years, and is in agreement with Albert Einstein's later formula for mass–energy equivalence, which was derived by Einstein as a consequence of special relativity. Radioactive decay De Pretto's paper discussed the radioactive decay of uranium and thorium and was the first to conclude that this decay was energy transformation from mass into energy. He also presented a hypothesis that the intense heat assumed to be in the center of the Earth (theory of central fire) was caused by the tremendous mass of the earth creating a massive radioactive core giving off heat and energy. Honors In 1906 De Pretto was accepted as a member of Accademia dei Lincei, a scientific organization whose members included Galileo Galilei. The director of the organization, Ernesto Mancini, was also a member of The Royal Society of London, an international scientific society. Mancini submitted De Pretto's paper to the Royal Society for international recognition. It was received favorably and was listed in the Society's International Catalogue of Scientific Literature. References 1857 births 1921 deaths 19th-century Italian geologists People from Schio 20th-century Italian physicists