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Timeline Of Knowledge About Galaxies, Clusters Of Galaxies, And Large-scale Structure
The following is a timeline of galaxy, galaxies, galaxy cluster, clusters of galaxies, and Observable universe#Large-scale structure, large-scale structure of the universe. Pre-20th century * 5th century BC — Democritus proposes that the bright band in the night sky known as the Milky Way might consist of stars. * 4th century BC — Aristotle believes the Milky Way to be caused by "the ignition of the fiery exhalation of some stars which were large, numerous and close together" and that the "ignition takes place in the upper part of the atmosphere, in the Sublunary sphere, region of the world which is continuous with the heavenly motions". * 964 — Abd al-Rahman al-Sufi (Azophi), a Astronomy in medieval Islam, Persian astronomer, makes the first recorded observations of the Andromeda Galaxy and the Large Magellanic Cloud in his ''Book of Fixed Stars'', and which are the first galaxies other than the Milky Way to be observed from Earth. * 11th century — Al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Galaxy
A galaxy is a system of stars, stellar remnants, interstellar gas, dust, dark matter, bound together by gravity. The word is derived from the Greek ' (), literally 'milky', a reference to the Milky Way galaxy that contains the Solar System. Galaxies, averaging an estimated 100 million stars, range in size from dwarfs with less than a hundred million stars, to the largest galaxies known – supergiants with one hundred trillion stars, each orbiting its galaxy's center of mass. Most of the mass in a typical galaxy is in the form of dark matter, with only a few percent of that mass visible in the form of stars and nebulae. Supermassive black holes are a common feature at the centres of galaxies. Galaxies are categorized according to their visual morphology as elliptical, spiral, or irregular. Many are thought to have supermassive black holes at their centers. The Milky Way's central black hole, known as Sagittarius A*, has a mass four million times greater than the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Islamic Astronomy
Islamic astronomy comprises the astronomical developments made in the Islamic world, particularly during the Islamic Golden Age (9th–13th centuries), and mostly written in the Arabic language. These developments mostly took place in the Middle East, Central Asia, Al-Andalus, and North Africa, and later in the Far East and India. It closely parallels the genesis of other Islamic sciences in its assimilation of foreign material and the amalgamation of the disparate elements of that material to create a science with Islamic characteristics. These included Greek, Sassanid, and Indian works in particular, which were translated and built upon. Islamic astronomy played a significant role in the revival of Byzantine and EuropeanSaliba (1999). astronomy following the loss of knowledge during the early medieval period, notably with the production of Latin translations of Arabic works during the 12th century. Islamic astronomy also had an influence on Chinese astronomy and M ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thomas Wright (astronomer)
Thomas Wright (22 September 171125 February 1786) was an English astronomer, mathematician, instrument maker, architect and garden designer. He was the first to describe the shape of the Milky Way and to speculate that faint nebulæ were distant galaxies. Early life Wright was born at Byers Green in County Durham being the third son of John and Margaret Wright of Pegg's Poole House. His father was a carpenter. He was educated at home as he suffered from speech impediment and then at King James I Academy. In 1725 he entered into clock-making apprenticeship to Bryan Stobart of Bishop Auckland, continuing to study on his own. He also took courses on mathematics and navigation at a free school in the parish of Gateshead founded by Dr. Theophilus Pickering. Then, he went to London to study mathematical instrument-making with Heath and Sisson and made a trial sea voyage to Amsterdam. In 1730, he set up a school in Sunderland, where he taught mathematics and navigation. He later moved ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telescope
