Today is the birthday of physicist Edmond Becquerel, born in Paris in 1820. He started out by assisting his father, the physicist Antoine Cesar, at France's National Museum of Natural History. Edmond was interested in light and studied the phenomena of fluorescence and phosphorescence. In 1839 he placed two electrodes in an acidic solution and exposed one of the electrodes to light. He found that the device generated electricity. Becquerel had created the first photovoltaic cell. It would take decades for scientists to figure out the mechanism behind the photovoltaic effect, but Becquerel's work set the stage for solar cells. Today photovoltaic cells generate energy on the ground and in space, including on the International Space Station. Becquerel's son, Henri, won the Nobel Prize in Physics for his discovery of radioactivity.
