From Radar to Radio Astronomy

Abstract

Today’s astronomers study the sky at a wide range of wavelengths, spread across the electromagnetic spectrum, from radio through microwave, infrared, the optical range, the ultraviolet, X-rays and gamma rays (Fig. 1.1). They also use cosmic rays and neutrinos, and the newest field is gravitational wave astronomy. Some of these types of radiation can be observed from the Earth’s surface, others rely on space telescopes. Some are comparatively recent innovations, while optical astronomy – in various guises – dates back many millennia.

Today’s astronomers study the sky at a wide range of wavelengths, spread across the electromagnetic spectrum, from radio through microwave, infrared, the optical range, the ultraviolet, X-rays and gamma rays (Fig. 1.1). They also use cosmic rays and neutrinos, and the newest field is gravitational wave astronomy. Some of these types of radiation can be observed from the Earth’s surface, others rely on space telescopes. Some are comparatively recent innovations, while optical astronomy – in various guises – dates back many millennia.

Fig. 1.1

The electromagnetic spectrum, showing the span of the radio window (courtesy: Orchiston collection)

In radio astronomy we study the radio waves emitted by the Sun, planets and comets of our Solar System, and the stars, dust and gas in our Galaxy and in other galaxies and clusters of galaxies. While the concept of extraterrestrial radio emission dates back to the 1890s, radio astronomy as a new and exciting branch of astronomy only had its origins in the early 1930s when the American physicist Karl Jansky (1905–1950) detected 20 MHz radio emission from the Galaxy (Fig. 1.2; see Sullivan, 2009 for a comprehensive and definitive history of radio astronomy through to 1953). Jansky was a remarkable man (see Biobox 1.1), and it is unfortunate that his employer, the Bell Telephone Laboratories, did not let him pursue these early ground-breaking discoveries further. Instead it was left to Grote Reber (1911–2002; Biobox 1.2) to take radio astronomy to the next level, and to interest optical astronomers in the research potential of this new field. Radio engineering was Reber’s profession and hobby, and after trying unsuccessfully to obtain a position with Jansky and to interest some leading optical astronomers in ‘cosmic static’, he realised “Nobody was going to do anything. So … maybe I should do something. So I consulted with myself and decided to build a dish!” (Kellermann, 2005: 49).

Fig. 1.2

Karl Jansky used the 20.5 MHz ‘merry-go-round’ antenna at Holmdel, New Jersey, for his studies of extraterrestrial radio emission (courtesy: US National Radio Astronomy Observatory)

FormalPara Biobox 1.1: Karl Jansky

Karl Guthe Jansky (Fig. 1.3) was born in Oklahoma on 23 October 1905, and graduated with a BSc in physics from the University of Wisconsin in 1927. After a year of post-graduate study, he joined the Bell Telephone Laboratories (BTL), but because he was diagnosed with a kidney disease (Bright’s disease) was posted to a rural radio field station at Cliffwood, New Jersey, rather than the main research laboratory in New York. He began researching static associated with shortwave radio transmissions in August 1928, and in 1930 the group transferred to nearby Holmdel. It was there that he built the ‘merry-go-round’ antenna. In an August 1931 report “… we find what in retrospect appears to be the first recognition of a new, weak component of static.” (Sullivan, 1984b: 10). This weak emission, recorded at 20.5 MHz, was researched during 1932 and first mentioned in a research paper by Jansky published that year in the Proceedings of the Institute of Radio Engineers.

Fig. 1.3

Karl Jansky (1905–1950) was the founding father of radio astronomy (courtesy: US National Radio Astronomy Observatory)

Jansky continued his investigations on an intermittent basis during 1931 and through 1932 as the Great Depression altered the BTL’s research priorities, but by December 1932 he was in a position to conclude that the mysterious ‘static’ was extraterrestrial in origin. The concept of radio astronomy was born. In 1933 Karl spoke about his research at meetings in Washington and Chicago on 27 April and 27 June respectively. He also published research papers on this work in Nature and Proc. IRE. Following the Washington meeting, the BTL issued a press release, and on 5 May the front page of the New York Times devoted an entire column to the “New radio waves traced to the center of the Milky Way …”. Jansky became an instant international celebrity! By August 1933 Jansky was convinced that the static originated from the entire Milky Way, and not just from the central region. The following month Jansky targeted his findings at an astronomical audience through an article in the magazine Popular Astronomy, but this was also the time that Jansky turned to other static-related research that was more appropriate to BTL’s practical needs.

Only in 1935 did he briefly return to his ‘star noise’ research, and publish two final papers in Proc. IRE in 1935 and 1937. This marked the end of Jansky’s exciting foray into the field that would ultimately be known as radio astronomy, but within months of submitting his 1937 paper the cause would be taken up by another pioneer, Grote Reber, who began building a 9.75 m diameter parabolic radio telescope at Wheaton, Illinois. For his part, Jansky “… continued on the same theme of understanding and minimising the sources of noise in radio communications, whether they were internal to the electronics or external to the antenna, manmade or natural.” (Sullivan, 1984b: 24), and his merry-go-round was used as a mount for a variety of different antennas (see also Sullivan, 1984c).

With the passage of the years, Jansky’s lifelong kidney ailment led to blood pressure problems, and he eventually died of a stroke in February 1950; he was just 44 years of age. While he never received any official honours or rewards during his short lifetime, other than being made a Fellow of the Institute of Radio Engineers, Karl will always be warmly remembered as the founder of radio astronomy:

There can be no doubt that he is the father of radio astronomy – but (shifting metaphors) only in the sense of finding and sowing the seed, not in raising the crop. Through a combination of circumstances, his discovery fell on stony ground and was not to yield fruit until the technical demands of a war created a new generation of men and equipment. (Sullivan, 1984b: 35–36).

FormalPara Biobox 1.2: Grote Reber

Grote Reber (Fig. 1.4) was born in Chicago on 22 December 1911, and obtained a degree in Electrical Engineering from the Armour Institute of Technology (now the Illinois Institute of Technology). From his teens, he was an avid radio ham, and after reading about Jansky’s work he decided to conduct research in this new field and in 1937 he built a 9.75 m parabolic transit dish. Subsequently, he published a succession of research papers, mostly on ‘Cosmic static’. It is fair to say that initially his work was viewed with skepticism by most optical astronomers (see Reber, 1984 for a personal account).

