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Chlorhexidine mouthwash is known to have minor adverse effects. Chlorhexidine binds to tannins, meaning that prolonged use in persons who consume coffee, tea or red wine is associated with extrinsic staining (i.e. removable staining) of teeth. A systematic review of commercial chlorhexidine products with anti-discolora... | Mouthwash | Wikipedia | 486 | 782 | https://en.wikipedia.org/wiki/Mouthwash | Biology and health sciences | Hygiene products | Health |
The mouth is rinsed with approximately one tablespoon of oil for 10–20 minutes then spat out. Sesame oil, coconut oil and ghee are traditionally used, but newer oils such as sunflower oil are also used.
Essential oils
Phenolic compounds and monoterpenes include essential oil constituents that have some antibacterial p... | Mouthwash | Wikipedia | 494 | 782 | https://en.wikipedia.org/wiki/Mouthwash | Biology and health sciences | Hygiene products | Health |
Lactoperoxidase (saliva substitute)
Enzymes and non-enzymatic proteins, such as lactoperoxidase, lysozyme, and lactoferrin, have been used in mouthwashes (e.g., Biotene) to reduce levels of oral bacteria, and, hence, of the acids produced by these bacteria.
Lidocaine/xylocaine
Oral lidocaine is useful for the treatmen... | Mouthwash | Wikipedia | 398 | 782 | https://en.wikipedia.org/wiki/Mouthwash | Biology and health sciences | Hygiene products | Health |
Sanguinarine
Sanguinarine-containing mouthwashes are marketed as anti-plaque and anti-malodor treatments. Sanguinarine is a toxic alkaloid herbal extract, obtained from plants such as Sanguinaria canadensis (bloodroot), Argemone mexicana (Mexican prickly poppy), and others. However, its use is strongly associated with ... | Mouthwash | Wikipedia | 476 | 782 | https://en.wikipedia.org/wiki/Mouthwash | Biology and health sciences | Hygiene products | Health |
Saltwater mouthwashes are also routinely used after oral surgery, to keep food debris out of healing wounds and to prevent infection. Some oral surgeons consider saltwater mouthwashes the mainstay of wound cleanliness after surgery. In dental extractions, hot saltwater mouthbaths should start about 24 hours after a den... | Mouthwash | Wikipedia | 457 | 782 | https://en.wikipedia.org/wiki/Mouthwash | Biology and health sciences | Hygiene products | Health |
Tranexamic acid
A 4.8% tranexamic acid solution is sometimes used as an antifibrinolytic mouthwash to prevent bleeding during and after oral surgery in persons with coagulopathies (clotting disorders) or who are taking anticoagulants (blood thinners such as warfarin).
Triclosan
Triclosan is a non-ionic chlorinate bisp... | Mouthwash | Wikipedia | 224 | 782 | https://en.wikipedia.org/wiki/Mouthwash | Biology and health sciences | Hygiene products | Health |
Asparagales (asparagoid lilies) are a diverse order of flowering plants in the monocots. Under the APG IV system of flowering plant classification, Asparagales are the largest order of monocots with 14 families, 1,122 genera, and about 36,000 species, with members as varied as asparagus, orchids, yuccas, irises, onions... | Asparagales | Wikipedia | 347 | 786 | https://en.wikipedia.org/wiki/Asparagales | Biology and health sciences | Asparagales | Plants |
The order Asparagales takes its name from the type family Asparagaceae and has only recently been recognized in classification systems. The order is clearly circumscribed on the basis of molecular phylogenetics, but it is difficult to define morphologically since its members are structurally diverse. The order was firs... | Asparagales | Wikipedia | 448 | 786 | https://en.wikipedia.org/wiki/Asparagales | Biology and health sciences | Asparagales | Plants |
Almost all species have a tight cluster of leaves (a rosette), either at the base of the plant or at the end of a more-or-less woody stem as with Yucca. In some cases, the leaves are produced along the stem. The flowers are in the main not particularly distinctive, being of a general 'lily type', with six tepals, eithe... | Asparagales | Wikipedia | 278 | 786 | https://en.wikipedia.org/wiki/Asparagales | Biology and health sciences | Asparagales | Plants |
The orders which have been separated from the old Liliales are difficult to characterize. No single morphological character appears to be diagnostic of the order Asparagales.
The flowers of Asparagales are of a general type among the lilioid monocots. Compared to Liliales, they usually have plain tepals without markin... | Asparagales | Wikipedia | 460 | 786 | https://en.wikipedia.org/wiki/Asparagales | Biology and health sciences | Asparagales | Plants |
Microsporogenesis (part of pollen formation) distinguishes some members of Asparagales from Liliales. Microsporogenesis involves a cell dividing twice (meiotically) to form four daughter cells. There are two kinds of microsporogenesis: successive and simultaneous (although intermediates exist). In successive microsporo... | Asparagales | Wikipedia | 306 | 786 | https://en.wikipedia.org/wiki/Asparagales | Biology and health sciences | Asparagales | Plants |
According to telomere sequence, at least two evolutionary switch-points happened within the order. The basal sequence is formed by TTTAGGG like in the majority of higher plants. Basal motif was changed to vertebrate-like TTAGGG and finally, the most divergent motif CTCGGTTATGGG appears in Allium.
