Henri Becquerel was a French physicist born on December 15, 1852, in Paris, into a family of distinguished scientists. His grandfather and father were both physicists, and this legacy deeply influenced his academic path. Becquerel studied engineering at the École Polytechnique and later earned a doctorate in science, eventually becoming a professor at the Muséum national d’histoire naturelle and École Polytechnique.

His early research focused on optics, particularly the interaction of light with crystals and the phenomenon of phosphorescence. However, his most ground-breaking work came in 1896 when he discovered natural radioactivity. Inspired by Wilhelm Röntgen’s discovery of X-rays, Becquerel investigated whether phosphorescent materials emitted similar rays. He found that uranium salts emitted penetrating radiation without any external energy source, revealing a previously unknown property of matter.

This discovery laid the foundation for the field of nuclear physics and was further developed by Marie and Pierre Curie, who expanded on his findings. In recognition of their collective contributions, Becquerel shared the 1903 Nobel Prize in Physics with the Curies. His work not only revolutionised physics but also had profound implications for medicine and energy.

Henri Becquerel died on August 25, 1908, in Le Croisic, France. His legacy endures in the scientific community, and the SI unit of radioactivity, the becquerel (Bq), is named in his honour.