Al-Ashraf Umar II
Al‐Malik Al‐Ashraf (Mumahhid Al‐Din) Umar Ibn Yūsuf Ibn Umar Ibn Alī Ibn Rasul (), also as Umar Ibn Yusuf (or also Al-Asharaf Umar II) was the third Rasulid sultan and also an mathematician, astronomer and physician. Biography Umar Ibn Yusuf was born in 1242 in Yemen and he died in 1296. He is known for writing the first description of the use of a magnetic compass for determining the qibla. Also, his works on astronomy contain important information on earlier sources. In a treatise about astrolabes and sundials, al-Ashraf includes several paragraphs on the construction of a compass bowl (ṭāsa). He then uses the compass to determine the north point, the meridian (khaṭṭ niṣf al-nahār), and the Qibla towards Mecca. This is the first mention of a compass in a medieval Islamic scientific text and its earliest known use as a qibla indicator, although al-Ashraf did not claim to be the first to use it for this purpose. http://www.uib.no/jais/v001ht/01-081-132schmidl ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Astronomy
Astronomy () is a natural science that studies astronomical object, celestial objects and phenomena. It uses mathematics, physics, and chemistry in order to explain their origin and chronology of the Universe, evolution. Objects of interest include planets, natural satellite, moons, stars, nebulae, galaxy, galaxies, and comets. Relevant phenomena include supernova explosions, gamma ray bursts, quasars, blazars, pulsars, and cosmic microwave background radiation. More generally, astronomy studies everything that originates beyond atmosphere of Earth, Earth's atmosphere. Cosmology is a branch of astronomy that studies the universe as a whole. Astronomy is one of the oldest natural sciences. The early civilizations in recorded history made methodical observations of the night sky. These include the Babylonian astronomy, Babylonians, Greek astronomy, Greeks, Indian astronomy, Indians, Egyptian astronomy, Egyptians, Chinese astronomy, Chinese, Maya civilization, Maya, and many anc ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Mecca
Mecca (; officially Makkah al-Mukarramah, commonly shortened to Makkah ()) is a city and administrative center of the Mecca Province of Saudi Arabia, and the Holiest sites in Islam, holiest city in Islam. It is inland from Jeddah on the Red Sea, in a narrow valley above sea level. Its last recorded population was 1,578,722 in 2015. Its estimated metro population in 2020 is 2.042million, making it the List of cities in Saudi Arabia by population, third-most populated city in Saudi Arabia after Riyadh and Jeddah. Pilgrims more than triple this number every year during the Pilgrimage#Islam, pilgrimage, observed in the twelfth Islamic calendar, Hijri month of . Mecca is generally considered "the fountainhead and cradle of Islam". Mecca is revered in Islam as the birthplace of the Prophets and messengers in Islam, Islamic prophet Muhammad. The Hira cave atop the ("Mountain of Light"), just outside the city, is where Muslims believe the Quran was first revealed to Muhammad. Vis ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Rulers Of Yemen
A ruler, sometimes called a rule, line gauge, or scale, is a device used in geometry and technical drawing, as well as the engineering and construction industries, to measure distances or draw straight lines. Variants Rulers have long been made from different materials and in multiple sizes. Some are wooden. Plastics have also been used since they were invented; they can be molded with length markings instead of being scribed. Metal is used for more durable rulers for use in the workshop; sometimes a metal edge is embedded into a wooden desk ruler to preserve the edge when used for straight-line cutting. in length is useful for a ruler to be kept on a desk to help in drawing. Shorter rulers are convenient for keeping in a pocket. Longer rulers, e.g., , are necessary in some cases. Rigid wooden or plastic yardsticks, 1 yard long, and meter sticks, 1 meter long, are also used. Classically, long measuring rods were used for larger projects, now superseded by tap ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Yemeni Astronomers
Yemen (; ar, ٱلْيَمَن, al-Yaman), officially the Republic of Yemen,, ) is a country in Western Asia. It is situated on the southern end of the Arabian Peninsula, and borders Saudi Arabia to the north and Oman to the northeast and shares maritime borders with Eritrea, Djibouti, and Somalia. Yemen is the second-largest Arab sovereign state in the peninsula, occupying , with a coastline stretching about . Its constitutionally stated capital, and largest city, is Sanaa. As of 2021, Yemen has an estimated population of some 30.4 million. In ancient times, Yemen was the home of the Sabaeans, a trading state that included parts of modern-day Ethiopia and Eritrea. Later in 275 AD, the Himyarite Kingdom was influenced by Judaism. Christianity arrived in the fourth century. Islam spread quickly in the seventh century and Yemenite troops were crucial in the early Islamic conquests. Several dynasties emerged in the 9th to 16th centuries, such as the Rasulid dynasty. The coun ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Astronomers Of The Medieval Islamic World
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, moons, comets and galaxies – in either observational (by analyzing the data) or theoretical astronomy. Examples of topics or fields astronomers study include planetary science, solar astronomy, the origin or evolution of stars, or the 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 and theoretical. Observational astronomers make direct observations of celestial objects and analyze the data. In contrast, theoretical astronomers create and investigate models of things that cannot be observed. Because it takes millions to billions of years for a system of stars or a galaxy to complete a life cycle, astronomers must observe snapshots of differe ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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13th-century Astronomers
The 13th century was the century which lasted from January 1, 1201 ( MCCI) through December 31, 1300 ( MCCC) in accordance with the Julian calendar. The Mongol Empire was founded by Genghis Khan, which stretched from Eastern Asia to Eastern Europe. The conquests of Hulagu Khan and other Mongol invasions changed the course of the Muslim world, most notably the Siege of Baghdad (1258), the destruction of the House of Wisdom and the weakening of the Mamluks and Rums which, according to historians, caused the decline of the Islamic Golden Age. Other Muslim powers such as the Mali Empire and Delhi Sultanate conquered large parts of West Africa and the Indian subcontinent, while Buddhism witnessed a decline through the conquest led by Bakhtiyar Khilji. The Southern Song dynasty would begin the century as a prosperous kingdom but would eventually be invaded and annexed into the Yuan dynasty of the Mongols. The Kamakura Shogunate of Japan would be invaded by the Mongols. Goryeo resiste ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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13th-century Arabs
