LEFT: Nicolas de Largillière, “Portrait of Fontenelle,” 18th century. RIGHT: Frontispiece to Fontenelle’s 1686 ‘Conversations on the Plurality of Worlds.’
PART II: When thinkers like Fontenelle popularized the idea of a Plurality of Worlds in the 17th century, it grew to be widely supported by astronomers — but science offered nothing to support it, and offered easily reproducible results to question it.