Lyrically, the 1975 version of the song plays upon the meaning of its title, with the line " Discovered by Madame Curie ( In fact, Natural radioactivity was discovered by Henri Becquerel ( and independently by Silvanus Thompson ); induced radioactivity by Ir�ne Joliot-Curie, Marie Curie's daughter.
32.
The natural radioactivity of thorium and uranium made it hard to determine what was happening when these elements were bombarded with neutrons but, after correctly eliminating the presence of elements lighter than uranium but heavier than lead, Fermi concluded that they had created new elements, which he called hesperium and ausonium.
33.
He was also the author of the very first textbooks of physics, as " Kurs i fizik�s s?p�rgjithshme " ( General physics course ) in 1974, " Kurs i mekanik�s teorike " ( Theoretical mechanics course ) of 1981, etc . He performed studies in the field of natural radioactivity of the waters systems.
34.
But Sadoulet added that " there is a lot of skepticism in the community " as to whether the Rome group has really detected the elusive WIMP . He said that unrelated seasonal effects, such as temperature variations around the sensitive detectors or changes in levels of natural radioactivity, could still be mimicking the expected signal.
35.
Nonetheless, estimates of radioactivity leakage into the Pacific Ocean remain modest with " National Geographic " reporting the leakage of approximately 0.3 Tbq per month of both 137 Cs and 134 Cs . 0.3 TBq is equal to 1 / 40 th of the natural radiation in one km 3 of seawater and 1 / 50000000000 th of the total natural radioactivity in the oceans.
