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Gan De
Gan De (; fl. 4th century BC), also known as the Lord Gan (Gan Gong), was an ancient Chinese astronomer and astrologer born in the State of Qi. Along with Shi Shen, he is believed to be the first in history known by name to compile a star catalogue, preceded by the anonymous authors of the early Babylonian star catalogues and followed by the Greek Hipparchus who is the first known in the Western tradition of Hellenistic astronomy to have compiled a star catalogue. He also made observations of the planets, particularly Jupiter. His writings are lost, but some of his works' titles and fragments quoted from them are known from later texts. Gan De may have been the first to describe one of the Galilean moons of Jupiter, usually invisible without the aid of telescopes. In the 20th century, a fragment of Gan's work, in a later compilation of astronomical texts, was identified by Xi Zezong as describing a naked-eye observation of either of the two largest and brightest moons, Ganymed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Floruit
''Floruit'' (; abbreviated fl. or occasionally flor.; from Latin for "they flourished") denotes a date or period during which a person was known to have been alive or active. In English, the unabbreviated word may also be used as a noun indicating the time when someone flourished. Etymology and use la, flōruit is the third-person singular perfect active indicative of the Latin verb ', ' "to bloom, flower, or flourish", from the noun ', ', "flower". Broadly, the term is employed in reference to the peak of activity for a person or movement. More specifically, it often is used in genealogy and historical writing when a person's birth or death dates are unknown, but some other evidence exists that indicates when they were alive. For example, if there are wills attested by John Jones in 1204, and 1229, and a record of his marriage in 1197, a record concerning him might be written as "John Jones (fl. 1197–1229)". The term is often used in art history when dating the career ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chinese Astronomy
Astronomy in China has a long history stretching from the Shang dynasty, being refined over a period of more than 3,000 years. The ancient Chinese people have identified stars from 1300 BCE, as Chinese star names later categorized in the twenty-eight mansions have been found on oracle bones unearthed at Anyang, dating back to the mid-Shang dynasty. The core of the "mansion" (宿 ''xiù'') system also took shape around this period, by the time of King Wu Ding (1250–1192 BCE). Detailed records of astronomical observations began during the Warring States period (fourth century BCE) and flourished from the Han period onward. Chinese astronomy was equatorial, centered on close observation of circumpolar stars, and was based on different principles from those in traditional Western astronomy, where heliacal risings and settings of zodiac constellations formed the basic ecliptic framework. Joseph Needham has described the ancient Chinese as the most persistent and accurate o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aquarius (constellation)
Aquarius is an equatorial constellation of the zodiac, between Capricornus and Pisces. Its name is Latin for "water-carrier" or "cup-carrier", and its old astronomical symbol is (♒︎), a representation of water. Aquarius is one of the oldest of the recognized constellations along the zodiac (the Sun's apparent path). It was one of the 48 constellations listed by the 2nd century astronomer Ptolemy, and it remains one of the 88 modern constellations. It is found in a region often called the Sea due to its profusion of constellations with watery associations such as Cetus the whale, Pisces the fish, and Eridanus the river. At apparent magnitude 2.9, Beta Aquarii is the brightest star in the constellation. History and mythology Aquarius is identified as "The Great One" in the Babylonian star catalogues and represents the god Ea himself, who is commonly depicted holding an overflowing vase. The Babylonian star-figure appears on entitlement stones and cylinder seals fro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lunar Station
Often called lunar mansion, a lunar station or lunar house is a segment of the ecliptic through which the Moon passes in its orbit around the Earth. The concept was used by several ancient cultures as part of their calendrical system. Stations in different cultures In general, though not always, the zodiac is divided into 27 or 28 segments relative to the vernal equinox point or the fixed stars – one for each day of the lunar month. (A sidereal month lasts about days.) The Moon's position is charted with respect to those fixed segments. Since the Moon's position at any given stage will vary according to Earth's position in its own orbit, lunar stations are an effective system for keeping track of the passage of seasons. Various cultures have used sets of lunar stations astrologically; for example, the Jyotisha astrological '' nakshatras'' of Hindu culture, the Arabic manzils (''manazil al-qamar''), the Twenty-Eight Mansions of Chinese astronomy, and the 36&n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synodic Period
The orbital period (also revolution period) is the amount of time a given astronomical object takes to complete one orbit around another object. In astronomy, it usually applies to planets or asteroids orbiting the Sun, moons orbiting planets, exoplanets orbiting other stars, or binary stars. For celestial objects in general, the sidereal period (sidereal year) is referred to by the orbital period, determined by a 360° revolution of one body around its primary, e.g. Earth around the Sun, relative to the fixed stars projected in the sky. Orbital periods can be defined in several ways. The tropical period is more particularly about the position of the parent star. It is the basis for the solar year, and respectively the calendar year. The synodic period incorporates not only the orbital relation to the parent star, but also to other celestial objects, making it not a mere different approach to the orbit of an object around its parent, but a period of orbital relations with ot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Julian Year (astronomy)
