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, one component of the Fourier transform of the spatial distribution of the brightness of the observed object; the image of the source is produced from these measurements. Astronomical interferometers are used for high-resolution optical, infrared and radio astronomy observations. For example, the Event Horizon Telescope project derived the first image of a black hole using aperture synthesis. Aperture synthesis is possible only if both the amplitude and the phase of the incoming signal are measured by each telescope. For radio frequencies, this is possible by electronics, while for optical frequencies, the electromagnetic field cannot be measured directly and correlated in software, but must be propagated by sensitive optics and interfered optically.
Accurate optical delay and atmospheric wavefront aberration correction is required, a demanding technology that became possible only in the 1990s. This is why imaging with aperture synthesis has been used in radio astronomy since the 1950s and in optical/infrared astronomy only since the turn of the millennium. See astronomical interferometer for more information. In order to produce a high quality image, a large number of different separations between different telescopes is required – as many different baselines as possible are required in order to get a good quality image; the number of baselines for an array of n telescopes is given by nb=/2. For example, the Very Large Array has 27 telescopes giving 351 independent baselines at once, can give high quality images. In contrast to radio arrays, the largest optical arrays have only 6 telescopes, giving poorer image quality from the 15 baselines between the telescopes. Most aperture synthesis interferometers use the rotation of the Earth to increase the number of different baselines included in an observation.
Taking data at different times provides measurements with different telescope separations and angles without the need for buying additional telescopes or moving the telescopes manually, as the rotation of the Earth moves the telescopes to new baselines. The use of Earth rotation was discussed in detail in the 1950 paper A preliminary survey of the radio stars in the Northern Hemisphere; some instruments use artificial rotation of the interferometer array instead of Earth rotation, such as in aperture masking interferometry. Aperture synthesis imaging was first developed at radio wavelengths by Martin Ryle and coworkers from the Radio Astronomy Group at Cambridge University. Martin Ryle and Tony Hewish jointly received a Nobel Prize for this and other contributions to the development of radio interferometry; the radio astronomy group in Cambridge went on to found the Mullard Radio Astronomy Observatory near Cambridge in the 1950s. During the late 1960s and early 1970s, as computers became capable of handling the computationally intensive Fourier transform inversions required, they used aperture synthesis to create a'One-Mile' and a'5 km' effective aperture using the One-Mile and Ryle telescopes, respectively.
The technique was subsequently further developed in very-long-baseline interferometry to obtain baselines of thousands of kilometres. Aperture synthesis is used by a type of radar system known as synthetic aperture radar, in optical telescopes, it was thought necessary to make measurements at every baseline length and orientation out to some maximum: such a sampled Fourier transform formally contains the information equivalent to the image from a conventional telescope with an aperture diameter equal to the maximum baseline, hence the name aperture synthesis. It was discovered that in many cases useful images could be made with a sparse and irregular set of baselines with the help of non-linear deconvolution algorithms such as the maximum entropy method; the alternative name synthesis imaging acknowledges the shift in emphasis from trying to synthesise the complete aperture to trying to synthesise the image from whatever data is available, using powerful but computationally expensive algorithms.
Beamforming Interferometric synthetic-aperture radar Light field Optical heterodyne detection Synthetic-aperture magnetometry Synthetic aperture sonar Synthetic-aperture radar and Inverse synthetic-aperture radar Development of radio interferometry, from Astronomical Optical Interferometry, A Literature Review by Bob Tubbs, Cambridge, 2002 Cambridge Optical Aperture Synthesis Telescope APerture SYNthesis SIMulator
World War II
World War II known as the Second World War, was a global war that lasted from 1939 to 1945. The vast majority of the world's countries—including all the great powers—eventually formed two opposing military alliances: the Allies and the Axis. A state of total war emerged, directly involving more than 100 million people from over 30 countries; the major participants threw their entire economic and scientific capabilities behind the war effort, blurring the distinction between civilian and military resources. World War II was the deadliest conflict in human history, marked by 50 to 85 million fatalities, most of whom were civilians in the Soviet Union and China, it included massacres, the genocide of the Holocaust, strategic bombing, premeditated death from starvation and disease, the only use of nuclear weapons in war. Japan, which aimed to dominate Asia and the Pacific, was at war with China by 1937, though neither side had declared war on the other. World War II is said to have begun on 1 September 1939, with the invasion of Poland by Germany and subsequent declarations of war on Germany by France and the United Kingdom.
