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47532
https://en.wikipedia.org/wiki/Cumulus%20cloud
Cumulus cloud
Cumulus clouds are clouds that have flat bases and are often described as puffy, cotton-like, or fluffy in appearance. Their name derives from the Latin , meaning "heap" or "pile". Cumulus clouds are low-level clouds, generally less than in altitude unless they are the more vertical cumulus congestus form. Cumulus clo...
Physical sciences
Clouds
null
47535
https://en.wikipedia.org/wiki/Haptophyte
Haptophyte
The haptophytes, classified either as the Haptophyta, Haptophytina or Prymnesiophyta (named for Prymnesium), are a clade of algae. The names Haptophyceae or Prymnesiophyceae are sometimes used instead. This ending implies classification at the class rank rather than as a division. Although the phylogenetics of this gr...
Biology and health sciences
Other organisms
null
47544
https://en.wikipedia.org/wiki/Carrying%20capacity
Carrying capacity
The carrying capacity of an environment is the maximum population size of a biological species that can be sustained by that specific environment, given the food, habitat, water, and other resources available. The carrying capacity is defined as the environment's maximal load, which in population ecology corresponds to...
Biology and health sciences
Ecology
Biology
47548
https://en.wikipedia.org/wiki/Daylight%20saving%20time
Daylight saving time
Daylight saving time (DST), also referred to as daylight saving(s), daylight savings time, daylight time (United States and Canada), or summer time (United Kingdom, European Union, and others), is the practice of advancing clocks to make better use of the longer daylight available during summer so that darkness falls a...
Technology
Timekeeping
null
47568
https://en.wikipedia.org/wiki/Low%20Earth%20orbit
Low Earth orbit
A low Earth orbit (LEO) is an orbit around Earth with a period of 128 minutes or less (making at least 11.25 orbits per day) and an eccentricity less than 0.25. Most of the artificial objects in outer space are in LEO, peaking in number at an altitude around , while the farthest in LEO, before medium Earth orbit (MEO),...
Physical sciences
Orbital mechanics
null
47569
https://en.wikipedia.org/wiki/Appian%20Way
Appian Way
The Appian Way (Latin and Italian: Via Appia) is one of the earliest and strategically most important Roman roads of the ancient republic. It connected Rome to Brindisi, in southeast Italy. Its importance is indicated by its common name, recorded by Statius, of ("the Appian Way, the queen of the long roads"). The road...
Technology
Ground transportation networks
null
47571
https://en.wikipedia.org/wiki/American%20pickerel
American pickerel
The American pickerel (Esox americanus) is a medium-sized species of North American freshwater predatory fish belonging to the pike family. The genus Esox is placed in family Esocidae in order Esociformes). Two subspecies are sometimes recognised: Redfin pickerel, sometimes called the brook pickerel, E. americanus a...
Biology and health sciences
Esociformes
Animals
47578
https://en.wikipedia.org/wiki/Muskellunge
Muskellunge
The muskellunge (Esox masquinongy), often shortened to muskie, musky, ski, or lunge, is a species of large freshwater predatory fish native to North America. It is the largest member of the pike family, Esocidae. Origin of name The name "muskellunge" originates from the Ojibwe words maashkinoozhe meaning "great fish",...
Biology and health sciences
Esociformes
Animals
47579
https://en.wikipedia.org/wiki/Pollock
Pollock
Pollock or pollack (pronounced ) is the common name used for either of the two species of North Atlantic marine fish in the genus Pollachius. Pollachius pollachius is referred to as "pollock" in North America, Ireland and the United Kingdom, while Pollachius virens is usually known as saithe or coley in Great Britain a...
Biology and health sciences
Acanthomorpha
Animals
47588
https://en.wikipedia.org/wiki/Neurosis
Neurosis
Neurosis (: neuroses) is a term mainly used today by followers of Freudian thinking to describe mental disorders caused by past anxiety, often that has been repressed. In recent history, the term has been used to refer to anxiety-related conditions more generally. The term "neurosis" is no longer used in condition nam...
Biology and health sciences
Mental disorder
null
47592
https://en.wikipedia.org/wiki/Waveform
Waveform
In electronics, acoustics, and related fields, the waveform of a signal is the shape of its graph as a function of time, independent of its time and magnitude scales and of any displacement in time. Periodic waveforms repeat regularly at a constant period. The term can also be used for non-periodic or aperiodic signals...
Physical sciences
Waves
Physics
47607
https://en.wikipedia.org/wiki/Suspension%20bridge
Suspension bridge
A suspension bridge is a type of bridge in which the deck is hung below suspension cables on vertical suspenders. The first modern examples of this type of bridge were built in the early 1800s. Simple suspension bridges, which lack vertical suspenders, have a long history in many mountainous parts of the world. Beside...
