Radcliffe Observatory was the astronomical observatory of the University of Oxford from 1773 until 1934, when the Radcliffe Trustees sold it and built a new observatory in Pretoria, South Africa. It is a Grade I listed building. Today, the observatory forms a part of Green Templeton College of the University of Oxford; the observatory was named after John Radcliffe by the Radcliffe Trustees. It was built on the suggestion of the astronomer Thomas Hornsby, occupying the Savilian Chair of Astronomy, following his observation of the notable transit of Venus across the sun's disc in 1769 from a room in the nearby Radcliffe Infirmary; the observatory building commenced to designs by Henry Keene in 1772, was completed in 1794 to the designs of James Wyatt, with a prominent octagonal tower based on the Tower of the Winds in Athens. Its tower is topped with a statue by John Bacon of Atlas holding up the World; until 1839, the Savilian Chair of Astronomy was responsible for the observatory. At this date the appointment of George Henry Sacheverell Johnson an astronomer with no observational experience caused the creation of the new role of Radcliffe Observer.
Because of the viewing conditions, urban development and light pollution at Oxford, the observatory moved to South Africa in 1939. That site, in Pretoria became untenable and the facility was combined with others into the South African Astronomical Observatory in the 1970s; the building is now used by Green Templeton College off the Woodstock Road and is a centrepiece of the college. The original instruments are now in the Museum of the History of Science, except for the Radcliffe 18/24-inch Twin Refractor telescope, transferred to the University of London Observatory; the following have been Radcliffe Observers: 1839 Manuel John Johnson 1860 Robert Main 1879 Edward James Stone 1897 Arthur Alcock Rambaut 1924 Harold Knox-Shaw 1950 David Thackeray Observatory Street to the north Radcliffe Observatory Quarter, a local development project Tower of the Winds Sherwood, Jennifer. Oxfordshire; the Buildings of England. Harmondsworth: Penguin Books. Pp. 271–272. ISBN 0-14-071045-0. Tyack, Geoffrey. Oxford An Architectural Guide.
Oxford & New York: Oxford University Press. Pp. 183–185. ISBN 0-19-817423-3. Media related to Radcliffe Observatory at Wikimedia Commons
The parsec is a unit of length used to measure large distances to astronomical objects outside the Solar System. A parsec is defined as the distance at which one astronomical unit subtends an angle of one arcsecond, which corresponds to 648000/π astronomical units. One parsec is equal to 31 trillion kilometres or 19 trillion miles; the nearest star, Proxima Centauri, is about 1.3 parsecs from the Sun. Most of the stars visible to the unaided eye in the night sky are within 500 parsecs of the Sun; the parsec unit was first suggested in 1913 by the British astronomer Herbert Hall Turner. Named as a portmanteau of the parallax of one arcsecond, it was defined to make calculations of astronomical distances from only their raw observational data quick and easy for astronomers. For this reason, it is the unit preferred in astronomy and astrophysics, though the light-year remains prominent in popular science texts and common usage. Although parsecs are used for the shorter distances within the Milky Way, multiples of parsecs are required for the larger scales in the universe, including kiloparsecs for the more distant objects within and around the Milky Way, megaparsecs for mid-distance galaxies, gigaparsecs for many quasars and the most distant galaxies.
In August 2015, the IAU passed Resolution B2, which, as part of the definition of a standardized absolute and apparent bolometric magnitude scale, mentioned an existing explicit definition of the parsec as 648000/π astronomical units, or 3.08567758149137×1016 metres. This corresponds to the small-angle definition of the parsec found in many contemporary astronomical references; the parsec is defined as being equal to the length of the longer leg of an elongated imaginary right triangle in space. The two dimensions on which this triangle is based are its shorter leg, of length one astronomical unit, the subtended angle of the vertex opposite that leg, measuring one arc second. Applying the rules of trigonometry to these two values, the unit length of the other leg of the triangle can be derived. One of the oldest methods used by astronomers to calculate the distance to a star is to record the difference in angle between two measurements of the position of the star in the sky; the first measurement is taken from the Earth on one side of the Sun, the second is taken half a year when the Earth is on the opposite side of the Sun.
