| Nigel Weiss | |
| Birth Name: | Nigel Oscar Weiss |
| Birth Date: | 1936 12, df=yes |
| Birth Place: | South Africa |
| Workplaces: | University of Cambridge |
| Alma Mater: | Clare College, Cambridge |
| Thesis Title: | Variable Hydromagnetic Motions |
| Thesis1 Url: | and |
| Thesis2 Url: | )--> |
| Thesis Year: | 1961 |
| Doctoral Advisor: | Edward Bullard |
| Known For: | flux expulsion |
Nigel Oscar Weiss FRS[1] (16 December 1936 – 24 June 2020) was an astronomer and mathematician, and leader in the field of astrophysical and geophysical fluid dynamics. He was Emeritus Professor of Mathematical Astrophysics at the University of Cambridge.
Born in South Africa, Weiss studied at Hilton College, Natal, Rugby School and Clare College, Cambridge, and had been a fellow of Clare College since 1965. He read for his PhD in 1961 with a thesis on Variable Hydromagnetic Motions.
In 1987 he became Professor of Mathematical Astrophysics at the University of Cambridge.
Between 2000 and 2002 he was President of the Royal Astronomical Society, and in 2007 was awarded the Gold Medal, the society's highest award.
Weiss published extensively in the field of mathematical astrophysics, specialising in solar and stellar magnetic fields, astrophysical and geophysical fluid dynamics and nonlinear dynamical systems.
In 1966 he was the first to demonstrate and describe the process of 'flux expulsion' by which a conducting fluid undergoing rotating motion acts to expel the magnetic flux from the region of motion, a process now known to occur in the photosphere of the Sun and other stars.
Weiss was elected a Fellow of the Royal Society (FRS) in 1992. His nomination reads