Kant was the first person to put forward a serious and well-reasoned theory about the origin of the solar system from clouds of gas and dust. The sun appeared at the centre of the cloud and the planets at the edges, according to his hypothesis. Decades later, in the late 18th century, Kant's contemporary, the French mathematician Pierre Simon Laplace, hypothesised that the solar system originated from a hot cloud of dust. Later, these similar ideas of two scientists of the XVII-XVIII century were combined. They were called the «Kant-Laplace hypothesis».