Technology
Transport infrastructure
null
47610
https://en.wikipedia.org/wiki/Great%20Belt%20Bridge
Great Belt Bridge
The Great Belt Bridge () or Great Belt fixed link () is a multi-element fixed link crossing the Great Belt strait between the Danish islands of Zealand and Funen. It consists of a road suspension bridge and a railway tunnel between Zealand and the small island Sprogø in the middle of the Great Belt, and a box-girder br...
Technology
Bridges
null
47612
https://en.wikipedia.org/wiki/Hexactinellid
Hexactinellid
Hexactinellid sponges are sponges with a skeleton made of four- and/or six-pointed siliceous spicules, often referred to as glass sponges. They are usually classified along with other sponges in the phylum Porifera, but some researchers consider them sufficiently distinct to deserve their own phylum, Symplasma. Some ex...
Biology and health sciences
Porifera
Animals
47628
https://en.wikipedia.org/wiki/Bomb
Bomb
A bomb is an explosive weapon that uses the exothermic reaction of an explosive material to provide an extremely sudden and violent release of energy. Detonations inflict damage principally through ground- and atmosphere-transmitted mechanical stress, the impact and penetration of pressure-driven projectiles, pressure ...
Technology
Weapons
null
47641
https://en.wikipedia.org/wiki/Standard%20Model
Standard Model
The Standard Model of particle physics is the theory describing three of the four known fundamental forces (electromagnetic, weak and strong interactions – excluding gravity) in the universe and classifying all known elementary particles. It was developed in stages throughout the latter half of the 20th century, throug...
Physical sciences
Physics
null
47651
https://en.wikipedia.org/wiki/Reproducibility
Reproducibility
Reproducibility, closely related to replicability and repeatability, is a major principle underpinning the scientific method. For the findings of a study to be reproducible means that results obtained by an experiment or an observational study or in a statistical analysis of a data set should be achieved again with a h...
Physical sciences
Science basics
Basics and measurement
47671
https://en.wikipedia.org/wiki/Toxic%20heavy%20metal
Toxic heavy metal
A toxic heavy metal is a common but misleading term for a metal-like element noted for its potential toxicity. Not all heavy metals are toxic and some toxic metals are not heavy. Elements often discussed as toxic include cadmium, mercury and lead, all of which appear in the World Health Organization's list of 10 chemi...
Physical sciences
Periodic table
Chemistry
47687
https://en.wikipedia.org/wiki/Cosmic%20ray
Cosmic ray
Cosmic rays or astroparticles are high-energy particles or clusters of particles (primarily represented by protons or atomic nuclei) that move through space at nearly the speed of light. They originate from the Sun, from outside of the Solar System in our own galaxy, and from distant galaxies. Upon impact with Earth's ...
Physical sciences
Basics_3
null
47696
https://en.wikipedia.org/wiki/SUV
SUV
A sport utility vehicle (SUV) is a car classification that combines elements of road-going passenger cars with features from off-road vehicles, such as raised ground clearance and four-wheel drive. There is no commonly agreed-upon definition of an SUV, and usage of the term varies between countries. Thus, it is "a loo...
Technology
Motorized road transport
null
47700
https://en.wikipedia.org/wiki/Coral
Coral
Corals are colonial marine invertebrates within the subphylum Anthozoa of the phylum Cnidaria. They typically form compact colonies of many identical individual polyps. Coral species include the important reef builders that inhabit tropical oceans and secrete calcium carbonate to form a hard skeleton. A coral "group" ...
Biology and health sciences
Cnidarians
null
47710
https://en.wikipedia.org/wiki/Cotton%20gin
Cotton gin
A cotton gin—meaning "cotton engine"—is a machine that quickly and easily separates cotton fibers from their seeds, enabling much greater productivity than manual cotton separation. The separated seeds may be used to grow more cotton or to produce cottonseed oil. Handheld roller gins had been used in the Indian subc...
Technology
Farm and garden machinery
null
47713
https://en.wikipedia.org/wiki/Direct%20current
Direct current
Direct current (DC) is one-directional flow of electric charge. An electrochemical cell is a prime example of DC power. Direct current may flow through a conductor such as a wire, but can also flow through semiconductors, insulators, or even through a vacuum as in electron or ion beams. The electric current flows in a...
Physical sciences
Electrical circuits
null
47716
https://en.wikipedia.org/wiki/High-voltage%20direct%20current
High-voltage direct current
A high-voltage direct current (HVDC) electric power transmission system uses direct current (DC) for electric power transmission, in contrast with the more common alternating current (AC) transmission systems. Most HVDC links use voltages between 100 kV and 800 kV. HVDC lines are commonly used for long-distance power ...
Technology
Electricity transmission and distribution
null
47719
https://en.wikipedia.org/wiki/Coulomb
Coulomb
The coulomb (symbol: C) is the unit of electric charge in the International System of Units (SI). It is defined to be equal to the electric charge delivered by a 1 ampere current in 1 second. It is used to define the elementary charge e. Definition The SI defines the coulomb as "the quantity of electricity carried in...
