Professor L.C. Woods

Maverick Oxford mathematician

Leslie Colin Woodhead (Leslie Colin Woods), applied mathematician: born Reporoa, New Zealand 6 December 1922; fighter pilot, RNZAF 1942-45; Rhodes Scholar, Merton College, Oxford 1948-51; scientist, Aerodynamics Division, NPL Middlesex 1951-54; Senior Lecturer in Applied Maths, Sydney University 1954-56; Nuffield Research Professor of Engineering, University of New South Wales 1956-60; Tutor in Engineering Science, Balliol College, Oxford 1960-70, Fellow 1960-90 (Emeritus Fellow since 1991); Reader in Applied Mathematics, Oxford University 1964-70, Professor of Mathematics (Theory of Plasma) 1970-90 (Emeritus); three times married (three daughters and two daughters deceased); died Oxford 15 April 2007.

L.C. Woods had an extraordinary career that took him from fighter pilot in the Pacific to Professor of Mathematics at Oxford University. His military service was as colourful as his academic life and, even when his scientific eminence had been recognised, he always relished his role as enfant terrible. Woods's fearlessly questioning and even impish approach made him a prophet and maverick of his times. Alas, at a time when such scepticism is most needed, modern scientific management in government laboratories and universities has all but exterminated it.

Born Leslie Woodhead in 1922, he was the son of a fearsome fisherman who lived near Auckland and his teenage years involved working in an abattoir, an abrupt conversion to atheism and the beginnings of a degree in Mathematics at Auckland University College. Financial pressures and a role model led him to join the Royal New Zealand Air Force in late 1941, which is when his bravery and irreverence were given free rein.

His delight in unauthorised aerobatics led to confrontations with authority ensuring that, initially, he stayed firmly in New Zealand as an instructor. Even that was dangerous enough; once, when he was demoted to drogue-towing, a steep turn wrapped the tow-rope around the tailplane and only a last-minute wire-cutting saved the day. He married Betty Bayley early in 1944 and, with offspring in mind, he changed his name to Woods, a decision he later regretted.

Volunteering for active service, he flew nearly a hundred missions in the Pacific in Kittyhawks and Corsairs, many of them over the heavily defended port of Rabaul; his favourite escapade involved the realisation that a supposed Japanese submarine was a whale. Amazingly, all the while he worked without instruction on mathematics, to the level of a second-class MSc in 1944; Auckland University awarded him an honorary doctorate in 1983.

With his colourful background, Les Woods was astounded to be awarded, in 1947, a Rhodes Scholarship, for which married candidates were only eligible after military service. This enabled him to research computational aerodynamics with Alexander Thom in an engineering department then held in low regard in Oxford. Despite colossal culture shock, Woods completed his DPhil on control reversal in two years, annoyingly having to pay Merton College for the tuition he would have received had he been an ordinary undergraduate student. He almost missed his opportunity to indulge in low flying over Oxford when he firmly informed the Air Squadron's interview panel that his father's job was "minding his own business".

For Woods the natural next step was a first class degree in mathematics in 1951, by which time he was father of five daughters, much to the astonishment of his more theoretical contemporaries. Then, after a brief but intellectually thrilling spell at the National Physical Laboratory, he took a Senior Lectureship at the University of Sydney, working under a colleague who, in Woods's words "found it hard to rise above his international status".

This led to a further move to the University of New South Wales, where Woods became a professor at the age of 33. This was Woods's induction into high-level university politics and the battle between intellectual freedom and chains of command was one in which he passionately engaged forever after. More importantly, having published his brilliant text The Theory of Subsonic Planar Flow in 1961, he realised well ahead of his time that the future of applied mathematics lay in its new frontiers. The modelling of ionised gases, or plasmas, was the perfect vehicle for his attentions.

The pivot of Woods' career came during his sabbatical in Oxford in 1960 when he became embroiled with the plasma physics community at the UK Atomic Energy Authority at Harwell, shortly to move to Culham. This was a key factor in his decision to "demote" himself to the engineering fellowship at Balliol College, where he stayed for the rest of his academic career and which eventually became his home from home. This post provided a wonderful opportunity for Woods's warmth and sense of fun to enthuse his students, graduate and undergraduate, many of whom followed glittering academic careers.

However, more skirmishes with authority followed which, with the involvement of the equally bonhomous George Temple, led Woods to move to a Readership in the university's Mathematical Institute, of which he later became chairman. A final golden opportunity arose when the chair of Plasma Physics was willingly bequeathed to the Mathematics Faculty. Woods' appointment as Professor of Mathematics (Theory of Plasma) in 1970 left him free as a bird, his world travels including a legendary depletion of Cornell's whisky supply and handsome reward from a so-called Institute for Advanced Salaries in Texas.

Most importantly he could throw all his modelling skills into the science behind the Tokamak machine with its promise of limitless clean energy through nuclear fusion. The key question was how to confine the plasma for long enough for the fusion reaction to take place at a significant rate, when all the current experiments showed an unforeseen tendency for the ions and electrons to spread out from their initially toroidal paths.

The traditional explanation blamed some kind of turbulence, a word often used to describe phenomena that are poorly understood. Woods rightly believed that the confinement problem was nearly insuperable and, true to style, came up with a simple speculation which brought him head to head with an immensely powerful and wealthy scientific community.

His ideas never survived peer review, and so they can only be found in his rather idiosyncratic textbooks. However, a layman's version appears in his wonderfully informative and entertaining autobiography Against the Tide, an expurgated version of which was published in 2000 by the Institute of Physics only after two other well-known publishing houses found it too cuttingly forthright. The book received a better review in The Aeroplane than in the physics literature, and it seems to have been ignored by the axiomatic applied mathematics community, with whom Woods had also become embattled.

He remained intensely active throughout his last decade, working especially on solar phenomena such as prominences and coronal heating.

John Ockendon

12 May 2007 Independent