1678-1771

French physicist who played a minor role in various important eighteenth-century scientific debates, typically seeking to reconcile Cartesian and Newtonian positions. Mairan was involved in controversies over Earth's shape, conservation of vis viva—the "living force" concept later called energy—and the nature of light. He correctly noted the cooling effect of evaporation (1749), and his climate studies led him to postulate a central fire within Earth as an important heat source. Mairan's Physical and Historical Treatise on the Aurora Borealis (1733) contains the first application of geophysical data to an astronomical problem.