He is one of one hundred and sixty-six Frenchmen who gave their name to a crater on the Moon.
Incredible but true ! A Bagnolais gave his name to a crater on the Moon. Levi Ben Gerson, also called Gersonide, was an illustrious figure of the fourteenth century. There are nearly 1,600 craters bearing a name on the star of the night, of which one hundred and sixty-six designate illustrious French characters, including Gersonide.
Born in Bagnols-sur-Cèze in 1288
Born in Bagnols-sur-Cèze in 1288, Gersonide practiced in many fields. Mathematician, astronomer, physicist, philosopher, physician, theologian and rabbi. He lived between Bagnols, Orange and Avignon and died in 1344 in the city of the Popes.
His biography and the description of his crater on the Moon can be found in the book which has just been reissued These French in the Moon… Craters and biographies, by Jean-Michel Faidit, mathematician, doctor in the history of astronomy, lecturer and founder of the Montpellier Planetarium. He also wrote a thesis on the astronomers of Languedoc in the 18th century, work which then motivated him to write this book.
The inventor of Jacob’s staff
It was in 1651 that the Italian astronomer Giovanni Battista Riccioli had the idea of naming the craters of the Moon with the names of personalities. Later, other astronomers take over in these denominations. Nowadays, it is NASA that mainly plays this role. But why Gersonides? This illustrious man marked his time and beyond.
He is well known in the field of astronomy for having invented Jacob’s stick, an instrument for measuring the angle between two stars. A precursor of trigonometry and revolutionary for the time, which was used by sailors for navigation. Gersonide was able to observe nearly ten eclipses as well as Mars, the red planet. Although his activities as a rabbi and as astronomers were somewhat antagonistic, he dissociated the birth of time and that of the Universe and believed that an already existing matter or entity participated in the creation of the Universe. He was a universal spirit, a scholar, he was avant-garde in a very rich and modern period.