Martin Ryle

Sir Martin Ryle FRS[4] (27 September 1918 – 14 October 1984) was an English radio astronomer who developed revolutionary radio telescope systems (see e.g. aperture synthesis) and used them for accurate location and imaging of weak radio sources. In 1946 Ryle and Derek Vonberg were the first people to publish interferometric astronomical measurements at radio wavelengths. With improved equipment, Ryle observed the most distant known galaxies in the universe at that time. He was the first Professor of Radio Astronomy at the University of Cambridge, and founding director of the Mullard Radio Astronomy Observatory. He was Astronomer Royal from 1972 to 1982.[5] Ryle and Antony Hewish shared the Nobel Prize for Physics in 1974, the first Nobel prize awarded in recognition of astronomical research.[6] In the 1970s, Ryle turned the greater part of his attention from astronomy to social and political issues which he considered to be more urgent.

Sir Martin Ryle

Martin Ryle
Born27 September 1918
Died14 October 1984 (aged 66)
NationalityUnited Kingdom
EducationBradfield College
Alma materUniversity of Oxford (BA, DPhil)
Known forAperture synthesis
Radio astronomy
Rowena Palmer (m. 1947)
Scientific career
Doctoral advisorJ. A. Ratcliffe[1]
Doctoral studentsMalcolm Longair[1][2]
Peter Rentzepis
Jan Högbom[3]

Education and early life

Martin Ryle was born in Brighton, the son of Professor John Alfred Ryle and Miriam (née Scully) Ryle. He was the nephew of Oxford University Professor of Philosophy Gilbert Ryle. After studying at Bradfield College, Ryle studied physics at Christ Church, Oxford. In 1939, Ryle worked with the Telecommunications Research Establishment (TRE) on the design of antennas for airborne radar equipment during World War II. After the war, he received a fellowship at the Cavendish Laboratory.

Career and research

The focus of Ryle's early work in Cambridge was on radio waves from the Sun.[7][8][9][10] His interest quickly shifted to other areas, however, and he decided early on that the Cambridge group should develop new observing techniques. As a result, Ryle was the driving force in the creation and improvement of astronomical interferometry and aperture synthesis, which paved the way for massive upgrades in the quality of radio astronomical data. In 1946 Ryle built the first multi-element astronomical radio interferometer.[11]

Ryle guided the Cambridge radio astronomy group in the production of several important radio source catalogues. One such catalogue, the Third Cambridge Catalogue of Radio Sources (3C) in 1959 helped lead to the discovery of the first quasi-stellar object (quasar).

While serving as university lecturer in physics at Cambridge from 1948 to 1959, Ryle became director of the Mullard Radio Astronomy Observatory in 1957 and professor of radio astronomy in 1959. He was elected a Fellow of the Royal Society (FRS) in 1952,[4] was knighted in 1966 (p 519 of [4]) and succeeded Sir Richard Woolley as Astronomer Royal from 1972–1982. Ryle and Antony Hewish shared the Nobel Prize for Physics in 1974, the first Nobel prize awarded in recognition of astronomical research. In 1968 Ryle served as professor of astronomy at Gresham College, London.


According to numerous reports Ryle was quick-thinking, impatient with those slower than himself and charismatic (pp 502, 508, 510 of [4]). He was also idealistic (p 519 of [4]), a characteristic he shared with his father (p 499 of [4], [12]). In an interview (p271 of [13]) in 1982 he said "At times one feels that one should almost have a car sticker saying 'Stop Science Now' because we're getting cleverer and cleverer, but we do not increase the wisdom to go with it."

He was also intense and volatile (p 327 of [14]), the latter characteristic being associated with his mother (p 499 of [4], Folder A.20 of [12]). The historian Owen Chadwick described him as "a rare personality, of exceptional sensitivity of mind, fears and anxieties, care and compassion, humour and anger." (Folder A.28 of [12])

Ryle was sometimes considered difficult to work with – he often worked in an office at the Mullard Radio Astronomy Observatory to avoid disturbances from other members of the Cavendish Laboratory and to avoid getting into heated arguments, as Ryle had a hot temper. Ryle worried that Cambridge would lose its standing in the radio astronomy community as other radio astronomy groups had much better funding, so he encouraged a certain amount of secrecy about his aperture synthesis methods in order to keep an advantage for the Cambridge group. Ryle had heated arguments with Fred Hoyle of the Institute of Astronomy about Hoyle's Steady State Universe, which restricted collaboration between the Cavendish Radio Astronomy Group and the Institute of Astronomy during the 1960s.