The distance between the two positions of the Earth when the two measurements were taken is twice the distance between the Earth and the Sun. The difference in angle between the two measurements is twice the parallax angle, formed by lines from the Sun and Earth to the star at the distant vertex; the distance to the star could be calculated using trigonometry. The first successful published direct measurements of an object at interstellar distances were undertaken by German astronomer Friedrich Wilhelm Bessel in 1838, who used this approach to calculate the 3.5-parsec distance of 61 Cygni. The parallax of a star is defined as half of the angular distance that a star appears to move relative to the celestial sphere as Earth orbits the Sun. Equivalently, it is the subtended angle, from that star's perspective, of the semimajor axis of the Earth's orbit; the star, the Sun and the Earth form the corners of an imaginary right triangle in space: the right angle is the corner at the Sun, the corner at the star is the parallax angle.
The length of the opposite side to the parallax angle is the distance from the Earth to the Sun (defined as one astronomical unit, the length of the adjacent side gives the distance from the sun to the star. Therefore, given a measurement of the parallax angle, along with the rules of trigonometry, the distance from the Sun to the star can be found. A parsec is defined as the length of the side adjacent to the vertex occupied by a star whose parallax angle is one arcsecond; the use of the parsec as a unit of distance follows from Bessel's method, because the distance in parsecs can be computed as the reciprocal of the parallax angle in arcseconds. No trigonometric functions are required in this relationship because the small angles involved mean that the approximate solution of the skinny triangle can be applied. Though it may have been used before, the term parsec was first mentioned in an astronomical publication in 1913. Astronomer Royal Frank Watson Dyson expressed his concern for the need of a name for that unit of distance.
He proposed the name astron, but mentioned that Carl Charlier had suggested siriometer and Herbert Hall Turner had proposed parsec. It was Turner's proposal. In the diagram above, S represents the Sun, E the Earth at one point in its orbit, thus the distance ES is one astronomical unit. The angle SDE is one arcsecond so by definition D is a point in space at a distance of one parsec from the Sun. Through trigonometry, the distance SD is calculated as follows: S D = E S tan 1 ″ S D ≈ E S 1 ″ = 1 au 1 60 × 60 × π
The Times is a British daily national newspaper based in London. It began in 1785 under the title The Daily Universal Register, adopting its current name on 1 January 1788; the Times and its sister paper The Sunday Times are published by Times Newspapers, since 1981 a subsidiary of News UK, itself wholly owned by News Corp. The Times and The Sunday Times do not share editorial staff, were founded independently, have only had common ownership since 1967. In 1959, the historian of journalism Allan Nevins analysed the importance of The Times in shaping the views of events of London's elite: For much more than a century The Times has been an integral and important part of the political structure of Great Britain, its news and its editorial comment have in general been coordinated, have at most times been handled with an earnest sense of responsibility. While the paper has admitted some trivia to its columns, its whole emphasis has been on important public affairs treated with an eye to the best interests of Britain.
To guide this treatment, the editors have for long periods been in close touch with 10 Downing Street. The Times is the first newspaper to have borne that name, lending it to numerous other papers around the world, such as The Times of India and The New York Times. In countries where these other titles are popular, the newspaper is referred to as The London Times or The Times of London, although the newspaper is of national scope and distribution; the Times is the originator of the used Times Roman typeface developed by Stanley Morison of The Times in collaboration with the Monotype Corporation for its legibility in low-tech printing. In November 2006 The Times began printing headlines in Times Modern; the Times was printed in broadsheet format for 219 years, but switched to compact size in 2004 in an attempt to appeal more to younger readers and commuters using public transport. The Sunday Times remains a broadsheet; the Times had an average daily circulation of 417,298 in January 2019. An American edition of The Times has been published since 6 June 2006.
