Gassend, Pierre known as Gassendi (1592-1655)

French philosopher, mathematician and savant. A priest and professor of mathematics, he was a supporter of Copernicus’ heliocentric theory (the Earth is not the centre of the Universe; it gravitates around the Sun) and an admirer of Galileo, with whom he corresponded, as he did with the majority of the astronomers of his time. A tireless observer of eclipses, a pioneer of observing planets by telescope, he made the first scientific description of an aurora borealis in 1621. In physics he studied falling bodies and the laws of impact. In acoustics he explained the pitch of sounds and measured the speed they spread at. An adversary of Descartes.