A telescope is a device used to observe distant objects by their emission, absorption, or reflection of electromagnetic radiation. Originally meaning only an optical instrument using lenses, curved mirrors, or a combination of both to observe distant objects, the word ''telescope'' now refers to a wide range of instruments capable of detecting different regions of the electromagnetic spectrum, and in some cases other types of detectors. The first known practical telescopes were refracting telescopes with glass lenses and were invented in the Netherlands at the beginning of the 17th century. They were used for both terrestrial applications and astronomy. The reflecting telescope, which uses mirrors to collect and focus light, was invented within a few decades of the first refracting telescope. In the 20th century, many new types of telescopes were invented, including radio telescopes in the 1930s and infrared telescopes in the 1960s. Etymology The word ''telescope'' w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Galileo Galilei
Galileo di Vincenzo Bonaiuti de' Galilei (15 February 1564 – 8 January 1642) was an Italian astronomer, physicist and engineer, sometimes described as a polymath. Commonly referred to as Galileo, his name was pronounced (, ). He was born in the city of Pisa, then part of the Duchy of Florence. Galileo has been called the "father" of observational astronomy, modern physics, the scientific method, and modern science. Galileo studied speed and velocity, gravity and free fall, the principle of relativity, inertia, projectile motion and also worked in applied science and technology, describing the properties of pendulums and " hydrostatic balances". He invented the thermoscope and various military compasses, and used the telescope for scientific observations of celestial objects. His contributions to observational astronomy include telescopic confirmation of the phases of Venus, observation of the four largest satellites of Jupiter, observation of Sa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magellanic Clouds
The Magellanic Clouds (''Magellanic system'' or ''Nubeculae Magellani'') are two irregular dwarf galaxies in the southern celestial hemisphere. Orbiting the Milky Way galaxy, these satellite galaxies are members of the Local Group. Because both show signs of a bar structure, they are often reclassified as Magellanic spiral galaxies. The two galaxies are: * Large Magellanic Cloud (LMC), approximately 163,000 light-years away * Small Magellanic Cloud (SMC), approximately 206,000 light years away Magellanic clouds are visible to the unaided eye in the Southern Hemisphere but they cannot be observed from the most northern latitudes. History The Magellanic Clouds have been known since ancient times to indigenous peoples across South America and Africa, and from the first millennium in Western Asia. The first preserved mention of the Large Magellanic Cloud is believed to be in petroglyphs and rock drawings found in Chile. They may be the objects mentioned by the polymath Ibn Qu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ferdinand Magellan
Ferdinand Magellan ( or ; pt, Fernão de Magalhães, ; es, link=no, Fernando de Magallanes, ; 4 February 1480 – 27 April 1521) was a Portuguese explorer. He is best known for having planned and led the 1519 Spanish expedition to the East Indies across the Pacific Ocean to open a maritime trade route, during which he discovered the interoceanic passage bearing thereafter his name and achieved the first European navigation from the Atlantic to Asia. During this voyage, Magellan was killed in the Battle of Mactan in 1521 in the present-day Philippines, after running into resistance by the indigenous population led from Lapulapu, who consequently became a Philippines national symbol of resistance to colonialism. After Magellan's death, Juan Sebastián Elcano took the lead of the expedition, and with its few other surviving members in one of the two remaining ships, completed the first circumnavigation of Earth when they returned to Spain in 1522. Born 4 February 1480 in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Planet
A planet is a large, rounded astronomical body that is neither a star nor its remnant. The best available theory of planet formation is the nebular hypothesis, which posits that an interstellar cloud collapses out of a nebula to create a young protostar orbited by a protoplanetary disk. Planets grow in this disk by the gradual accumulation of material driven by gravity, a process called accretion. The Solar System has at least eight planets: the terrestrial planets Mercury, Venus, Earth and Mars, and the giant planets Jupiter, Saturn, Uranus and Neptune. These planets each rotate around an axis tilted with respect to its orbital pole. All of them possess an atmosphere, although that of Mercury is tenuous, and some share such features as ice caps, seasons, volcanism, hurricanes, tectonics, and even hydrology. Apart from Venus and Mars, the Solar System planets generate magnetic fields, and all except Venus and Mercury have natural satellites. The giant planets ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Syria