It has been used by scholars and researchers because of its widespread availability in libraries and its detailed index. A complete historical file of the digitised paper, up to 2010, is online from Gale Cengage Learning; the Times was founded by publisher John Walter on 1 January 1785 as The Daily Universal Register, with Walter in the role of editor. Walter had lost his job by the end of 1784 after the insurance company where he worked went bankrupt due to losses from a Jamaican hurricane. Unemployed, Walter began a new business venture. Henry Johnson had invented the logography, a new typography, reputedly faster and more precise. Walter bought the logography's patent and with it opened a printing house to produce a daily advertising sheet; the first publication of the newspaper The Daily Universal Register in Great Britain was 1 January 1785. Unhappy because the word Universal was omitted from the name, Walter changed the title after 940 editions on 1 January 1788 to The Times. In 1803, Walter handed editorship to his son of the same name.
In spite of Walter Sr's sixteen-month stay in Newgate Prison for libel printed in The Times, his pioneering efforts to obtain Continental news from France, helped build the paper's reputation among policy makers and financiers. The Times used contributions from significant figures in the fields of politics, science and the arts to build its reputation. For much of its early life, the profits of The Times were large and the competition minimal, so it could pay far better than its rivals for information or writers. Beginning in 1814, the paper was printed on the new steam-driven cylinder press developed by Friedrich Koenig. In 1815, The Times had a circulation of 5,000. Thomas Barnes was appointed general editor in 1817. In the same year, the paper's printer James Lawson and passed the business onto his son John Joseph Lawson. Under the editorship of Barnes and his successor in 1841, John Thadeus Delane, the influence of The Times rose to great heights in politics and amongst the City of London.
Peter Fraser and Edward Sterling were two noted journalists, gained for The Times the pompous/satirical nickname'The Thunderer'. The increased circulation and influence of the paper was based in part to its early adoption of the steam-driven rotary printing press. Distribution via steam trains to growing concentrations of urban populations helped ensure the profitability of the paper and its growing influence; the Times was the first newspaper to send war correspondents to cover particular conflicts. W. H. Russell, the paper's correspondent with the army in the Crimean War, was immensely influential with his dispatches back to England. In other events of the nineteenth century, The Times opposed the repeal of the Corn Laws until the number of demonstrations convinced the editorial board otherwise, only reluctantly supported aid to victims of the Irish Potato Famine, it enthusiastically supported the Great Reform Bill of 1832, which reduced corruption and increased the electorate from 400,000 people to 800,000 people.
During the American Civil War, The Times represented the view of the wealthy classes, favouring the secessionists, but it was not a supporter of slavery. The third John Walter, the founder's grandson, succeeded his father in 1847; the paper continued as more or less independent, but from t
Turner is a small lunar impact crater that lies in the Mare Insularum, near the Moon's equator. The crater was named after British astronomer Herbert Hall Turner, it is located to the southeast of the crater Gambart. Turner is a cone-shaped crater with inner walls that slope down to the midpoint. A similar-sized ghost crater is attached to the western rim, its interior floor submerged by lava and the surviving rim broken in the southwest. By convention these features are identified on lunar maps by placing the letter on the side of the crater midpoint, closest to Turner. Turner at The Moon Wiki
John Greaves was an English mathematician and antiquarian. Educated at Balliol College, Oxford, he was elected a Fellow of Merton College in 1624, he studied Persian and Arabic, acquired a number of old books & manuscripts for archbishop William Laud, wrote a treatise on the Persian language. He travelled in Italy and the Levant from 1636 to 1640 and made a survey of the Great Pyramid of Giza, he was Gresham Professor of Geometry at Gresham College and Savilian professor of astronomy at Oxford University, collected astrolabes and astronomical measuring devices. He was interested in the study of weights and measures, wrote a treatise on the Roman foot and denarius, was a keen numismatist. In 1645 he attempted a reform of the Julian calendar in 1645, not adopted. During the English Civil War he supported Charles I, who stayed at Merton College while in Oxford, but lost his academic positions at Oxford in 1647 through the animosity of Nathaniel Brent, Warden of Merton College and a Parliamentarian.
