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Aristillus
Aristyllus ( el, Ἀρίστυλλος; fl. c. 261 BC) was a Greek astronomer, presumably of the school of Timocharis (c. 300 BC). He was among the earliest meridian-astronomy observers. Six of his stellar declinations are preserved at Almajest 7.3. All are exactly correct within his over-cautious rounding to 1/4 degree. See discussion (and lessons) aDIO 7.1‡1 p. 13 (2007). Aristyllus was long mis-dated to c. 300 BC (which made his data look among the poorest of the ancients); but when his correct date was found by least-squares (Isis 73:259-265 982p. 263), it warealizedthat his star declinations' accuracy was unexcelled in antiquity. His data suggest that he worked in Alexandria: seDIO 4.1‡3 Table 3 p. 45 (2004). A lunar crater, Aristillus, aptly near the Moon's meridian and at a lunar latitude roughly equal to the terrestrial latitude of Alexandria, is named after him. Sources * Thomas Hockey's '' Biographical Encyclopedia of Astronomers' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aristillus (crater)
Aristillus is a prominent lunar impact crater that lies in the eastern Mare Imbrium. It was named after Greek astronomer Aristyllus. Directly to the south is the smaller crater Autolycus, while to the southwest is the large Archimedes. To the northeast are the craters Theaetetus and Cassini. The rim of Aristillus has a wide, irregular outer rampart of ejecta that is relatively easy to discern against the smooth surface of the surrounding mare. The crater impact created a ray system that extends for a distance of over 600 kilometers. Due to its rays, Aristillus is mapped as part of the Copernican System. The rim is generally circular in form, but possesses a slight hexagonal shape. The inner walls of the rim have a terraced surface, and descend to a relatively rough interior that has not been flooded with lava. In the middle of the crater is a set of three clustered peaks, which rise to a height of about 0.9 km. In the northern outer ramparts of Aristillus is a gho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Timocharis
Timocharis of Alexandria ( grc-gre, Τιμόχαρις or Τιμοχάρης, ''gen.'' Τιμοχάρους; c. 320–260 BC) was a Greek astronomer and philosopher. Likely born in Alexandria, he was a contemporary of Euclid. Work What little is known about Timocharis comes from citations by Ptolemy in the ''Almagest''. These indicate that Timocharis worked in Alexandria during the 290s and 280s BC. Ptolemy lists the declination of 18 stars as recorded by Timocharis or Aristillus in roughly the year 290 BC. Between 295 and 272 BC, Timocharis recorded four lunar occultations and the passage of the planet Venus across a star. These were recorded using both the Egyptian and Athenian calendars. The observed stellar passage by Venus may have occurred on October 12, 272 BC when the planet came within 15 arcminutes of the star η Virginis. The observations by Timocharis are among the oldest Greek records that can be assigned a specific date. They are only exceeded by records of the summer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astronomer
An astronomer is a scientist in the field of astronomy who focuses their studies on a specific question or field outside the scope of Earth. They observe astronomical objects such as stars, planets, natural satellite, moons, comets and galaxy, galaxies – in either observational astronomy, observational (by analyzing the data) or theoretical astronomy. Examples of topics or fields astronomers study include planetary science, Sun, solar astronomy, the Star formation, origin or stellar evolution, evolution of stars, or the galaxy formation and evolution, formation of galaxies. A related but distinct subject is physical cosmology, which studies the Universe as a whole. Types Astronomers usually fall under either of two main types: observational astronomy, observational and theoretical astronomy, theoretical. Observational astronomers make direct observations of Astronomical object, celestial objects and analyze the data. In contrast, theoretical astronomers create and investigate C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lunar Crater
Lunar craters are impact craters on Earth's Moon. The Moon's surface has many craters, all of which were formed by impacts. The International Astronomical Union currently recognizes 9,137 craters, of which 1,675 have been dated. History The word ''crater'' was adopted from the Greek word for "vessel" (, a Greek vessel used to mix wine and water). Galileo built his first telescope in late 1609, and turned it to the Moon for the first time on November 30, 1609. He discovered that, contrary to general opinion at that time, the Moon was not a perfect sphere, but had both mountains and cup-like depressions. These were named craters by Johann Hieronymus Schröter (1791), extending its previous use with volcanoes. Robert Hooke in ''Micrographia'' (1665) proposed two hypotheses for lunar crater formation: one, that the craters were caused by projectile bombardment from space, the other, that they were the products of subterranean lunar volcanism. Scientific opinion as to the origin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biographical Encyclopedia Of Astronomers
The ''Biographical Encyclopedia of Astronomers'' (''BEA'') is a two-volume biographical dictionary, first published in 2007, with a second edition released in 2014. The work covers astronomers from all geographies, born from antiquity to mid-1918. It includes more than 1500 biographies of both well-known and more obscure astronomers, produced by 410 contributors. The encyclopedia has been published in both a print and online format by the publisher, Springer Springer or springers may refer to: Publishers * Springer Science+Business Media, aka Springer International Publishing, a worldwide publishing group founded in 1842 in Germany formerly known as Springer-Verlag. ** Springer Nature, a multinationa .... Editions * References External links Publisher's webpage(1st Edition) Publisher's webpage(2nd Edition) Biographical dictionaries by topic Historiography of science 21st-century encyclopedias 2007 non-fiction books {{science-hist-book-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
William Smith (lexicographer)
Sir William Smith (20 May 1813 – 7 October 1893) was an English lexicographer. He became known for his advances in the teaching of Greek and Latin in schools. Early life Smith was born in Enfield in 1813 to Nonconformist parents. He attended the Madras House school of John Allen in Hackney. Originally destined for a theological career, he instead became articled to a solicitor. Meanwhile, he taught himself classics in his spare time, and when he entered University College London carried off both the Greek and Latin prizes. He was entered at Gray's Inn in 1830, but gave up his legal studies for a post at University College School and began to write on classical subjects. Lexicography Smith next turned his attention to lexicography. His first attempt was ''A Dictionary of Greek and Roman Antiquities'', which appeared in 1842, the greater part being written by him. Then followed the ''Dictionary of Greek and Roman Biography and Mythology'' in 1849. A parallel '' Dictionary of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dictionary Of Greek And Roman Biography And Mythology