Fig. 1.4

Grote Reber (1911–2002) laid the foundations of radio astronomy during the late 1930s and early 1940s (courtesy: US National Radio Astronomy Observatory)

Soon after WWII, Reber accepted a position at the Central Radio Propagation Laboratory of the National Bureau of Standards and sold his dish and associated instrumentation to his employer on the expectation of building a 23–30 m dish for research. This did not happen, and he quickly became disillusioned and decided to move to Hawaii where he could conduct independent research in radio astronomy. There he erected a sea interferometer on the summit of Mt Haleakala but it produced disappointing results. In November 1954 he moved to Tasmania, and over the next half-century built a succession of very low frequency arrays and published a series of paper on his research (George et al., 2015b, 2015c, 2017). Whilst widely regarded as one of the ‘fathers of radio astronomy’, Reber unfortunately promoted cosmological views that were at odds with most other astronomers. He also had little respect for the standard refereeing process used by scientific journals, and was openly critical of politicians, the National Academy of Science and the National Science Foundation in the USA and the work done at the US National Radio Astronomy Observatory. He was able to adopt this stance and maintain his independent status because he received strong financial support over several decades from the Research Foundation.

Although Reber operated outside the ‘mainstream astronomical community’, he was awarded the Bruce Medal by the Astronomical Society of the Pacific, the Elliot Cresson Medal of the Franklin Institute, and the Russell Lectureship of the American Astronomical Society. He received an honorary DSc degree from Ohio State University, and in 1999 was named ‘Man of the Millennium’ by the Illinois Institute of Technology. A man of diverse interests, he also conducted research and published on radio-circuitry, ionospheric physics, cosmic rays, meteorology, botany and archaeology. Grote was also deeply concerned about environmental, social and political issues. In Bothwell, Tasmania, he built his modest energy-efficient home, and a battery-powered car. After a long and eventful life, he died in Bothwell in December 2002. For further details of his remarkable life, see Robertson (1986) and Kellermann (2005).

In his spare time he built a 9.75 m (32 ft) diameter parabolic dish in the property next door to his mother’s home in Wheaton, Illinois (Fig. 1.5). This was in 1937, and although “Neighbours speculated about the purpose of the unfamiliar-looking structure … Reber’s mother found it a convenient place to hang her washing!” (Kellermann, 2005: 49). After experimenting with different receivers, he eventually detected Jansky’s ‘cosmic static’ in 1939, and went on to observe the sky at 160 and 408 MHz and to produce the first high-resolution contour maps of Galactic radio noise. Reber wrote papers on his ‘cosmic static’ and they were quickly published in the Proceedings of the Institute of Radio Engineers, but it was a different story when he tried to share his exciting new finds with astronomers. When he submitted a paper to the prestigious Astrophysical Journal it caused a flurry of excitement and curiosity. Who was this fellow without an astronomy degree or an observatory affiliation, what equipment did he use for these strange observations, and what did they mean? Several delegations of astronomers, mainly from the famous Yerkes Observatory, went to Wheaton to meet Reber and see his equipment for themselves. They seemed suitably impressed, and the editor Otto Struve eventually decided to accept Reber’s paper, but only after some editorial censoring. Reber was less than impressed with these delays and changes and later stated that while Struve may not have rejected the paper,

Fig. 1.5

Grote Reber’s home-made 9.75-metre parabolic antenna mystified his neighbours at Wheaton, Illinois (courtesy: US National Radio Astronomy Observatory)

He merely sat on it until it got mouldy. I got tired of waiting, so I sent some other material to the Proceedings of the IRE. It was published promptly … During the early days of radio astronomy, the astronomy community had a poor [publication] track record. The engineering fraternity did much better. (Kellermann, 2005: 52).

After making pioneering Milky Way observations, in 1943 Reber went on to detect radio emission from the Sun. Jansky and Reber, joined by essentially no one else, can rightly be considered the ‘founding fathers’ of radio astronomy.

But if radio astronomy was born during the 1930s, it only began to grow during the late 1940s, mainly because of independent discoveries of solar radio emission in England, the USA, Australia and New Zealand during World War II. Most of these involved radar antennas, and since the ‘solar noise’ was initially thought to be some form of enemy jamming technique these discoveries were treated as ‘secret’ or ‘top secret’. Strangely, it was the New Zealand discoveries that had the greatest impact in Australia, and led directly to the launch of an ambitious radio astronomy research program by the Radiophysics Laboratory in Sydney (which we shall often refer to simply as RP). The New Zealand solar research was the responsibility of Dr Elizabeth Alexander (1908–1958), Head of the Operational Research Section of the Radio Development Laboratory. Between March and December of 1945 she arranged for solar monitoring to be carried out at a number of different Air Force radar stations (Fig. 1.6). British-born Alexander (see Biobox 3.1 in Chapter 3)

Fig. 1.6

The RNZAF Wainui radar station near the northern-most tip of the North Island of New Zealand, showing the 200 MHz antenna used for solar observations immediately after sunrise (courtesy: Orchiston collection)

… prepared a number of reports on this work, and in early 1946 she published a short paper in the newly-launched journal, Radio & Electronics. A geologist by training, Elizabeth Alexander happened to be in the right place at the right time, and unwittingly became the first woman in the world to work in the field that would later become known as radio astronomy. (Orchiston, 2005b: 71).

In Australia, Radiophysics had been established at the beginning of WWII in order to develop radar technology for Australian sites and the Pacific theatre (Fig. 1.7). Radiophysics was one of a number of divisions that made up the Council for Scientific and Industrial Research, Australia’s leading research organisation. In 1949 CSIR was reconstituted and renamed the Commonwealth Scientific and Industrial Research Organisation (CSIRO) [see Schedvin (1987) and Collis (2002) for official histories of CSIR and CSIRO respectively].

Fig. 1.7

(left) The experimental radar antenna at the Dover Heights field station in Sydney. The antenna was used for the detection of ships along the Australian coast, but then a new version was hurriedly developed for air warning following the Japanese attack on Pearl Harbor. (right) The light-weight/air-warning (LW/AW) portable radar developed by the Radiophysics Lab especially for tropical conditions in the Pacific. The equipment could be airlifted to forward areas and then rapidly assembled. This unit was installed on Tumleo Island near the north coast of New Guinea [courtesy: CSIRO Radio Astronomy Image Archive (henceforth CRAIA)]

In mid-1945 one of Elizabeth Alexander’s confidential reports reached the RP Chief, Dr E.G. (‘Taffy’) Bowen (1911–1991; Biobox 1.3), and his deputy, Dr Joe Pawsey (1908–1962). The New Zealand work fascinated them, and they decided to try and repeat it using a Royal Australian Air Force radar antenna at Collaroy, in suburban Sydney. Pawsey’s initial success profoundly influenced the direction of research to be undertaken by Radiophysics in the immediate post-war years, for the Laboratory was under considerable pressure to reinvent itself and find a range of peace-time research projects – any surviving projects with military applications had to be transferred to the defense services.

