id
stringlengths
2
8
url
stringlengths
31
117
title
stringlengths
1
71
text
stringlengths
153
118k
topic
stringclasses
4 values
section
stringlengths
4
49
sublist
stringclasses
9 values
838151
https://en.wikipedia.org/wiki/Hilbert%27s%20axioms
Hilbert's axioms
Hilbert's axioms are a set of 20 assumptions proposed by David Hilbert in 1899 in his book Grundlagen der Geometrie (tr. The Foundations of Geometry) as the foundation for a modern treatment of Euclidean geometry. Other well-known modern axiomatizations of Euclidean geometry are those of Alfred Tarski and of George Bir...
Mathematics
Axiomatic systems
null
839672
https://en.wikipedia.org/wiki/Spotted%20skunk
Spotted skunk
The genus Spilogale includes all skunks commonly known as spotted skunks. Currently, there are four accepted extant species: S. gracilis, S. putorius, S. pygmaea, and S. angustifrons. New research, however, proposes that there may be up to seven. Extant species In the past, anywhere between two and fourteen species of...
Biology and health sciences
Other carnivora
Animals
839943
https://en.wikipedia.org/wiki/Bone%20fracture
Bone fracture
A bone fracture (abbreviated FRX or Fx, Fx, or #) is a medical condition in which there is a partial or complete break in the continuity of any bone in the body. In more severe cases, the bone may be broken into several fragments, known as a comminuted fracture. An open fracture (or compound fracture) is a bone fractur...
Biology and health sciences
Injury
null
840191
https://en.wikipedia.org/wiki/Sagittarius%20A%2A
Sagittarius A*
Sagittarius A*, abbreviated as Sgr A* ( ), is the supermassive black hole at the Galactic Center of the Milky Way. Viewed from Earth, it is located near the border of the constellations Sagittarius and Scorpius, about 5.6° south of the ecliptic, visually close to the Butterfly Cluster (M6) and Lambda Scorpii. The obje...
Physical sciences
Notable galaxies
null
841429
https://en.wikipedia.org/wiki/Synthetic%20biology
Synthetic biology
Synthetic biology (SynBio) is a multidisciplinary field of science that focuses on living systems and organisms, and it applies engineering principles to develop new biological parts, devices, and systems or to redesign existing systems found in nature. It is a branch of science that encompasses a broad range of metho...
Biology and health sciences
Biology basics
Biology
282377
https://en.wikipedia.org/wiki/Anvil
Anvil
An anvil is a metalworking tool consisting of a large block of metal (usually forged or cast steel), with a flattened top surface, upon which another object is struck (or "worked"). Anvils are massive because the higher their inertia, the more efficiently they cause the energy of striking tools to be transferred to t...
Technology
Metallurgy
null
282457
https://en.wikipedia.org/wiki/Drongo
Drongo
A drongo is a member of the family Dicruridae of passerine birds of the Old World tropics. The 28 species in the family are placed in a single genus, Dicrurus. Drongos are mostly black or dark grey, short-legged birds, with an upright stance when perched. They have forked tails and some have elaborate tail decorations...
Biology and health sciences
Passerida
Animals
282473
https://en.wikipedia.org/wiki/Manganese%20nodule
Manganese nodule
Polymetallic nodules, also called manganese nodules, are mineral concretions on the sea bottom formed of concentric layers of iron and manganese hydroxides around a core. As nodules can be found in vast quantities, and contain valuable metals, deposits have been identified as a potential economic interest. Depending on...
Physical sciences
Sedimentary rocks
Earth science
282956
https://en.wikipedia.org/wiki/Ironstone
Ironstone
Ironstone is a sedimentary rock, either deposited directly as a ferruginous sediment or created by chemical replacement, that contains a substantial proportion of an iron ore compound from which iron (Fe) can be smelted commercially. Not to be confused with native or telluric iron, which is very rare and found in meta...
Physical sciences
Sedimentary rocks
Earth science
282998
https://en.wikipedia.org/wiki/Prism%20%28optics%29
Prism (optics)
An optical prism is a transparent optical element with flat, polished surfaces that are designed to refract light. At least one surface must be angled — elements with two parallel surfaces are not prisms. The most familiar type of optical prism is the triangular prism, which has a triangular base and rectangular sides....
Technology
Optics
null
283007
https://en.wikipedia.org/wiki/Prism%20%28geometry%29
Prism (geometry)
In geometry, a prism is a polyhedron comprising an polygon base, a second base which is a translated copy (rigidly moved without rotation) of the first, and other faces, necessarily all parallelograms, joining corresponding sides of the two bases. All cross-sections parallel to the bases are translations of the bases...
Mathematics
Three-dimensional space
null
283610
https://en.wikipedia.org/wiki/Juicer
Juicer
A juicer, also known as a juice extractor, is a tool used to extract juice from fruits, herbs, leafy greens and other types of vegetables in a process called juicing. It crushes, grinds, and/or squeezes the juice out of the pulp. A juicer clarifies the juice through a screening mesh to remove the pulp unlike a blender ...