Taxonomy
As circumsc... | Asparagales | Wikipedia | 254 | 786 | https://en.wikipedia.org/wiki/Asparagales | Biology and health sciences | Asparagales | Plants |
The type genus, Asparagus, from which the name of the order is derived, was described by Carl Linnaeus in 1753, with ten species. He placed Asparagus within the Hexandria Monogynia (six stamens, one carpel) in his sexual classification in the Species Plantarum. The majority of taxa now considered to constitute Asparaga... | Asparagales | Wikipedia | 481 | 786 | https://en.wikipedia.org/wiki/Asparagales | Biology and health sciences | Asparagales | Plants |
In 1810, Brown proposed that a subgroup of Liliaceae be distinguished on the basis of the position of the ovaries and be referred to as Amaryllideae and in 1813 de Candolle described Liliacées Juss. and Amaryllidées Brown as two quite separate families | Asparagales | Wikipedia | 58 | 786 | https://en.wikipedia.org/wiki/Asparagales | Biology and health sciences | Asparagales | Plants |
The literature on the organisation of genera into families and higher ranks became available in the English language with Samuel Frederick Gray's A natural arrangement of British plants (1821). Gray used a combination of Linnaeus' sexual classification and Jussieu's natural classification to group together a number of ... | Asparagales | Wikipedia | 313 | 786 | https://en.wikipedia.org/wiki/Asparagales | Biology and health sciences | Asparagales | Plants |
By 1846, in his final scheme Lindley had greatly expanded and refined the treatment of the monocots, introducing both an intermediate ranking (Alliances) and tribes within orders (i.e. families). Lindley placed the Liliaceae within the Liliales, but saw it as a paraphyletic ("catch-all") family, being all Liliales not ... | Asparagales | Wikipedia | 335 | 786 | https://en.wikipedia.org/wiki/Asparagales | Biology and health sciences | Asparagales | Plants |
The number of known genera (and species) continued to grow and by the time of the next major British classification, that of the Bentham & Hooker system in 1883 (published in Latin) several of Lindley's other families had been absorbed into the Liliaceae. They used the term 'series' to indicate suprafamilial rank, with... | Asparagales | Wikipedia | 391 | 786 | https://en.wikipedia.org/wiki/Asparagales | Biology and health sciences | Asparagales | Plants |
Engler, in his system developed Eichler's ideas into a much more elaborate scheme which he treated in a number of works including Die Natürlichen Pflanzenfamilien (Engler and Prantl 1888) and Syllabus der Pflanzenfamilien (1892–1924). In his treatment of Liliiflorae the Liliineae were a suborder which included both fam... | Asparagales | Wikipedia | 362 | 786 | https://en.wikipedia.org/wiki/Asparagales | Biology and health sciences | Asparagales | Plants |
These various proposals to separate small groups of genera into more homogeneous families made little impact till that of Dahlgren (1985) incorporating new information including synapomorphy. Dahlgren developed Huber's ideas further and popularised them, with a major deconstruction of existing families into smaller uni... | Asparagales | Wikipedia | 482 | 786 | https://en.wikipedia.org/wiki/Asparagales | Biology and health sciences | Asparagales | Plants |
From the Dahlgren system of 1985 onwards, studies based mainly on morphology had identified the Asparagales as a distinct group, but had also included groups now located in Liliales, Pandanales and Zingiberales. Research in the 21st century has supported the monophyly of Asparagales, based on morphology, 18S rDNA, and ... | Asparagales | Wikipedia | 438 | 786 | https://en.wikipedia.org/wiki/Asparagales | Biology and health sciences | Asparagales | Plants |
The tree shown above can be divided into a basal paraphyletic group, the 'lower Asparagales (asparagoids)', from Orchidaceae to Asphodelaceae, and a well-supported monophyletic group of 'core Asparagales' (higher asparagoids), comprising the two largest families, Amaryllidaceae sensu lato and Asparagaceae sensu lato.
... | Asparagales | Wikipedia | 473 | 786 | https://en.wikipedia.org/wiki/Asparagales | Biology and health sciences | Asparagales | Plants |
Orchid clade
Orchidaceae is possibly the largest family of all angiosperms (only Asteraceae might – or might not – be more speciose) and hence by far the largest in the order. The Dahlgren system recognized three families of orchids, but DNA sequence analysis later showed that these families are polyphyletic and so sho... | Asparagales | Wikipedia | 490 | 786 | https://en.wikipedia.org/wiki/Asparagales | Biology and health sciences | Asparagales | Plants |
Ixioliriaceae to Xeronemataceae
The relationship shown between Ixioliriaceae and Tecophilaeaceae is still unclear. Some studies have supported a clade of these two families, others have not. The position of Doryanthaceae has also varied, with support for the position shown above, but also support for other positions.
... | Asparagales | Wikipedia | 477 | 786 | https://en.wikipedia.org/wiki/Asparagales | Biology and health sciences | Asparagales | Plants |
A 2009 study suggests that the Asparagales have the highest diversification rate in the monocots, about the same as the order Poales, although in both orders the rate is little over half that of the eudicot order Lamiales, the clade with the highest rate.
Comparison of family structures
The taxonomic diversity of ... | Asparagales | Wikipedia | 478 | 786 | https://en.wikipedia.org/wiki/Asparagales | Biology and health sciences | Asparagales | Plants |
The earlier 2003 version, APG II, allowed 'bracketed' families, i.e. families which could either be segregated from more comprehensive families or could be included in them. These are the families given under "including" in the list above. APG III does not allow bracketed families, requiring the use of the more compreh... | Asparagales | Wikipedia | 284 | 786 | https://en.wikipedia.org/wiki/Asparagales | Biology and health sciences | Asparagales | Plants |
Asterales ( ) is an order of dicotyledonous flowering plants that includes the large family Asteraceae (or Compositae) known for composite flowers made of florets, and ten families related to the Asteraceae. While asterids in general are characterized by fused petals, composite flowers consisting of many florets create... | Asterales | Wikipedia | 512 | 789 | https://en.wikipedia.org/wiki/Asterales | Biology and health sciences | Asterales | Plants |
Only the Asteraceae have composite flower heads; the other families do not, but share other characteristics such as storage of inulin that define the 11 families as more closely related to each other than to other plant families or orders such as the rosids.
