I was born in Fowey, Cornwall, on 11 May 1924, the youngest of three sons and my father was a banker. I grew up in Newquay, on the Atlantic coast and there developed a love of the sea and boats. I was educated at King’s College, Taunton and went to the University of Cambridge in 1942. From 1943-46 I was engaged in war service at the Royal Aircraft Establishment, Farnborough and also at the Telecommunications Research Establishment, Malvern. I was involved with airborne radar-counter-measure devices and during this period I also worked with Martin Ryle.
Returning to Cambridge in 1946 I graduated in 1948 and immediately joined Ryle’s research team at the Cavendish Laboratory. I obtained my Ph.D. in 1952, became a Research Fellow at Gonville and Caius College where I had been an undergraduate, and in 1961 transferred to Churchill College as Director of Studies in Physics. I was University Lecturer during 1961-69, Reader during 1969-71 and Professor of Radio Astronomy from 1971 until my retirement in 1989. Following Ryle’s illness in 1977 I assumed leadership of the Cambridge radio astronomy group and was head of the Mullard Radio Astronomy Observatory from 1982-88.
My decision to begin research in radio astronomy was influenced both by my wartime experience with electronics and antennas and by one of my teachers, Jack Ratcliffe, who had given an excellent course on electromagnetic theory during my final undergraduate year and whom I had also encountered at Malvern. He was head of radiophysics at the Cavendish Laboratory at that time.
My first research was concerned with propagation of radiation through inhomogeneous transparent media and this has remained a lifelong interest. The first two radio “stars” had just been discovered and I realised that their scintillation, or “twinkling”, could be used to probe conditions in the ionosphere. I developed the theory of diffraction by phase-modulating screens and set up radio interferometers to exploit my ideas. Thus I was able to make pioneering measurements of the height and physical scale of plasma clouds in the ionosphere and also to estimate wind speeds in this region. Following our Cambridge discovery of interplanetary scintillation in 1964 I developed similar methods to make the first ground-based measurements of the solar wind and these were later adopted in the USA, Japan and India for long term observations. I also showed how interplanetary scintillation could be used to obtain very high angular resolution in radio astronomy, equivalent to an interferometer with a baseline of 1000 km – something which had not then been achieved in this field. It was to exploit this technique on a large sample of radio galaxies that I conceived the idea of a giant phased-array antenna for a major sky survey. This required instrumental capabilities quite different from those of any existing radio telescope, namely very high sensitivity at long wavelengths, and a multi-beam capability for repeated whole-sky surveys on a day to day basis.
I obtained funds to construct the antenna in 1965 and it was completed in 1967. The sky survey to detect all scintillating sources down to the sensitivity threshold began in July. By a stroke of good fortune the observational requirements were precisely those needed to detect pulsars. Jocelyn Bell joined the project as a graduate student in 1965, helping as a member of the construction team and then analysing the paper charts of the sky survey. She was quick to spot the week to week variability of one scintillating source which I thought might be a radio flare star, but our more detailed observations subsequently revealed the pulsed nature of the signal.
Surprisingly, the phased array is still a useful research instrument. It has been doubled in area and considerably improved over the years and one of my present interests is the way our daily observations of scintillation over the whole sky can be used to map large-scale disturbances in the solar wind. At present this is the only means of seeing the shape of interplanetary weather patterns so our observations make an useful addition to in-situ measurements from spacecraft such as Ulysses, now (1992) on its way to Jupiter.
Looking back over my forty years in radio astronomy I feel extremely privileged to have been in at the beginning as a member of Martin Ryle’s group at the Cavendish. We were a closely-knit team and besides my own research programmes I was also involved in the design and construction of Ryle’s first antennas employing the novel principle of aperture synthesis.
Teaching physics at the University, and more general lecturing to wider audiences has been a major concern. I developed an association with the Royal Institution in London when it was directed by Sir Lawrence Bragg, giving one of the well known Christmas Lectures and subsequently several Friday Evening Discourses. I believe scientists have a duty to share the excitement and pleasure of their work with the general public, and I enjoy the challenge of presenting difficult ideas in an understandable way.
I have been happily married since 1950. My son is a physicist and obtained his Ph.D. for neutron scattering in liquids, while my daughter is a language teacher.
|Honours and Awards|
|Hamilton Prize, Cambridge (1952)|
|Eddington Medal, Royal Astronomical Society (1969)|
|Charles Vernon Boys Prize, Institute of Physics (1970)|
|Dellinger Medal, International Union of Radio Science (1972)|
|Michelson Medal, Franklin Institute (1973)|
|Hopkins Prize, Cambridge Philosophical Society (1973)|
|Holwech Medal and Prize, Societé Française de Physique (1974)|
|Nobel Prize in Physics (1974)|
|Hughes Medal, Royal Society (1976)|
|Honorary ScD.s from the Universities of Leicester (1976), Exeter (1977), Manchester (1989) and Santa Maria, Brazil (1989)|
|Fellow of the Royal Society (1968)|
|Foreign Honorary Member, American Academy of Arts and Sciences (1977)|
|Foreign Fellow, Indian National Science Academy (1982)|
|Honorary Fellow, Indian Institution of Electronics and Telecommunication Engineers (1985)|
|Associate Member, Belgian Royal Academy (1989)|
This autobiography/biography was written at the time of the award and later published in the book series Les Prix Nobel/ Nobel Lectures/The Nobel Prizes. The information is sometimes updated with an addendum submitted by the Laureate.