FormalPara Biobox 1.3: Taffy Bowen

Edward George Bowen (Fig. 1.8) was born near Swansea in January 1911 and later in life was proudly known by his Welsh nickname of ‘Taffy’. As a boy he took a keen interest in radio technology, which sowed the seeds for his future career. He studied physics at the University College of Swansea and in 1934 he was awarded a PhD at King’s College London, under the supervision of Edward Appleton. In 1935 Bowen joined Robert Watson Watt’s group at the Bawdsey Manor research station working on the highly secret technique of radio detection finding (later known as radar). Taffy was given the responsibility of building the first airborne radar system, which was successfully tested in September 1937. Bowen’s other major contribution to the war effort was as a member of the Tizard mission to the United States in 1940 to inform the Americans about recent British technical advances, including radar. He spent most of the war years shuttling between England and the Massachusetts Institute of Technology which was the centre of US radar research and development (Bowen, 1987).

Fig. 1.8

Dr Edward (‘Taffy’) Bowen (1911–1991) was Chief of the Radiophysics Lab from 1946 to 1971 (courtesy: CRAIA)

In late 1943 Taffy accepted an offer to become Assistant Chief of the Radiophysics Lab in Sydney and, two years later, he was elevated to the position of Chief. At the end of the war, the Lab had a group of highly talented staff looking for new research directions. Two major peacetime programs emerged: cloud and rain physics under Bowen’s direction, and radio astronomy led by Joe Pawsey. Taffy was a pioneer of cloud seeding experiments in Australia, although his controversial ideas about the influence of meteoric dust on rainfall were mostly discredited. Bowen believed that future advances in radio astronomy would require large and expensive aerial systems and he became the driving force behind the planning and construction of the Parkes Radio Telescope (see Chapter 5). Opened in 1961, the iconic Parkes dish has been at the forefront of astronomical research for over sixty years. The dish was also involved in the series of Apollo missions to the Moon over the period 1969–72. Bowen also made a significant contribution to the establishment of the Anglo-Australian Telescope at Siding Spring in NSW as the inaugural chair of the AAT Board.

In 1972 he was appointed scientific counsellor at the Australian Embassy in Washington, DC, where he spent the remainder of his career. Taffy received a number of prestigious awards and honours over his distinguished career, including the Medal of Freedom USA (1947) for his contributions to radar research and a Commander of the Order of the British Empire (CBE, 1962) for his services to Australian science. In 1975 he was elected a Fellow of the Royal Society of London. For more on Taffy Bowen see Hanbury Brown et al. (1992) and Bhathal (2014).

Various fields were investigated in the ten years following WWII, including cloud physics and rainmaking, navigational aids for civilian aircraft and ships (Fig. 1.9), a mobile traffic radar system for the NSW police force (Fig. 1.10), and radio astronomy (or, more properly, ‘solar noise’ and ‘cosmic noise’, to use the terminology of the day) (see Bowen, 1988; Sullivan, 2005). A vacuum physics laboratory was set up, work was carried out on transistors, and plans were made for a linear accelerator for nuclear physics. Australia’s first computer was constructed at this time, known as CSIRAC – the CSIRO Automatic Computer (Fig. 1.11). CSIRAC was put to work on a number of RP research programs, but surprisingly had little impact on the radio astronomy program. Most of the tedious calculations required to reduce observational data were made by the radio astronomers themselves or by other RP staff (mostly women). Apart from radio astronomy, the aim of the RP research work was to come up with technological developments that would assist the Australian economy, and the Division’s exploits in rainmaking (Fig. 1.12) certainly had the potential to do this if they proved successful.

Fig. 1.9

Testing a navigational radar system housed under the ‘dome’ on the nose of the aircraft (courtesy: CRAIA)

Fig. 1.10

A mobile traffic radar system was developed by the Radiophysics Lab for the New South Wales Police Force. RP scientist Harry Minnett (left) explains the system to the NSW Minister for Police (courtesy: CRAIA)

Fig. 1.11

Trevor Pearcey and CSIRAC, the first (and last) computer to be wholly designed and built in Australia. CSIRAC is now on display at the ScienceWorks Museum in Melbourne and is the oldest first-generation computer still in existence (courtesy: CRAIA)

Fig. 1.12

During the 1950s and 1960s, apart from radio astronomy, the other major research area at Radiophysics was rainmaking. Silver iodide burners were attached to aircraft and used to seed clouds in selected areas of eastern Australia. Military aircraft were used for the trials because silver iodide is highly inflammable and too dangerous to use on commercial aircraft (courtesy: CRAIA)

From the start, the RP radio astronomy program was under the capable leadership of Joe Pawsey (Biobox 1.4). Australian by birth, but Cambridge-trained, Pawsey was a brilliant antenna expert and a real science fanatic, and he simply “… infected everyone with his enthusiasm … He just went from group to group stimulating them, giving them ideas, criticising, and stuff … He was absolutely first class … [and] extremely modest.” (Christiansen, 1976). He was seen by most as a respected father figure – even though, for many, he was only ten years their senior – and he was warmly-revered as the “… father of Radio Astronomy in Australia ... [and] one of the greatest men in the history of [world] radio astronomy.” (Kerr, 1971). While Taffy Bowen was the tough and successful leader of the Radiophysics Lab, Pawsey was the academic scientist and the ideal radio astronomy team leader.

FormalPara Biobox 1.4: Joe Pawsey

Joseph Lade Pawsey (Fig. 1.13) was born in Ararat, Victoria, on 14 May 1908 and died in Sydney on 30 November 1962. Despite comparatively little formal schooling he won a scholarship to Queen’s College at the University of Melbourne, and graduated with BSc and MSc degrees in Natural Philosophy (both with First Class Honours) in 1929 and 1931 respectively. He was then awarded an 1851 Exhibition scholarship, and completed a PhD at Cambridge under Jack Ratcliffe in 1934. Up until the outbreak of WWII he worked for EMI Electronics Ltd, and then returned to Australia and joined the CSIR’s Division of Radiophysics in Sydney where he carried out radar-related research.

Fig. 1.13

Dr Joe Pawsey (1908–1962) was the inspirational leader of the radio astronomy group (courtesy: CRAIA)

After the war, Pawsey led the radio astronomy group, formally becoming Assistant Chief of the Radiophysics Division in 1951. He played a pivotal role in most of the important contributions made by this group right up until the time of his decision at the end of 1961 to accept the Directorship of the US National Radio Astronomy Observatory at Green Bank, West Virginia. Joe received the Lyle Medal of the Australian National Research Council in 1953 and the Hughes Medal of the Royal Society in 1960, having been elected a Fellow of the Society in 1954. He was awarded an honorary DSc by the Australian National University in 1961, and from 1952 to 1958 was President of Commission 40 (Radio Astronomy) of the International Astronomical Union. Apart from his various research papers, Pawsey was well known for his book Radio Astronomy (1955) which was co-authored by one of his disciples, Ron Bracewell. In a 1962 letter to Joe’s widow Lenore, the Director of Mount Stromlo Observatory, the inimitable Bart Bok, wrote:

There are very few scientists in the world who will be able to look back upon a life in which they have helped produce so many distinguished scientists. The young men of Australia who are now the great names of radio astronomy, and who have helped place Australia at the top of the list in the field on a world-wide basis, all express great personal debts for the way in which Joe helped them get started and how he saw to it that their work came to fruition. (Bok, 1962).