Physical sciences
Electromagnetism
null
47742
https://en.wikipedia.org/wiki/Brooklyn%20Bridge
Brooklyn Bridge
The Brooklyn Bridge is a hybrid cable-stayed/suspension bridge in New York City, spanning the East River between the boroughs of Manhattan and Brooklyn. Opened on May 24, 1883, the Brooklyn Bridge was the first fixed crossing of the East River. It was also the longest suspension bridge in the world at the time of its o...
Technology
Transport infrastructure
null
47769
https://en.wikipedia.org/wiki/Transistor%E2%80%93transistor%20logic
Transistor–transistor logic
Transistor–transistor logic (TTL) is a logic family built from bipolar junction transistors. Its name signifies that transistors perform both the logic function (the first "transistor") and the amplifying function (the second "transistor"), as opposed to earlier resistor–transistor logic (RTL) and diode–transistor logi...
Technology
Semiconductors
null
47772
https://en.wikipedia.org/wiki/Instruction%20set%20architecture
Instruction set architecture
In computer science, an instruction set architecture (ISA) is an abstract model that generally defines how software controls the CPU in a computer or a family of computers. A device or program that executes instructions described by that ISA, such as a central processing unit (CPU), is called an implementation of that ...
Technology
Computer architecture concepts
null
47789
https://en.wikipedia.org/wiki/Quality%20of%20life
Quality of life
Quality of life (QOL) is defined by the World Health Organization as "an individual's perception of their position in life in the context of the culture and value systems in which they live and in relation to their goals, expectations, standards and concerns". Standard indicators of the quality of life include wealth...
Biology and health sciences
Health and fitness: General
Health
47795
https://en.wikipedia.org/wiki/Voyager%20program
Voyager program
The Voyager program is an American scientific program that employs two interstellar probes, Voyager 1 and Voyager 2. They were launched in 1977 to take advantage of a favorable planetary alignment to explore the two gas giants Jupiter and Saturn and potentially also the ice giants, Uranus and Neptune - to fly near them...
Technology
Programs and launch sites
null
47798
https://en.wikipedia.org/wiki/Trogon
Trogon
The trogons and quetzals are birds in the order Trogoniformes which contains only one family, the Trogonidae. The family Trogonidae contains 46 species in seven genera. The fossil record of the trogons dates back 49 million years to the Early Eocene. They might constitute a member of the basal radiation of the order C...
Biology and health sciences
Trogoniformes
null
47877
https://en.wikipedia.org/wiki/Pickup%20truck
Pickup truck
A pickup truck or pickup is a light or medium duty truck that has an enclosed cabin, and a back end made up of a cargo bed that is enclosed by three low walls with no roof (this cargo bed back end sometimes consists of a tailgate and removable covering). In Australia and New Zealand, both pickups and coupé utilities ar...
Technology
Motorized road transport
null
47878
https://en.wikipedia.org/wiki/Huntington%27s%20disease
Huntington's disease
Huntington's disease (HD), also known as Huntington's chorea, is an incurable neurodegenerative disease that is mostly inherited. The earliest symptoms are often subtle problems with mood or mental/psychiatric abilities. A general lack of coordination and an unsteady gait often follow. It is also a basal ganglia diseas...
Biology and health sciences
Specific diseases
Health
47895
https://en.wikipedia.org/wiki/Stochastic%20process
Stochastic process
In probability theory and related fields, a stochastic () or random process is a mathematical object usually defined as a family of random variables in a probability space, where the index of the family often has the interpretation of time. Stochastic processes are widely used as mathematical models of systems and phen...
Mathematics
Statistics and probability
null
47949
https://en.wikipedia.org/wiki/Union%20%28set%20theory%29
Union (set theory)
In set theory, the union (denoted by ∪) of a collection of sets is the set of all elements in the collection. It is one of the fundamental operations through which sets can be combined and related to each other. A refers to a union of zero () sets and it is by definition equal to the empty set. For explanation of t...
Mathematics
Discrete mathematics
null
47967
https://en.wikipedia.org/wiki/Authentication
Authentication
Authentication (from authentikos, "real, genuine", from αὐθέντης authentes, "author") is the act of proving an assertion, such as the identity of a computer system user. In contrast with identification, the act of indicating a person or thing's identity, authentication is the process of verifying that identity. It mig...
Technology
Cryptography
null
48065
https://en.wikipedia.org/wiki/Polder
Polder
A polder () is a low-lying tract of land that forms an artificial hydrological entity, enclosed by embankments known as dikes. The three types of polder are: Land reclaimed from a body of water, such as a lake or the seabed Flood plains separated from the sea or river by a dike Marshes separated from the surroundi...
Physical sciences
Artificial landforms
null
48130
https://en.wikipedia.org/wiki/Hare
Hare
Hares and jackrabbits are mammals belonging to the genus Lepus. They are herbivores, and live solitarily or in pairs. They nest in slight depressions called forms, and their young are able to fend for themselves shortly after birth. The genus includes the largest lagomorphs. Most are fast runners with long, powerful hi...