Technology
Household appliances
null
283810
https://en.wikipedia.org/wiki/Mass%20spectrometry
Mass spectrometry
Mass spectrometry (MS) is an analytical technique that is used to measure the mass-to-charge ratio of ions. The results are presented as a mass spectrum, a plot of intensity as a function of the mass-to-charge ratio. Mass spectrometry is used in many different fields and is applied to pure samples as well as complex m...
Physical sciences
Analytical chemistry
null
283974
https://en.wikipedia.org/wiki/Coot
Coot
Coots are medium-sized water birds that are members of the rail family, Rallidae. They constitute the genus Fulica, the name being the Latin term for "coot". Coots have predominantly black plumage, and—unlike many rails—they are usually easy to see, often swimming in open water. Taxonomy and systematics The genus Fuli...
Biology and health sciences
Gruiformes
Animals
284027
https://en.wikipedia.org/wiki/Kidney%20failure
Kidney failure
Kidney failure, also known as renal failure or end-stage renal disease (ESRD), is a medical condition in which the kidneys can no longer adequately filter waste products from the blood, functioning at less than 15% of normal levels. Kidney failure is classified as either acute kidney failure, which develops rapidly and...
Biology and health sciences
Specific diseases
Health
284029
https://en.wikipedia.org/wiki/Immunization
Immunization
Immunization, or immunisation, is the process by which an individual's immune system becomes fortified against an infectious agent (known as the immunogen). When this system is exposed to molecules that are foreign to the body, called non-self, it will orchestrate an immune response, and it will also develop the abilit...
Biology and health sciences
Concepts
Health
284266
https://en.wikipedia.org/wiki/Bowerbird
Bowerbird
Bowerbirds () make up the bird family Ptilonorhynchidae. They are renowned for their unique courtship behaviour, where males build a structure and decorate it with sticks and brightly coloured objects in an attempt to attract a mate. The family has 27 species in eight genera. These are medium to large-sized passerines...
Biology and health sciences
Corvoidea
Animals
284788
https://en.wikipedia.org/wiki/Cornus
Cornus
Cornus is a genus of about 30–60 species of woody plants in the family Cornaceae, commonly known as dogwoods or cornels, which can generally be distinguished by their blossoms, berries, and distinctive bark. Most are deciduous trees or shrubs, but a few species are nearly herbaceous perennial subshrubs, and some specie...
Biology and health sciences
Others
null
284851
https://en.wikipedia.org/wiki/Draco%20%28constellation%29
Draco (constellation)
Draco is a constellation in the far northern sky. Its name is Latin for dragon. It was one of the 48 constellations listed by the 2nd century Greek astronomer Ptolemy, and remains one of the 88 modern constellations today. The north pole of the ecliptic is in Draco. Draco is circumpolar from northern latitudes, meaning...
Physical sciences
Other
Astronomy
284899
https://en.wikipedia.org/wiki/Whale%20shark
Whale shark
The whale shark (Rhincodon typus) is a slow-moving, filter-feeding carpet shark and the largest known extant fish species. The largest confirmed individual had a length of . The whale shark holds many records for size in the animal kingdom, most notably being by far the most massive living non-cetacean animal. It is th...
Biology and health sciences
Sharks
null
285152
https://en.wikipedia.org/wiki/Pineal%20gland
Pineal gland
The pineal gland (also known as the pineal body or epiphysis cerebri) is a small endocrine gland in the brain of most vertebrates. It produces melatonin, a serotonin-derived hormone, which modulates sleep patterns following the diurnal cycles. The shape of the gland resembles a pine cone, which gives it its name. The p...
Biology and health sciences
Endocrine system
Biology
285157
https://en.wikipedia.org/wiki/Melatonin
Melatonin
Melatonin, an indoleamine, is a natural compound produced by various organisms, including bacteria and eukaryotes. Its discovery in 1958 by Aaron B. Lerner and colleagues stemmed from the isolation of a substance from the pineal gland of cows that could induce skin lightening in common frogs. This compound was later id...
Biology and health sciences
Animal hormones
Biology
285235
https://en.wikipedia.org/wiki/Dacite
Dacite
Dacite () is a volcanic rock formed by rapid solidification of lava that is high in silica and low in alkali metal oxides. It has a fine-grained (aphanitic) to porphyritic texture and is intermediate in composition between andesite and rhyolite. It is composed predominantly of plagioclase feldspar and quartz. Dacite i...
Physical sciences
Igneous rocks
Earth science
285239
https://en.wikipedia.org/wiki/Andesite
Andesite
Andesite () is a volcanic rock of intermediate composition. In a general sense, it is the intermediate type between silica-poor basalt and silica-rich rhyolite. It is fine-grained (aphanitic) to porphyritic in texture, and is composed predominantly of sodium-rich plagioclase plus pyroxene or hornblende. Andesite is th...
Physical sciences
Igneous rocks
Earth science
285247
https://en.wikipedia.org/wiki/Migmatite
Migmatite
Migmatite is a composite rock found in medium and high-grade metamorphic environments, commonly within Precambrian cratonic blocks. It consists of two or more constituents often layered repetitively: one layer is an older metamorphic rock that was reconstituted subsequently by partial melting ("paleosome"), while the a...