He was born near Alresford, Hampshire. He was the eldest son of John Greaves, rector of Colemore, Sarah Greaves, his brothers were Nicholas Greaves, Thomas Greaves and Sir Edward Greaves, physician to Charles II. His father ran a school for sons of the neighbouring gentry. Aged 15, he went to Balliol College, Oxford between 1617–1621, gaining a B. A. degree. In 1624 he was the first of five newly elected Fellows of Merton College, becoming M. A. in 1628. He began to study astronomy and oriental languages, the works of the ancient eastern astronomers. In 1630 Greaves was chosen Gresham Professor of Geometry at London. Through his predecessor, Peter Turner, he met archbishop William Laud, the chancellor of Oxford University and Visitor of Merton College. Laud was keen to make English editions of Greek and Arabic authors, Greaves' travels abroad involved collecting manuscripts and books for presentation to his new patron. Greaves enrolled at University of Leyden in 1633, where he became friends with Jacob Golius, professor of Arabic at Leyden.
He enrolled at the University of Padua in 1635 along with George Ent, meeting the Dane Johan Rode, an expert on ancient weights and measures, who made a commentary on Celsus. A brief return to England was followed by a second European journey. In the same month he met and consulted with the Earl of Arundel's art-collecting agent, William Petty, on the Earl's attempted acquisition of the Obelisk of Domitian still lying broken in the Circus of Maxentius. Though'now it is broken into 5 stones' he measured these and including a sketch of the obelisk as hypothetically repaired in his almanac-notebook. Though Arundel paid a 60 crown deposit for the obelisk, pope Urban VIII vetoed its export and it was erected by his successor Innocent X above Bernini's Fountain of the Four Rivers in the Piazza Navona. Greaves made drawings of the Pantheon and Pyramid of Cestius. During his stay in Rome he instituted inquiries into the ancient weights and measures that are among the early classics of metrology. In 1637 he made a journey to the Levant, one intention being to fix the latitude of Alexandria where Ptolemy had made his astronomical observations.
He sailed from England to Livorno in the company of Edward Pococke. There he made the acquaintance of the English ambassador Sir Peter Wyche, he procured various manuscripts there, including a copy of Ptolemy's Almagest. Greaves ended up owning two copies of the Almagest, he was going to have visited the many monastic libraries at Mount Athos, in order to make a catalogue of their MSS and unprinted books. Athos was open only to members of the Orthodox church, but thanks to a special dispensation from the Patriarch of Constantinople Cyril Lucaris, Greaves would have had access. Instead, Greaves continued on to Alexandria, where he collected a number of Arabic and Greek manuscripts, he was an inveterate note-taker, making countless observations in notebooks and on blank pages of other books he bought. He returned to England in 1640. On the death of John Bainbridge in 1643, Greaves was appointed as Savilian professor of astronomy and senior reader of the Linacre lecture at Oxford, but he was deprived of his Gresham professorship for having neglected its duties.
In 1645 he essayed a reformation of the Julian calendar. The Gregorian calendar was not adopted in Britain until 1752. In 1642 Greaves had been elected subwarden of Merton College. Merton was the only Oxford college to side with the Parliamentarians in the English Civil War, through an earlier dispute in 1638 between Nathaniel Brent, the Warden of Merton, Greaves' patron William Laud. Brent had been a witness for the prosecution at Laud's 1644 trial. After Laud was exe
The President and Fellows of the Royal Society of London for Improving Natural Knowledge known as the Royal Society, is a learned society. Founded on 28 November 1660, it was granted a royal charter by King Charles II as "The Royal Society", it is the oldest national scientific institution in the world. The society is the United Kingdom's and Commonwealth of Nations' Academy of Sciences and fulfils a number of roles: promoting science and its benefits, recognising excellence in science, supporting outstanding science, providing scientific advice for policy, fostering international and global co-operation and public engagement; the society is governed by its Council, chaired by the Society's President, according to a set of statutes and standing orders. The members of Council and the President are elected from and by its Fellows, the basic members of the society, who are themselves elected by existing Fellows; as of 2016, there are about 1,600 fellows, allowed to use the postnominal title FRS, with up to 52 new fellows appointed each year.