In an obituary two of Pawsey’s protégés, Chris Christiansen and Bernie Mills (1964), stated that despite his short life,

It is difficult indeed to over-estimate the value of his contribution to the recent development of the radio sciences and radio astronomy in Australia. Apart from his direct influence in the Radiophysics Division … his influence was felt in the field of optical astronomy, in ionospheric research and in many applications of Radiophysics techniques in other fields.

In 1967 the Australian Academy of Science established the annual Pawsey Medal to recognise outstanding research in physics by an early- or mid-career researcher. For further details of Pawsey’s distinguished career see the full-length biography by Goss et al. (2021). See also the Royal Society memoir by Lovell (1964) and for a brief summary Robertson (2000).

Most of the radio astronomy carried out by RP staff between 1946 and 1961 took place at twenty-one different field stations and remote sites in and near Sydney (Fig. 1.14), at two solar eclipse sites in Victoria, two further eclipse sites in Tasmania, and at two temporary field stations in the North Island of New Zealand. Through these,

Fig. 1.14

Map showing the location of field stations (in blue), remote sites (red) and other localities (black) in the Sydney and Wollongong regions (indicated by the dotted outlines) that were used for radio astronomy between 1945 and 1961. Key: 1 = Badgery’s Creek, 2 = Collaroy, 3 = Cumberland Park, 4 = Dapto, 5 = Dover Heights, 6 = Fleurs, 7 = Freeman’s Reach, 8 = Georges Heights, 9 = Hornsby Valley, 10 = Llandilo, 11 = Long Reef, 12 = Marsfield (ATNF Headquarters), 13 = Murraybank, 14 = North Head, 15 = Penrith, 16 = Potts Hill, 17 = Radiophysics Laboratory (grounds of the University of Sydney), 18 = Rossmore, 19 = Wallacia, 20 = West Head, 21 = Bankstown Aerodrome (map Wayne Orchiston)

… Australia played a key role in the international development of radio astronomy … In addition to standard Yagis and parabolic dishes, innovative new types of instruments were invented, including solar radiospectrographs, solar grating arrays, cross-type radio telescopes, H-line multi-channel receivers, and an assortment of long-baseline interferometers …

Collectively, the radio telescopes at the field stations and associated remote sites were used to address a wide range of research problems, and important contributions were made to solar, Jovian, Galactic and extra-galactic astronomy … largely through the key roles played by leaders such as John Bolton, Chris Christiansen, Frank Kerr, Bernie Mills, Joe Pawsey, Ruby Payne-Scott, Alex Shain, Bruce Slee, Gordon Stanley and Paul Wild. (Orchiston and Slee, 2017: 567).

Rod Davies (1930–2015), who came to Radiophysics in 1950 as a young BSc Honours graduate from the University of Adelaide, described the field station era:

People tended to explode out first thing in the morning and you didn’t see them until the evening. They tended to be quite independent groups [see e.g. Fig. 1.15] and competitive in some ways … Joe Pawsey knew the story well and he would move from one place to another [field station to field station] and keep a very close contact with the various groups (Davies, 1971).

Fig. 1.15

The Fleurs group in 1956 (from left): Ken Hawkins, Alex Shain, Bruce Slee, Bernie Mills, Kevin Sheridan, Alec Little and Henry Rishbeth (Charlie Higgins was absent at the time). Rishbeth was a visiting PhD student from the Cavendish Laboratory in Cambridge (courtesy:CRAIA)

There was a good deal of flexibility about field station life, where staff were free to pursue their own specific research interests (though not all of it was serious science – see Fig. 1.16).

Fig. 1.16

Bush cricket at the Potts Hill field station with Charlie Fryer (left) and Chris Christiansen (courtesy: CRAIA)

By 1950, the term ‘radio astronomy’ was meeting gradual acceptance as the generic term for the ‘solar noise’ and ‘cosmic noise’ research conducted by the RP staff (indeed it was Pawsey himself who coined the term in a letter to a colleague in January 1948). And yet the name ‘astronomy’ was in a sense misleading for none of the early pioneers could by any stretch of the imagination initially be classed as ‘astronomers’. Indeed, hardly any were former amateur astronomers, and very few had any interest whatsoever in astronomy! Rather, most came to ‘solar noise’ and ‘cosmic noise’ studies via engineering and physics, although a few had joint engineering/science degrees. Thus the astronomical knowledge of RP staff during the formative years of Australian radio astronomy was almost non-existent, and it is somewhat surprising that Bowen or Pawsey did not devise some formalised means of redressing this shortcoming. Perhaps the fact that many staff were based at the scattered field stations was part of the problem. Instead, it was left to each individual to bone up on astronomy as the need arose. As for basic astronomy references, there were two stalwarts: Norton’s Star Atlas (which even today remains a favourite with many amateur astronomers), and the two-volume text Astronomy by Russell, Dugan and Stewart. But the RP Library did offer other titles, including the Harvard Series in Astronomy, and most of the RP research staff read rapaciously. One of those who sought to bring his overall astronomical knowledge ‘up to speed’ in a novel way was John Bolton (1922–1993), who methodically read volume after volume of the Astrophysical Journal and Monthly Notices of the Royal Astronomical Society during lonely nights at the Dover Heights field station when there was nothing significant appearing on the chart records.

Many RP staff also drew widely on the astronomical knowledge of two noted Australian optical astronomers, Claborn (‘Cla’) Allen (1904–1987) at Mount Stromlo Observatory and the Director of Sydney Observatory, Harley Wood (Fig. 1.17), while distinguished overseas astronomers such as Walter Baade (1893–1960) and Rudolph Minkowski (1895–1976) in California and Jan Oort (1900–1992) in Holland were quick to realise the research potential of radio astronomy and to offer their expertise and their friendship. Following up on these and other contacts, a number of RP staff members attended graduate coursework programs at overseas universities in a bid to rectify their astronomical ignorance. For example, Bernie Mills (1920–2011) went to Caltech in order “… to learn some basic astronomy, which I felt I was sadly in need of in those days. [Also] Caltech was … the obvious place to go to talk to Minkowski and Baade ...” (Mills, 1976; see Fig. 1.18). Later Mills (ibid.) was to reminisce:

Fig. 1.17

Dr Harley Wood, Director of Sydney Observatory, was a source of astronomical information for the fledgling RP radio astronomers (courtesy: Ros Madden)

Fig. 1.18

Rudolph Minkowski (left) from the Mt Wilson–Palomar Observatories and Bernie Mills. Minkowski visited Radiophysics in March 1956 in an attempt to clear up a controversy between the Radiophysics and Cambridge astronomers (courtesy: Sydney Morning Herald)

From my point of view this was a very fruitful part of my life because I could stop worrying about instrumental developments and sit down and start thinking about astronomy, astrophysics and physics generally ... I learned all my astronomy in one year … It put me right in the forefront of thought at that time.