Physical sciences
Metamorphic rocks
Earth science
285510
https://en.wikipedia.org/wiki/New%20York%20City%20Subway
New York City Subway
The New York City Subway is a rapid transit system in New York City serving the boroughs of Manhattan, Brooklyn, Queens, and the Bronx. It is owned by the government of New York City and leased to the New York City Transit Authority, an affiliate agency of the state-run Metropolitan Transportation Authority (MTA). Open...
Technology
Trains
null
285522
https://en.wikipedia.org/wiki/Superheating
Superheating
In thermodynamics, superheating (sometimes referred to as boiling retardation, or boiling delay) is the phenomenon in which a liquid is heated to a temperature higher than its boiling point, without boiling. This is a so-called metastable state or metastate, where boiling might occur at any time, induced by external or...
Physical sciences
Phase transitions
Physics
285759
https://en.wikipedia.org/wiki/Limit%20of%20a%20function
Limit of a function
Although the function is not defined at zero, as becomes closer and closer to zero, becomes arbitrarily close to 1. In other words, the limit of as approaches zero, equals 1. In mathematics, the limit of a function is a fundamental concept in calculus and analysis concerning the behavior of that function near a p...
Mathematics
Calculus and analysis
null
285773
https://en.wikipedia.org/wiki/Limit%20of%20a%20sequence
Limit of a sequence
As the positive integer becomes larger and larger, the value becomes arbitrarily close to . We say that "the limit of the sequence equals ." In mathematics, the limit of a sequence is the value that the terms of a sequence "tend to", and is often denoted using the symbol (e.g., ). If such a limit exists and is fin...
Mathematics
Calculus and analysis
null
285802
https://en.wikipedia.org/wiki/Marabou%20stork
Marabou stork
The marabou stork (Leptoptilos crumenifer) is a large wading bird in the stork family Ciconiidae native to sub-Saharan Africa. It breeds in both wet and arid habitats, often near human habitation, especially landfill sites. It is sometimes called the "undertaker bird" due to its shape from behind: cloak-like wings and...
Biology and health sciences
Pelecanimorphae
Animals
286069
https://en.wikipedia.org/wiki/Mixture
Mixture
In chemistry, a mixture is a material made up of two or more different chemical substances which can be separated by physical method. It is an impure substance made up of 2 or more elements or compounds mechanically mixed together in any proportion. A mixture is the physical combination of two or more substances in whi...
Physical sciences
Chemical mixtures: General
null
286217
https://en.wikipedia.org/wiki/Flash%20evaporation
Flash evaporation
Flash evaporation (or partial evaporation) is the partial vapor that occurs when a saturated liquid stream undergoes a reduction in pressure by passing through a throttling valve or other throttling device. This process is one of the simplest unit operations. If the throttling valve or device is located at the entry in...
Physical sciences
Phase separations
Chemistry
286245
https://en.wikipedia.org/wiki/Sodium%20silicate
Sodium silicate
Sodium silicate is a generic name for chemical compounds with the formula or ·, such as sodium metasilicate (), sodium orthosilicate (), and sodium pyrosilicate (). The anions are often polymeric. These compounds are generally colorless transparent solids or white powders, and soluble in water in various amounts. Sod...
Physical sciences
Salts
null
286260
https://en.wikipedia.org/wiki/Precipitation
Precipitation
In meteorology, precipitation is any product of the condensation of atmospheric water vapor that falls from clouds due to gravitational pull. The main forms of precipitation include drizzle, rain, sleet, snow, ice pellets, graupel and hail. Precipitation occurs when a portion of the atmosphere becomes saturated with w...
Physical sciences
Precipitation
null
286262
https://en.wikipedia.org/wiki/Precipitation%20%28chemistry%29
Precipitation (chemistry)
In an aqueous solution, precipitation is the "sedimentation of a solid material (a precipitate) from a liquid solution". The solid formed is called the precipitate. In case of an inorganic chemical reaction leading to precipitation, the chemical reagent causing the solid to form is called the precipitant. The clear li...
Physical sciences
Other reactions
Chemistry
286454
https://en.wikipedia.org/wiki/Settling
Settling
Settling is the process by which particulates move towards the bottom of a liquid and form a sediment. Particles that experience a force, either due to gravity or due to centrifugal motion will tend to move in a uniform manner in the direction exerted by that force. For gravity settling, this means that the particles w...
Physical sciences
Other separations
Chemistry
286560
https://en.wikipedia.org/wiki/Bastion
Bastion
A bastion is a structure projecting outward from the curtain wall of a fortification, most commonly angular in shape and positioned at the corners of the fort. The fully developed bastion consists of two faces and two flanks, with fire from the flanks being able to protect the curtain wall and the adjacent bastions. Co...
Technology
Fortification
null
286621
https://en.wikipedia.org/wiki/Web%20colors
Web colors
Web colors are colors used in displaying web pages on the World Wide Web; they can be described by way of three methods: a color may be specified as an RGB triplet, in hexadecimal format (a hex triplet) or according to its common English name in some cases. A color tool or other graphics software is often used to ge...