Biology and health sciences
Lagomorphs
null
48144
https://en.wikipedia.org/wiki/Microcomputer
Microcomputer
A microcomputer is a small, relatively inexpensive computer having a central processing unit (CPU) made out of a microprocessor. The computer also includes memory and input/output (I/O) circuitry together mounted on a printed circuit board (PCB). Microcomputers became popular in the 1970s and 1980s with the advent of i...
Technology
Computer hardware
null
48146
https://en.wikipedia.org/wiki/Fossil%20fuel
Fossil fuel
A fossil fuel is a carbon compound- or hydrocarbon-containing material formed naturally in the Earth's crust from the buried remains of prehistoric organisms (animals, plants or planktons), a process that occurs within geological formations. Reservoirs of such compound mixtures, such as coal, petroleum and natural gas,...
Technology
Energy
null
48239
https://en.wikipedia.org/wiki/Celestial%20sphere
Celestial sphere
In astronomy and navigation, the celestial sphere is an abstract sphere that has an arbitrarily large radius and is concentric to Earth. All objects in the sky can be conceived as being projected upon the inner surface of the celestial sphere, which may be centered on Earth or the observer. If centered on the observer,...
Physical sciences
Celestial sphere
null
48317
https://en.wikipedia.org/wiki/Lagomorpha
Lagomorpha
The lagomorphs () are the members of the taxonomic order Lagomorpha, of which there are two living families: the Leporidae (rabbits and hares) and the Ochotonidae (pikas). There are 110 recent species of lagomorph, of which only 109 species in twelve genera are extant, including ten genera of rabbits (42 species); one ...
Biology and health sciences
Lagomorphs
null
48334
https://en.wikipedia.org/wiki/Retina
Retina
The retina (; or retinas) is the innermost, light-sensitive layer of tissue of the eye of most vertebrates and some molluscs. The optics of the eye create a focused two-dimensional image of the visual world on the retina, which then processes that image within the retina and sends nerve impulses along the optic nerve ...
Biology and health sciences
Visual system
Biology
48336
https://en.wikipedia.org/wiki/Electrolyte
Electrolyte
An electrolyte is a substance that conducts electricity through the movement of ions, but not through the movement of electrons. This includes most soluble salts, acids, and bases, dissolved in a polar solvent like water. Upon dissolving, the substance separates into cations and anions, which disperse uniformly through...
Physical sciences
Electrochemistry
Chemistry
48337
https://en.wikipedia.org/wiki/Caterpillar
Caterpillar
Caterpillars ( ) are the larval stage of members of the order Lepidoptera (the insect order comprising butterflies and moths). As with most common names, the application of the word is arbitrary, since the larvae of sawflies (suborder Symphyta) are commonly called caterpillars as well. Both lepidopteran and symphytan ...
Biology and health sciences
Lepidoptera
Animals
48338
https://en.wikipedia.org/wiki/Butterfly
Butterfly
Butterflies are winged insects from the lepidopteran suborder Rhopalocera, characterized by large, often brightly coloured wings that often fold together when at rest, and a conspicuous, fluttering flight. The group comprises the superfamilies Hedyloidea (moth-butterflies in the Americas) and Papilionoidea (all others)...
Biology and health sciences
Lepidoptera
null
48339
https://en.wikipedia.org/wiki/Parachute
Parachute
A parachute is a device used to slow the motion of an object through an atmosphere by creating drag or aerodynamic lift. A major application is to support people, for recreation or as a safety device for aviators, who can exit from an aircraft at height and descend safely to earth. A parachute is usually made of a lig...
Technology
Aviation
null
48340
https://en.wikipedia.org/wiki/Pesticide
Pesticide
Pesticides are substances that are used to control pests. They include herbicides, insecticides, nematicides, fungicides, and many others (see table). The most common of these are herbicides, which account for approximately 50% of all pesticide use globally. Most pesticides are used as plant protection products (also k...
Technology
Horticultural techniques
null
48366
https://en.wikipedia.org/wiki/Polyurethane
Polyurethane
Polyurethane (; often abbreviated PUR and PU) refers to a class of polymers composed of organic units joined by carbamate (urethane) links. In contrast to other common polymers such as polyethylene and polystyrene, polyurethane term does not refer to the single type of polymer but a group of polymers. Unlike polyethyle...
Physical sciences
Polymers
Chemistry
48381
https://en.wikipedia.org/wiki/Astronomical%20coordinate%20systems
Astronomical coordinate systems
In astronomy, coordinate systems are used for specifying positions of celestial objects (satellites, planets, stars, galaxies, etc.) relative to a given reference frame, based on physical reference points available to a situated observer (e.g. the true horizon and north to an observer on Earth's surface). Coordinate sy...
Physical sciences
Celestial sphere
null
48384
https://en.wikipedia.org/wiki/Equatorial%20coordinate%20system
Equatorial coordinate system
The equatorial coordinate system is a celestial coordinate system widely used to specify the positions of celestial objects. It may be implemented in spherical or rectangular coordinates, both defined by an origin at the centre of Earth, a fundamental plane consisting of the projection of Earth's equator onto the celes...