From late 1939 to early 1941, in a series of campaigns and treaties, Germany conquered or controlled much of continental Europe, formed the Axis alliance with Italy and Japan. Under the Molotov–Ribbentrop Pact of August 1939, Germany and the Soviet Union partitioned and annexed territories of their European neighbours, Finland and the Baltic states. Following the onset of campaigns in North Africa and East Africa, the fall of France in mid 1940, the war continued between the European Axis powers and the British Empire. War in the Balkans, the aerial Battle of Britain, the Blitz, the long Battle of the Atlantic followed. On 22 June 1941, the European Axis powers launched an invasion of the Soviet Union, opening the largest land theatre of war in history; this Eastern Front trapped most crucially the German Wehrmacht, into a war of attrition. In December 1941, Japan launched a surprise attack on the United States as well as European colonies in the Pacific. Following an immediate U. S. declaration of war against Japan, supported by one from Great Britain, the European Axis powers declared war on the U.
S. in solidarity with their Japanese ally. Rapid Japanese conquests over much of the Western Pacific ensued, perceived by many in Asia as liberation from Western dominance and resulting in the support of several armies from defeated territories; the Axis advance in the Pacific halted in 1942. Key setbacks in 1943, which included a series of German defeats on the Eastern Front, the Allied invasions of Sicily and Italy, Allied victories in the Pacific, cost the Axis its initiative and forced it into strategic retreat on all fronts. In 1944, the Western Allies invaded German-occupied France, while the Soviet Union regained its territorial losses and turned toward Germany and its allies. During 1944 and 1945 the Japanese suffered major reverses in mainland Asia in Central China, South China and Burma, while the Allies crippled the Japanese Navy and captured key Western Pacific islands; the war in Europe concluded with an invasion of Germany by the Western Allies and the Soviet Union, culminating in the capture of Berlin by Soviet troops, the suicide of Adolf Hitler and the German unconditional surrender on 8 May 1945.
Following the Potsdam Declaration by the Allies on 26 July 1945 and the refusal of Japan to surrender under its terms, the United States dropped atomic bombs on the Japanese cities of Hiroshima and Nagasaki on 6 and 9 August respectively. With an invasion of the Japanese archipelago imminent, the possibility of additional atomic bombings, the Soviet entry into the war against Japan and its invasion of Manchuria, Japan announced its intention to surrender on 15 August 1945, cementing total victory in Asia for the Allies. Tribunals were set up by fiat by the Allies and war crimes trials were conducted in the wake of the war both against the Germans and the Japanese. World War II changed the political social structure of the globe; the United Nations was established to foster international co-operation and prevent future conflicts. The Soviet Union and United States emerged as rival superpowers, setting the stage for the nearly half-century long Cold War. In the wake of European devastation, the influence of its great powers waned, triggering the decolonisation of Africa and Asia.
Most countries whose industries had been damaged moved towards economic expansion. Political integration in Europe, emerged as an effort to end pre-war enmities and create a common identity; the start of the war in Europe is held to be 1 September 1939, beginning with the German invasion of Poland. The dates for the beginning of war in the Pacific include the start of the Second Sino-Japanese War on 7 July 1937, or the Japanese invasion of Manchuria on 19 September 1931. Others follow the British historian A. J. P. Taylor, who held that the Sino-Japanese War and war in Europe and its colonies occurred and the two wars merged in 1941; this article uses the conventional dating. Other starting dates sometimes used for World War II include the Italian invasion of Abyssinia on 3 October 1935; the British historian Antony Beevor views the beginning of World War II as the Battles of Khalkhin Gol fought between Japan and the fo
University of Cambridge
The University of Cambridge is a collegiate public research university in Cambridge, United Kingdom. Founded in 1209 and granted a Royal Charter by King Henry III in 1231, Cambridge is the second-oldest university in the English-speaking world and the world's fourth-oldest surviving university; the university grew out of an association of scholars who left the University of Oxford after a dispute with the townspeople. The two'ancient universities' share many common features and are referred to jointly as'Oxbridge'; the history and influence of the University of Cambridge has made it one of the most prestigious universities in the world. Cambridge is formed from a variety of institutions which include 31 constituent Colleges and over 100 academic departments organised into six schools. Cambridge University Press, a department of the university, is the world's oldest publishing house and the second-largest university press in the world; the university operates eight cultural and scientific museums, including the Fitzwilliam Museum, as well as a botanic garden.