The ''Dictionary of Greek and Roman Biography and Mythology'' (1849, originally published 1844 under a slightly different title) is an encyclopedia/biographical dictionary. Edited by William Smith, the dictionary spans three volumes and 3,700 pages. It is a classic work of 19th-century lexicography. The work is a companion to Smith's ''Dictionary of Greek and Roman Antiquities'' and '' Dictionary of Greek and Roman Geography''. Authors and scope The work lists thirty-five authors in addition to the editor, who was also the author of the unsigned articles. The other authors were classical scholars, primarily from Oxford, Cambridge, Rugby School, and the University of Bonn, but some were from other institutions. Many of the mythological entries were the work of the German expatriate Leonhard Schmitz, who helped to popularise German classical scholarship in Britain. With respect to biographies, Smith intended to be comprehensive. In the preface, he writes: Much of the value ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ancient Greek Astronomers
Ancient history is a time period from the beginning of writing and recorded human history to as far as late antiquity. The span of recorded history is roughly 5,000 years, beginning with the Sumerian cuneiform script. Ancient history covers all continents inhabited by humans in the period 3000 BCAD 500. The three-age system periodizes ancient history into the Stone Age, the Bronze Age, and the Iron Age, with recorded history generally considered to begin with the Bronze Age. The start and end of the three ages varies between world regions. In many regions the Bronze Age is generally considered to begin a few centuries prior to 3000 BC, while the end of the Iron Age varies from the early first millennium BC in some regions to the late first millennium AD in others. During the time period of ancient history, the world population was already exponentially increasing due to the Neolithic Revolution, which was in full progress. While in 10,000 BC, the world population stood at ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
3rd-century BC Greek People
The 3rd century was the period from 201 ( CCI) to 300 (CCC) Anno Domini (AD) or Common Era (CE) in the Julian calendar.. In this century, the Roman Empire saw a crisis, starting with the assassination of the Roman Emperor Severus Alexander in 235, plunging the empire into a period of economic troubles, barbarian incursions, political upheavals, civil wars, and the split of the Roman Empire through the Gallic Empire in the west and the Palmyrene Empire in the east, which all together threatened to destroy the Roman Empire in its entirety, but the reconquests of the seceded territories by Emperor Aurelian and the stabilization period under Emperor Diocletian due to the administrative strengthening of the empire caused an end to the crisis by 284. This crisis would also mark the beginning of Late Antiquity. In Persia, the Parthian Empire was succeeded by the Sassanid Empire in 224 after Ardashir I defeated and killed Artabanus V during the Battle of Hormozdgan. The Sassanids t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
3rd-century BC Writers
The 3rd century was the period from 201 ( CCI) to 300 (CCC) Anno Domini (AD) or Common Era (CE) in the Julian calendar.. In this century, the Roman Empire saw a crisis, starting with the assassination of the Roman Emperor Severus Alexander in 235, plunging the empire into a period of economic troubles, barbarian incursions, political upheavals, civil wars, and the split of the Roman Empire through the Gallic Empire in the west and the Palmyrene Empire in the east, which all together threatened to destroy the Roman Empire in its entirety, but the reconquests of the seceded territories by Emperor Aurelian and the stabilization period under Emperor Diocletian due to the administrative strengthening of the empire caused an end to the crisis by 284. This crisis would also mark the beginning of Late Antiquity. In Persia, the Parthian Empire was succeeded by the Sassanid Empire in 224 after Ardashir I defeated and killed Artabanus V during the Battle of Hormozdgan. The Sassanids th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
3rd-century BC Deaths
The 3rd century was the period from 201 ( CCI) to 300 (CCC) Anno Domini (AD) or Common Era (CE) in the Julian calendar.. In this century, the Roman Empire saw a crisis, starting with the assassination of the Roman Emperor Severus Alexander in 235, plunging the empire into a period of economic troubles, barbarian incursions, political upheavals, civil wars, and the split of the Roman Empire through the Gallic Empire in the west and the Palmyrene Empire in the east, which all together threatened to destroy the Roman Empire in its entirety, but the reconquests of the seceded territories by Emperor Aurelian and the stabilization period under Emperor Diocletian due to the administrative strengthening of the empire caused an end to the crisis by 284. This crisis would also mark the beginning of Late Antiquity. In Persia, the Parthian Empire was succeeded by the Sassanid Empire in 224 after Ardashir I defeated and killed Artabanus V during the Battle of Hormozdgan. The Sassanids ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Year Of Birth Unknown
A year or annus is the orbital period of a planetary body, for example, the Earth, moving in its orbit around the Sun. Due to the Earth's axial tilt, the course of a year sees the passing of the seasons, marked by change in weather, the hours of daylight, and, consequently, vegetation and soil fertility. In temperate and subpolar regions around the planet, four seasons are generally recognized: spring, summer, autumn and winter. In tropical and subtropical regions, several geographical sectors do not present defined seasons; but in the seasonal tropics, the annual wet and dry seasons are recognized and tracked. A calendar year is an approximation of the number of days of the Earth's orbital period, as counted in a given calendar. The Gregorian calendar, or modern calendar, presents its calendar year to be either a common year of 365 days or a leap year of 366 days, as do the Julian calendars. For the Gregorian calendar, the average length of the calendar year ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