Physical sciences
Basics
Physics
18716923
https://en.wikipedia.org/wiki/Algebra
Algebra
Algebra is the branch of mathematics that studies certain abstract systems, known as algebraic structures, and the manipulation of expressions within those systems. It is a generalization of arithmetic that introduces variables and algebraic operations other than the standard arithmetic operations, such as addition and...
Mathematics
Algebra
null
18717261
https://en.wikipedia.org/wiki/Trigonometry
Trigonometry
Trigonometry () is a branch of mathematics concerned with relationships between angles and side lengths of triangles. In particular, the trigonometric functions relate the angles of a right triangle with ratios of its side lengths. The field emerged in the Hellenistic world during the 3rd century BC from applications o...
Mathematics
Geometry and topology
null
13010605
https://en.wikipedia.org/wiki/Load%20management
Load management
Load management, also known as demand-side management (DSM), is the process of balancing the supply of electricity on the network with the electrical load by adjusting or controlling the load rather than the power station output. This can be achieved by direct intervention of the utility in real time, by the use of fre...
Technology
Electricity transmission and distribution
null
19857818
https://en.wikipedia.org/wiki/Mandibular%20fracture
Mandibular fracture
Mandibular fracture, also known as fracture of the jaw, is a break through the mandibular bone. In about 60% of cases the break occurs in two places. It may result in a decreased ability to fully open the mouth. Often the teeth will not feel properly aligned or there may be bleeding of the gums. Mandibular fractures oc...
Biology and health sciences
Types
Health
23982752
https://en.wikipedia.org/wiki/Light-dependent%20reactions
Light-dependent reactions
Light-dependent reactions are certain photochemical reactions involved in photosynthesis, the main process by which plants acquire energy. There are two light dependent reactions: the first occurs at photosystem II (PSII) and the second occurs at photosystem I (PSI). PSII absorbs a photon to produce a so-called high e...
Biology and health sciences
Metabolic processes
Biology
20975731
https://en.wikipedia.org/wiki/Lamprey
Lamprey
Lampreys (sometimes inaccurately called lamprey eels) are a group of jawless fish comprising the order Petromyzontiformes . The adult lamprey is characterized by a toothed, funnel-like sucking mouth. The common name "lamprey" is probably derived from Latin , which may mean "stone licker" ( "to lick" + "stone"), thoug...
Biology and health sciences
Agnatha
null
20975773
https://en.wikipedia.org/wiki/Colossal%20squid
Colossal squid
The colossal squid (Mesonychoteuthis hamiltoni) is the world’s largest squid species and the world’s largest mollusc. It belongs to the Cranchiidae family, that of the cockatoo squids or glass squids. It is sometimes called the Antarctic cranch squid or giant squid (not to be confused with the giant squid in genus Arch...
Biology and health sciences
Cephalopods
Animals
20976473
https://en.wikipedia.org/wiki/Eel
Eel
Eels are ray-finned fish belonging to the order Anguilliformes (), which consists of eight suborders, 20 families, 164 genera, and about 1000 species. Eels undergo considerable development from the early larval stage to the eventual adult stage and are usually predators. The term "eel" is also used for some other eel-...
Biology and health sciences
Fishes
null
20976520
https://en.wikipedia.org/wiki/Cuttlefish
Cuttlefish
Cuttlefish, or cuttles, are marine molluscs of the suborder Sepiina. They belong to the class Cephalopoda which also includes squid, octopuses, and nautiluses. Cuttlefish have a unique internal shell, the cuttlebone, which is used for control of buoyancy. Cuttlefish have large, W-shaped pupils, eight arms, and two ten...
Biology and health sciences
Cephalopods
Animals
1914541
https://en.wikipedia.org/wiki/Northern%20giraffe
Northern giraffe
The northern giraffe (Giraffa camelopardalis), also known as three-horned giraffe, is the type species of giraffe, G. camelopardalis, and is native to North Africa, although alternative taxonomic hypotheses have proposed the northern giraffe as a separate species. Once abundant throughout Africa since the 19th century...
Biology and health sciences
Giraffidae
Animals
1914985
https://en.wikipedia.org/wiki/Lingulata
Lingulata
Lingulata is a class of brachiopods, among the oldest of all brachiopods having existed since the Cambrian period (). They are also among the most morphologically conservative of the brachiopods, having lasted from their earliest appearance to the present with very little change in shape. Shells of living specimens fou...
Biology and health sciences
Lophotrochozoa
Animals
1915903
https://en.wikipedia.org/wiki/Tegenaria%20domestica
Tegenaria domestica
The spider species Tegenaria domestica, commonly known as the barn funnel weaver in North America and the domestic house spider in Europe, is a member of the funnel-web family Agelenidae. Distribution and habitat Domestic house spiders range nearly worldwide. Their global distribution encompasses Europe, North Africa...