Cambridge's libraries hold a total of around 15 million books, eight million of which are in Cambridge University Library, a legal deposit library. In the fiscal year ending 31 July 2018, the university had a total income of £1.965 billion, of which £515.5 million was from research grants and contracts. In the financial year ending 2017, the central university and colleges had combined net assets of around £11.8 billion, the largest of any university in the country. However, the true extent of Cambridge's wealth is much higher as many colleges hold their historic main sites, which date as far back as the 13th century, at depreceated valuations. Furthermore, many of the wealthiest colleges do not account for “heritage assets” such as works of art, libraries or artefacts, whose value many college accounts describe as “immaterial”; the university is linked with the development of the high-tech business cluster known as'Silicon Fen'. It is a member of numerous associations and forms part of the'golden triangle' of English universities and Cambridge University Health Partners, an academic health science centre.
As of 2018, Cambridge is the top-ranked university in the United Kingdom according to all major league tables. As of September 2017, Cambridge is ranked the world's second best university by the Times Higher Education World University Rankings, is ranked 3rd worldwide by Academic Ranking of World Universities, 6th by QS, 7th by US News. According to the Times Higher Education ranking, no other institution in the world ranks in the top 10 for as many subjects; the university has educated many notable alumni, including eminent mathematicians, politicians, philosophers, writers and foreign Heads of State. As of March 2019, 118 Nobel Laureates, 11 Fields Medalists, 7 Turing Award winners and 15 British Prime Ministers have been affiliated with Cambridge as students, faculty or research staff. By the late 12th century, the Cambridge area had a scholarly and ecclesiastical reputation, due to monks from the nearby bishopric church of Ely. However, it was an incident at Oxford, most to have led to the establishment of the university: two Oxford scholars were hanged by the town authorities for the death of a woman, without consulting the ecclesiastical authorities, who would take precedence in such a case, but were at that time in conflict with King John.
The University of Oxford went into suspension in protest, most scholars moved to cities such as Paris and Cambridge. After the University of Oxford reformed several years enough scholars remained in Cambridge to form the nucleus of the new university. In order to claim precedence, it is common for Cambridge to trace its founding to the 1231 charter from King Henry III granting it the right to discipline its own members and an exemption from some taxes. A bull in 1233 from Pope Gregory IX gave graduates from Cambridge the right to teach "everywhere in Christendom". After Cambridge was described as a studium generale in a letter from Pope Nicholas IV in 1290, confirmed as such in a bull by Pope John XXII in 1318, it became common for researchers from other European medieval universities to visit Cambridge to study or to give lecture courses; the colleges at the University of Cambridge were an incidental feature of the system. No college is as old as the university itself; the colleges were endowed fellowships of scholars.
There were institutions without endowments, called hostels. The hostels were absorbed by the colleges over the centuries, but they have left some traces, such as the name of Garret Hostel Lane. Hugh Balsham, Bishop of Ely, founded Peterhouse, Cambridge's first college, in 1284. Many colleges were founded during the 14th and 15th centuries, but colleges continued to be established until modern times, although there was a gap of 204 years between the founding of Sidney Sussex in 1596 and that of Downing in 1800; the most established college is Robinson, built in the late 1970s. However, Homerton College only achieved full university college status in March 2010, making it the newest full college. In medieval times, many colleges were founded so that their members would pray for the souls of the founders, were associated with chapels or abbeys; the colleges' focus changed in 1536 with the Dissolution of the Monasteries. King Henry VIII ordered the university to disband its Faculty of Canon Law and to stop teaching "scholastic philosophy".
