Antoine Henri Becquerel (1852-1908): a scientist who endeavored to discover natural radioactivity.

Antoine Henri Becquerel [1] (Fig. 1) was born in Paris on December 15, 1852, in the Becquerel family, which was a family of renowned scientists. Starting with his grandfather, members of three generations of the Becquerel family were physicists, and they had an extraordinary interest in phosphorescence and fluorescence. His grandfather, Antoine César Becquerel (1788–1878), was a member of the inaugural class of the École Polytechnique [2]. He joined the army during the war waged by Napoleon against Spain. After that, he became a first-generation professor in the department of applied physics of the Musée d’ Histoire Naturelle [3], which is dedicated to scientific research. He wrote two books on phosphorescence. His father, Alexandre Edmond Becquerel (1820–1891), started as an assistant and became a professor at the École Polytechnique. He was also a professor at the Musée d’ Histoire Naturelle. He received a degree of Doctor of Science from the University of Paris. He conducted scientific research on the effect of light, and he was among those who photographed the spectrum of sunlight for the first time. Moreover, he was an authority on fluorescence and had a particularly good knowledge about uranium. He designed a phosphoroscope with which he measured the intensity and duration of the fluorescence of uranium under various lightrays. Antoine Henri Becquerel of the third generation entered the École Polytechnique in 1872. In 1874, he was enrolled at the École des Ponts et Chaussées and studied civil engineering for 3 years. For some time, he worked in the Ministry of Construction as a civil engineer, but after pursuing research as an assistant to his father, he also became a professor of applied physics at the Musée d’ Histoire Naturelle in 1892. He received a degree of Doctor of Science from the University of Paris. He was also selected as a member of the Académie des Sciences, published research articles on fluorescence and phosphorescence, and joined the École Polytechnique as a professor. He became a leading scientist in the field of phosphorescence and fluorescence along with his father, and he held high-ranking positions in academic societies with his many research achievements.