The phylogenetic tree according to APG III for the Campanuli... | Asterales | Wikipedia | 476 | 789 | https://en.wikipedia.org/wiki/Asterales | Biology and health sciences | Asterales | Plants |
Biogeography
The core Asterales are Stylidiaceae (six genera), APA clade (Alseuosmiaceae, Phellinaceae and Argophyllaceae, together seven genera), MGCA clade (Menyanthaceae, Goodeniaceae, Calyceraceae, in total twenty genera), and Asteraceae (about sixteen hundred genera). Other Asterales are Rousseaceae (four genera),... | Asterales | Wikipedia | 297 | 789 | https://en.wikipedia.org/wiki/Asterales | Biology and health sciences | Asterales | Plants |
An asteroid is a minor planet—an object that is neither a true planet nor an identified comet— that orbits within the inner Solar System. They are rocky, metallic, or icy bodies with no atmosphere, classified as C-type (carbonaceous), M-type (metallic), or S-type (silicaceous). The size and shape of asteroids vary sign... | Asteroid | Wikipedia | 480 | 791 | https://en.wikipedia.org/wiki/Asteroid | Physical sciences | Astronomy | null |
In 2006, the International Astronomical Union (IAU) introduced the currently preferred broad term small Solar System body, defined as an object in the Solar System that is neither a planet, a dwarf planet, nor a natural satellite; this includes asteroids, comets, and more recently discovered classes. According to IAU, ... | Asteroid | Wikipedia | 492 | 791 | https://en.wikipedia.org/wiki/Asteroid | Physical sciences | Astronomy | null |
For almost two centuries after the discovery of Ceres in 1801, all known asteroids spent most of their time at or within the orbit of Jupiter, though a few, such as 944 Hidalgo, ventured farther for part of their orbit. Starting in 1977 with 2060 Chiron, astronomers discovered small bodies that permanently resided furt... | Asteroid | Wikipedia | 507 | 791 | https://en.wikipedia.org/wiki/Asteroid | Physical sciences | Astronomy | null |
Discovery of Ceres
In 1772, German astronomer Johann Elert Bode, citing Johann Daniel Titius, published a numerical procession known as the Titius–Bode law (now discredited). Except for an unexplained gap between Mars and Jupiter, Bode's formula seemed to predict the orbits of the known planets. He wrote the following ... | Asteroid | Wikipedia | 496 | 791 | https://en.wikipedia.org/wiki/Asteroid | Physical sciences | Astronomy | null |
The light was a little faint, and of the colour of Jupiter, but similar to many others which generally are reckoned of the eighth magnitude. Therefore I had no doubt of its being any other than a fixed star. [...] The evening of the third, my suspicion was converted into certainty, being assured it was not a fixed star... | Asteroid | Wikipedia | 476 | 791 | https://en.wikipedia.org/wiki/Asteroid | Physical sciences | Astronomy | null |
Three other asteroids (2 Pallas, 3 Juno, and 4 Vesta) were discovered by von Zach's group over the next few years, with Vesta found in 1807. No new asteroids were discovered until 1845. Amateur astronomer Karl Ludwig Hencke started his searches of new asteroids in 1830, and fifteen years later, while looking for Vesta,... | Asteroid | Wikipedia | 452 | 791 | https://en.wikipedia.org/wiki/Asteroid | Physical sciences | Astronomy | null |
These first three steps do not constitute asteroid discovery: the observer has only found an apparition, which gets a provisional designation, made up of the year of discovery, a letter representing the half-month of discovery, and finally a letter and a number indicating the discovery's sequential number (example: ). ... | Asteroid | Wikipedia | 491 | 791 | https://en.wikipedia.org/wiki/Asteroid | Physical sciences | Astronomy | null |
The first asteroids to be discovered were assigned iconic symbols like the ones traditionally used to designate the planets. By 1852 there were two dozen asteroid symbols, which often occurred in multiple variants.
In 1851, after the fifteenth asteroid, Eunomia, had been discovered, Johann Franz Encke made a major cha... | Asteroid | Wikipedia | 484 | 791 | https://en.wikipedia.org/wiki/Asteroid | Physical sciences | Astronomy | null |
The majority of known asteroids orbit within the asteroid belt between the orbits of Mars and Jupiter, generally in relatively low-eccentricity (i.e. not very elongated) orbits. This belt is estimated to contain between 1.1 and 1.9 million asteroids larger than in diameter, and millions of smaller ones. These asteroid... | Asteroid | Wikipedia | 384 | 791 | https://en.wikipedia.org/wiki/Asteroid | Physical sciences | Astronomy | null |
In the Solar System, most known trojans share the orbit of Jupiter. They are divided into the Greek camp at (ahead of Jupiter) and the Trojan camp at (trailing Jupiter). More than a million Jupiter trojans larger than one kilometer are thought to exist, of which more than 7,000 are currently catalogued. In other plan... | Asteroid | Wikipedia | 340 | 791 | https://en.wikipedia.org/wiki/Asteroid | Physical sciences | Astronomy | null |
Near-Earth asteroids are divided into groups based on their semi-major axis (a), perihelion distance (q), and aphelion distance (Q):
The Atiras or Apoheles have orbits strictly inside Earth's orbit: an Atira asteroid's aphelion distance (Q) is smaller than Earth's perihelion distance (0.983 AU). That is, , which impli... | Asteroid | Wikipedia | 506 | 791 | https://en.wikipedia.org/wiki/Asteroid | Physical sciences | Astronomy | null |
Phobos could be a second-generation Solar System object that coalesced in orbit after Mars formed, rather than forming concurrently out of the same birth cloud as Mars.