War, peace and energy

Ryle was a new physics graduate and an experienced radio ham in 1939, when the Second World War started. He played an important part in the Allied war effort,[4] working mainly in radar countermeasures. After the war, "He returned to Cambridge with a determination to devote himself to pure science, unalloyed by the taint of war."[4]

In the 1970s, Ryle turned the greater part of his attention from astronomy to social and political issues which he considered to be more urgent. With publications from 1976 and continuing, despite illness[4] until he died in 1984, he pursued a passionate and intensive program on the socially responsible use of science and technology.[15] His main themes were:

  • Warning the world of the horrific dangers of nuclear armaments, notably in his pamphlet Towards the Nuclear Holocaust.[16]
  • Criticism of nuclear power, as in Is there a case for nuclear power?[17]
  • Research and promotion of alternative energy and energy efficiency, as in Short-term Storage and Wind Power Availability.[18]
  • Calling for the responsible use of science and technology. "...we should strive to see how the vast resources now diverted towards the destruction of life are turned instead to the solution of the problems which both rich - but especially the poor - countries of the world now face."[15]

In 1983 Ryle responded to a request from the President of the Pontifical Academy of Sciences for suggestions of topics to be discussed at a meeting on Science and Peace. Ryle's reply was published posthumously in Martin Ryle's Letter.[15] An abridged version appears in New Scientist with the title Martin Ryle's Last Testament.[19] The letter ends with "Our cleverness has grown prodigiously – but not our wisdom."

Honours and awards

Ryle was awarded numerous prizes and honours including:

Personal life

In their early years Martin and his elder brother received lessons at home in carpentry (p 498 of [4]) and manual skills became important for him throughout his life. This was for relaxation - he built boats to his own designs (p 498 of [4]) - and professionally. In his wartime radar work ([24]), his post-war radio-telescope building (p 510 of [4]) and his late researches into wind energy (p 517 of [4]) he was a hands-on practical engineer as well as a scientist.

Ryle also had a lifelong interest in sailing (p 498 of [4]) and this matched his choice when in the 1970s he turned his research subject from astronomy to wind energy (pp 420-422 of [25])

Another practical skill acquired by Martin in youth that later served him well in his professional career was as a radio 'ham'. While still at School (Bradfield College) he built his own transmitter and obtained a Post Office licence to operate it (pp 498-499 of [4]), with the GB-Callsign G3CY.

In 1936 the family moved to a house in Cambridge which became Martin's home after the war. In 1947 he and Rowena Palmer married and they lived in this house for rest of Martin's life. They had three children, born in 1949, 1951 and 1952. Ryle died on 14 October 1984, in Cambridge. He was celebrated on a first class stamp issued in 2009 as part of an Eminent Britons set [26]. Lady Ryle died in 2013 [27]


