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Sir Michael James Lighthill, FRS (23 January 1924 – 17 July 1998) was a British applied mathematician, known for his pioneering work in the field of Aeroacoustics.

Biography

Lighthill specialised in fluid dynamics, and worked at the National Physical Laboratory, Trinity College, Cambridge and between 1946 and 1959 at the University of Manchester where he held the Beyer Chair. Lighthill then moved from Manchester to become director of the Royal Aircraft Establishment at Farnborough. There he worked on the development of television and communications satellites, and on the development of manned spacecraft. This latter work was used in the development of the Concorde supersonic airliner.

In 1955, together with G. B. Whitham, Lighthill set out the first comprehensive theory of kinematic waves (an application of the method of characteristics), with a multitude of applications, prime among them fluid flow and traffic flow.

Lighthill's early work included two dimensional aerofoil theory, and supersonic flow around solids of revolution. In addition to the dynamics of gas at high speeds he studied shock and blast waves. He is credited with founding the subject of aeroacoustics, a subject vital to the reduction of noise in jet engines. Lighthill's eighth power law states that the acoustic power radiated by a jet engine is proportional to the eighth power of the jet speed. He also founded non-linear acoustics, and showed that the same non-linear differential equations could model both flood waves in rivers and traffic flow in highways.

In 1964 he became the Royal Society's resident professor at Imperial College London, before returning to Trinity College, Cambridge, five years later as Lucasian Professor of Mathematics, a chair he held until 1979, when he was succeeded by Stephen Hawking. Lighthill then became Provost of University College London (UCL) — a post he held until 1989.

Lighthill founded the Institute of Mathematics and its Applications in 1964.

In the early 1970s, partly in reaction to significant internal discord within that field, the Science and Engineering Research Council asked Lighthill to compile a review of academic research in Artificial Intelligence. Lighthill's report, which was published in 1973 and became known as the "Lighthill report", was highly critical of basic research in foundational areas such as robotics and language processing, and "formed the basis for the decision by the British government to end support for AI research in all but two universities" [1], starting what is sometimes referred to as the "AI winter".

Although he had previously swum around the Island of Sark on numerous occasions, an attempt in 1998 claimed his life.[2]

Publications

* M. J. Lighthill & G. B. Whitham, On kinematic waves. I. Flood movement in long rivers, Proceedings of the Royal Society of London, Piccadilly, London, 10 May 1955, A229(1178):281–316
* M. J. Lighthill & G. B. Whitham, On kinematic waves. II. A theory of traffic flow on long crowded roads, Proceedings of the Royal Society of London, Piccadilly, London, 10 May 1955, A229(1178):317–345
* Lighthill, M. J., An Introduction to Fourier Analysis and Generalised Functions, Cambridge University Press, 1958, ISBN 0-521-09128-4
* Lighthill, Sir James, Mathematical Biofluiddynamics, Society for Industrial and Applied Mathematics, 1975, ISBN 0-89871-014-6
* Lighthill, M. J., Waves in Fluids. Cambridge University Press, 1978. ISBN 0-521-01045-4
* Lighthill, M. J. An Informal Introduction to Theoretical Fluid Mechanics. Oxford University Press, 1986, ISBN 0-19-853630-5
* Collected Papers of Sir James Lighthill: 4 Volume Set ISBN 0-19-509222-8