Another hypothesis is that Mars was once surrounded by many Phobos- and Deimos-sized bodies, perhaps ejected into orbit around it by a collision with ... | Asteroid | Wikipedia | 406 | 791 | https://en.wikipedia.org/wiki/Asteroid | Physical sciences | Astronomy | null |
The mass of all the objects of the asteroid belt, lying between the orbits of Mars and Jupiter, is estimated to be , ≈ 3.25% of the mass of the Moon. Of this, Ceres comprises , about 40% of the total. Adding in the next three most massive objects, Vesta (11%), Pallas (8.5%), and Hygiea (3–4%), brings this figure up to ... | Asteroid | Wikipedia | 403 | 791 | https://en.wikipedia.org/wiki/Asteroid | Physical sciences | Astronomy | null |
Vesta, too, has a differentiated interior, though it formed inside the Solar System's frost line, and so is devoid of water; its composition is mainly of basaltic rock with minerals such as olivine. Aside from the large crater at its southern pole, Rheasilvia, Vesta also has an ellipsoidal shape. Vesta is the parent bo... | Asteroid | Wikipedia | 504 | 791 | https://en.wikipedia.org/wiki/Asteroid | Physical sciences | Astronomy | null |
Color
Asteroids become darker and redder with age due to space weathering. However evidence suggests most of the color change occurs rapidly, in the first hundred thousand years, limiting the usefulness of spectral measurement for determining the age of asteroids.
Surface features
Except for the "big four" (Ceres, ... | Asteroid | Wikipedia | 302 | 791 | https://en.wikipedia.org/wiki/Asteroid | Physical sciences | Astronomy | null |
Composition
Asteroids are classified by their characteristic emission spectra, with the majority falling into three main groups: C-type, M-type, and S-type. These describe carbonaceous (carbon-rich), metallic, and silicaceous (stony) compositions, respectively. The physical composition of asteroids is varied and in mo... | Asteroid | Wikipedia | 376 | 791 | https://en.wikipedia.org/wiki/Asteroid | Physical sciences | Astronomy | null |
Composition is calculated from three primary sources: albedo, surface spectrum, and density. The last can only be determined accurately by observing the orbits of moons the asteroid might have. So far, every asteroid with moons has turned out to be a rubble pile, a loose conglomeration of rock and metal that may be hal... | Asteroid | Wikipedia | 509 | 791 | https://en.wikipedia.org/wiki/Asteroid | Physical sciences | Astronomy | null |
Acfer 049, a meteorite discovered in Algeria in 1990, was shown in 2019 to have an ultraporous lithology (UPL): porous texture that could be formed by removal of ice that filled these pores, this suggests that UPL "represent fossils of primordial ice".
Organic compounds
Asteroids contain traces of amino acids and ot... | Asteroid | Wikipedia | 440 | 791 | https://en.wikipedia.org/wiki/Asteroid | Physical sciences | Astronomy | null |
Some asteroids have unusual horseshoe orbits that are co-orbital with Earth or another planet. Examples are 3753 Cruithne and . The first instance of this type of orbital arrangement was discovered between Saturn's moons Epimetheus and Janus. Sometimes these horseshoe objects temporarily become quasi-satellites for a f... | Asteroid | Wikipedia | 509 | 791 | https://en.wikipedia.org/wiki/Asteroid | Physical sciences | Astronomy | null |
Active asteroids are objects that have asteroid-like orbits but show comet-like visual characteristics. That is, they show comae, tails, or other visual evidence of mass-loss (like a comet), but their orbit remains within Jupiter's orbit (like an asteroid). These bodies were originally designated main-belt comets (MBCs... | Asteroid | Wikipedia | 370 | 791 | https://en.wikipedia.org/wiki/Asteroid | Physical sciences | Astronomy | null |
Observation and exploration
Until the age of space travel, objects in the asteroid belt could only be observed with large telescopes, their shapes and terrain remaining a mystery. The best modern ground-based telescopes and the Earth-orbiting Hubble Space Telescope can only resolve a small amount of detail on the surf... | Asteroid | Wikipedia | 342 | 791 | https://en.wikipedia.org/wiki/Asteroid | Physical sciences | Astronomy | null |
Mid- to thermal-infrared observations, along with polarimetry measurements, are probably the only data that give some indication of actual physical properties. Measuring the heat flux of an asteroid at a single wavelength gives an estimate of the dimensions of the object; these measurements have lower uncertainty than ... | Asteroid | Wikipedia | 403 | 791 | https://en.wikipedia.org/wiki/Asteroid | Physical sciences | Astronomy | null |
Both space and ground-based observatories conducted asteroid search programs; the space-based searches are expected to detect more objects because there is no atmosphere to interfere and because they can observe larger portions of the sky. NEOWISE observed more than 100,000 asteroids of the main belt, Spitzer Space Tel... | Asteroid | Wikipedia | 476 | 791 | https://en.wikipedia.org/wiki/Asteroid | Physical sciences | Astronomy | null |
The first dedicated asteroid probe was NASA's NEAR Shoemaker, which photographed 253 Mathilde in 1997, before entering into orbit around 433 Eros, finally landing on its surface in 2001. It was the first spacecraft to successfully orbit and land on an asteroid. From September to November 2005, the Japanese Hayabusa pro... | Asteroid | Wikipedia | 448 | 791 | https://en.wikipedia.org/wiki/Asteroid | Physical sciences | Astronomy | null |
NASA's Psyche, launched in October 2023, is intended to study the large metallic asteroid of the same name, and is on track to arrive there in 2029.
ESA's Hera, launched in October 2024, is intended study the results of the DART impact. It is expected to measure the size and morphology of the crater, and momentum tran... | Asteroid | Wikipedia | 482 | 791 | https://en.wikipedia.org/wiki/Asteroid | Physical sciences | Astronomy | null |
The near-Earth asteroid 433 Eros had been discovered as long ago as 1898, and the 1930s brought a flurry of similar objects. In order of discovery, these were: 1221 Amor, 1862 Apollo, 2101 Adonis, and finally 69230 Hermes, which approached within 0.005 AU of Earth in 1937. Astronomers began to realize the possibilities... | Asteroid | Wikipedia | 438 | 791 | https://en.wikipedia.org/wiki/Asteroid | Physical sciences | Astronomy | null |
Strategies fall into two basic sets: fragmentation and delay. Fragmentation concentrates on rendering the impactor harmless by fragmenting it and scattering the fragments so that they miss the Earth or are small enough to burn up in the atmosphere. Delay exploits the fact that both the Earth and the impactor are in orb... | Asteroid | Wikipedia | 425 | 791 | https://en.wikipedia.org/wiki/Asteroid | Physical sciences | Astronomy | null |
Aries is one of the constellations of the zodiac. It is located in the Northern celestial hemisphere between Pisces to the west and Taurus to the east. The name Aries is Latin for ram. Its old astronomical symbol is (♈︎). It is one of the 48 constellations described by the 2nd century astronomer Ptolemy, and remains ... | Aries (constellation) | Wikipedia | 272 | 798 | https://en.wikipedia.org/wiki/Aries%20%28constellation%29 | Physical sciences | Zodiac | Astronomy |
Aries is now recognized as an official constellation, albeit as a specific region of the sky, by the International Astronomical Union. It was originally defined in ancient texts as a specific pattern of stars, and has remained a constellation since ancient times; it now includes the ancient pattern and the surrounding ... | Aries (constellation) | Wikipedia | 449 | 798 | https://en.wikipedia.org/wiki/Aries%20%28constellation%29 | Physical sciences | Zodiac | Astronomy |
Aries was not fully accepted as a constellation until classical times. In Hellenistic astrology, the constellation of Aries is associated with the golden ram of Greek mythology that rescued Phrixus and Helle on orders from Hermes, taking Phrixus to the land of Colchis. Phrixus and Helle were the son and daughter of Kin... | Aries (constellation) | Wikipedia | 500 | 798 | https://en.wikipedia.org/wiki/Aries%20%28constellation%29 | Physical sciences | Zodiac | Astronomy |
Medieval Muslim astronomers depicted Aries in various ways. Astronomers like al-Sufi saw the constellation as a ram, modelled on the precedent of Ptolemy. However, some Islamic celestial globes depicted Aries as a nondescript four-legged animal with what may be antlers instead of horns. Some early Bedouin observers saw... | Aries (constellation) | Wikipedia | 427 | 798 | https://en.wikipedia.org/wiki/Aries%20%28constellation%29 | Physical sciences | Zodiac | Astronomy |
In non-Western astronomy
In traditional Chinese astronomy, stars from Aries were used in several constellations. The brightest stars—Alpha, Beta, and Gamma Arietis—formed a constellation called 'Lou',variously translated as "bond" or "lasso" also "sickle", which was associated with the ritual sacrifice of cattle. Thi... | Aries (constellation) | Wikipedia | 245 | 798 | https://en.wikipedia.org/wiki/Aries%20%28constellation%29 | Physical sciences | Zodiac | Astronomy |
In a similar system to the Chinese, the first lunar mansion in Hindu astronomy was called "Aswini", after the traditional names for Beta and Gamma Arietis, the Aswins. Because the Hindu new year began with the vernal equinox, the Rig Veda contains over 50 new-year's related hymns to the twins, making them some of the m... | Aries (constellation) | Wikipedia | 512 | 798 | https://en.wikipedia.org/wiki/Aries%20%28constellation%29 | Physical sciences | Zodiac | Astronomy |
β Arietis, also known as Sheratan, is a blue-white star with an apparent visual magnitude of 2.64. Its traditional name is derived from "sharatayn", the Arabic word for "the two signs", referring to both Beta and Gamma Arietis in their position as heralds of the vernal equinox. The two stars were known to the Bedouin a... | Aries (constellation) | Wikipedia | 199 | 798 | https://en.wikipedia.org/wiki/Aries%20%28constellation%29 | Physical sciences | Zodiac | Astronomy |
γ Arietis, with a common name of Mesarthim, is a binary star with two white-hued components, located in a rich field of magnitude 8–12 stars. Its traditional name has conflicting derivations. It may be derived from a corruption of "al-sharatan", the Arabic word meaning "pair" or a word for "fat ram". However, it may al... | Aries (constellation) | Wikipedia | 340 | 798 | https://en.wikipedia.org/wiki/Aries%20%28constellation%29 | Physical sciences | Zodiac | Astronomy |
The constellation is home to several double stars, including Epsilon, Lambda, and Pi Arietis. ε Arietis is a binary star with two white components. The primary is of magnitude 5.2 and the secondary is of magnitude 5.5. The system is 290 light-years from Earth. Its overall magnitude is 4.63, and the primary has an absol... | Aries (constellation) | Wikipedia | 298 | 798 | https://en.wikipedia.org/wiki/Aries%20%28constellation%29 | Physical sciences | Zodiac | Astronomy |
