Optics and phosphorescence
Born into a Parisian scientific family, Becquerel trained in engineering and physics and later held posts at the Museum of Natural History and the École Polytechnique. His early investigations concerned polarised light, phosphorescence and the absorption of light by crystals, the subject of his 1888 doctorate.
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Uranium and photographic plates
In 1896 discussion of Röntgen’s X-rays led Becquerel to test phosphorescent substances for penetrating radiation. Uranium salts affected photographic plates through opaque paper, even without prior exposure to sunlight. The investigation shifted from light-induced phosphorescence to radiation emitted spontaneously by the material.
Further radiation research
Becquerel continued studying the rays and their ionising effects. The Curies investigated further radioactive substances through quantitative measurement and chemical separation. The 1903 prize recognised both the initial discovery and their subsequent work. Becquerel died in 1908.