|
Antony Hewish
Antony Hewish (11 May 1924 – 13 September 2021) was 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. Early life and education Hewish attended King's College, Taunton. His undergraduate degree, at Gonville and Caius College, Cambridge, was interrupted by the Second World War. He was assigned to war service at the Royal Aircraft Establishment, and at the Telecommunications Research Establishment where he worked with Martin Ryle. Returning to the University of Cambridge in 1946, Hewish completed his undergraduate degree and became a postgraduate student in Ryle's research team at the Cavendish Laboratory. For his PhD thesis, awarded in 1952, Hewish made practical and theoretical advances in the observation and exploitation of the scintillations of astronomical radio sources, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fowey
Fowey ( ; kw, Fowydh, meaning 'Beech Trees') is a port town and civil parish at the mouth of the River Fowey in south Cornwall, England, United Kingdom. The town has been in existence since well before the Norman invasion, with the local church first established some time in the 7th century; the estuary of the River Fowey forms a natural harbour which enabled the town to become an important trading centre. Privateers also made use of the sheltered harbourage. The Lostwithiel and Fowey Railway brought China clay here for export. History Early history The Domesday Book survey at the end of the 11th century records manors at Penventinue and Trenant, and a priory was soon established nearby at Tywardreath. the prior granted a charter to people living in Fowey itself. This medieval town ran from a north gate near Boddinick Passage to a south gate at what is now Lostwithiel Street; the town extended a little way up the hillside and was bounded on the other side by the river whe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Royal Aircraft Establishment
The Royal Aircraft Establishment (RAE) was a British research establishment, known by several different names during its history, that eventually came under the aegis of the UK Ministry of Defence (MoD), before finally losing its identity in mergers with other institutions. The first site was at Farnborough Airfield ("RAE Farnborough") in Hampshire to which was added a second site RAE Bedford (Bedfordshire) in 1946. In 1988 it was renamed the Royal Aerospace Establishment (RAE) before merging with other research entities to become part of the new Defence Research Agency in 1991. History In 1904–1906 the Army Balloon Factory, which was part of the Army School of Ballooning, under the command of Colonel James Templer, relocated from Aldershot to the edge of Farnborough Common in order to have enough space to inflate the new "dirigible balloon" or airship which was then under construction.Walker, P; Early Aviation at Farnborough, Volume I: Balloons, Kites and Airships, Macdo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cambridge
Cambridge ( ) is a College town, university city and the county town in Cambridgeshire, England. It is located on the River Cam approximately north of London. As of the 2021 United Kingdom census, the population of Cambridge was 145,700. Cambridge became an important trading centre during the Roman and Viking ages, and there is archaeological evidence of settlement in the area as early as the Bronze Age. The first Town charter#Municipal charters, town charters were granted in the 12th century, although modern city status was not officially conferred until 1951. The city is most famous as the home of the University of Cambridge, which was founded in 1209 and consistently ranks among the best universities in the world. The buildings of the university include King's College Chapel, Cambridge, King's College Chapel, Cavendish Laboratory, and the Cambridge University Library, one of the largest legal deposit libraries in the world. The city's skyline is dominated by several Colleg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 part of the Cambridge University, Cavendish Laboratories, Astrophysics Department. History Radio interferometry started in the mid-1940s on the outskirts of Cambridge, but with funding from the Science Research Council and a corporate donation of £100,000 from Mullard Limited, a leading commercial manufacturer of thermionic valves. Construction of the Mullard Radio Astronomy Observatory commenced at Lords Bridge Air Ammunition Park, a few kilometres to the west of Cambridge. The observatory was founded under Martin Ryle of the Radio-Astronomy Group of the Cavendish Laboratory, University of Cambridge and was opened by Sir Edward Victor Appleton ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interplanetary Scintillation Array
The Interplanetary Scintillation Array (also known as the IPS Array or Pulsar Array) is a radio telescope that was built in 1967 at the Mullard Radio Astronomy Observatory, in Cambridge, United Kingdom, and was operated by the Cavendish Astrophysics Group. The instrument originally covered 4 acres (16,000 m²). It was enlarged to 9 acres in 1978, and was refurbished in 1989. The array operates at a radio frequency of 81.5 MHz (3.7 m wavelength), and is made up of 4,096 dipole antennas in a phased array. Using 14 beams, it can map the northern sky in one day. The observatory's staff use sheep to keep grass away from the antennas because a lawn mower cannot fit in the spaces. Antony Hewish designed the IPS Array to measure the high-frequency fluctuations of radio sources, originally for monitoring interplanetary scintillation. Hewish received a Nobel prize after the high time-resolution of the array allowed the detection of pulsars by Jocelyn Bell Dame Susan Jocelyn Be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interplanetary Scintillation