Syria ( ar, سُورِيَا or سُورِيَة, translit=Sūriyā), officially the Syrian Arab Republic ( ar, الجمهورية العربية السورية, al-Jumhūrīyah al-ʻArabīyah as-Sūrīyah), is a Western Asian country located in the Eastern Mediterranean and the Levant. It is a unitary state, unitary republic that consists of Governorates of Syria, 14 governorates (subdivisions), and is bordered by the Mediterranean Sea to the west, Turkey to the north, Iraq to Iraq–Syria border, the east and southeast, Jordan to Jordan–Syria border, the south, and Israel and Lebanon to Lebanon–Syria border, the southwest. Cyprus lies to the west across the Mediterranean Sea. A country of fertile plains, high mountains, and deserts, Syria is home to demographics of Syria, diverse ethnic and religious groups, including the majority Syrians, Syrian Arabs, Kurds in Syria, Kurds, Syrian Turkmen, Turkmens, Assyrians in Syria, Assyrians, Armenians in Syria, Armenians, Circa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ibn Qayyim Al-Jawziyya
Shams al-Dīn Abū ʿAbd Allāh Muḥammad ibn Abī Bakr ibn Ayyūb al-Zurʿī l-Dimashqī l-Ḥanbalī (29 January 1292–15 September 1350 CE / 691 AH–751 AH), commonly known as Ibn Qayyim al-Jawziyya ("The son of the principal of he school ofJawziyyah") or Ibn al-Qayyim ("Son of the principal"; ابن القيّم) for short, or reverentially as Imam Ibn al-Qayyim in Sunni tradition, was an important medieval Islamic jurisconsult, theologian, and spiritual writer. Belonging to the Hanbali school of orthodox Sunni jurisprudence, of which he is regarded as "one of the most important thinkers," Ibn al-Qayyim was also the foremost disciple and student of Ibn Taymiyyah,Hoover, Jon, "Ibn Qayyim al-Jawziyya", in: Christian-Muslim Relations 600 - 1500, General Editor David Thomas. with whom he was imprisoned in 1326 for dissenting against established tradition during Ibn Taymiyyah's famous incarceration in the Citadel of Damascus. Of humble origin, Ibn al-Qayyim's father was the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Earth's Atmosphere
The atmosphere of Earth is the layer of gases, known collectively as air, retained by Earth's gravity that surrounds the planet and forms its planetary atmosphere. The atmosphere of Earth protects life on Earth by creating pressure allowing for liquid water to exist on the Earth's surface, absorbing ultraviolet solar radiation, warming the surface through heat retention ( greenhouse effect), and reducing temperature extremes between day and night (the diurnal temperature variation). By mole fraction (i.e., by number of molecules), dry air contains 78.08% nitrogen, 20.95% oxygen, 0.93% argon, 0.04% carbon dioxide, and small amounts of other gases. Air also contains a variable amount of water vapor, on average around 1% at sea level, and 0.4% over the entire atmosphere. Air composition, temperature, and atmospheric pressure vary with altitude. Within the atmosphere, air suitable for use in photosynthesis by terrestrial plants and breathing of terrestrial animals is fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Refraction
In physics, refraction is the redirection of a wave as it passes from one medium to another. The redirection can be caused by the wave's change in speed or by a change in the medium. Refraction of light is the most commonly observed phenomenon, but other waves such as sound waves and water waves also experience refraction. How much a wave is refracted is determined by the change in wave speed and the initial direction of wave propagation relative to the direction of change in speed. For light, refraction follows Snell's law, which states that, for a given pair of media, the ratio of the sines of the angle of incidence ''θ1'' and angle of refraction ''θ2'' is equal to the ratio of phase velocities (''v''1 / ''v''2) in the two media, or equivalently, to the refractive indices (''n''2 / ''n''1) of the two media. :\frac =\frac=\frac Optical prisms and lenses use refraction to redirect light, as does the human eye. The refractive index of materials varies with the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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