Most of the other stars in Aries visible to the naked eye have magnitudes between 3 and 5. δ Ari, called Boteïn, is a star of magnitude 4.35, 170 light-years away. It has an absolute magnitude of −0.1 and a spectral class of K2. ζ Arietis is a star of magnitude 4.89, 263 light-years away. Its spectral class is A0 and i... | Aries (constellation) | Wikipedia | 375 | 798 | https://en.wikipedia.org/wiki/Aries%20%28constellation%29 | Physical sciences | Zodiac | Astronomy |
Variable stars
Aries has its share of variable stars, including R and U Arietis, Mira-type variable stars, and T Arietis, a semi-regular variable star. R Arietis is a Mira variable star that ranges in magnitude from a minimum of 13.7 to a maximum of 7.4 with a period of 186.8 days. It is 4,080 light-years away. U Arie... | Aries (constellation) | Wikipedia | 348 | 798 | https://en.wikipedia.org/wiki/Aries%20%28constellation%29 | Physical sciences | Zodiac | Astronomy |
NGC 772 is a spiral galaxy with an integrated magnitude of 10.3, located southeast of β Arietis and 15 arcminutes west of 15 Arietis. It is a relatively bright galaxy and shows obvious nebulosity and ellipticity in an amateur telescope. It is 7.2 by 4.2 arcminutes, meaning that its surface brightness, magnitude 13.6, i... | Aries (constellation) | Wikipedia | 326 | 798 | https://en.wikipedia.org/wiki/Aries%20%28constellation%29 | Physical sciences | Zodiac | Astronomy |
NGC 678 and NGC 680 are a pair of galaxies in Aries that are only about 200,000 light-years apart. Part of the NGC 691 group of galaxies, both are at a distance of approximately 130 million light-years. NGC 678 is an edge-on spiral galaxy that is 4.5 by 0.8 arcminutes. NGC 680, an elliptical galaxy with an asymmetrical... | Aries (constellation) | Wikipedia | 468 | 798 | https://en.wikipedia.org/wiki/Aries%20%28constellation%29 | Physical sciences | Zodiac | Astronomy |
Meteor showers
Aries is home to several meteor showers. The Daytime Arietid meteor shower is one of the strongest meteor showers that occurs during the day, lasting from 22 May to 2 July. It is an annual shower associated with the Marsden group of comets that peaks on 7 June with a maximum zenithal hourly rate of 54 m... | Aries (constellation) | Wikipedia | 464 | 798 | https://en.wikipedia.org/wiki/Aries%20%28constellation%29 | Physical sciences | Zodiac | Astronomy |
Planetary systems
Aries contains several stars with extrasolar planets. HIP 14810, a G5 type star, is orbited by three giant planets (those more than ten times the mass of Earth). HD 12661, like HIP 14810, is a G-type main sequence star, slightly larger than the Sun, with two orbiting planets. One planet is 2.3 times ... | Aries (constellation) | Wikipedia | 215 | 798 | https://en.wikipedia.org/wiki/Aries%20%28constellation%29 | Physical sciences | Zodiac | Astronomy |
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). I... | Aquarius (constellation) | Wikipedia | 382 | 799 | https://en.wikipedia.org/wiki/Aquarius%20%28constellation%29 | Physical sciences | Zodiac | Astronomy |
In Greek mythology, Aquarius is sometimes associated with Deucalion, the son of Prometheus who built a ship with his wife Pyrrha to survive an imminent flood. They sailed for nine days before washing ashore on Mount Parnassus. Aquarius is also sometimes identified with beautiful Ganymede, a youth in Greek mythology and... | Aquarius (constellation) | Wikipedia | 287 | 799 | https://en.wikipedia.org/wiki/Aquarius%20%28constellation%29 | Physical sciences | Zodiac | Astronomy |
In Eastern astronomy
In Chinese astronomy, the stream of water flowing from the Water Jar was depicted as the "Army of Yu-Lin" (Yu-lim-kiun or Yulinjun, Hanzi: 羽林君). The name "Yu-lin" means "feathers and forests", referring to the numerous light-footed soldiers from the northern reaches of the empire represented by the... | Aquarius (constellation) | Wikipedia | 416 | 799 | https://en.wikipedia.org/wiki/Aquarius%20%28constellation%29 | Physical sciences | Zodiac | Astronomy |
Three of the Chinese lunar mansions shared their name with constellations. Nu, also the name for the 10th lunar mansion, was a handmaiden represented by Epsilon, Mu, 3, and 4 Aquarii. The 11th lunar mansion shared its name with the constellation Xu ("emptiness"), formed by Beta Aquarii and Alpha Equulei; it represented... | Aquarius (constellation) | Wikipedia | 424 | 799 | https://en.wikipedia.org/wiki/Aquarius%20%28constellation%29 | Physical sciences | Zodiac | Astronomy |
γ Aquarii, also called Sadachbia, is a white main sequence star of spectral type star of spectral type A0V that is between 158 and 315 million years old and is around 2.5 times the Sun's mass (), and double its radius. Its magnitude is 3.85, and it is away, hence its luminosity is . The name Sadachbia comes from the A... | Aquarius (constellation) | Wikipedia | 364 | 799 | https://en.wikipedia.org/wiki/Aquarius%20%28constellation%29 | Physical sciences | Zodiac | Astronomy |
Planetary systems
Twelve exoplanet systems have been found in Aquarius as of 2013. Gliese 876, one of the nearest stars to Earth at a distance of 15 light-years, was the first red dwarf star to be found to possess a planetary system. It is orbited by four planets, including one terrestrial planet 6.6 times the mass of ... | Aquarius (constellation) | Wikipedia | 188 | 799 | https://en.wikipedia.org/wiki/Aquarius%20%28constellation%29 | Physical sciences | Zodiac | Astronomy |
