Kant, Immanuel (1724–1804)
- German philosopher remembered in astronomy mainly for the suggestion, made in 1775, that the Sun and the planets formed from a single source of material, as is now thought. He proposed that a disc-shaped nebula had produced both the Sun and the planets, a speculation which is now generally accepted. The idea produced by Kant has now been developed into a detailed model of the aggregation of the Sun and planets – although there is still disagreement between scientists about the exact mechanics. Small solar system objects like comets are regarded as pieces not swept up – at least yet – into bigger bodies.