Biology and health sciences
Spiders
Animals
1917015
https://en.wikipedia.org/wiki/Taxodium%20distichum
Taxodium distichum
Taxodium distichum (baldcypress, bald-cypress, bald cypress, swamp cypress; ; cipre in Louisiana) is a deciduous conifer in the family Cupressaceae. It is native to the southeastern United States. Hardy and tough, this tree adapts to a wide range of soil types, whether wet, salty, dry, or swampy. It is noted for the ru...
Biology and health sciences
Cupressaceae
Plants
1917508
https://en.wikipedia.org/wiki/PC-98
PC-98
The , commonly shortened to PC-98 or simply , is a lineup of Japanese 16-bit and 32-bit personal computers manufactured by NEC from 1982 to 2003. While based on Intel processors, it uses an in-house architecture making it incompatible with IBM clones; some PC-98 computers used NEC's own V30 processor. The platform esta...
Technology
Specific hardware
null
1918188
https://en.wikipedia.org/wiki/Galley
Galley
A galley is a type of ship optimised for propulsion by oars. Galleys were historically used for warfare, trade, and piracy mostly in the seas surrounding Europe. It developed in the Mediterranean world during antiquity and continued to exist in various forms until the early 19th century. It typically had a long, slende...
Technology
Naval warfare
null
134572
https://en.wikipedia.org/wiki/Mountain%20bike
Mountain bike
A mountain bike (MTB) or mountain bicycle is a bicycle designed for off-road cycling. Mountain bikes share some similarities with other bicycles, but incorporate features designed to enhance durability and performance in rough terrain, which often makes them heavier, more complex and less efficient on smooth surfaces. ...
Technology
Human-powered transport
null
134880
https://en.wikipedia.org/wiki/Eardrum
Eardrum
In the anatomy of humans and various other tetrapods, the eardrum, also called the tympanic membrane or myringa, is a thin, cone-shaped membrane that separates the external ear from the middle ear. Its function is to transmit changes in pressure of sound from the air to the ossicles inside the middle ear, and thence to...
Biology and health sciences
Sensory nervous system
Biology
134971
https://en.wikipedia.org/wiki/Cochlea
Cochlea
The cochlea is the part of the inner ear involved in hearing. It is a spiral-shaped cavity in the bony labyrinth, in humans making 2.75 turns around its axis, the modiolus. A core component of the cochlea is the organ of Corti, the sensory organ of hearing, which is distributed along the partition separating the fluid ...
Biology and health sciences
Sensory nervous system
Biology
135316
https://en.wikipedia.org/wiki/Sexagesimal
Sexagesimal
Sexagesimal, also known as base 60, is a numeral system with sixty as its base. It originated with the ancient Sumerians in the 3rd millennium BC, was passed down to the ancient Babylonians, and is still used—in a modified form—for measuring time, angles, and geographic coordinates. The number 60, a superior highly co...
Mathematics
Basics
null
3613142
https://en.wikipedia.org/wiki/Agricultural%20philosophy
Agricultural philosophy
Agricultural philosophy (or philosophy of agriculture) is, roughly and approximately, a discipline devoted to the systematic critique of the philosophical frameworks (or ethical world views) that are the foundation for decisions regarding agriculture. Many of these views are also used to guide decisions dealing with la...
Technology
Academic disciplines
null
3616597
https://en.wikipedia.org/wiki/Digital%20photography
Digital photography
Digital photography uses cameras containing arrays of electronic photodetectors interfaced to an analog-to-digital converter (ADC) to produce images focused by a lens, as opposed to an exposure on photographic film. The digitized image is stored as a computer file ready for further digital processing, viewing, electron...
Technology
Optical instruments
null
3616613
https://en.wikipedia.org/wiki/Work%20%28thermodynamics%29
Work (thermodynamics)
Thermodynamic work is one of the principal kinds of process by which a thermodynamic system can interact with and transfer energy to its surroundings. This results in externally measurable macroscopic forces on the system's surroundings, which can cause mechanical work, to lift a weight, for example, or cause changes i...
Physical sciences
Statistical mechanics
Physics
3618030
https://en.wikipedia.org/wiki/Astrophysical%20maser
Astrophysical maser
An astrophysical maser is a naturally occurring source of stimulated spectral line emission, typically in the microwave portion of the electromagnetic spectrum. This emission may arise in molecular clouds, comets, planetary atmospheres, stellar atmospheres, or various other conditions in interstellar space. Backgroun...
Physical sciences
Radio astronomy
Astronomy
3618245
https://en.wikipedia.org/wiki/Safety%20glass
Safety glass
Safety glass is glass with additional safety features that make it less likely to break, or less likely to pose a threat when broken. Common designs include toughened glass (also known as tempered glass), laminated glass, and wire mesh glass (also known as wired glass). Toughened glass was invented in 1874 by Francois ...
Technology
Materials
null
8371972
https://en.wikipedia.org/wiki/Tetrigidae
Tetrigidae
Tetrigidae is an ancient family in the order Orthoptera, which also includes similar families such as crickets, grasshoppers, and their allies. Species within the Tetrigidae are variously called groundhoppers, pygmy grasshoppers, pygmy devils or (mostly historical) "grouse locusts". Diagnostic characteristics Tetrigi...