The 13th century was the century which lasted from January 1, 1201 ( MCCI) through December 31, 1300 ( MCCC) in accordance with the Julian calendar. The Mongol Empire was founded by Genghis Khan, which stretched from Eastern Asia to Eastern Europe. The conquests of Hulagu Khan and other Mongol invasions changed the course of the Muslim world, most notably the Siege of Baghdad (1258), the destruction of the House of Wisdom and the weakening of the Mamluks and Rums which, according to historians, caused the decline of the Islamic Golden Age. Other Muslim powers such as the Mali Empire and Delhi Sultanate conquered large parts of West Africa and the Indian subcontinent, while Buddhism witnessed a decline through the conquest led by Bakhtiyar Khilji. The Southern Song dynasty would begin the century as a prosperous kingdom but would eventually be invaded and annexed into the Yuan dynasty of the Mongols. The Kamakura Shogunate of Japan would be invaded by the Mongols. Goryeo resist ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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1296 Deaths
1 (one, unit, unity) is a number representing a single or the only entity. 1 is also a numerical digit and represents a single unit of counting or measurement. For example, a line segment of ''unit length'' is a line segment of length 1. In conventions of sign where zero is considered neither positive nor negative, 1 is the first and smallest positive integer. It is also sometimes considered the first of the infinite sequence of natural numbers, followed by 2, although by other definitions 1 is the second natural number, following 0. The fundamental mathematical property of 1 is to be a multiplicative identity, meaning that any number multiplied by 1 equals the same number. Most if not all properties of 1 can be deduced from this. In advanced mathematics, a multiplicative identity is often denoted 1, even if it is not a number. 1 is by convention not considered a prime number; this was not universally accepted until the mid-20th century. Additionally, 1 is the s ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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1242 Births
1 (one, unit, unity) is a number representing a single or the only entity. 1 is also a numerical digit and represents a single unit of counting or measurement. For example, a line segment of ''unit length'' is a line segment of length 1. In conventions of sign where zero is considered neither positive nor negative, 1 is the first and smallest positive integer. It is also sometimes considered the first of the infinite sequence of natural numbers, followed by 2, although by other definitions 1 is the second natural number, following 0. The fundamental mathematical property of 1 is to be a multiplicative identity, meaning that any number multiplied by 1 equals the same number. Most if not all properties of 1 can be deduced from this. In advanced mathematics, a multiplicative identity is often denoted 1, even if it is not a number. 1 is by convention not considered a prime number; this was not universally accepted until the mid-20th century. Additionally, 1 is ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Metropolitan Museum Of Art
The Metropolitan Museum of Art of New York City, colloquially "the Met", is the largest art museum in the Americas. Its permanent collection contains over two million works, divided among 17 curatorial departments. The main building at 1000 Fifth Avenue, along the Museum Mile on the eastern edge of Central Park on Manhattan's Upper East Side, is by area one of the world's largest art museums. The first portion of the approximately building was built in 1880. A much smaller second location, The Cloisters at Fort Tryon Park in Upper Manhattan, contains an extensive collection of art, architecture, and artifacts from medieval Europe. The Metropolitan Museum of Art was founded in 1870 with its mission to bring art and art education to the American people. The museum's permanent collection consists of works of art from classical antiquity and ancient Egypt, paintings, and sculptures from nearly all the European masters, and an extensive collection of American and modern ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Meridian (astronomy)
In astronomy, the meridian is the great circle passing through the celestial poles, as well as the zenith and nadir of an observer's location. Consequently, it contains also the north and south points on the horizon, and it is perpendicular to the celestial equator and horizon. Meridians, celestial and geographical, are determined by the pencil of planes passing through the Earth's rotation axis. For a location ''not'' at a geographical pole, there is a unique meridian plane in this axial-pencil through that location. The intersection of this plane with Earth's surface is the '' geographical meridian'', and the intersection of the plane with the celestial sphere is the celestial meridian for that location and time. There are several ways to divide the meridian into semicircles. In the horizontal coordinate system, the observer's meridian is divided into halves terminated by the horizon's north and south points. The observer's upper meridian passes through the zenith while the l ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Mathematician
A mathematician is someone who uses an extensive knowledge of mathematics in their work, typically to solve mathematical problems. Mathematicians are concerned with numbers, data, quantity, structure, space, models, and change. History One of the earliest known mathematicians were Thales of Miletus (c. 624–c.546 BC); he has been hailed as the first true mathematician and the first known individual to whom a mathematical discovery has been attributed. He is credited with the first use of deductive reasoning applied to geometry, by deriving four corollaries to Thales' Theorem. The number of known mathematicians grew when Pythagoras of Samos (c. 582–c. 507 BC) established the Pythagorean School, whose doctrine it was that mathematics ruled the universe and whose motto was "All is number". It was the Pythagoreans who coined the term "mathematics", and with whom the study of mathematics for its own sake begins. The first woman mathematician recorded by history was Hypati ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |