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Mensa (constellation)
Mensa is a constellation in the Southern Celestial Hemisphere near the south celestial pole, one of fourteen constellations drawn up in the 18th century by French astronomer Nicolas-Louis de Lacaille. Its name is Latin for table, though it originally commemorated Table Mountain and was known as "Mons Mensae". One of the IAU designated constellations, eighty-eight constellations designated by the International Astronomical Union (IAU), it covers a Keystone (architecture), keystone-shaped wedge of sky 153.5 square degrees in area. Other than the south polar constellation of Octans, it is the most southerly of constellations and is observable only south of the 5th parallel north, 5th parallel of the Northern hemisphere, Northern Hemisphere. One of the faintest constellations in the night sky, Mensa contains no apparently bright stars—the brightest, Alpha Mensae, is barely visible in suburban skies. Part of the Large Magellanic Cloud, several star clusters and a quasar lie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Table Mountain
Table Mountain (; ) is a flat-topped mountain forming a prominent landmark overlooking the city of Cape Town in South Africa. It is a significant tourist attraction, with many visitors using the Table Mountain Aerial Cableway, cableway or hiking to the top. The mountain has 8,200 plant species, of which around 80% are fynbos (Afrikaans for 'fine bush'). Table Mountain National Park is the most visited national park in South Africa, attracting 4.2 million people every year for various activities. It forms part of the lands formerly ranged by Khoe-Kwadi, Khoe-speaking clans, such as the (the "High Clan"). Table Mountain is home to a large array of mostly Endemism, endemic fauna and flora. Its top elevates about 1,000 m above the surrounding city, making the popular Hiking, hike upwards on a large variety of different, often steep and Rock (geology), rocky pathways a serious Mountaineering, mountain tour which requires Physical fitness, fitness, preparation and hiking equipment. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Keystone (architecture)
A keystone (or capstone) is the wedge-shaped stone at the apex (geometry), apex of a masonry arch or typically round-shaped one at the apex of a Vault (architecture), vault. In both cases it is the final piece placed during construction and locks all the stones into position, allowing the arch or vault to bear weight. In arches and vaults (such as quasi-domes) keystones are often enlarged beyond the structural requirements and decorated. A variant in domes and crowning vaults is a lantern (architecture), lantern. A portion of the arch surrounding the keystone is called a Crown (arch), crown. Keystones or their suggested form are sometimes placed for decorative effect in the centre of the flat top of doors, recesses and windows, so as to form an upward projection of a lintel, as a hallmark of strength or good architecture. Although a masonry arch or vault cannot be self-supporting until the keystone is placed, the keystone experiences the least stress of any of the voussoirs, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bartolomeu Dias
Bartolomeu Dias ( – 29 May 1500) was a Portuguese mariner and explorer. In 1488, he became the first European navigator to round the Cape Agulhas, southern tip of Africa and to demonstrate that the most effective southward route for ships lies in the open ocean, well to the west of the African coast. His discoveries were later used by Vasco da Gama to establish a sea route between Europe and Asia. Early life Bartolomeu Dias was born around 1450 in the Faro District of Portugal. His family had a maritime background, and one of his ancestors, Dinis Dias, explored the African coast in the 1440s and discovered the Cap-Vert peninsula in today's Senegal in 1445. Tracing his biography is complicated by the existence of several contemporary Portuguese seafarers with the same name. In 1481, Dias accompanied an expedition, led by Diogo de Azambuja, to construct a fortress and trading post called São Jorge da Mina in the Gulf of Guinea. Indirect evidence also points to his possible pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Herschel
Sir John Frederick William Herschel, 1st Baronet (; 7 March 1792 – 11 May 1871) was an English polymath active as a mathematician, astronomer, chemist, inventor and experimental photographer who invented the blueprint and did botanical work. Herschel originated the use of the Julian day system in astronomy. He named seven moons of Saturn and four moons of Uranus – the seventh planet, discovered by his father Sir William Herschel. He made many contributions to the science of photography, and investigated colour blindness and the chemical power of ultraviolet rays. His ''Preliminary Discourse'' (1831), which advocated an Inductive reasoning, inductive approach to scientific experiment and theory-building, was an important contribution to the philosophy of science. Early life and work on astronomy Herschel was born in Slough, Buckinghamshire, the son of Mary Baldwin and astronomer Sir William Herschel. He was the nephew of astronomer Caroline Herschel. He studied short ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Age Of Enlightenment
The Age of Enlightenment (also the Age of Reason and the Enlightenment) was a Europe, European Intellect, intellectual and Philosophy, philosophical movement active from the late 17th to early 19th century. Chiefly valuing knowledge gained through rationalism and empiricism, the Enlightenment was concerned with a wide range of social and Politics, political ideals such as natural law, liberty, and progress, toleration and fraternity (philosophy), fraternity, constitutional government, and the formal separation of church and state. The Enlightenment was preceded by and overlapped the Scientific Revolution, which included the work of Johannes Kepler, Galileo Galilei, Francis Bacon, Pierre Gassendi, Christiaan Huygens and Isaac Newton, among others, as well as the philosophy of Descartes, Hobbes, Spinoza, Leibniz, and John Locke. The dating of the period of the beginning of the Enlightenment can be attributed to the publication of René Descartes' ''Discourse on the Method'' in 1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cape Of Good Hope