There are royal fellows, honorary fellows and foreign members, the last of which are allowed to use the postnominal title ForMemRS. The Royal Society President is Venkatraman Ramakrishnan, who took up the post on 30 November 2015. Since 1967, the society has been based at 6–9 Carlton House Terrace, a Grade I listed building in central London, used by the Embassy of Germany, London; the Invisible College has been described as a precursor group to the Royal Society of London, consisting of a number of natural philosophers around Robert Boyle. The concept of "invisible college" is mentioned in German Rosicrucian pamphlets in the early 17th century. Ben Jonson in England referenced the idea, related in meaning to Francis Bacon's House of Solomon, in a masque The Fortunate Isles and Their Union from 1624/5; the term accrued currency for the exchanges of correspondence within the Republic of Letters. In letters in 1646 and 1647, Boyle refers to "our invisible college" or "our philosophical college".
The society's common theme was to acquire knowledge through experimental investigation. Three dated letters are the basic documentary evidence: Boyle sent them to Isaac Marcombes, Francis Tallents who at that point was a fellow of Magdalene College and London-based Samuel Hartlib; the Royal Society started from groups of physicians and natural philosophers, meeting at a variety of locations, including Gresham College in London. They were influenced by the "new science", as promoted by Francis Bacon in his New Atlantis, from 1645 onwards. A group known as "The Philosophical Society of Oxford" was run under a set of rules still retained by the Bodleian Library. After the English Restoration, there were regular meetings at Gresham College, it is held that these groups were the inspiration for the foundation of the Royal Society. Another view of the founding, held at the time, was that it was due to the influence of French scientists and the Montmor Academy in 1657, reports of which were sent back to England by English scientists attending.
This view was held by Jean-Baptiste du Hamel, Giovanni Domenico Cassini, Bernard le Bovier de Fontenelle and Melchisédech Thévenot at the time and has some grounding in that Henry Oldenburg, the society's first secretary, had attended the Montmor Academy meeting. Robert Hooke, disputed this, writing that: makes Mr Oldenburg to have been the instrument, who inspired the English with a desire to imitate the French, in having Philosophical Clubs, or Meetings. I will not say, that Mr Oldenburg did rather inspire the French to follow the English, or, at least, did help them, hinder us. But'tis well known who were the principal men that began and promoted that design, both in this city and in Oxford, and not only these Philosophic Meetings were. On 28 November 1660, the 1660 committee of 12 announced the formation of a "College for the Promoting of Physico-Mathematical Experimental Learning", which would meet weekly to discuss science and run experiments. At the second meeting, Sir Robert Moray announced that the King approved of the gatherings, a royal charter was signed on 15 July 1662 which created the "Royal Society of London", with Lord Brouncker serving as the first president.
A second royal charter was signed on 23 April 1663, with the king noted as the founder and with the name of "the Royal Society of London for the Improvement of Natural Knowledge". This initial royal favour has continued and, since every monarch has been the patron of the society; the society's early meetings included experiments performed first by Hooke and by Denis Papin, appointed in 1684. These experiments varied in their subject area, were both important in some cases and trivial in others; the society published an English translation of Essays of Natural Experiments Made in the Accademia del Cimento, under the Protection of the Most Serene Prince Leopold of Tuscany in 1684, an Italian book documenting experiments at the Accademia del Cimento. Although meeting at Gresham College, the Society temporarily moved to Arundel House in 1666 after the Great Fire of London, which did not harm Gresham but did lead to its appropriation by the Lord Mayor; the Society r
The Moon is an astronomical body that orbits planet Earth and is Earth's only permanent natural satellite. It is the fifth-largest natural satellite in the Solar System, the largest among planetary satellites relative to the size of the planet that it orbits; the Moon is after Jupiter's satellite Io the second-densest satellite in the Solar System among those whose densities are known. The Moon is thought to have formed not long after Earth; the most accepted explanation is that the Moon formed from the debris left over after a giant impact between Earth and a Mars-sized body called Theia. The Moon is in synchronous rotation with Earth, thus always shows the same side to Earth, the near side; the near side is marked by dark volcanic maria that fill the spaces between the bright ancient crustal highlands and the prominent impact craters. After the Sun, the Moon is the second-brightest visible celestial object in Earth's sky, its surface is dark, although compared to the night sky it appears bright, with a reflectance just higher than that of worn asphalt.