The earliest research at the RP field stations was carried out with simple antennas (e.g. see Fig. 1.19) and with receivers and other equipment that were often left over from WWII, but the international emergence of radio astronomy during the 1950s saw the invention of amazing new types of radio telescopes. These not only opened up exciting new avenues of research, but they also created problems for their inventors as the demand for funds for new instruments began to surpass the funds available in the annual RP budget. In the early 1950s, John Bolton and his Dover Heights team wanted a large new sea interferometer, Jack Piddington (1910–1997) a 6 m diameter dish, Joe Pawsey a large hole-in-the-ground antenna in the Blue Mountains, Bernie Mills a new cross-type radio telescope, and Paul Wild (1923–2008) a suite of solar radiospectrographs. Independent of these proposals that would require internal funding, Taffy Bowen was actively seeking external funds to build a giant radio telescope (Fig. 1.20) that would rival the aperture of the 76 m instrument under construction at Jodrell Bank in England by Bernard Lovell (1913–2012; Fig. 1.21) (see Chapter 5 for details).

Fig. 1.19

Simple single, twin and four Yagi antennas, such as this twin Yagi antenna at Dover Heights, were used at the RP field stations in the early days of radio astronomy (courtesy: CRAIA)

Fig. 1.20

What might have been – some of the designs for a giant radio telescope investigated at Radiophysics in 1954 (courtesy: CRAIA)

Fig. 1.21

A sketch prepared early in 1952 of the 76 m dish planned by Bernard Lovell at Jodrell Bank in Cheshire (courtesy: Robertson collection)

After the success of a small pilot model, Mills submitted a proposal for a full-scale cross telescope, which sat on the table alongside the Dover Heights interferometer, Pawsey’s hole-in-the-ground antenna, Piddington’s dish (which had miraculously grown to about 24 m in diameter), and Wild’s new initiative, a solar radioheliograph. Pawsey was placed in the difficult position of having to adjudicate on the competing radio telescope options. If Pawsey had a fault, it was that he hated making ‘hard’ decisions, and with the passing of the years this was to lead to many problems. In contrast, Bowen was a seasoned campaigner, and “… when Taffy felt strong enough about something, he’d overcome any opposition … Taffy was an enormously energetic person who knew how to get things going on big projects. He knew all the top-level people. He was a very good organiser …” (Minnett, 1978).

An immediate loser in this decision-making process was the Dover Heights team, and despite secretly constructing their own large ‘hole-in-the-ground’ dish-shaped antenna (see Chapter 4), team-leader, John Bolton, soon transferred to the Cloud Physics group within RP (Milne, 1994) and subsequently to the California Institute of Technology where he and Gordon Stanley (1921–2001) established the first major radio astronomy observatory in the United States (Fig. 1.22). By the late 1950s, Radiophysics had “… too many entrepreneurs for the institution to hold them anymore. It was inevitable that some would move out to other ponds” (Kerr, 1986). As we discuss in Chapter 5, Christiansen (1913–2007) and Mills both lost out when the Culgoora Radioheliograph (Fig. 1.23) was given priority over their own research programs. Consequently, in 1960, both moved to senior posts at the University of Sydney, where Mills went on to build the Molonglo Cross (Fig. 1.24), near Canberra, and Christiansen developed his earlier ‘Chris Cross’ at Fleurs, in the process converting it into the Fleurs Synthesis Telescope (Fig. 1.25).

Fig. 1.22

In 1955 John Bolton and Gordon Stanley from Radiophysics were recruited by Caltech to establish a new radio astronomy group. They founded the Owens Valley Radio Observatory in northern California and designed an interferometer consisting of two 27 m dishes. The dishes were mounted on rail tracks so that the distance between the two could be varied (courtesy: Jim Roberts)

Fig. 1.23

Sketch of Paul Wild’s 96-element solar Radioheliograph (courtesy: CRAIA)

Fig. 1.24

Sketch of the giant Molonglo Cross, planned for Hoskinstown near Canberra (courtesy: CRAIA)

Fig. 1.25

View looking west along the E–W arm of the Fleurs Synthesis Telescope. In the foreground is one of the new 13.7 m antennas, and beyond it the smaller dishes belonging to the original Chris Cross (courtesy: CRAIA)

Earlier, Ron Bracewell (1921–2007) had transferred to Stanford University in California (Biobox 1.5, Fig. 1.26). Similarly, Rod Davies (1930–2015, Fig. 1.27) joined Bernard Lovell’s group at the University of Manchester in 1953 and later became Director of the Jodrell Bank Observatory (1988–1997). Another RP ‘graduate’ was Kevin Westfold (1921–2001, Fig. 1.27) who moved to the University of Sydney in 1954 and then to Monash University in Melbourne where he eventually became Deputy Vice-Chancellor. We see that as RP’s international reputation grew, so too did the outflow of major talent, many of them dedicated Pawsey disciples. Even Pawsey eventually joined the exodus, accepting the Directorship of the US National Radio Astronomy Observatory in West Virginia (see Chapter 5).

Fig. 1.26

Ron Bracewell and Joe Pawsey co-authored Radio Astronomy, the first scholarly book on the subject. It was published by The Clarendon Press, the imprint of Oxford University (courtesy: NRAO/Associated Universities, Inc. Archives)

Fig. 1.27

Two of the talented young radio astronomers who pursued careers beyond the doors of Radiophysics: Rod Davies (left, University of Manchester) and Kevin Westfold (Monash University) (courtesy: NRAO/Associated Universities, Inc. Archives and CRAIA)

FormalPara Biobox 1.5: Ron Bracewell

Ronald Newbold Bracewell (Fig. 1.26) was born in Sydney in July 1921. He was educated at Sydney Boys High and at the University of Sydney where he graduated with the degrees BSc (1941), BEng (1943) and MEng (1948). He then studied for a PhD in ionospheric physics at Cambridge University, under the supervision of Jack Ratcliffe, before joining the Radiophysics Lab in 1949. The physicist Joan Freeman, who was briefly on the RP staff, recalled: “Ron was extremely bright, and had an encyclopaedic range of knowledge: he could discourse eloquently (though sometimes with tongue-in-cheek) on subjects as diverse as metaphysics, ancient history, and cryptography.” (Freeman, 1991: 89).

Two examples illustrate Bracewell’s various talents. He was appointed secretary of the organising committee for the URSI Congress held in Sydney in August 1952 (see below) and his meticulous planning proved a major factor in the success of the meeting. Although Ron’s expertise was in ionospheric physics, Joe Pawsey shrewdly converted him to radio astronomy by inviting him to co-author a book on the subject (Pawsey and Bracewell, 1955).

In 1955 Bracewell was recruited to establish radio astronomy in the Department of Electrical Engineering at Stanford University, near San Francisco. There he would spend the rest of his career, working well into his eighties. Ron’s first project was to build the Stanford Microwave Spectroheliograph, a crossed-grating array consisting of 32 dishes to produce daily radio maps of the Sun (Bracewell, 2005).

The polymath Bracewell was a prolific author of books and research papers. The most important was his book on Fourier transforms and their applications, published in 1965. It was considered the ‘bible’ on the subject, not only by radio astronomers but also by medical researchers where Ron’s mathematical formalism underpinned the development of computer aided tomography (CAT scans). Ron received numerous honours, both astronomical and medical, and in 1998 was made an Officer of the Order of Australia (AO). He died in August 2007. For more on Bracewell’s life see Frater et al. (2017) and Thompson and Frater (2010).

By the time the Parkes Radio Telescope opened in late 1961, Radiophysics was widely regarded as one of the world’s foremost radio astronomical institutions, and a number of people have opined on the range of factors that combined during the late 1940s and through the 1950s to bring about this situation (e.g., see Stewart et al., 2011; Sullivan, 2009). All would agree that having a sizeable highly-skilled radar-orientated workforce that largely stayed together after WWII was a primary ingredient, only made possible by the enlightened view of Sir David Rivett (1886–1961; Fig. 1.28) and the CSIRO Executive towards post-war research in its various Divisions. Another factor was the appointment of a number of first-rate and enthusiastic senior staff members soon after the war; Harry Minnett (1917–2003; 1978), who was later destined to be Chief of the Division, referred to the RP staff of this period as “… a pretty talented bunch of people by any standards.” Add to this the initial availability of suitable WWII surplus equipment, an excellently equipped and staffed RP workshop, and the fact that radio astronomy was a new field of endeavour worldwide. It was almost virgin territory and – with some nostalgia – Gordon Stanley (1974) later recalled: “It’s the one thing I can never recapture in this game. I mean, the excitement of the whole darn thing at that time … it was so exciting to be in on it … It was simply great fun.” (see Fig. 1.29). In a similar vein, Paul Wild (1978) reminisced: “I think we were very lucky in being involved in a very new field. It’s so much easier to contribute … [and it] was a marvelously-exciting thing at the time …”. As John Murray (b. ca. 1927; 1978) pointed out, “… it was hard to get a non-result …” in this emerging field of science! The lack of any tradition in astrophysics in Australia may also have helped, as it left the early radio astronomers free to ‘follows their noses’, without being strait-jacketed by optical research priorities.

Fig. 1.28

Sir David Rivett (1885–1961) was the inspirational CEO of CSIR during the early post-war years when RP was building its international reputation. He was a strong supporter of radio astronomy and viewed RP as one of CSIR’s ‘glamour’ Divisions (courtesy: CSIRO Corporate Archives)

Fig. 1.29

Gordon Stanley and his Dover Heights receivers in January 1952. Although he went on to become Director of the Owens Valley Radio Observatory in California, Gordon never forgot the nostalgic late 1940s when he, John Bolton and Bruce Slee were among the pioneers of radio astronomy (courtesy: CRAIA)

One reflection of Australia’s international standing in radio science generally and in the emerging new field of radio astronomy was the decision to hold the 1952 General Assembly of the International Union of Radio Sciences (known by the acronym of its French name as URSI) in Sydney. This was the first time a major international science meeting of any kind had been assigned to a nation outside of Europe or North America (Robinson, 2002), and the decision consigned the non-Australian participants to a lengthy voyage by ship out to what was the far side of the globe. Upon their arrival the President, Sir Edward Appleton (1892–1965), and other dignitaries were greeted with due pomp and ceremony (Fig. 1.30). The conference brought together for the first time many of the world’s leading radio astronomers (Fig. 1.31), and combined formal paper sessions with visits to some of the RP field stations (Figs 1.32 and 1.33). It was a great success (see Bolton, 1953; Kerr, 1953).

Fig. 1.30

Upon arrival in Sydney by ship, President of the 1952 URSI Congress, Sir Edward Appleton (centre) is welcomed by Taffy Bowen and Joe Pawsey. At far left is the former RP Chief, Dr David Martyn (courtesy: CRAIA)

Fig. 1.31

(above) The URSI delegates outside the Wallace Theatre at the University of Sydney. (below) Some famous faces from the early years of radio astronomy (from left): Chris Christiansen, Graham Smith (England), Paul Wild, Charlie Higgins, Bernie Mills, Jack Piddington, John Hagen (US), Jean-Louis Steinberg (France), Steve Smerd, Jim Hindman, Eric Hill, Alex Shain, Harold ‘Doc’ Ewen (US), Frank Kerr, Robert Hanbury Brown (England), Lou Davies, Alexander Muller (Netherlands), Ruby Payne-Scott, Alec Little, Marius Laffineur (France), Bruce Slee and John Bolton (courtesy: CRAIA)

Fig. 1.32

The Congress delegates visited a number of field stations including Potts Hill where they examined the grating array (from left): Chris Christiansen, Sir Edward Appleton (UK) and Balthasar van der Pol (Netherlands) (courtesy: CRAIA)

Fig. 1.33

The URSI delegates also visited the Hornsby Valley field station. Robert Hanbury Brown and Graham Smith are fourth and fifth from the left, respectively, while the two RP radio astronomers based at Hornsby Valley, Alex Shain and Charlie Higgins, are third and fifth from the right, respectively (courtesy: CRAIA)

All of his contemporaries agree that Australia would not have achieved such international renown without the brilliance, guidance and dedication of one man, namely Joe Pawsey. Initially, Joe believed that there had to be a reasonable compromise between long-term ‘mainstream’ projects and short-term speculative projects which, if successful, might reveal unexpected exciting new phenomena. By 1954 priorities had changes somewhat, and he felt that while in the past projects were

… planned on the basis of a small group building apparatus and using it to get all information possible. We are now moving towards the observatory procedure, where complex equipment is used by a succession of observers to investigate explicit problems (Pawsey, 1954: 1).