The Cape of Good Hope ( ) is a rocky headland on the Atlantic Ocean, Atlantic coast of the Cape Peninsula in South Africa. A List of common misconceptions#Geography, common misconception is that the Cape of Good Hope is the southern tip of Africa, based on the misbelief that the Cape was the dividing point between the Atlantic Ocean, Atlantic and Indian Ocean, Indian oceans. In fact, the southernmost point of Africa is Cape Agulhas about to the east-southeast. The currents of the two oceans meet at the point where the warm-water Agulhas current meets the cold-water Benguela current and turns back on itself. That oceanic meeting point fluctuates between Cape Agulhas and Cape Point (about east of the Cape of Good Hope). When following the western side of the African coastline from the equator, however, the Cape of Good Hope marks the point where a ship begins to travel more eastward than southward. Thus, the first modern rounding of the cape in 1487 by Portuguese discoveries, ... [...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 the following: * Large Magellanic Cloud (LMC), about away * Small Magellanic Cloud (SMC), about away The Magellanic Clouds are visible to the unaided eye from the Southern Hemisphere, but cannot be observed from the most northern latitudes. History They may be the objects mentioned by the polymath Ibn Qutaybah (d. 889 CE), in his book on ''Al-Anwā̵’'' (the stations of the Moon in pre-Islamic Arabian culture): وأسفل من سهيل قدما سهيل . وفى مجرى قدمى سهيل، من خلفهما كواكب زهر كبار، لا ترى بالعراق، يسميها أهل تهامة الأعبار And be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cape Town
Cape Town is the legislature, legislative capital city, capital of South Africa. It is the country's oldest city and the seat of the Parliament of South Africa. Cape Town is the country's List of municipalities in South Africa, second-largest city by population, after Johannesburg, and the largest city in the Western Cape. The city is part of the City of Cape Town metropolitan municipality (South Africa), metropolitan municipality. The city is known for Port of Cape Town, its harbour, its natural setting in the Cape Floristic Region, and for landmarks such as Table Mountain and Cape Point. In 2014, Cape Town was named the best place in the world to visit by ''The New York Times'', and was similarly ranked number one by ''The Daily Telegraph'' in both 2016 and 2023. Located on the shore of Table Bay, the City Bowl area of Cape Town, which contains its Cape Town CBD, central business district (CBD), is History of Cape Town, the oldest urban area in the Western Cape, with a signi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exoplanets
An exoplanet or extrasolar planet is a planet outside the Solar System. The first confirmed detection of an exoplanet was in 1992 around a pulsar, and the first detection around a main-sequence star was in 1995. A different planet, first detected in 1988, was confirmed in 2003. In 2016, it was recognized that the first possible evidence of an exoplanet had been noted in 1917. In collaboration with ground-based and other space-based observatories the James Webb Space Telescope (JWST) is expected to give more insight into exoplanet traits, such as their composition, environmental conditions, and potential for life. There are many methods of detecting exoplanets. Transit photometry and Doppler spectroscopy have found the most, but these methods suffer from a clear observational bias favoring the detection of planets near the star; thus, 85% of the exoplanets detected are inside the tidal locking zone. In several cases, multiple planets have been observed around a star. A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quasar
A quasar ( ) is an extremely Luminosity, luminous active galactic nucleus (AGN). It is sometimes known as a quasi-stellar object, abbreviated QSO. The emission from an AGN is powered by accretion onto a supermassive black hole with a mass ranging from millions to tens of billions of solar masses, surrounded by a gaseous Accretion disk, accretion disc. Gas in the disc falling towards the black hole heats up and releases energy in the form of electromagnetic radiation. The radiant energy of quasars is enormous; the most powerful quasars have luminosity, luminosities thousands of times greater than that of a galaxy such as the Milky Way. Quasars are usually categorized as a subclass of the more general category of AGN. The redshifts of quasars are of Expansion of the universe, cosmological origin. The term originated as a Contraction (grammar), contraction of "quasi-stellar ''[star-like]'' radio source"—because they were first identified during the 1950s as sources of radio-wave ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Star Clusters
A star cluster is a group of stars held together by self-gravitation. Two main types of star clusters can be distinguished: globular clusters, tight groups of ten thousand to millions of old stars which are gravitationally bound; and open clusters, less tight groups of stars, generally containing fewer than a few hundred members. As they move through the galaxy, over time, open clusters become disrupted by the gravitational influence of giant molecular clouds, so that the clusters we observe are often young. Even though they are no longer gravitationally bound, they will continue to move in broadly the same direction through space and are then known as stellar associations, sometimes referred to as ''moving groups''. Globular clusters, with more members and more mass, remain intact for far longer and the globular clusters we observe are usually billions of years old. Star clusters visible to the naked eye include the Pleiades and Hyades open clusters, and the globular cluster ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Large Magellanic Cloud
The Large Magellanic Cloud (LMC) is a dwarf galaxy and satellite galaxy of the Milky Way. At a distance of around , the LMC is the second- or third-closest galaxy to the Milky Way, after the Sagittarius Dwarf Spheroidal Galaxy, Sagittarius Dwarf Spheroidal ( away) and the possible dwarf irregular galaxy called the Canis Major Overdensity. Based on the D25 isophote at the B-band (445 nm wavelength of light), the Large Magellanic Cloud is about across. It is roughly one-hundredth the mass of the Milky Way and is the fourth-largest galaxy in the Local Group, after the Andromeda Galaxy (M31), the Milky Way, and the Triangulum Galaxy (M33). The LMC is classified as a Magellanic spiral. It contains a stellar bar that is geometrically off-center, suggesting that it was once a barred dwarf spiral galaxy before its spiral arms were disrupted, likely by tidal interactions from the nearby Small Magellanic Cloud (SMC) and the Milky Way's gravity. The LMC is predicted to merge with the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