Its gravitational influence produces the ocean tides, body tides, the slight lengthening of the day. The Moon's average orbital distance is 1.28 light-seconds. This is about thirty times the diameter of Earth; the Moon's apparent size in the sky is the same as that of the Sun, since the star is about 400 times the lunar distance and diameter. Therefore, the Moon covers the Sun nearly during a total solar eclipse; this matching of apparent visual size will not continue in the far future because the Moon's distance from Earth is increasing. The Moon was first reached in September 1959 by an unmanned spacecraft; the United States' NASA Apollo program achieved the only manned lunar missions to date, beginning with the first manned orbital mission by Apollo 8 in 1968, six manned landings between 1969 and 1972, with the first being Apollo 11. These missions returned lunar rocks which have been used to develop a geological understanding of the Moon's origin, internal structure, the Moon's history. Since the Apollo 17 mission in 1972, the Moon has been visited only by unmanned spacecraft.
Both the Moon's natural prominence in the earthly sky and its regular cycle of phases as seen from Earth have provided cultural references and influences for human societies and cultures since time immemorial. Such cultural influences can be found in language, lunar calendar systems and mythology; the usual English proper name for Earth's natural satellite is "the Moon", which in nonscientific texts is not capitalized. The noun moon is derived from Old English mōna, which stems from Proto-Germanic *mēnô, which comes from Proto-Indo-European *mḗh₁n̥s "moon", "month", which comes from the Proto-Indo-European root *meh₁- "to measure", the month being the ancient unit of time measured by the Moon; the name "Luna" is used. In literature science fiction, "Luna" is used to distinguish it from other moons, while in poetry, the name has been used to denote personification of Earth's moon; the modern English adjective pertaining to the Moon is lunar, derived from the Latin word for the Moon, luna. The adjective selenic is so used to refer to the Moon that this meaning is not recorded in most major dictionaries.
It is derived from the Ancient Greek word for the Moon, σελήνη, from, however derived the prefix "seleno-", as in selenography, the study of the physical features of the Moon, as well as the element name selenium. Both the Greek goddess Selene and the Roman goddess Diana were alternatively called Cynthia; the names Luna and Selene are reflected in terminology for lunar orbits in words such as apolune and selenocentric. The name Diana comes from the Proto-Indo-European *diw-yo, "heavenly", which comes from the PIE root *dyeu- "to shine," which in many derivatives means "sky and god" and is the origin of Latin dies, "day"; the Moon formed 4.51 billion years ago, some 60 million years after the origin of the Solar System. Several forming mechanisms have been proposed, including the fission of the Moon from Earth's crust through centrifugal force, the gravitational capture of a pre-formed Moon, the co-formation of Earth and the Moon together in the primordial accretion disk; these hypotheses cannot account for the high angular momentum of the Earth–Moon system.
The prevailing hypothesis is that the Earth–Moon system formed after an impact of a Mars-sized body with the proto-Earth. The impact blasted material into Earth's orbit and the material accreted and formed the Moon; the Moon's far side has a crust, 30 mi thicker than that of the near side. This is thought to be; this hypothesis, although not perfect best explains the evidence. Eighteen months prior to an October 1984 conference on lunar origins, Bill Hartmann, Roger Phillips, Jeff Taylor challenged fellow lunar scientists: "You have eighteen months. Go back to your Apollo data, go back to your computer, do whatever you have to, but make up your mind. Don't come to our conference unless you have something to say about the Moon's birth." At the 1984 conference at Kona, the giant impact hypothesis emerged as the most consensual theory. Before the conference, there were parti