There are also less-prominent systems in Aquarius. WASP-6, a type G8 star of magnitude 12.4, is host to one exoplanet, WASP-6 b. The star is 307 parsecs from Earth and has a mass of 0.888 solar masses and a radius of 0.87 solar radii. WASP-6 b was discovered in 2008 by the transit method. It orbits its parent star ever... | Aquarius (constellation) | Wikipedia | 343 | 799 | https://en.wikipedia.org/wiki/Aquarius%20%28constellation%29 | Physical sciences | Zodiac | Astronomy |
There are several more single-planet systems in Aquarius. HD 210277, a magnitude 6.63 yellow star located 21.29 parsecs from Earth, is host to one known planet: HD 210277 b. The 1.23 Jupiter mass planet orbits at nearly the same distance as Earth orbits the Sun1.1 AU, though its orbital period is significantly longer a... | Aquarius (constellation) | Wikipedia | 497 | 799 | https://en.wikipedia.org/wiki/Aquarius%20%28constellation%29 | Physical sciences | Zodiac | Astronomy |
On 23 February 2017, NASA announced that ultracool dwarf star TRAPPIST-1 in Aquarius has seven Earth-like rocky planets. Of these, as many as four may lie within the system's habitable zone, and may have liquid water on their surfaces. The discovery of the TRAPPIST-1 system is seen by astronomers as a significant step ... | Aquarius (constellation) | Wikipedia | 361 | 799 | https://en.wikipedia.org/wiki/Aquarius%20%28constellation%29 | Physical sciences | Zodiac | Astronomy |
Aquarius is also home to several planetary nebulae. NGC 7009, also known as the Saturn Nebula, is an 8th magnitude planetary nebula located 3,000 light-years from Earth. It was given its moniker by the 19th century astronomer Lord Rosse for its resemblance to the planet Saturn in a telescope; it has faint protrusions o... | Aquarius (constellation) | Wikipedia | 430 | 799 | https://en.wikipedia.org/wiki/Aquarius%20%28constellation%29 | Physical sciences | Zodiac | Astronomy |
The Delta Aquariids is a double radiant meteor shower that peaks first on 29 July and second on 6 August. The first radiant is located in the south of the constellation, while the second radiant is located in the northern circlet of Pisces asterism. The southern radiant's peak rate is about 20 meteors per hour, while t... | Aquarius (constellation) | Wikipedia | 212 | 799 | https://en.wikipedia.org/wiki/Aquarius%20%28constellation%29 | Physical sciences | Zodiac | Astronomy |
Anacondas or water boas are a group of large boas of the genus Eunectes. They are a semiaquatic group of snakes found in tropical South America. Three to five extant and one extinct species are currently recognized, including one of the largest snakes in the world, E. murinus, the green anaconda.
Description
Although ... | Anaconda | Wikipedia | 505 | 809 | https://en.wikipedia.org/wiki/Anaconda | Biology and health sciences | Snakes | Animals |
The name commonly used for the anaconda in Brazil is sucuri, sucuriju or sucuriuba.
Distribution and habitat
Found in tropical South America from Ecuador, Brazil, Colombia and Venezuela south to Argentina.
Feeding
All five species are aquatic snakes that prey on other aquatic animals, including fish, river fowl, and ... | Anaconda | Wikipedia | 450 | 809 | https://en.wikipedia.org/wiki/Anaconda | Biology and health sciences | Snakes | Animals |
Sexual dimorphism
Sexual size dimorphism in Eunectes is the opposite of most other vertebrates. Females are larger than males in most snakes, and green anacondas (E. murinus) have one of the most extreme size differences, where females average roughly and males average only around . This size difference has several be... | Anaconda | Wikipedia | 447 | 809 | https://en.wikipedia.org/wiki/Anaconda | Biology and health sciences | Snakes | Animals |
Cannibalism is quite easy in anacondas since females are so much larger than males, but sexual cannibalism has only been confirmed in E. murinus. Females gain the direct benefit of a post-copulatory high-protein meal when they consume their mates, along with the indirect benefit of additional resources to use for the f... | Anaconda | Wikipedia | 349 | 809 | https://en.wikipedia.org/wiki/Anaconda | Biology and health sciences | Snakes | Animals |
In mathematics, the axiom of choice, abbreviated AC or AoC, is an axiom of set theory equivalent to the statement that a Cartesian product of a collection of non-empty sets is non-empty. Informally put, the axiom of choice says that given any collection of sets, each containing at least one element, it is possible to c... | Axiom of choice | Wikipedia | 508 | 840 | https://en.wikipedia.org/wiki/Axiom%20of%20choice | Mathematics | Discrete mathematics | null |
Although originally controversial, the axiom of choice is now used without reservation by most mathematicians, and is included in the standard form of axiomatic set theory, Zermelo–Fraenkel set theory with the axiom of choice (ZFC). One motivation for this is that a number of generally accepted mathematical results, su... | Axiom of choice | Wikipedia | 474 | 840 | https://en.wikipedia.org/wiki/Axiom%20of%20choice | Mathematics | Discrete mathematics | null |
Variants
There are many other equivalent statements of the axiom of choice. These are equivalent in the sense that, in the presence of other basic axioms of set theory, they imply the axiom of choice and are implied by it.