In astronomy, interplanetary scintillation refers to random fluctuations in the intensity of radio waves of celestial origin, on the timescale of a few seconds. It is analogous to the twinkling one sees looking at stars in the sky at night, but in the radio part of the electromagnetic spectrum rather than the visible one. Interplanetary scintillation is the result of radio waves traveling through fluctuations in the density of the electron and protons that make up the solar wind. Early study Scintillation, meaning rapid modification, in radio waves due to the small scale structures in the ionosphere, known as ionospheric scintillation, was observed as early as 1951 by Antony Hewish, and he then reported irregularities in radiation received during an observation of a bright radio source in Taurus in 1954. Hewish considered various possibilities, and suggested that irregularities in the solar corona would cause scattering by refraction and could produce the irregularities he obs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Time-domain Astronomy
Time-domain astronomy is the study of how astronomical objects change with time. Though the study may be said to begin with Galileo's ''Letters on Sunspots'', the term now refers especially to variable objects beyond the Solar System. This may be due to movement or changes in the object itself. Common targets included are supernovae, pulsating stars, novas, flare stars, blazars and active galactic nuclei. Visible light time domain studies include OGLE, HAT-South, PanSTARRS, SkyMapper, ASAS, WASP, CRTS, and in a near future the LSST at the Vera C. Rubin Observatory. Time-domain astronomy studies transient astronomical events, often shortened by astronomers to a transients as well as various types of variable stars, including periodic, quasi-periodic, and that of changing behavior or type. Other causes of time variability are asteroids, high proper motion stars, planetary transits and comets. Transients characterize astronomical objects or phenomena whose duration of pres ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astronomical Survey
An astronomical survey is a general map or image of a region of the sky (or of the whole sky) that lacks a specific observational target. Alternatively, an astronomical survey may comprise a set of images, spectra, or other observations of objects that share a common type or feature. Surveys are often restricted to one band of the electromagnetic spectrum due to instrumental limitations, although multiwavelength surveys can be made by using multiple detectors, each sensitive to a different bandwidth. Surveys have generally been performed as part of the production of an astronomical catalog. They may also search for transient astronomical events. They often use wide-field astrographs. Scientific value Sky surveys, unlike targeted observation of a specific object, allow astronomers to catalog celestial objects and perform statistical analyses on them without complex corrections for selection effects. In some cases, an astronomer interested in a particular object will find ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phased Array
In antenna theory, a phased array usually means an electronically scanned array, a computer-controlled array of antennas which creates a beam of radio waves that can be electronically steered to point in different directions without moving the antennas. In a simple array antenna, the radio frequency current from the transmitter is fed to multiple individual antenna elements with the proper phase relationship so that the radio waves from the separate elements combine ( superpose) to form beams, to increase power radiated in desired directions and suppress radiation in undesired directions. In a phased array, the power from the transmitter is fed to the radiating elements through devices called '' phase shifters'', controlled by a computer system, which can alter the phase or signal delay electronically, thus steering the beam of radio waves to a different direction. Since the size of an antenna array must extend many wavelengths to achieve the high gain needed for narrow ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plasma (physics)
Plasma ()πλάσμα , Henry George Liddell, Robert Scott, ''A Greek English Lexicon'', on Perseus is one of the four fundamental states of matter. It contains a significant portion of charged particles – ions and/or s. The presence of these charged particles is what primarily sets plasma apart from the other fundamental states of matter. It is the most abundant form of ordi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interplanetary Scintillation
In astronomy, interplanetary scintillation refers to random fluctuations in the intensity of radio waves of celestial origin, on the timescale of a few seconds. It is analogous to the twinkling one sees looking at stars in the sky at night, but in the radio part of the electromagnetic spectrum rather than the visible one. Interplanetary scintillation is the result of radio waves traveling through fluctuations in the density of the electron and protons that make up the solar wind. Early study Scintillation, meaning rapid modification, in radio waves due to the small scale structures in the ionosphere, known as ionospheric scintillation, was observed as early as 1951 by Antony Hewish, and he then reported irregularities in radiation received during an observation of a bright radio source in Taurus in 1954. Hewish considered various possibilities, and suggested that irregularities in the solar corona would cause scattering by refraction and could produce the irregularities he obs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PhD Thesis
A thesis ( : theses), or dissertation (abbreviated diss.), is a document submitted in support of candidature for an academic degree or professional qualification presenting the author's research and findings.International Standard ISO 7144: DocumentationâPresentation of theses and similar documents International Organization for Standardization, Geneva, 1986. In some contexts, the word "thesis" or a cognate is used for part of a bachelor's or master's course, while "dissertation" is normally applied to a doctorate. This is the typical arrangement in American English. In other contexts, such as within most institutions of the United Kingdom and Republic of Ireland, the reverse is true. The term graduate thesis is sometimes used to refer to both master's theses and doctoral dissertations. The required complexity or quality of research of a thesis or dissertation can vary by country, university, or program, and the required minimum study period may thus vary significantly in du ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
