Joseph Lade Pawsey
Encyclopedia
Joseph Lade Pawsey was an Australia
n engineer
, radiophysicist, and radio astronomer
.
He was born in Ararat, Victoria
to a family of farmers. At the age of 14 he was awarded a government scholarship to study at Wesley College, Melbourne
, followed by a scholarship to study at the University of Melbourne
. In 1929 he earned his B.Sc. from the university, followed by a M.Sc. in Natural Philosophy in 1931. He was then awarded an Exhibition Research Scholarship to study at Cambridge University
, where he worked under the direction of J.A. Ratcliffe. He studied the effects of the ionosphere on radio propagation and his discovery of the presence of irregularities in the Kennelly-Heaviside Layer
proved vital to the later development of this branch of ionospheric physics. In 1935 he was awarded a Ph.D.
from Cambridge and in September of that year he married Greta Lenore Nicoll, a 32-year-old Canadian. He then became a research physicist at EMI. until 1939.
In February 1940 he returned to Australia to work at the recently formed Radiophysics Division of the CSIR/CSIRO
. One group he led developed a microwave
set for the Royal Australian Navy
, while another group under his direction investigated the 'super-refraction' of radio waves in the earth's atmosphere. Pawsey continued as a research physicist at the CSIR/CSIRO Division of Radiophysics until 1962, becoming assistant chief in 1952.
At the end of World War II
he became a pioneer of the new science of Radio Astronomy
, his interest being stirred by the discovery of radio waves from the Galaxy
and by reports of intense interference in metre-wave radar receivers caused by disturbances on the Sun
. To investigate the latter Pawsey, along with Ruby Payne-Scott
and Lindsay McCready used an existing RAAF antenna at Collaroy, a northern Sydney
suburb. As well as confirming that the Sun was a source of radio noise their data also showed that the temperature in some regions of the Sun were as high as one million degrees. This temperature was far higher than was thought possible at the time. Work by the physicist David Forbes Martyn
showed that temperatures peak in the Sun's corona
at one million degrees. The observations with the Collaroy antenna not only marked the beginning of radio astronomy in Australia, but also the first time radio astronomy had provided important information on a problem in traditional optical astronomy
In early 1946 Pawsey turned his attention to sunspots as a source of strong fluctuating radio noise. To overcome the limitations of the available antennas Pawsey used sea interferometry
and began observations at Dover Heights which provided a better vantage point than Collaroy. The observations confirmed beyond doubt that sunspots were the source of the strong increase in radio noise. This work was confirmed four months later by radio astronomers at Cambridge University led by Martin Ryle
Members of Pawsey's group invented techniques that were subsequently incorporated into general use in radio astronomy as well as making important discoveries about the discrete sources of radio emission in the Milky Way and external galaxies. Pawsey did some work on his own, but his main focus was on guiding and administering his research group.
In 1952 he became president of the Radio Astronomy Commission of the IAU
, serving until 1958. From 1960 until 1961 he was president of the Australian Branch for the Institute of Physics. He was appointed as director of the U.S. National Radio Astronomy Observatory
in 1962, but he died in Sydney of a brain tumour before he took office. He was survived by his wife, two sons and a daughter
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
n engineer
Engineer
An engineer is a professional practitioner of engineering, concerned with applying scientific knowledge, mathematics and ingenuity to develop solutions for technical problems. Engineers design materials, structures, machines and systems while considering the limitations imposed by practicality,...
, radiophysicist, and radio astronomer
Astronomer
An astronomer is a scientist who studies celestial bodies such as planets, stars and galaxies.Historically, astronomy was more concerned with the classification and description of phenomena in the sky, while astrophysics attempted to explain these phenomena and the differences between them using...
.
He was born in Ararat, Victoria
Ararat, Victoria
Ararat is a city in south-west Victoria, Australia, about west of Melbourne, on the Western Highway on the eastern slopes of the Ararat Hills and Cemetery Creek valley between Victoria's Western District and the Wimmera...
to a family of farmers. At the age of 14 he was awarded a government scholarship to study at Wesley College, Melbourne
Wesley College, Melbourne
Wesley College, Melbourne is an independent, co-educational, Christian day school in Melbourne, Victoria, Australia. Established in 1866, the college is a school of the Uniting Church in Australia. Wesley is the largest school in Australia by enrolment, with 3,511 students and 564 full-time staff...
, followed by a scholarship to study at the University of Melbourne
University of Melbourne
The University of Melbourne is a public university located in Melbourne, Victoria. Founded in 1853, it is the second oldest university in Australia and the oldest in Victoria...
. In 1929 he earned his B.Sc. from the university, followed by a M.Sc. in Natural Philosophy in 1931. He was then awarded an Exhibition Research Scholarship to study at Cambridge University
University of Cambridge
The University of Cambridge is a public research university located in Cambridge, United Kingdom. It is the second-oldest university in both the United Kingdom and the English-speaking world , and the seventh-oldest globally...
, where he worked under the direction of J.A. Ratcliffe. He studied the effects of the ionosphere on radio propagation and his discovery of the presence of irregularities in the Kennelly-Heaviside Layer
Kennelly-Heaviside layer
The Kennelly–Heaviside layer, named after Arthur Edwin Kennelly and Oliver Heaviside, also known as the E region or simply the Heaviside layer, is a layer of ionised gas occurring between roughly 90–150 km above the ground — one of several layers in the Earth's ionosphere...
proved vital to the later development of this branch of ionospheric physics. In 1935 he was awarded a Ph.D.
Ph.D.
A Ph.D. is a Doctor of Philosophy, an academic degree.Ph.D. may also refer to:* Ph.D. , a 1980s British group*Piled Higher and Deeper, a web comic strip*PhD: Phantasy Degree, a Korean comic series* PhD Docbook renderer, an XML renderer...
from Cambridge and in September of that year he married Greta Lenore Nicoll, a 32-year-old Canadian. He then became a research physicist at EMI. until 1939.
In February 1940 he returned to Australia to work at the recently formed Radiophysics Division of the CSIR/CSIRO
Commonwealth Scientific and Industrial Research Organisation
The Commonwealth Scientific and Industrial Research Organisation is the national government body for scientific research in Australia...
. One group he led developed a microwave
Microwave
Microwaves, a subset of radio waves, have wavelengths ranging from as long as one meter to as short as one millimeter, or equivalently, with frequencies between 300 MHz and 300 GHz. This broad definition includes both UHF and EHF , and various sources use different boundaries...
set for the Royal Australian Navy
Royal Australian Navy
The Royal Australian Navy is the naval branch of the Australian Defence Force. Following the Federation of Australia in 1901, the ships and resources of the separate colonial navies were integrated into a national force: the Commonwealth Naval Forces...
, while another group under his direction investigated the 'super-refraction' of radio waves in the earth's atmosphere. Pawsey continued as a research physicist at the CSIR/CSIRO Division of Radiophysics until 1962, becoming assistant chief in 1952.
At the end of World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
he became a pioneer of the new science of Radio Astronomy
Radio astronomy
Radio astronomy is a subfield of astronomy that studies celestial objects at radio frequencies. The initial detection of radio waves from an astronomical object was made in the 1930s, when Karl Jansky observed radiation coming from the Milky Way. Subsequent observations have identified a number of...
, his interest being stirred by the discovery of radio waves from the Galaxy
Milky Way
The Milky Way is the galaxy that contains the Solar System. This name derives from its appearance as a dim un-resolved "milky" glowing band arching across the night sky...
and by reports of intense interference in metre-wave radar receivers caused by disturbances on the Sun
Sun
The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields...
. To investigate the latter Pawsey, along with Ruby Payne-Scott
Ruby Payne-Scott
Ruby Violet Payne-Scott was an Australian pioneer in radiophysics and radio astronomy and is the first female radio astronomer.-Early life:Payne-Scott was born in Grafton, New South Wales, Australia, on 28 May 1912...
and Lindsay McCready used an existing RAAF antenna at Collaroy, a northern Sydney
Sydney
Sydney is the most populous city in Australia and the state capital of New South Wales. Sydney is located on Australia's south-east coast of the Tasman Sea. As of June 2010, the greater metropolitan area had an approximate population of 4.6 million people...
suburb. As well as confirming that the Sun was a source of radio noise their data also showed that the temperature in some regions of the Sun were as high as one million degrees. This temperature was far higher than was thought possible at the time. Work by the physicist David Forbes Martyn
David Forbes Martyn
David Forbes Martyn was a Scottish-born Australian physicist and radiographer.Martyn was born in Cambuslang, Scotland , the son of a local doctor. He was educated at Alan Glen's School then the Royal College of Science at Imperial College London....
showed that temperatures peak in the Sun's corona
Corona
A corona is a type of plasma "atmosphere" of the Sun or other celestial body, extending millions of kilometers into space, most easily seen during a total solar eclipse, but also observable in a coronagraph...
at one million degrees. The observations with the Collaroy antenna not only marked the beginning of radio astronomy in Australia, but also the first time radio astronomy had provided important information on a problem in traditional optical astronomy
In early 1946 Pawsey turned his attention to sunspots as a source of strong fluctuating radio noise. To overcome the limitations of the available antennas Pawsey used sea interferometry
Sea interferometry
Sea interferometry, also known as Sea-cliff interferometry, is a form of radio astronomy that uses radio waves reflected off the sea to produce an interference pattern. It is the radio wave analogue to Lloyd's mirror...
and began observations at Dover Heights which provided a better vantage point than Collaroy. The observations confirmed beyond doubt that sunspots were the source of the strong increase in radio noise. This work was confirmed four months later by radio astronomers at Cambridge University led by Martin Ryle
Martin Ryle
Sir Martin Ryle was an English radio astronomer who developed revolutionary radio telescope systems and used them for accurate location and imaging of weak radio sources...
Members of Pawsey's group invented techniques that were subsequently incorporated into general use in radio astronomy as well as making important discoveries about the discrete sources of radio emission in the Milky Way and external galaxies. Pawsey did some work on his own, but his main focus was on guiding and administering his research group.
In 1952 he became president of the Radio Astronomy Commission of the IAU
International Astronomical Union
The International Astronomical Union IAU is a collection of professional astronomers, at the Ph.D. level and beyond, active in professional research and education in astronomy...
, serving until 1958. From 1960 until 1961 he was president of the Australian Branch for the Institute of Physics. He was appointed as director of the U.S. National Radio Astronomy Observatory
National Radio Astronomy Observatory
The National Radio Astronomy Observatory is a Federally Funded Research and Development Center of the United States National Science Foundation operated under cooperative agreement by Associated Universities, Inc for the purpose of radio astronomy...
in 1962, but he died in Sydney of a brain tumour before he took office. He was survived by his wife, two sons and a daughter
Awards and honors
- Thomas Ranken Lyle MedalThomas Ranken Lyle MedalThe Thomas Ranken Lyle Medal is awarded at most every two years by the Australian Academy of Science to a mathematician or physicist for his or her outstanding research accomplishments. It is named after Thomas Ranken Lyle, an Irish mathematical physicist who became a professor at the University of...
, 1953. - Royal SocietyRoyal SocietyThe Royal Society of London for Improving Natural Knowledge, known simply as the Royal Society, is a learned society for science, and is possibly the oldest such society in existence. Founded in November 1660, it was granted a Royal Charter by King Charles II as the "Royal Society of London"...
Hughes MedalHughes MedalThe Hughes Medal is awarded by the Royal Society of London "in recognition of an original discovery in the physical sciences, particularly electricity and magnetism or their applications". Named after David E. Hughes, the medal is awarded with a gift of £1000. The medal was first awarded in 1902 to...
, 1960. - Fellow of the Royal Society, 1954.
- Foundation Fellow of the Australian Academy of ScienceAustralian Academy of ScienceThe Australian Academy of Science was founded in 1954 by a group of distinguished Australians, including Australian Fellows of the Royal Society of London. The first president was Sir Mark Oliphant. The Academy is modelled after the Royal Society and operates under a Royal Charter; as such it is...
, 1954. - Honorable D.Sc. from Australian National University, 1961.
- The Pawsey Medal of the Australian Academy of Science commemorates his contributions, and has been awarded since 1967.
- The Pawsey Memorial Lecture is delivered annually by a distinguished scientist.
- The crater PawseyPawsey (crater)Pawsey is a worn impact crater that lies next to the northern outer ramparts of the crater Wiener, on the far side of the Moon. To the east-northeast of Pawsey is the large crater Campbell, and farther to the west is Bridgman....
on the MoonMoonThe Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...
is named after him.