In response, colleges changed
Henry Draper Medal
The Henry Draper Medal is awarded every 4 years by the United States National Academy of Sciences "for investigations in astronomical physics". Named after Henry Draper, the medal is awarded with a gift of USD $15,000; the medal was established under the Draper Fund by his widow, Anna Draper, in honor of her husband, was first awarded in 1886 to Samuel Pierpont Langley "for numerous investigations of a high order of merit in solar physics, in the domain of radiant energy". It has since been awarded 45 times; the medal has been awarded to multiple individuals in the same year: in 1977 it was awarded to Arno Allan Penzias and Robert Woodrow Wilson "for their discovery of the cosmic microwave radiation, their leading role in the discovery of interstellar molecules". Source: National Academy of Sciences
Christ Church, Oxford
Christ Church is a constituent college of the University of Oxford in England. Christ Church is a joint foundation of the college and the cathedral of the Oxford diocese, which serves as the college chapel and whose dean is ex officio the college head. Founded in 1546 by King Henry VIII, it is one of the larger colleges of the University of Oxford with 629 students in 2016, it is the second wealthiest college with an endowment of £550m as of 2018. Christ Church has a number of architecturally significant buildings including Tom Tower, Tom Quad, the Great Dining Hall, the seat of the parliament assembled by King Charles I during the English Civil War; the buildings have inspired replicas throughout the world in addition to being featured in films such as Harry Potter and The Golden Compass. This has helped Christ Church become the most popular Oxford college for tourists with half a million visitors annually. Christ Church has many notable alumni including thirteen British prime ministers, King Edward VII, King William II of the Netherlands, seventeen Archbishops, writers Lewis Carroll and W.
H. Auden, philosopher John Locke, scientist Robert Hooke. Christ Church is partly responsible for the creation of University College Reading, which gained its own Royal Charter and became the University of Reading; the first female undergraduates matriculated at Christ Church in 1980. In 1525, at the height of his power, Thomas Wolsey, Lord Chancellor of England and Cardinal Archbishop of York, suppressed the Priory of St Frideswide in Oxford and founded Cardinal College on its lands, using funds from the dissolution of Wallingford Priory and other minor priories, he planned the establishment on a magnificent scale, but fell from grace in 1529, with the buildings only three-quarters complete, as they were to remain for 140 years. In 1531 the college was itself suppressed, but it was refounded in 1532 as King Henry VIII's College by Henry VIII, to whom Wolsey's property had escheated. In 1546 the King, who had broken from the Church of Rome and acquired great wealth through the dissolution of the monasteries in England, refounded the college as Christ Church as part of the reorganisation of the Church of England, making the demolished priory church the cathedral of the created Diocese of Oxford.
Christ Church's sister college in the University of Cambridge is Trinity College, founded the same year by Henry VIII. Since the time of Queen Elizabeth I the college has been associated with Westminster School; the dean remains to ex officio member of the school's governing body. Major additions have been made to the buildings through the centuries, Wolsey's Great Quadrangle was crowned with the famous gate-tower designed by Sir Christopher Wren. To this day the bell in the tower, Great Tom, is rung 101 times at 9 pm at the former Oxford time every night, for the 100 original scholars of the college. In former times this was done at midnight, signalling the close of all college gates throughout Oxford. Since it took 20 minutes to ring the 101, Christ Church gates, unlike those of other colleges, did not close until 12:20; when the ringing was moved back to 9:00 pm, Christ Church gates still remained open until 12.20, 20 minutes than any other college. Although the clock itself now shows GMT/BST, Christ Church still follows Oxford time in the timings of services in the cathedral.
King Charles I made the Deanery his palace and held his Parliament in the Great Hall during the English Civil War. In the evening of 29 May 1645, during the second siege of Oxford, a "bullet of IX lb. weight" shot from the Parliamentarians warning-piece at Marston fell against the wall of the north side of the Hall. Several of Christ Church's deans achieved high academic distinction, notably Owen under the Commonwealth and Fell in the Restoration period and Gaisford in the early 19th century and Liddell in the high Victorian era. For over four centuries Christ Church admitted men only. Christ Church, formally titled "The Dean and Students of the Cathedral Church of Christ in Oxford of the Foundation of King Henry the Eighth", is the only academic institution in the world, a cathedral, the seat of the Bishop of Oxford; the Visitor of Christ Church is the reigning British sovereign, the Bishop of Oxford is unique among English bishops in not being the Visitor of his own cathedral. The head of the college is the Dean of Christ Church, an Anglican cleric appointed by the crown as dean of the cathedral church.
