James Lighthill

Sir James Lighthill
Michael James Lighthill
Born	(1924-01-23)23 January 1924 Paris, France
Died	Sark, Channel Islands
Nationality	United Kingdom
Fields	Mathematics, Acoustics
Institutions	Victoria University of Manchester University College London Cambridge University Imperial College London
Alma mater	Cambridge University
Doctoral students	Gerald B. Whitham
Known for	Lighthill report Lighthill mechanism Aeroacoustics Fluid dynamics
Notable awards	Timoshenko Medal (1963) Royal Medal (1964) Elliott Cresson Medal (1975) Naylor Prize and Lectureship (1977) Otto Laporte Award (1984) Copley Medal (1998)

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 was educated at Winchester College. He specialised in fluid dynamics, and worked at the National Physical Laboratory, Trinity College, Cambridge. Between 1946 and 1959 he was Beyer Professor of Applied Mathematics at the University of Manchester. 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 and introduced the squirmer model. 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 1968, he was awarded an Honorary Degree (Doctor of Science) by the University of Bath. In 1972 he was invited to deliver the MacMillan Memorial Lecture to the Institution of Engineers and Shipbuilders in Scotland. He chose the subject 'Aquatic Animal Locomotion'.

In the early 1970s, partly in reaction to significant internal discord within that field, the Science Research Council (SRC), as it was then known, 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", starting what is sometimes referred to as the "AI winter."

Lighthill was awarded the Ludwig-Prandtl-Ring from the Deutsche Gesellschaft für Luft- und Raumfahrt (German Society for Aeronautics and Astronautics) for "outstanding contribution in the field of aerospace engineering" in 1983.

His hobby was open-water swimming. He died in the water in 1998 when the mitral valve in his heart ruptured while swimming round the island of Sark, a feat which he had accomplished many times before.

See also

• Lighthill method in differential equations
• James Lighthill House

References

Academic offices
Preceded by Sydney Goldstein	Beyer Chair of Applied Mathematics at University of Manchester 1950–1959	Succeeded by Fritz Ursell
Preceded by Paul Dirac	Lucasian Professor of Mathematics at Cambridge University 1969–1978	Succeeded by Stephen Hawking
Preceded by Noel Annan	Provost of University College London 1979–1989	Succeeded by Derek Roberts