This instrumental constraint was precisely what Christiansen and Mills – amongst others – hoped to avoid. After providing an historical context to his thinking, Christiansen (1986) elaborated:

The 1950s decade, which I think was by far the best in the history of RP radio astronomy, was not one of transition but one of conflict between two tendencies. One was to continue the invention of new techniques (to beat poverty with brains) and the other was to revert to conventional astronomical observatory practice (of everyone working on one or two large and conventional instruments). Bowen and Bolton represented the latter tendency and Joe [Pawsey] and the rest of us the first. We (Joe etc.) won the first rounds but Bowen won at the end.

Just look at the work of the first half of the decade! There was the radiospectrograph of Wild and McCready, the radio-linked interferometer of Mills and Thomas, my grating interferometers (with resolving power not surpassed in Radiophysics to the present day), and the first maps made by earth-rotation synthesis at Potts Hill, all world firsts, plus the Mills Cross and the interferometry work of Payne-Scott and Little.

Christiansen noted that Pawsey delighted in these developments and felt that it was in the ‘true tradition’ of the Cavendish Laboratory in Cambridge, where Joe had studied for his PhD. The Cavendish tradition was known as the ‘string and sealing wax’ approach where major breakthroughs could be made with simple improvised equipment. In other words, for progress in science, brain power was more important than expensive equipment. Christiansen continued:

Joe was becoming famous while Bowen’s own projects were either stalled, or as in the case of his rainfall/meteor shower statistics, treated with derision by statistical experts. Bowen was most impressed by the publicity that Lovell had obtained with the Jodrell Bank telescope and probably felt that if he followed that pattern he could make a real input to radio astronomy which was the only success story in his division of CSIRO. He found an ally in John Bolton who was not amongst the “inventors” and felt that it was time that the group should drop gadgetry and become astronomers. Hence Bowen and Bolton moved for a large simple paraboloid. At first the rest of us looked with favour at this but when it was realised that this was to be all that we would have in the future, revolt set in. Most of us had no wish to become conventional astronomers – observers not pioneers.

Pawsey was also the one who facilitated communication between the field stations. Apart from his regular visits, he had staff attend seminars back at the RP Lab, which was situated in the grounds of the University of Sydney in the inner Sydney suburb of Chippendale (Fig. 1.34). These ranged in frequency over the years, from weekly in the early 1950s to perhaps every couple of months in the late 1950s, towards the close of the field station era. Christiansen (1976) fondly remembers them as

Fig. 1.34

At the main entrance to the Radiophysics Lab. The administrative, library and workshop staff provided essential support to the RP radio astronomers (courtesy: CRAIA)

… sort of what the Americans call “bull sessions”, thinking of every conceivable sort of aerial and we just about invented every sort possible to invent. It was really good stuff … a really good one [meeting] would last all day. Joe Pawsey was one to stimulate that. He was a marvelous chap.

Staff also received non-intellectual stimulation through social activities, such as parties at the Dapto field station, and there were various avocational outings and specialist-interest group activities (for example, one of the authors (WO) was involved in regular rock-collecting fieldtrips). There was also the Radiophysics cricket team (Fig. 1.35), which started in 1948 and for a number of years participated – with varying degrees of success – in the Sydney inter-club competition. Members of the RP eleven and their supporters practiced religiously at lunchtimes on nearby St Paul’s Oval.

Fig. 1.35

The Radiophysics Cricket Team at Chatswood Oval in 1954 (standing from left): John Bolton, Dick McGee, Joe Warburton, Noel Seddon, Alec Weir, Charlie Attwood. (sitting) Charlie Fryer, Paul Wild, Stuart Dryden, Kevin Sheridan, Alan Wightley. Other members of the team, at various times, were Taffy Bowen, Alec Little, Gordon Stanley and Gil Trent (courtesy: CRAIA)

Within Australia, during the late 1940s and early 1950s, RP did not quite have a monopoly on radio astronomy. Two small teams of researchers were active in the immediate post-war years, one at Mount Stromlo Observatory near Canberra and the other at the University of Western Australia in Perth (Orchiston et al., 2006). Their work is discussed in Chapter 3. The Stromlo excursion into radio astronomy was an interesting one and – for a time – promised to threaten RP’s supremacy. This only became an issue in 1951 when a meeting of the Observatory’s governing board “… reaffirmed the decision that it took a year previously that the radio-astronomy activity of the Observatory ought to be greatly enlarged …” (Woolley, 1951). This was partly inspired by the fact that the Australian National University (with which Stromlo was newly-affiliated) wanted to offer training in astronomy. Mark Oliphant (1901–2000; Fig. 1.36) was the prime mover at the ANU, and he offered to assist the Observatory in setting up a radio telescope. Observatory Director, Richard Woolley (1906–1986; Fig. 1.36), was expected to draw up a detailed proposal for a Department of Radio Astronomy which would conduct research on Galactic structure, and he looked forward to closely co-operating with Radiophysics.

Fig. 1.36

(left) Sir Mark Oliphant (Australian National University) was the driving force behind Mount Stromlo’s attempts to develop a Department of Radio Astronomy during the early 1950s. (right) Richard Woolley was Director of the Commonwealth Solar Observatory at Mt Stromlo until his appointment in 1955 as Astronomer Royal in England (courtesy: Life magazine and Mount Stromlo and Siding Spring Observatories)

In February 1951 Woolley announced these plans to Dr Fred White (1905–1994) at CSIRO headquarters (Fig. 1.37). White was Chief Executive Officer of CSIRO and, as a former radio scientist and Chief of RP, he had warm – almost paternal – feelings for the Division, and he immediately discussed the matter with Bowen and Pawsey. The following month, Pawsey and White went to Stromlo where they met with Woolley. In exchange for RP’s co-operation Pawsey asked Stromlo to provide optical support for RP’s solar radio astronomy program, but Woolley would not agree to this because he intended closing down Stromlo’s solar work and redirecting the Observatory’s research efforts into Galactic studies. Pawsey and White then suggested that some RP Galactic research could be conducted from Stromlo, to which Woolley agreed.

Fig. 1.37

Sir Fred White (1905–1994), the charismatic New Zealand physicist who came to Australia during WWII to become Chief of RP. He subsequently became CSIRO Chief Executive Officer in 1949 and then Chairman of CSIRO (1959–70) (courtesy: CSIRO Corporate Archives)

A major concern for Pawsey was that, even though RP was a world leader in radio astronomy, there had been no involvement of post-graduate students in this research. In the long term, a lack of new talent coming into the field could threaten RP’s leadership. He saw Stromlo (through the ANU) as a potential source of students if radio astronomy were developed there. Consequently, as he wrote to Oliphant there “… are obviously good arguments for this and I incline towards it on a long-term view.” (Pawsey, 1951). Given Woolley’s intention to focus on optical research, Pawsey suggested that RP could establish a radio astronomy branch in Canberra and that at some appropriate time in the future it could break away and join Stromlo.

