Heinrich Wilhelm Mathias Olbers (1758-1840), German astronomer and physician. (1864). Olbers was founder member of the astronomers called the 'Celestial Police' who searched for a suppposed missing planet. In 1826 he put forward Olbers' paradox, the question that if the universe is infinite and full of stars, why is the sky dark at night?. He also did much work on comets. From Bahn eines Cometen zu berechnen Heinrich Olbers, (Leipzig, 1864). Lithograph.