There are a senior and a junior censor the former of whom is responsible for academic matters, the latter for undergraduate discipline. A censor theologiae is appointed to act as the dean's deputy; the form "Christ Church College" is considered incorrect, in part because it ignores the cathedral, an integral part of the unique dual foundation. The governing body of Christ Church consists of the dean and chapter of the cathedral, together with the "Students of Christ Church", who are not junior members but rather the equivalent of the fellows of the other colleges; until the 19th century, the students differed from fellows in that they had no governing powers in their own college, these residing with the dean and chapter. Christ Church si
England is a country, part of the United Kingdom. It shares land borders with Wales to Scotland to the north-northwest; the Irish Sea lies west of England and the Celtic Sea lies to the southwest. England is separated from continental Europe by the North Sea to the east and the English Channel to the south; the country covers five-eighths of the island of Great Britain, which lies in the North Atlantic, includes over 100 smaller islands, such as the Isles of Scilly and the Isle of Wight. The area now called England was first inhabited by modern humans during the Upper Palaeolithic period, but takes its name from the Angles, a Germanic tribe deriving its name from the Anglia peninsula, who settled during the 5th and 6th centuries. England became a unified state in the 10th century, since the Age of Discovery, which began during the 15th century, has had a significant cultural and legal impact on the wider world; the English language, the Anglican Church, English law – the basis for the common law legal systems of many other countries around the world – developed in England, the country's parliamentary system of government has been adopted by other nations.
The Industrial Revolution began in 18th-century England, transforming its society into the world's first industrialised nation. England's terrain is chiefly low hills and plains in central and southern England. However, there is upland and mountainous terrain in the west; the capital is London, which has the largest metropolitan area in both the United Kingdom and the European Union. England's population of over 55 million comprises 84% of the population of the United Kingdom concentrated around London, the South East, conurbations in the Midlands, the North West, the North East, Yorkshire, which each developed as major industrial regions during the 19th century; the Kingdom of England – which after 1535 included Wales – ceased being a separate sovereign state on 1 May 1707, when the Acts of Union put into effect the terms agreed in the Treaty of Union the previous year, resulting in a political union with the Kingdom of Scotland to create the Kingdom of Great Britain. In 1801, Great Britain was united with the Kingdom of Ireland to become the United Kingdom of Great Britain and Ireland.
In 1922 the Irish Free State seceded from the United Kingdom, leading to the latter being renamed the United Kingdom of Great Britain and Northern Ireland. The name "England" is derived from the Old English name Englaland, which means "land of the Angles"; the Angles were one of the Germanic tribes that settled in Great Britain during the Early Middle Ages. The Angles came from the Anglia peninsula in the Bay of Kiel area of the Baltic Sea; the earliest recorded use of the term, as "Engla londe", is in the late-ninth-century translation into Old English of Bede's Ecclesiastical History of the English People. The term was used in a different sense to the modern one, meaning "the land inhabited by the English", it included English people in what is now south-east Scotland but was part of the English kingdom of Northumbria; the Anglo-Saxon Chronicle recorded that the Domesday Book of 1086 covered the whole of England, meaning the English kingdom, but a few years the Chronicle stated that King Malcolm III went "out of Scotlande into Lothian in Englaland", thus using it in the more ancient sense.
According to the Oxford English Dictionary, its modern spelling was first used in 1538. The earliest attested reference to the Angles occurs in the 1st-century work by Tacitus, Germania, in which the Latin word Anglii is used; the etymology of the tribal name itself is disputed by scholars. How and why a term derived from the name of a tribe, less significant than others, such as the Saxons, came to be used for the entire country and its people is not known, but it seems this is related to the custom of calling the Germanic people in Britain Angli Saxones or English Saxons to distinguish them from continental Saxons of Old Saxony between the Weser and Eider rivers in Northern Germany. In Scottish Gaelic, another language which developed on the island of Great Britain, the Saxon tribe gave their name to the word for England. An alternative name for England is Albion; the name Albion referred to the entire island of Great Britain. The nominally earliest record of the name appears in the Aristotelian Corpus the 4th-century BC De Mundo: "Beyond the Pillars of Hercules is the ocean that flows round the earth.