One variation avoids the use of choice functions by, in effect, replacing each choice function w... | Axiom of choice | Wikipedia | 318 | 840 | https://en.wikipedia.org/wiki/Axiom%20of%20choice | Mathematics | Discrete mathematics | null |
Another equivalent axiom only considers collections X that are essentially powersets of other sets:
For any set A, the power set of A (with the empty set removed) has a choice function.
Authors who use this formulation often speak of the choice function on A, but this is a slightly different notion of choice function. ... | Axiom of choice | Wikipedia | 501 | 840 | https://en.wikipedia.org/wiki/Axiom%20of%20choice | Mathematics | Discrete mathematics | null |
Examples
The nature of the individual nonempty sets in the collection may make it possible to avoid the axiom of choice even for certain infinite collections. For example, suppose that each member of the collection X is a nonempty subset of the natural numbers. Every such subset has a smallest element, so to specify ou... | Axiom of choice | Wikipedia | 320 | 840 | https://en.wikipedia.org/wiki/Axiom%20of%20choice | Mathematics | Discrete mathematics | null |
Additionally, consider for instance the unit circle S, and the action on S by a group G consisting of all rational rotations, that is, rotations by angles which are rational multiples of π. Here G is countable while S is uncountable. Hence S breaks up into uncountably many orbits under G. Using the axiom of choice, we ... | Axiom of choice | Wikipedia | 474 | 840 | https://en.wikipedia.org/wiki/Axiom%20of%20choice | Mathematics | Discrete mathematics | null |
The axiom of choice asserts the existence of these intangibles (objects that are proved to exist, but which cannot be explicitly constructed), which may conflict with some philosophical principles. Because there is no canonical well-ordering of all sets, a construction that relies on a well-ordering may not produce a c... | Axiom of choice | Wikipedia | 510 | 840 | https://en.wikipedia.org/wiki/Axiom%20of%20choice | Mathematics | Discrete mathematics | null |
In constructive mathematics
As discussed above, in the classical theory of ZFC, the axiom of choice enables nonconstructive proofs in which the existence of a type of object is proved without an explicit instance being constructed. In fact, in set theory and topos theory, Diaconescu's theorem shows that the axiom of c... | Axiom of choice | Wikipedia | 429 | 840 | https://en.wikipedia.org/wiki/Axiom%20of%20choice | Mathematics | Discrete mathematics | null |
In 1938, Kurt Gödel showed that the negation of the axiom of choice is not a theorem of ZF by constructing an inner model (the constructible universe) that satisfies ZFC, thus showing that ZFC is consistent if ZF itself is consistent. In 1963, Paul Cohen employed the technique of forcing, developed for this purpose, to... | Axiom of choice | Wikipedia | 466 | 840 | https://en.wikipedia.org/wiki/Axiom%20of%20choice | Mathematics | Discrete mathematics | null |
The proof of the independence result also shows that a wide class of mathematical statements, including all statements that can be phrased in the language of Peano arithmetic, are provable in ZF if and only if they are provable in ZFC. Statements in this class include the statement that P = NP, the Riemann hypothesis, ... | Axiom of choice | Wikipedia | 429 | 840 | https://en.wikipedia.org/wiki/Axiom%20of%20choice | Mathematics | Discrete mathematics | null |
Set theory
Tarski's theorem about choice: For every infinite set A, there is a bijective map between the sets A and A×A.
Trichotomy: If two sets are given, then either they have the same cardinality, or one has a smaller cardinality than the other.
Given two non-empty sets, one has a surjection to the other.
Every sur... | Axiom of choice | Wikipedia | 505 | 840 | https://en.wikipedia.org/wiki/Axiom%20of%20choice | Mathematics | Discrete mathematics | null |
Every free abelian group is projective.
Baer's criterion: Every divisible abelian group is injective.
Every set is a projective object in the category Set of sets.
Functional analysis
The closed unit ball of the dual of a normed vector space over the reals has an extreme point.
Point-set topology
The Cartesian product ... | Axiom of choice | Wikipedia | 227 | 840 | https://en.wikipedia.org/wiki/Axiom%20of%20choice | Mathematics | Discrete mathematics | null |
Category theory
Several results in category theory invoke the axiom of choice for their proof. These results might be weaker than, equivalent to, or stronger than the axiom of choice, depending on the strength of the technical foundations. For example, if one defines categories in terms of sets, that is, as sets of obj... | Axiom of choice | Wikipedia | 481 | 840 | https://en.wikipedia.org/wiki/Axiom%20of%20choice | Mathematics | Discrete mathematics | null |
Results requiring AC (or weaker forms) but weaker than it
One of the most interesting aspects of the axiom of choice is the large number of places in mathematics where it shows up. Here are some statements that require the axiom of choice in the sense that they are not provable from ZF but are provable from ZFC (ZF plu... | Axiom of choice | Wikipedia | 96 | 840 | https://en.wikipedia.org/wiki/Axiom%20of%20choice | Mathematics | Discrete mathematics | null |
Set theory
The ultrafilter lemma (with ZF) can be used to prove the Axiom of choice for finite sets: Given and a collection of non-empty sets, their product is not empty.
The union of any countable family of countable sets is countable (this requires countable choice but not the full axiom of choice).
If the set A ... | Axiom of choice | Wikipedia | 473 | 840 | https://en.wikipedia.org/wiki/Axiom%20of%20choice | Mathematics | Discrete mathematics | null |
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