But the winds of astronomical change were blowing at Mount Stromlo. By the end of 1951 Cla Allen had moved to London and solar research on the mountain was winding down. The Stromlo staff were increasingly preoccupied with the acquisition of a new 74-in telescope (Fig. 1.38), and “Government policy was against any increase in staff … [so] It was impracticable to undertake new work in radio astronomy ...” (Notes of a meeting, 1952). Any potential collaboration with Stromlo faded away and RP was left to dominate Australian radio astronomy unchallenged.

Fig. 1.38

The 74-in Grubb Parsons reflector at Mount Stromlo Observatory near Canberra. Although the telescope was commissioned in 1955, there were ‘teething’ problems, and it took until 1961 before the telescope was functioning satisfactorily (courtesy: Orchiston collection)

Bowen and Pawsey felt this threat from Mount Stromlo keenly, but they were more concerned about RP’s standing as a forefront radio astronomy institution, and the threat of international competition. During the decade following WWII, scientists in Australia, Britain, Canada, France, Japan, the Netherlands, the USA and the USSR all made useful studies of ‘solar noise’ and/or ‘cosmic noise’. Australia and Britain quickly became the two leading nations in this new field, and initially relations between all of the radio astronomers were cordial. For instance, in 1948 Pawsey visited Cambridge’s Martin Ryle (1918–1984; Fig. 1.39) and discussed the publication of their respective Cygnus A research, along with the results obtained by Bernard Lovell (Fig. 1.40) at Jodrell Bank, as three consecutive letters in Nature. Before he returned to Australia, Pawsey also discussed the Cambridge and Sydney solar programs with Graham Smith (b. 1923). Pawsey asked Bowen, to “... arrange [for] a resume of this [RP] work to be sent to him in an attempt to prevent undesirable duplication.” (Pawsey, 1948; these are our italics). In contrast, a distinct chilling in relations between the Cambridge and RP radio astronomers – or more precisely between Martin Ryle and Bernie Mills – took place in the mid-1950s when sources in the Cambridge 2C catalogue were found to be at odds with those discovered by Mills’ group at the Fleurs field station (later the 2C catalogue was completely discredited – see Chapter 4 for details). Personalities, credibility and prestige are key ingredients in science, and it took many years before amicable relations were re-established between these two leading research groups.

Fig. 1.39

Sir Martin Ryle was head of the Cambridge radio astronomy group and Director of the Mullard Radio Astronomy Observatory (after Hey, 1973: 64). The principal radio telescope by 1958 was an interferometer consisting of a parabolic cylinder reflector 475 m long and 20 m wide, and a smaller mobile reflector which could move along railway tracks (courtesy: CRAIA)

Fig. 1.40

Sir Bernard Lovell, head of the radio astronomy group at the University of Manchester, with the 76 m Jodrell Bank dish in the background (courtesy: Jodrell Bank Observatory; all rights reserved)

One of the problems associated with leading a newly-emerging research field from the far side of the globe was the difficulty sometimes encountered in getting credit for discoveries made or new equipment invented. The conventional way to bring such developments forward internationally was through publication, but when it came to supposedly reputable journals like Nature and even the Proceedings of the Royal Society, time and again papers reporting Australian ‘firsts’ would be held up – sometimes for many months – while English colleagues suddenly came up with the very same findings and were first to rush into print. Sir Edward Appleton, Professor Jack Ratcliffe (1902–1987) and others at Cambridge University were deemed to be the principal culprits (Sullivan, 2009: 90–91 and 110–112). In 1946 Taffy Bowen wrote to Fred White at CSIRO Headquarters in Melbourne following an inexplicable delay in the publication of one of their key papers in Nature: “… Appleton is making a song and dance about our letter to Nature, but I suppose he is just expressing his well-known “ownership” of all radio and ionospheric work.” (Bowen, 1946). Bowen was by no means alone in suspecting Appleton’s ultimate motives.

It was partly as a result of this situation, not just at Radiophysics but across the organisation, that CSIRO in 1948 began publication of its own research journal, the Australian Journal of Scientific Research, and over the next decade the great majority of research papers penned by RP staff found their way into this journal and its 1953 successor, the Australian Journal of Physics. At that time, Australia had no scientific journal devoted solely to professional astronomy, let alone radio astronomy.

To conclude this chapter, let us take a very brief overview of the future development of Australian radio astronomy. Shortly after the Mt Stromlo threat evaporated in 1952, a radio astronomy group was formed at the University of Tasmania (Fig. 1.41), and in 1954 Grote Reber arrived in Tasmania and largely worked as an independent scholar from his home in Bothwell, north of Hobart (Fig. 1.42). For the most part, the Tasmanian work focused on very low frequencies, and as such it complemented – rather than challenged – the RP endeavours (see George et al., 2015a). RP’s dominance was not challenged until the 1960s with the advent of the Molonglo Cross (Fig. 1.24) and the Fleurs Synthesis Telescope (Fig. 1.25), constructed and operated by the University of Sydney. Unlike the numerous field stations of the 1950s (the subject of our next chapter), RP operated only two main field stations. The first was the site at Parkes with its famous 64 m radio telescope (Fig. 1.43) that concentrated on Galactic and extragalactic studies (and still does over sixty years later). The other site at Culgoora in northern NSW operated the Radioheliograph (Fig. 1.23) and the radiospectrographs (Fig. 1.44) and concentrated on solar studies. The two University of Sydney instruments, Parkes and Culgoora were the four work-horses of Australian radio astronomy for the 1970s and most of the 1980s. As we will see in Chapter 5, Australian radio astronomy entered a new era with the inauguration of the Australia Telescope in 1988, the year marking the bicentennial of European settlement.

Fig. 1.41

The mechanically phase-switched 100 MHz interferometer built around 1952 at Mount Nelson, Hobart, by Gordon Newstead (shown at right) from the Department of Electrical Engineering at the University of Tasmania (courtesy: Martin George)

Fig. 1.42

Grote Reber and the low-frequency array he built at Bothwell in Tasmania. At the time the array had a significantly larger overall collecting area than any other radio telescope in the world (courtesy: Robertson collection and Ken Kellermann)

Fig. 1.43

The famous 64 m Parkes Radio Telescope and the 18 m Kennedy dish that originally was sited at the Fleurs field station (courtesy: CRAIA)

Fig. 1.44

The three radiospectrographs at Culgoora eventually spanned the impressive frequency range of 8 to 8000 MHz (courtesy: CRAIA)