  1. ^ a b Martin Ryle at the Mathematics Genealogy Project
  2. ^ Longair, Malcolm Sim (1967). The evolution of radio galaxies. (PhD thesis). University of Cambridge. OCLC 657635513. EThOS
  3. ^ Högbom, Jan A. (1959). The structure and magnetic field of the solar corona. (PhD thesis). University of Cambridge.
  4. ^ a b c d e f g h i j k l m n o p q Graham-Smith, Francis (1986). "Martin Ryle. 27 September 1918-14 October 1984". Biographical Memoirs of Fellows of the Royal Society. Royal Society. 32: 496–524. doi:10.1098/rsbm.1986.0016.
  5. ^ About Sir Martin Ryle
  6. ^ Press release about Martin Ryle's Nobel Prize.
  7. ^ Martin Ryle publications indexed by the Scopus bibliographic database. (subscription required)
  8. ^ Obs 104 (1984) 283
  9. ^ QJRAS 26 (1985) 358
  10. ^ The Papers of Martin Ryle have been catalogued by Anna-K Mayer and Tim Powell, NCUACS, in 2009 and are deposited with the Churchill Archives Centre, Cambridge.
  11. ^ Ryle, M.; Vonberg, D. D. (1946). "Solar Radiation on 175 Mc./s". Nature. 158 (4010): 339. Bibcode:1946Natur.158..339R. doi:10.1038/158339b0. – Observations from the first multi-element astronomical radio interferometer
  12. ^ a b c Ryle catalogue at Churchill Archives Centre
  13. ^ Williams R ed The Best of The Science Show. Nelson, 1983.
  14. ^ Kragh, H. Cosmology and Controversy: the historical development of two theories of the universe. Princeton University Press, 1996.
  15. ^ a b c Rowan-Robinson, M. and Rudolf, A. (1985) Martin Ryle's Letter. Menard Press.
  16. ^ Ryle, M. Towards the Nuclear Holocaust. Menard Press, 1981.
  17. ^ Ryle, M (1981). "Is there a case for nuclear power?". Electronics and Power. 28 (7/8): 496–500. doi:10.1049/ep.1982.0267.
  18. ^ Anderson, M. B.; Newton, K.; Ryle, M.; Scott, P. F. (1978). "Short-term Storage and Wind Power Availability". Nature. 275 (5679): 432–434. Bibcode:1978Natur.275..432A. doi:10.1038/275432a0.
  19. ^ Ryle M. (1985) "Martin Ryle's Last Testament". New Scientist 105 (14 February): 36-37.
  20. ^ "Winners of the Gold Medal of the Royal Astronomical Society". Royal Astronomical Society. Archived from the original on 25 May 2011. Retrieved 24 February 2011.
  21. ^ "Henry Draper Medal". National Academy of Sciences. Archived from the original on 26 January 2013. Retrieved 24 February 2011.
  22. ^ "Franklin Laureate Database – Albert A. Michelson Medal Laureates". Franklin Institute. Archived from the original on 6 April 2012. Retrieved 14 June 2011.
  23. ^ "Past Winners of the Catherine Wolfe Bruce Gold Medal". Astronomical Society of the Pacific. Retrieved 24 February 2011.
  24. ^ Ryle M. (1985) "D-13:some personal memories of 24th-28th May 1944". IEE Proceedings 132 (6 October): 438-440.
  25. ^ Longair, M. Maxwell's Enduring Legacy: a scientific history of the Cavendish laboratory. Cambridge University Press, 2016.
  26. ^ Eminent Britons stamp set
  27. ^
Antony Hewish

Antony Hewish (born 11 May 1924) is a British radio astronomer who won the Nobel Prize for Physics in 1974 (together with fellow radio-astronomer Martin Ryle) for his role in the discovery of pulsars. He was also awarded the Eddington Medal of the Royal Astronomical Society in 1969.

Aperture synthesis

Aperture synthesis or synthesis imaging is a type of interferometry that mixes signals from a collection of telescopes to produce images having the same angular resolution as an instrument the size of the entire collection. At each separation and orientation, the lobe-pattern of the interferometer produces an output which is one component of the Fourier transform of the spatial distribution of the brightness of the observed object. The image (or "map") of the source is produced from these measurements. Astronomical interferometers are commonly used for high-resolution optical, infrared, submillimetre and radio astronomy observations. For example, the Event Horizon Telescope project derived the first image of a black hole using aperture synthesis.

Bruce Medal

The Catherine Wolfe Bruce Gold Medal is awarded every year by the Astronomical Society of the Pacific for outstanding lifetime contributions to astronomy. It is named after Catherine Wolfe Bruce, an American patroness of astronomy, and was first awarded in 1898.