In astronomy, a Julian year (symbol: a or aj) is a unit of measurement of time defined as exactly 365.25 days of SI seconds each.P. Kenneth Seidelmann, ed.''The explanatory supplement to the Astronomical Almanac'' (Mill Valley, Cal.: University Science Books, 1992), pp. 8, 696, 698–9, 704, 716, 730. Reprinted from the "IAU Style Manual" by G.A. Wilkinson, Comm. 5, in IAU Transactions XXB (1987).Harold Rabinowitz and Suzanne Vogel''The manual of scientific style''(Burlington, MA: Academic Press, 2009) 369. The length of the Julian year is the average length of the year in the Julian calendar that was used in Western societies until the adoption of the Gregorian Calendar, and from which the unit is named. Nevertheless, because astronomical Julian years are measuring duration rather than designating dates, this Julian year does not correspond to years in the Julian calendar or any other calendar. Nor does it correspond to the many other ways of defining a year. Usage The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sidereal Period
The orbital period (also revolution period) is the amount of time a given astronomical object takes to complete one orbit around another object. In astronomy, it usually applies to planets or asteroids orbiting the Sun, moons orbiting planets, exoplanets orbiting other stars, or binary stars. For celestial objects in general, the sidereal period (sidereal year) is referred to by the orbital period, determined by a 360° revolution of one body around its primary, e.g. Earth around the Sun, relative to the fixed stars projected in the sky. Orbital periods can be defined in several ways. The tropical period is more particularly about the position of the parent star. It is the basis for the solar year, and respectively the calendar year. The synodic period incorporates not only the orbital relation to the parent star, but also to other celestial objects, making it not a mere different approach to the orbit of an object around its parent, but a period of orbital relations with oth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Babylonian Astronomy
Babylonian astronomy was the study or recording of celestial objects during the early history of Mesopotamia. Babylonian astronomy seemed to have focused on a select group of stars and constellations known as Ziqpu stars. These constellations may have been collected from various earlier sources. The earliest catalogue, ''Three Stars Each'', mentions stars of the Akkadian Empire, of Amurru, of Elam and others. A numbering system based on sixty was used, a sexagesimal system. This system simplified the calculating and recording of unusually great and small numbers. The modern practices of dividing a circle into 360 degrees, of 60 minutes each, began with the Sumerians. During the 8th and 7th centuries BC, Babylonian astronomers developed a new empirical approach to astronomy. They began studying and recording their belief system and philosophies dealing with an ideal nature of the universe and began employing an internal logic within their predictive planetary systems. This ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Celestial Sphere
In astronomy and navigation, the celestial sphere is an abstract sphere that has an arbitrarily large radius and is concentric to Earth. All objects in the sky can be conceived as being projected upon the inner surface of the celestial sphere, which may be centered on Earth or the observer. If centered on the observer, half of the sphere would resemble a hemispherical screen over the observing location. The celestial sphere is a conceptual tool used in spherical astronomy to specify the position of an object in the sky without consideration of its linear distance from the observer. The celestial equator divides the celestial sphere into northern and southern hemispheres. Introduction Because astronomical objects are at such remote distances, casual observation of the sky offers no information on their actual distances. All celestial objects seem equally far away, as if fixed onto the inside of a sphere with a large but unknown radius, which appears to rotate westward ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Song Dynasty
The Song dynasty (; ; 960–1279) was an imperial dynasty of China that began in 960 and lasted until 1279. The dynasty was founded by Emperor Taizu of Song following his usurpation of the throne of the Later Zhou. The Song conquered the rest of the Ten Kingdoms, ending the Five Dynasties and Ten Kingdoms period. The Song often came into conflict with the contemporaneous Liao, Western Xia and Jin dynasties in northern China. After retreating to southern China, the Song was eventually conquered by the Mongol-led Yuan dynasty. The dynasty is divided into two periods: Northern Song and Southern Song. During the Northern Song (; 960–1127), the capital was in the northern city of Bianjing (now Kaifeng) and the dynasty controlled most of what is now Eastern China. The Southern Song (; 1127–1279) refers to the period after the Song lost control of its northern half to the Jurchen-led Jin dynasty in the Jin–Song Wars. At that time, the Song court retreated south of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Daozang
Daozang (), meaning ' Taoist Canon', consists of around 1,400 texts that were collected (after the '' Daodejing'' and '' Zhuangzi'' and Liezi which are the core Taoist texts). They were collected by Taoist monks of the period in an attempt to bring together all of the teachings of Taoism, including all the commentaries and expositions of the various masters from the original teachings found in the ''Daodejing'' and ''Zhuangzi''. These three divisions were based on the main focus of Taoism in Southern China during the time it was made, namely; meditation, ritual, and exorcism. These Three Grottoes were used as levels for the initiation of Taoist masters, from lowest (exorcism) to highest (meditation). As well as the Three Grottoes there were Four Supplements that were added to the canon c. 500. These were mainly taken from older core Taoist texts (e.g. ''Daodejing'') apart from one which was taken from an already established and separate philosophy known as Tianshi Dao (Way ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Book Of Han
The ''Book of Han'' or ''History of the Former Han'' (Qián Hàn Shū,《前汉书》) is a history of China finished in 111AD, covering the Western, or Former Han dynasty from the first emperor in 206 BCE to the fall of Wang Mang in 23 CE. It is also called the ''Book of Former Han''. The work was composed by Ban Gu (32–92 CE), an Eastern Han court official, with the help of his sister Ban Zhao, continuing the work of their father, Ban Biao. They modeled their work on the '' Records of the Grand Historian'', a cross-dynastic general history, but theirs was the first in this annals-biography form to cover a single dynasty. It is the best source, sometimes the only one, for many topics such as literature in this period. A second work, the ''Book of the Later Han'' covers the Eastern Han period from 25 to 220, and was composed in the fifth century by Fan Ye (398–445). Contents This history developed from a continuation of Sima Qian's '' Records of the Grand Historian' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