Physical sciences
Celestial sphere
null
48389
https://en.wikipedia.org/wiki/Galactic%20coordinate%20system
Galactic coordinate system
The galactic coordinate system is a celestial coordinate system in spherical coordinates, with the Sun as its center, the primary direction aligned with the approximate center of the Milky Way Galaxy, and the fundamental plane parallel to an approximation of the galactic plane but offset to its north. It uses the right...
Physical sciences
Celestial sphere: General
Astronomy
48395
https://en.wikipedia.org/wiki/Navier%E2%80%93Stokes%20equations
Navier–Stokes equations
The Navier–Stokes equations ( ) are partial differential equations which describe the motion of viscous fluid substances. They were named after French engineer and physicist Claude-Louis Navier and the Irish physicist and mathematician George Gabriel Stokes. They were developed over several decades of progressively b...
Physical sciences
Fluid mechanics
null
48396
https://en.wikipedia.org/wiki/Mathematical%20analysis
Mathematical analysis
Analysis is the branch of mathematics dealing with continuous functions, limits, and related theories, such as differentiation, integration, measure, infinite sequences, series, and analytic functions. These theories are usually studied in the context of real and complex numbers and functions. Analysis evolved from ca...
Mathematics
Analysis
null
48404
https://en.wikipedia.org/wiki/Ring%20%28mathematics%29
Ring (mathematics)
In mathematics, rings are algebraic structures that generalize fields: multiplication need not be commutative and multiplicative inverses need not exist. Informally, a ring is a set equipped with two binary operations satisfying properties analogous to those of addition and multiplication of integers. Ring elements may...
Mathematics
Algebra
null
48405
https://en.wikipedia.org/wiki/Caesar%20cipher
Caesar cipher
In cryptography, a Caesar cipher, also known as Caesar's cipher, the shift cipher, Caesar's code, or Caesar shift, is one of the simplest and most widely known encryption techniques. It is a type of substitution cipher in which each letter in the plaintext is replaced by a letter some fixed number of positions down the...
Technology
Computer security
null
48510
https://en.wikipedia.org/wiki/Terrestrial%20planet
Terrestrial planet
A terrestrial planet, tellurian planet, telluric planet, or rocky planet, is a planet that is composed primarily of silicate, rocks or metals. Within the Solar System, the terrestrial planets accepted by the IAU are the inner planets closest to the Sun: Mercury, Venus, Earth and Mars. Among astronomers who use the geop...
Physical sciences
Planetary science
null
48517
https://en.wikipedia.org/wiki/Antelope
Antelope
The term antelope refers to numerous extant or recently extinct species of the ruminant artiodactyl family Bovidae that are indigenous to most of Africa, India, the Middle East, Central Asia, and a small area of Eastern Europe. Antelopes do not form a monophyletic group, as some antelopes are more closely related to ot...
Biology and health sciences
Artiodactyla
null
48519
https://en.wikipedia.org/wiki/Highway
Highway
A highway is any public or private road or other public way on land. It includes not just major roads, but also other public roads and rights of way. In the United States, it is also used as an equivalent term to controlled-access highway, or a translation for motorway, Autobahn, autostrada, autoroute, etc. According ...
Technology
Road transport
null
48520
https://en.wikipedia.org/wiki/Sloop
Sloop
In modern usage, a sloop is a sailboat with a single mast generally having only one headsail in front of the mast and one mainsail abaft (behind) the mast. It is a type of fore-and-aft rig. The mainsail may be of any type, most often Bermuda rig, but also others, such as gaff or gunter. In naval terminology, "sloop-of...
Technology
Naval transport
null
48530
https://en.wikipedia.org/wiki/Blood%20vessel
Blood vessel
Blood vessels are the tubular structures of a circulatory system that transport blood throughout a vertebrate's body. Blood vessels transport blood cells, nutrients, and oxygen to most of the tissues of a body. They also take waste and carbon dioxide away from the tissues. Some tissues such as cartilage, epithelium, an...
Biology and health sciences
Circulatory system
Biology
48548
https://en.wikipedia.org/wiki/Dopamine
Dopamine
Dopamine (DA, a contraction of 3,4-dihydroxyphenethylamine) is a neuromodulatory molecule that plays several important roles in cells. It is an organic chemical of the catecholamine and phenethylamine families. Dopamine constitutes about 80% of the catecholamine content in the brain. It is an amine synthesized by remov...
Biology and health sciences
Biochemistry and molecular biology
null
48560
https://en.wikipedia.org/wiki/Tree%20%28graph%20theory%29
Tree (graph theory)
In graph theory, a tree is an undirected graph in which any two vertices are connected by path, or equivalently a connected acyclic undirected graph. A forest is an undirected graph in which any two vertices are connected by path, or equivalently an acyclic undirected graph, or equivalently a disjoint union of trees....
Mathematics
Graph theory
null
48563
https://en.wikipedia.org/wiki/Air%20traffic%20control
Air traffic control
Air traffic control (ATC) is a service provided by ground-based air traffic controllers who direct aircraft on the ground and through a given section of controlled airspace, and can provide advisory services to aircraft in non-controlled airspace. The primary purpose of ATC is to prevent collisions, organize and expedi...
Technology
Aviation
null
48628
https://en.wikipedia.org/wiki/Gaussian%20integer
Gaussian integer
In number theory, a Gaussian integer is a complex number whose real and imaginary parts are both integers. The Gaussian integers, with ordinary addition and multiplication of complex numbers, form an integral domain, usually written as or Gaussian integers share many properties with integers: they form a Euclidean ...
Mathematics
Basics
null
48774
https://en.wikipedia.org/wiki/Lance
Lance
The English term lance is derived, via Middle English launce and Old French lance, from the Latin lancea, a generic term meaning a spear or javelin employed by both infantry and cavalry, with English initially keeping these generic meanings. It developed later into a term for spear-like weapons specially designed and m...
Technology
Polearms
null
48775
https://en.wikipedia.org/wiki/Halberd
Halberd
A halberd (also called halbard, halbert or Swiss voulge) is a two-handed polearm that came to prominent use from the 13th to 16th centuries. The halberd consists of an axe blade topped with a spike mounted on a long shaft. It can have a hook or thorn on the back side of the axe blade for grappling mounted combatants an...
Technology
Polearms
null
48791
https://en.wikipedia.org/wiki/Pathology
Pathology
Pathology is the study of disease. The word pathology also refers to the study of disease in general, incorporating a wide range of biology research fields and medical practices. However, when used in the context of modern medical treatment, the term is often used in a narrower fashion to refer to processes and tests t...
Biology and health sciences
Fields of medicine
Health
48803
https://en.wikipedia.org/wiki/Gamma-ray%20burst
Gamma-ray burst
In gamma-ray astronomy, gamma-ray bursts (GRBs) are immensely energetic events occurring in distant galaxies which represent the brightest and "most powerful class of explosion in the universe." These extreme electromagnetic events are second only to the Big Bang as the most energetic and luminous phenomenon ever known...
Physical sciences
Stellar astronomy
null
48824
https://en.wikipedia.org/wiki/Gravitational%20lens
Gravitational lens
A gravitational lens is matter, such as a cluster of galaxies or a point particle, that bends light from a distant source as it travels toward an observer. The amount of gravitational lensing is described by Albert Einstein's general theory of relativity. If light is treated as corpuscles travelling at the speed of lig...
Physical sciences
Basics_2
Astronomy
48836
https://en.wikipedia.org/wiki/Kava
Kava
Kava or kava kava (Piper methysticum: Latin 'pepper' and Latinized Greek 'intoxicating') is a plant in the pepper family, native to the Pacific Islands. The name kava is from Tongan and Marquesan, meaning 'bitter.’ Other names for kava include ʻawa (Hawaiʻi), ʻava (Samoa), yaqona or yagona (Fiji), sakau (Pohnpei), seka...
Biology and health sciences
Piperales
Plants
48837
https://en.wikipedia.org/wiki/Sidereal%20time
Sidereal time
Sidereal time ("sidereal" pronounced ) is a system of timekeeping used especially by astronomers. Using sidereal time and the celestial coordinate system, it is easy to locate the positions of celestial objects in the night sky. Sidereal time is a "time scale that is based on Earth's rate of rotation measured relative...
Physical sciences
Celestial mechanics
Astronomy
48838
https://en.wikipedia.org/wiki/Hour%20angle
Hour angle
In astronomy and celestial navigation, the hour angle is the dihedral angle between the meridian plane (containing Earth's axis and the zenith) and the hour circle (containing Earth's axis and a given point of interest). It may be given in degrees, time, or rotations depending on the application. The angle may be exp...
Physical sciences
Celestial sphere: General
Astronomy
48866
https://en.wikipedia.org/wiki/Gadiformes
Gadiformes
Gadiformes , also called the Anacanthini, are an order of ray-finned fish that include the cod, hakes, pollock, haddock, burbot, rocklings and moras, many of which are food fish of major commercial value. They are mostly marine fish found throughout the world and the vast majority are found in temperate or colder regio...
Biology and health sciences
Acanthomorpha
Animals
48868
https://en.wikipedia.org/wiki/Sparidae
Sparidae
Sparidae is a family of ray-finned fishes belonging to the order Spariformes, the seabreams and porgies, although they were traditionally classified in the order Perciformes. They are found in shallow temperate and tropical waters around the world and are demersal carnivores. Taxonomy Sparidae was first proposed as a ...
Biology and health sciences
Acanthomorpha
Animals
48869
https://en.wikipedia.org/wiki/Clupeiformes
Clupeiformes
Clupeiformes is the order of ray-finned fish that includes the herring family, Clupeidae, and the anchovy family, Engraulidae and sardines. The group includes many of the most important forage and food fish. Clupeiformes are physostomes, which means that their gas bladder has a pneumatic duct connecting it to the gut...