Cambridge Interferometer

The Cambridge Interferometer was a radio telescope interferometer built by Martin Ryle and Antony Hewish in the early 1950s to the west of Cambridge (between the Grange Road football ground and the current Cavendish Laboratory). The interferometer consisted of an array of 4 fixed elements to survey the sky. It produced the two Cambridge catalogues of radio sources (the 2C catalogue of radio sources at 81.5 MHz, and the 3C catalogue of radio sources at 159 MHz, building on the work of the Preliminary survey of the radio stars in the Northern Hemisphere at 45 MHz - 214 MHz using the 2-element Long Michelson Interferometer), discovering some of the most interesting astronomical objects known. The telescope was operated by the Radio Astronomy Group of Cambridge University.

Martin Ryle and Antony Hewish received the Nobel Prize for Physics in 1974 for this and other related work.

Cassiopeia A

Cassiopeia A (Cas A) is a supernova remnant (SNR) in the constellation Cassiopeia and the brightest extrasolar radio source in the sky at frequencies above 1 GHz. The supernova occurred approximately 11,000 light-years (3.4 kpc) away within the Milky Way. The expanding cloud of material left over from the supernova now appears approximately 10 light-years (3 pc) across from Earth's perspective. In wavelengths of visible light, it has been seen with amateur telescopes down to 234mm (9.25 in) with filters.It is estimated that light from the stellar explosion first reached Earth approximately 300 years ago, but there are no historical records of any sightings of the supernova that created the remnant. Since Cas A is circumpolar for mid-Northern latitudes, this is probably due to interstellar dust absorbing optical wavelength radiation before it reached Earth (although it is possible that it was recorded as a sixth magnitude star 3 Cassiopeiae by John Flamsteed on August 16, 1680). Possible explanations lean toward the idea that the source star was unusually massive and had previously ejected much of its outer layers. These outer layers would have cloaked the star and re-absorbed much of the light released as the inner star collapsed.

Cas A was among the first discrete astronomical radio sources found. Its discovery was reported in 1948 by Martin Ryle and Francis Graham-Smith, astronomers at Cambridge, based on observations with the Long Michelson Interferometer. The optical component was first identified in 1950.Cas A is 3C461 in the Third Cambridge Catalogue of Radio Sources and G111.7-2.1 in the Green Catalog of Supernova Remnants.

Cavendish Laboratory

The Cavendish Laboratory is the Department of Physics at the University of Cambridge, and is part of the School of Physical Sciences. The laboratory was opened in 1874 on the New Museums Site as a laboratory for experimental physics and is named after the British chemist and physicist Henry Cavendish. The laboratory has had a huge influence on research in the disciplines of physics and biology.

The laboratory moved to its present site in West Cambridge in 1974.

As of 2011, 29 Cavendish researchers have won Nobel Prizes. Notable discoveries to have occurred at the Cavendish Laboratory include the discovery of the electron, neutron, and structure of DNA.

Derek Vonberg

Derek Vonberg (1922-2015) was a British electrical engineer, radio astronomer and medical research scientist.Vonberg studied at Imperial College then joined the Cavendish Laboratory in 1945 where he worked with Martin Ryle.In the late 1940s Vonberg joined the Cyclotron Group at Hammersmith Hospital.

J. A. Ratcliffe

John Ashworth Ratcliffe CB OBE FRS (12 December 1902 – 25 October 1987), "JAR" or "Jack", was an influential British radio physicist. (Several sources misspell his name as Radcliffe.)

He and his University of Cambridge group (which included physicist Frank Farmer) did much pioneering work on the ionosphere, immediately prior to World War II. He was one of many leading radio scientists who worked at the Telecommunications Research Establishment during WW2. Martin Ryle, Bernard Lovell, and Antony Hewish were co-workers there, and Ryle and Hewish joined his radio-physics group at Cambridge after WW2. He was elected to the Royal Society in 1951.

In 1953 Ratcliffe was invited to deliver the Royal Institution Christmas Lecture on The Uses of Radio Waves.

He served as President of the Institution of Electrical Engineers from 1966 to 1967.

From 1960 to 1966 he was Director of the Radio & Space Research Station at Slough.

Ratcliffe was awarded the Gold Medal of the Royal Astronomical Society in 1976.