Biology and health sciences
Orthoptera
Animals
8372004
https://en.wikipedia.org/wiki/Periodic%20trends
Periodic trends
In chemistry, periodic trends are specific patterns present in the periodic table that illustrate different aspects of certain elements when grouped by period and/or group. They were discovered by the Russian chemist Dmitri Mendeleev in 1863. Major periodic trends include atomic radius, ionization energy, electron affi...
Physical sciences
Periodic table
Chemistry
8372175
https://en.wikipedia.org/wiki/Krypton%20difluoride
Krypton difluoride
Krypton difluoride, KrF2 is a chemical compound of krypton and fluorine. It was the first compound of krypton discovered. It is a volatile, colourless solid at room temperature. The structure of the KrF2 molecule is linear, with Kr−F distances of 188.9 pm. It reacts with strong Lewis acids to form salts of the KrF+ and...
Physical sciences
Noble gas compounds
Chemistry
6390647
https://en.wikipedia.org/wiki/Wide-field%20Infrared%20Survey%20Explorer
Wide-field Infrared Survey Explorer
Wide-field Infrared Survey Explorer (WISE, observatory code C51, Explorer 92 and MIDEX-6) was a NASA infrared astronomy space telescope in the Explorers Program launched in December 2009. WISE discovered thousands of minor planets and numerous star clusters. Its observations also supported the discovery of the first Y-...
Technology
Space-based observatories
null
6395779
https://en.wikipedia.org/wiki/Dwarf%20planet
Dwarf planet
A dwarf planet is a small planetary-mass object that is in direct orbit around the Sun, massive enough to be gravitationally rounded, but insufficient to achieve orbital dominance like the eight classical planets of the Solar System. The prototypical dwarf planet is Pluto, which for decades was regarded as a planet bef...
Physical sciences
Planetary science
null
1291713
https://en.wikipedia.org/wiki/African%20civet
African civet
The African civet (Civettictis civetta) is a large viverrid native to sub-Saharan Africa, where it is considered common and widely distributed in woodlands and secondary forests. It is listed as Least Concern on the IUCN Red List since 2008. In some countries, it is threatened by hunting, and wild-caught individuals a...
Biology and health sciences
Other carnivora
Animals
1291730
https://en.wikipedia.org/wiki/Backfeeding
Backfeeding
Backfeeding is the flow of electric power in the direction reverse to that of the generally understood or typical flow of power. Depending on the source of the power, this reverse flow may be intentional or unintentional. If not prevented (in the case of unintentional backfeeding) or properly performed (in cases of int...
Technology
Concepts
null
1293340
https://en.wikipedia.org/wiki/Classical%20field%20theory
Classical field theory
A classical field theory is a physical theory that predicts how one or more fields in physics interact with matter through field equations, without considering effects of quantization; theories that incorporate quantum mechanics are called quantum field theories. In most contexts, 'classical field theory' is specifical...
Physical sciences
Physics basics: General
Physics
1294453
https://en.wikipedia.org/wiki/Insular%20biogeography
Insular biogeography
Insular biogeography or island biogeography is a field within biogeography that examines the factors that affect the species richness and diversification of isolated natural communities. The theory was originally developed to explain the pattern of the species–area relationship occurring in oceanic islands. Under eithe...
Biology and health sciences
Ecology
Biology
1294851
https://en.wikipedia.org/wiki/Millimetre%20of%20mercury
Millimetre of mercury
A millimetre of mercury is a manometric unit of pressure, formerly defined as the extra pressure generated by a column of mercury one millimetre high, and currently defined as exactly pascals or approximately pascals. It is denoted mmHg or mm Hg. Although not an SI unit, the millimetre of mercury is still often en...
Physical sciences
Pressure
Basics and measurement
1295947
https://en.wikipedia.org/wiki/Dysthymia
Dysthymia
Dysthymia ( ), also known as persistent depressive disorder (PDD), is a mental and behavioral disorder, specifically a disorder primarily of mood, consisting of similar cognitive and physical problems as major depressive disorder, but with longer-lasting symptoms. The concept was used by Robert Spitzer as a replacement...
Biology and health sciences
Mental disorders
Health
1295963
https://en.wikipedia.org/wiki/Empennage
Empennage
The empennage ( or ), also known as the tail or tail assembly, is a structure at the rear of an aircraft that provides stability during flight, in a way similar to the feathers on an arrow. The term derives from the French language verb which means "to feather an arrow". Most aircraft feature an empennage incorporatin...
Technology
Aircraft components
null
1297380
https://en.wikipedia.org/wiki/Police%20car
Police car
A police car is an emergency vehicle used by police for transportation during patrols and responses to calls for service. A type of emergency vehicle, police cars are used by police officers to patrol a beat, quickly reach incident scenes, and transport and temporarily detain suspects. Police vehicles, like other emer...