Biology and health sciences
Clupeiformes
Animals
48870
https://en.wikipedia.org/wiki/Clupeidae
Clupeidae
Clupeidae is a family of clupeiform ray-finned fishes, comprising, for instance, the herrings and sprats. Many members of the family have a body protected with shiny cycloid (very smooth and uniform) scales, a single dorsal fin, and a fusiform body for quick, evasive swimming and pursuit of prey composed of small plank...
Biology and health sciences
Clupeiformes
Animals
48872
https://en.wikipedia.org/wiki/Scombridae
Scombridae
The mackerel, tuna, and bonito family, Scombridae, includes many of the most important and familiar food fishes. The family consists of 51 species in 15 genera and two subfamilies. All species are in the subfamily Scombrinae, except the butterfly kingfish, which is the sole member of subfamily Gasterochismatinae. Scom...
Biology and health sciences
Acanthomorpha
Animals
48873
https://en.wikipedia.org/wiki/Serranidae
Serranidae
Serranidae is a large family of fishes belonging to the order Perciformes. The family contains about 450 species in 65 genera, including the sea basses and the groupers (subfamily Epinephelinae). Although many species are small, in some cases less than , the giant grouper (Epinephelus lanceolatus) is one of the largest...
Biology and health sciences
Acanthomorpha
null
48878
https://en.wikipedia.org/wiki/Salmonidae
Salmonidae
Salmonidae (, ) is a family of ray-finned fish that constitutes the only currently extant family in the order Salmoniformes (, lit. "salmon-shaped"), consisting of 11 extant genera and over 200 species collectively known as "salmonids" or "salmonoids". The family includes salmon (both Atlantic and Pacific species), tro...
Biology and health sciences
Salmoniformes
null
48885
https://en.wikipedia.org/wiki/Scorpaeniformes
Scorpaeniformes
The Scorpaeniformes are a diverse order of ray-finned fish, including the lionfishes and sculpins, but have also been called the Scleroparei. It is one of the five largest orders of bony fishes by number of species, with over 1,320. They are known as "mail-cheeked" fishes due to their distinguishing characteristic, t...
Biology and health sciences
Fishes
null
48896
https://en.wikipedia.org/wiki/Lyrebird
Lyrebird
A lyrebird is either of two species of ground-dwelling Australian birds that compose the genus Menura, and the family Menuridae. They are most notable for their impressive ability to mimic natural and artificial sounds from their environment, and the striking beauty of the male bird's huge tail when it is fanned out in...
Biology and health sciences
Corvoidea
null
48900
https://en.wikipedia.org/wiki/Atomic%20radius
Atomic radius
The atomic radius of a chemical element is a measure of the size of its atom, usually the mean or typical distance from the center of the nucleus to the outermost isolated electron. Since the boundary is not a well-defined physical entity, there are various non-equivalent definitions of atomic radius. Four widely used...
Physical sciences
Periodic table
Chemistry
48902
https://en.wikipedia.org/wiki/Kilogram%20per%20cubic%20metre
Kilogram per cubic metre
The kilogram per cubic metre (symbol: kg·m−3, or kg/m3) is the unit of density in the International System of Units (SI). It is defined by dividing the SI unit of mass, the kilogram, by the SI unit of volume, the cubic metre. Conversions 1 kg/m3 = 1 g/L (exactly) 1 kg/m3 = 0.001 g/cm3 (exactly) 1 kg/m3 ≈ 0.06243 lb/ft...
Physical sciences
Density
Basics and measurement
48903
https://en.wikipedia.org/wiki/Nucleosynthesis
Nucleosynthesis
Nucleosynthesis is the process that creates new atomic nuclei from pre-existing nucleons (protons and neutrons) and nuclei. According to current theories, the first nuclei were formed a few minutes after the Big Bang, through nuclear reactions in a process called Big Bang nucleosynthesis. After about 20 minutes, the un...
Physical sciences
Nuclear physics
null
48909
https://en.wikipedia.org/wiki/Zenith
Zenith
The zenith (, ) is the imaginary point on the celestial sphere directly "above" a particular location. "Above" means in the vertical direction (plumb line) opposite to the gravity direction at that location (nadir). The zenith is the "highest" point on the celestial sphere. Origin The word zenith derives from an inacc...
Physical sciences
Celestial sphere: General
Astronomy
48910
https://en.wikipedia.org/wiki/Horizon
Horizon
The horizon is the apparent curve that separates the surface of a celestial body from its sky when viewed from the perspective of an observer on or near the surface of the relevant body. This curve divides all viewing directions based on whether it intersects the relevant body's surface or not. The true horizon is a t...
Physical sciences
Celestial sphere
null
48963
https://en.wikipedia.org/wiki/Characiformes
Characiformes
Characiformes is an order of ray-finned fish, comprising the characins and their allies. Grouped in 18 recognized families, more than 2000 different species are described, including the well-known piranha and tetras. Taxonomy The Characiformes form part of a series called the Otophysi within the superorder Ostarioph...
