology. If this is true, which I believe, then we owe these developments to the discovery of artificial radioactivity."
The development of cerebral tomoscintigraphy scans is a telling example.
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