Jan Högbom

Jan Arvid Högbom (born 1929) is a Swedish radio astronomer and astrophysicist.

John Ryle (physician)

John Alfred Ryle (1889–1950) was a British physician and epidemiologist.

He was born the son of Brighton doctor R J Ryle and brother of the Oxford philosopher Gilbert Ryle. He was educated at Brighton College and Guy's Hospital where he qualified in 1913. He served in the military during World War I and afterwards qualified MD at the University of London. After teaching at Guy's Hospital he was appointed in 1935 Regius Professor of Physic [not Physics; "Physic" here is an archaic term for Medicine] at the University of Cambridge. In 1943 he was appointed chair of the newly created Institute of Social Medicine at the University of Oxford, initiating the academic discipline of Social Medicine (Epidemiology).He was elected a Fellow of the Royal College of Physicians in 1924 and delivered their Goulstonian Lecture in 1925 and their Croonian Lecture in 1939.

From 1932 to 1936 he was Physician to King George V's household and then Physician Extraordinary to the king.

Ryle was politically active at Cambridge, helping Jewish scholars emigrate from Germany and Austria before World War II. During World War II, he was working at Guy's Hospital to help them prepare for the Blitz. In February 1940 he contested the Cambridge University by-election, 1940 standing as an Independent Progressive.Ryle is credited with the discovery of Nasogastric intubation.He had married Miriam Power Scully in London on 23 October 1914. They had several children, including astronomer Martin Ryle.

Kate Soper

Kate Soper (born 1943) is a British philosopher. She is currently Visiting Professor at the University of Brighton.

Long Michelson Interferometer

The Long Michelson Interferometer was a radio telescope interferometer built by Martin Ryle and co-workers in the late 1940s beside the rifle range to the west of Cambridge, England. The interferometer consisted of 2 fixed elements 440m apart to survey the sky using Earth rotation. It produced the Preliminary survey of the radio stars in the Northern Hemisphere at 45 MHz - 214 MHz. The telescope was operated by the Radio Astronomy Group of Cambridge University.

Martin Ryle and Antony Hewish received the Nobel Prize for Physics in 1974 for this and later work in radio interferometry.

Mullard Radio Astronomy Observatory

The Mullard Radio Astronomy Observatory (MRAO) is located near Cambridge, UK and is home to a number of the largest and most advanced aperture synthesis radio telescopes in the world, including the One-Mile Telescope, 5-km Ryle Telescope, and the Arcminute Microkelvin Imager. It was founded by the University of Cambridge and is an institute of the Cambridge University Astronomy Department.

One-Mile Telescope

The One-Mile Telescope at the Mullard Radio Astronomy Observatory (MRAO), Cambridge, UK is an array of radio telescopes (2 fixed and 1 moveable, fully steerable 60-ft-diameter parabolic reflectors operating simultaneously at 1407 MHz and 408 MHz) designed to perform aperture synthesis interferometry.

Radio astronomy

Radio astronomy is a subfield of astronomy that studies celestial objects at radio frequencies. The first detection of radio waves from an astronomical object was in 1932, when Karl Jansky at Bell Telephone Laboratories observed radiation coming from the Milky Way. Subsequent observations have identified a number of different sources of radio emission. These include stars and galaxies, as well as entirely new classes of objects, such as radio galaxies, quasars, pulsars, and masers. The discovery of the cosmic microwave background radiation, regarded as evidence for the Big Bang theory, was made through radio astronomy.

Radio astronomy is conducted using large radio antennas referred to as radio telescopes, that are either used singularly, or with multiple linked telescopes utilizing the techniques of radio interferometry and aperture synthesis. The use of interferometry allows radio astronomy to achieve high angular resolution, as the resolving power of an interferometer is set by the distance between its components, rather than the size of its components.