In it are two large islands called Britannia. But modern scholarly consensus ascribes De Mundo not to Aristotle but to Pseudo-Aristotle, i.e. it was written in the Graeco-Roman period or afterwards. The word Albion or insula Albionum has two possible origins, it either derives from a cognate of the Latin albus meaning white, a reference to the white cliffs of Dover or from the phrase the "island of the Albiones" in the now lost Massaliote Periplus, attested through Avienus' Ora Maritima to which the former served as a source. Albion is now applied to England in a more poetic capacity. Another romantic name for England is Loegria, related to the Welsh word for England and made popular by its use in Arthurian legend; the earliest known evidence of human presence in the area now known as England was that of Homo antecessor, dating to approximate
Institute of Astronomy, Cambridge
The Institute of Astronomy is the largest of the three astronomy departments in the University of Cambridge, one of the largest astronomy sites in the UK. Around 180 academics, postdocs and assistant staff work at the department. Research at the department is made in a number of scientific areas, including exoplanets, star clusters, gravitational-wave astronomy, the high-redshift universe, AGN, galaxies and galaxy clusters; this is a mixture of observational astronomy, over the entire electromagnetic spectrum, computational theoretical astronomy, analytic theoretical research. The Kavli Institute for Cosmology is located on the department site; this Institute has an emphasis on The Universe at High Redshifts. The Cavendish Astrophysics Group are based in a building in the same grounds; the Institute was formed in 1972 from the amalgamation of earlier institutions: The University Observatory, founded in 1823. Its Cambridge Observatory building now houses the department library; the Solar Physics Observatory, which started in Cambridge in 1912.
The building was demolished in 2008 to make way for the Kavli Institute for Cosmology. The Institute of Theoretical Astronomy, created by Fred Hoyle in 1967, its building is the main departmental site, with a lecture theatre added in 1999, a second two-storey wing built in 2002. The department teaches 3rd and 4th year undergraduates as part of the Natural Sciences Tripos or Mathematical Tripos. In addition, there are around 12 to 18 graduate PhD and masters students at the department per year funded by the STFC; the graduate programme is unusual in the UK as the students are free to choose their own PhD supervisor or adviser from the staff at the department, this choice is made as late as the end of their first term. A list of notable current members of the department. Cathie Clarke Carolin Crawford Andrew Fabian Paul Hewett Christopher Reynolds George Efstathiou Gerry Gilmore Richard G. McMahon Max Pettini James E. Pringle Martin Rees Anna Zytkow Here are some notable members of the Department and its former institutes.
Suzanne Aigrain George Airy Robert Stawell Ball James Challis John Couch Adams Donald Clayton Arthur Eddington Richard Ellis Stephen Hawking Fred Hoyle Jamal Nazrul Islam Harold Jeffreys Donald Lynden-Bell Jayant Narlikar Jeremiah Ostriker Robert Woodhouse The Institute houses several telescopes on its site. Although some scientific work is done with the telescopes, they are used for public observing and astronomical societies; the poor weather and light-pollution in Cambridge makes most modern astronomy difficult. The telescopes on the site include: The Northumberland Telescope donated by the Duke of Northumberland in 1833; this is a 12-inch diameter refractor on an English mount. The smaller Thorrowgood Telescope, on extended loan from the Royal Astronomical Society; the telescope is an 8-inch refractor. The 36-inch Telescope, built in 1951; the Three-Mirror Telescope, a prototype telescope with a unique design to have wide field of view, sharp images and all-reflection optics. The Institute's former 24" Schmidt Camera was donated to the Spaceguard Centre in June 2009.
The Cambridge University Astronomical Society and Cambridge Astronomical Association both observe. The Institute holds public observing evenings on Wednesdays from October to March; the department holds a number of events involving the general public in astronomy. These include/ have included: Open evenings on Wednesdays during the winter, from October to March, with a talk given by a member of the Institute followed by observing in clear weather Hosting the Astroblast conference Annual sculpture exhibition showing work of Anglia Ruskin University Annual open day during the Cambridge Science Festival A monthly podcast, the'Astropod', aimed at the general public Extra observing nights for special events such as IYA Moonwatch and BBC stargazing live The Institute library is housed in the old Cambridge Observatory building, it is a specialist library concentrating on the subjects of astronomy and cosmology. The collection has 17,000 books and subscribes to about 80 current journals; the Library has a collection of rare astronomical books, many of which belonged to John Couch Adams.
Among the significant contributions to astronomy made by the institute, the now decommissioned Automatic Plate Measuring machine was used to create a major catalogue of astronomical objects in the northern sky. Institute of Astronomy at the University of Cambridge Kavli Institute of Cosmology, Cambridge Images from the Institute of Astronomy Library