Technology
Specific-purpose transportation
null
1297539
https://en.wikipedia.org/wiki/Free%20particle
Free particle
In physics, a free particle is a particle that, in some sense, is not bound by an external force, or equivalently not in a region where its potential energy varies. In classical physics, this means the particle is present in a "field-free" space. In quantum mechanics, it means the particle is in a region of uniform pot...
Physical sciences
Basics_4
Physics
1297796
https://en.wikipedia.org/wiki/Oxygen%20mask
Oxygen mask
An oxygen mask is a mask that provides a method to transfer breathing oxygen gas from a storage tank to the lungs. Oxygen masks may cover only the nose and mouth (oral nasal mask) or the entire face (full-face mask). They may be made of plastic, silicone, or rubber. In certain circumstances, oxygen may be delivered via...
Technology
Food, water and health
null
13020935
https://en.wikipedia.org/wiki/Gold%20dredge
Gold dredge
A gold dredge is a placer mining machine that extracts gold from sand, gravel, and dirt using water and mechanical methods. The original gold dredges were large, multi-story machines built in the first half of the 1900s. Small suction machines are currently marketed as "gold dredges" to individuals seeking gold: just...
Technology
Metallurgy
null
13021878
https://en.wikipedia.org/wiki/Geothermal%20power
Geothermal power
Geothermal power is electrical power generated from geothermal energy. Technologies in use include dry steam power stations, flash steam power stations and binary cycle power stations. Geothermal electricity generation is currently used in 26 countries, while geothermal heating is in use in 70 countries. As of 2019, w...
Technology
Energy and fuel
null
27208069
https://en.wikipedia.org/wiki/Contact%20fuze
Contact fuze
A contact fuze, impact fuze, percussion fuze or direct-action (D.A.) fuze (UK) is the fuze that is placed in the nose of a bomb or shell so that it will detonate on contact with a hard surface. Many impacts are unpredictable: they may involve a soft surface, or an off-axis grazing impact. The pure contact fuze is ofte...
Technology
Explosive weapons
null
26846483
https://en.wikipedia.org/wiki/Nucleic%20acid%20structure
Nucleic acid structure
Nucleic acid structure refers to the structure of nucleic acids such as DNA and RNA. Chemically speaking, DNA and RNA are very similar. Nucleic acid structure is often divided into four different levels: primary, secondary, tertiary, and quaternary. Primary structure Primary structure consists of a linear sequence of...
Biology and health sciences
Nucleic acids
Biology
841860
https://en.wikipedia.org/wiki/Oligomer
Oligomer
In chemistry and biochemistry, an oligomer () is a molecule that consists of a few repeating units which could be derived, actually or conceptually, from smaller molecules, monomers. The name is composed of Greek elements oligo-, "a few" and -mer, "parts". An adjective form is oligomeric. The oligomer concept is c...
Physical sciences
Polymers
Chemistry
842360
https://en.wikipedia.org/wiki/Paleomagnetism
Paleomagnetism
Paleomagnetism (occasionally palaeomagnetism) is the study of prehistoric Earth's magnetic fields recorded in rocks, sediment, or archeological materials. Geophysicists who specialize in paleomagnetism are called paleomagnetists. Certain magnetic minerals in rocks can record the direction and intensity of Earth's magn...
Physical sciences
Geochronology
Earth science
843566
https://en.wikipedia.org/wiki/Military%20base
Military base
A military base is a facility directly owned and operated by or for the military or one of its branches that shelters military equipment and personnel, and facilitates training and operations. A military base always provides accommodations for one or more units, but it may also be used as a command center, training gro...
Technology
Mixed-use buildings
null
844186
https://en.wikipedia.org/wiki/Modern%20physics
Modern physics
Modern physics is a branch of physics that developed in the early 20th century and onward or branches greatly influenced by early 20th century physics. Notable branches of modern physics include quantum mechanics, special relativity, and general relativity. Classical physics is typically concerned with everyday condit...
Physical sciences
Physics basics: General
Physics
844783
https://en.wikipedia.org/wiki/Forgetful%20functor
Forgetful functor
In mathematics, in the area of category theory, a forgetful functor (also known as a stripping functor) 'forgets' or drops some or all of the input's structure or properties 'before' mapping to the output. For an algebraic structure of a given signature, this may be expressed by curtailing the signature: the new signat...
Mathematics
Category theory
null
844811
https://en.wikipedia.org/wiki/Ceiling
Ceiling
A ceiling is an overhead interior roof that covers the upper limits of a room. It is not generally considered a structural element, but a finished surface concealing the underside of the roof structure or the floor of a story above. Ceilings can be decorated to taste, and there are many examples of frescoes and artwor...
Technology
Architectural elements
null
845042
https://en.wikipedia.org/wiki/Grass%20carp
Grass carp
The grass carp (Ctenopharyngodon idella) is a species of large herbivorous freshwater fish in the family Cyprinidae, native to the Pacific Far East, with a native range stretching from northern Vietnam to the Amur River on the Sino-Russian border. This Asian carp is the only species of the genus Ctenopharyngodon. Gras...