Ryle is the family name of the following individuals:

Anthony Ryle (1927–2016), psychotherapist

Edward Ryle (1885–1952), British athlete and competitor in the 1908 Summer Olympic Games

Gerard Ryle (born 1965), Australian journalist

Gilbert Ryle (1900–1976), English philosopher

Glenn Ryle (1927–1993), American television personality, in Ohio

Herbert Edward Ryle (1856–1925), Old Testament scholar in England

J. C. Ryle (John Charles Ryle, 1816–1900), Anglican bishop of Liverpool

John Ryle (disambiguation), any of several people

Martin Ryle (1918–1984), English astronomer

Mary Danforth Ryle (1833–1904), American philanthropist

William Ryle (1834–1881), American businessman in the silk industry

Ryle Telescope

The Ryle Telescope (named after Martin Ryle, and formerly known as the 5-km Array) was a linear east-west radio telescope array at the Mullard Radio Astronomy Observatory. In 2004, three of the telescopes were moved to create a compact two-dimensional array of telescopes at the east end of the interferometer. The remaining five antennas were switched off on 19 June 2006. The eight antennas have now become the Arcminute Microkelvin Imager Large Array.

The Ryle Telescope was an eight-element interferometer operating at 15 GHz (2cm wavelength). The elements were equatorially mounted 13-m Cassegrain antennas, on an (almost) east-west baseline. Four aerials were mounted on a 1.2 km rail track, and the others were fixed at 1.2 km intervals. Baselines between 18 m and 4.8 km were therefore available, in a variety of configurations. For high-resolution imaging, the mobile aerials were arranged along the track, to give uniform baseline coverage to 4.8 km; for low-brightness astronomy (e.g. the Sunyaev-Zel'dovich effect) the mobile aerials were arranged in a 'compact array', with a maximum baseline of about 100 m. All antenna pairs were correlated, so some long baseline data were always available, even in the 'compact array' configuration.

As the telescope was an east-west instrument, most imaging observations involved 12-hour observations in order to fill the synthesised aperture (calibration observations are routinely interleaved). Another consequence of the geometry was that it is not practical to image sources near the equator, or in the south. The two-dimensional Large Array overcomes this problem with its new north-south baselines.

Although the telescope was not designed as a common user instrument, the operators were happy to accept proposals for observing time on the instrument from outside observers, provided that they did not overlap substantially with existing observing programmes, on a 'best efforts' basis. Monitoring variable sources was possible using short observations which could often be inserted between longer 'standard' observations.

The telescope had three main scientific programs: study of the Sunyaev-Zel'dovich effect in galaxy clusters, particularly in determining the Hubble constant; surveying for radio sources that would contaminate degree-scale observations of the cosmic microwave background made with the Very Small Array, and flux monitoring of galactic variable sources.

William Charles Scully

William Charles Scully (29 October 1855 – 25 August 1943) is one of South Africa's best-known authors, although little known outside South Africa. In addition to his work as an author, his paid work was principally as a magistrate in Springfontein, South Africa, as well as in Namaqualand and the Transkei. His last position before retirement was as Chief Magistrate of Port Elizabeth, one of South Africa's larger cities. He organised the building of "New Brighton", a township for aboriginal African people in Port Elizabeth. At the time it was regarded as very progressive—a pleasant place to live.

Scully was born in Dublin, Ireland, raised in Cashel, County Tipperary, and then emigrated to southern Africa with his parents in 1867. During 1871 he prospected for diamonds with Cecil Rhodes in Africa. His daughter, Miriam Power (b. 1893), married Dr John A. Ryle; their children included Sir Martin Ryle, Nobel laureate and Astronomer Royal from 1972 to 1982. Scully died in Umbogintwini on KwaZulu-Natal's coast in 1943; his second wife (Nora) also died that same year.

His novel Daniel Vananda describes the violence engendered by the ethnic legislation of the time. Similarly, Kafir Stories contains stories that are generally sympathetic with the aboriginal African peoples of South Africa.

After the Boer War, Scully was appointed Chair of a commission to investigate war crimes by the British forces in the Cape Province. (The main war crimes were committed in the Transvaal and the Free State.) After this he wrote The Harrow, which was fictional but based on cases which the commission had investigated. He supplied the publishers with a key to every incident in the book—but with the proviso that this should never be published. Years later he regretted writing the book.

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