Biology and health sciences
Characiformes
null
48971
https://en.wikipedia.org/wiki/Characidae
Characidae
Characidae, the characids or characins, is a family of freshwater subtropical and tropical fish belonging to the order Characiformes. The name "characins" is a historical one, but scientists today tend to prefer "characids" to reflect their status as a, by and large, monophyletic group (at family rank). To arrive there...
Biology and health sciences
Characiformes
Animals
48980
https://en.wikipedia.org/wiki/Basidiomycota
Basidiomycota
Basidiomycota () is one of two large divisions that, together with the Ascomycota, constitute the subkingdom Dikarya (often referred to as the "higher fungi") within the kingdom Fungi. Members are known as basidiomycetes. More specifically, Basidiomycota includes these groups: agarics, puffballs, stinkhorns, bracket fu...
Biology and health sciences
Fungi
null
48981
https://en.wikipedia.org/wiki/Ascomycota
Ascomycota
Ascomycota is a phylum of the kingdom Fungi that, together with the Basidiomycota, forms the subkingdom Dikarya. Its members are commonly known as the sac fungi or ascomycetes. It is the largest phylum of Fungi, with over 64,000 species. The defining feature of this fungal group is the "ascus" (), a microscopic sexual ...
Biology and health sciences
Fungi
null
49020
https://en.wikipedia.org/wiki/Road%20transport
Road transport
Road transport or road transportation is a type of transport using roads. Transport on roads can be roughly grouped into the transportation of goods and transportation of people. In many countries licensing requirements and safety regulations ensure a separation of the two industries. Movement along roads may be by bik...
Technology
Road transport
null
49033
https://en.wikipedia.org/wiki/Epigenetics
Epigenetics
In biology, epigenetics is the study of heritable traits, or a stable change of cell function, that happen without changes to the DNA sequence. The Greek prefix epi- ( "over, outside of, around") in epigenetics implies features that are "on top of" or "in addition to" the traditional (DNA sequence based) genetic mechan...
Biology and health sciences
Genetics and taxonomy
null
49084
https://en.wikipedia.org/wiki/Glans%20penis
Glans penis
In male human anatomy, the glans penis or penile glans, commonly referred to as the glans, (; from Latin glans meaning "acorn") is the bulbous structure at the distal end of the human penis that is the human male's most sensitive erogenous zone and primary anatomical source of sexual pleasure. The glans penis is presen...
Biology and health sciences
Reproductive system
Biology
49090
https://en.wikipedia.org/wiki/Ohm%27s%20law
Ohm's law
Ohm's law states that the electric current through a conductor between two points is directly proportional to the voltage across the two points. Introducing the constant of proportionality, the resistance, one arrives at the three mathematical equations used to describe this relationship: where is the current through...
Physical sciences
Electrical circuits
null
49105
https://en.wikipedia.org/wiki/Vacuum%20cleaner
Vacuum cleaner
A vacuum cleaner, also known simply as a vacuum, is a device that uses suction, and often agitation, in order to remove dirt and other debris from carpets and hard floors. The dirt is collected into a dust bag or a plastic bin. Vacuum cleaners, which are used in homes as well as in commercial settings, exist in a vari...
Technology
Household appliances
null
49123
https://en.wikipedia.org/wiki/Phoenix%20%28constellation%29
Phoenix (constellation)
Phoenix is a minor constellation in the southern sky. Named after the mythical phoenix, it was first depicted on a celestial atlas by Johann Bayer in his 1603 Uranometria. The French explorer and astronomer Nicolas Louis de Lacaille charted the brighter stars and gave their Bayer designations in 1756. The constellatio...
Physical sciences
Other
Astronomy
49159
https://en.wikipedia.org/wiki/Hallucination
Hallucination
A hallucination is a perception in the absence of an external stimulus that has the compelling sense of reality. They are distinguishable from several related phenomena, such as dreaming (REM sleep), which does not involve wakefulness; pseudohallucination, which does not mimic real perception, and is accurately perceiv...
Biology and health sciences
Miscellaneous
null
49172
https://en.wikipedia.org/wiki/Interval%20%28mathematics%29
Interval (mathematics)
In mathematics, a real interval is the set of all real numbers lying between two fixed endpoints with no "gaps". Each endpoint is either a real number or positive or negative infinity, indicating the interval extends without a bound. A real interval can contain neither endpoint, either endpoint, or both endpoints, exc...
Mathematics
Real analysis
null
49176
https://en.wikipedia.org/wiki/Conjugacy%20class
Conjugacy class
In mathematics, especially group theory, two elements and of a group are conjugate if there is an element in the group such that This is an equivalence relation whose equivalence classes are called conjugacy classes. In other words, each conjugacy class is closed under for all elements in the group. Members of ...
Mathematics
Abstract algebra
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