Biology and health sciences
Cypriniformes
Animals
845253
https://en.wikipedia.org/wiki/Gonostomatidae
Gonostomatidae
The Gonostomatidae are a family of mesopelagic marine fish, commonly named bristlemouths, lightfishes, or anglemouths. It is a relatively small family, containing only eight known genera and 32 species. However, bristlemouths make up for their lack of diversity with relative abundance, numbering in the hundreds of tril...
Biology and health sciences
Stomiiformes
Animals
18733230
https://en.wikipedia.org/wiki/Leading-edge%20slat
Leading-edge slat
A slat is an aerodynamic surface on the leading edge of the wing of a fixed-wing aircraft. When retracted, the slat lies flush with the rest of the wing. A slat is deployed by sliding forward, opening a slot between the wing and the slat. Air from below the slat flows through the slot and replaces the boundary layer th...
Technology
Aircraft components
null
6410946
https://en.wikipedia.org/wiki/Atmosphere%20of%20Venus
Atmosphere of Venus
The atmosphere of Venus is the very dense layer of gases surrounding the planet Venus. Venus's atmosphere is composed of 96.5% carbon dioxide and 3.5% nitrogen, with other chemical compounds present only in trace amounts. It is much denser and hotter than that of Earth; the temperature at the surface is 740 K (467 °C, ...
Physical sciences
Solar System
Astronomy
19879434
https://en.wikipedia.org/wiki/Fang
Fang
A fang is a long, pointed tooth. In mammals, a fang is a modified maxillary tooth, used for biting and tearing flesh. In snakes, it is a specialized tooth that is associated with a venom gland (see snake venom). Spiders also have external fangs, which are part of the chelicerae. Fangs are most common in carnivores or ...
Biology and health sciences
Gastrointestinal tract
Biology
19881804
https://en.wikipedia.org/wiki/Fuze
Fuze
In military munitions, a fuze (sometimes fuse) is the part of the device that initiates its function. In some applications, such as torpedoes, a fuze may be identified by function as the exploder. The relative complexity of even the earliest fuze designs can be seen in cutaway diagrams. A fuze is a device that detonat...
Technology
Explosive weapons
null
1919367
https://en.wikipedia.org/wiki/QCD%20matter
QCD matter
Quark matter or QCD matter (quantum chromodynamic) refers to any of a number of hypothetical phases of matter whose degrees of freedom include quarks and gluons, of which the prominent example is quark-gluon plasma. Several series of conferences in 2019, 2020, and 2021 were devoted to this topic. Quarks are liberated ...
Physical sciences
Particle physics: General
Physics
1921259
https://en.wikipedia.org/wiki/Windcatcher
Windcatcher
A windcatcher, wind tower, or wind scoop () is a traditional architectural element used to create cross ventilation and passive cooling in buildings. Windcatchers come in various designs, depending on whether local prevailing winds are unidirectional, bidirectional, or multidirectional, on how they change with altitude...
Technology
Heating and cooling
null
1922158
https://en.wikipedia.org/wiki/Salix%20babylonica
Salix babylonica
Salix babylonica (Babylon willow or weeping willow; ) is a species of willow native to dry areas of northern China, Korea, Mongolia, Japan, and Siberia but cultivated for millennia elsewhere in Asia, being traded along the Silk Road to southwest Asia and Europe. Description Salix babylonica is a medium- to large-sized...
Biology and health sciences
Malpighiales
Plants
1922671
https://en.wikipedia.org/wiki/Cumulus%20mediocris%20cloud
Cumulus mediocris cloud
Cumulus mediocris is a low to middle level cloud with some vertical extent (Family D1) of the genus cumulus, larger in vertical development than Cumulus humilis. It also may exhibit small protuberances from the top and may show the cauliflower form characteristic of cumulus clouds. Cumulus mediocris clouds do not gener...
Physical sciences
Clouds
Earth science
1923966
https://en.wikipedia.org/wiki/Carbonate%20rock
Carbonate rock
Carbonate rocks are a class of sedimentary rocks composed primarily of carbonate minerals. The two major types are limestone, which is composed of calcite or aragonite (different crystal forms of CaCO3), and dolomite rock (also known as dolostone), which is composed of dolomite (CaMg(CO3)2). They are usually classified...
Physical sciences
Sedimentary rocks
Earth science
1924025
https://en.wikipedia.org/wiki/Tench
Tench
The tench or doctor fish (Tinca tinca) is a fresh- and brackish-water fish of the order Cypriniformes found throughout Eurasia from Western Europe including Britain and Ireland east into Asia as far as the Ob and Yenisei Rivers. It is also found in Lake Baikal. It normally inhabits slow-moving freshwater habitats, part...
Biology and health sciences
Cypriniformes
Animals
494553
https://en.wikipedia.org/wiki/Fagus%20grandifolia
Fagus grandifolia
Fagus grandifolia, the American beech or North American beech, is the only species of beech native to North America. Its current range comprises the eastern United States, isolated pockets of Mexico and southeastern Canada. Prior to the glacial maximum of the Pleistocene epoch, the tree flourished over most of North Am...
Biology and health sciences
Fagales
Plants