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1503750 | https://en.wikipedia.org/wiki/Rolling%20resistance | Rolling resistance | Rolling resistance, sometimes called rolling friction or rolling drag, is the force resisting the motion when a body (such as a ball, tire, or wheel) rolls on a surface. It is mainly caused by non-elastic effects; that is, not all the energy needed for deformation (or movement) of the wheel, roadbed, etc., is recovered... | Physical sciences | Classical mechanics | Physics |
1505215 | https://en.wikipedia.org/wiki/Tip%20of%20the%20red-giant%20branch | Tip of the red-giant branch | Tip of the red-giant branch (TRGB) is a primary distance indicator used in astronomy. It uses the luminosity of the brightest red-giant-branch stars in a galaxy as a standard candle to gauge the distance to that galaxy. It has been used in conjunction with observations from the Hubble Space Telescope to determine the r... | Physical sciences | Basics | Astronomy |
1505481 | https://en.wikipedia.org/wiki/Rail%20yard | Rail yard | A rail yard, railway yard, railroad yard (US) or simply yard, is a series of tracks in a rail network for storing, sorting, or loading and unloading rail vehicles and locomotives. Yards have many tracks in parallel for keeping rolling stock or unused locomotives stored off the main line, so that they do not obstruct th... | Technology | Concepts of ground transport | null |
39 | https://en.wikipedia.org/wiki/Albedo | Albedo | Albedo ( ; ) is the fraction of sunlight that is diffusely reflected by a body. It is measured on a scale from 0 (corresponding to a black body that absorbs all incident radiation) to 1 (corresponding to a body that reflects all incident radiation). Surface albedo is defined as the ratio of radiosity Je to the irradian... | Physical sciences | Astrometry | null |
334 | https://en.wikipedia.org/wiki/International%20Atomic%20Time | International Atomic Time | International Atomic Time (abbreviated TAI, from its French name ) is a high-precision atomic coordinate time standard based on the notional passage of proper time on Earth's geoid. TAI is a weighted average of the time kept by over 450 atomic clocks in over 80 national laboratories worldwide. It is a continuous scale ... | Technology | Timekeeping | null |
572 | https://en.wikipedia.org/wiki/Agricultural%20science | Agricultural science | Agricultural science (or agriscience for short) is a broad multidisciplinary field of biology that encompasses the parts of exact, natural, economic and social sciences that are used in the practice and understanding of agriculture. Professionals of the agricultural science are called agricultural scientists or agricul... | Technology | Basics | null |
573 | https://en.wikipedia.org/wiki/Alchemy | Alchemy | Alchemy (from the Arabic word , ) is an ancient branch of natural philosophy, a philosophical and protoscientific tradition that was historically practised in China, India, the Muslim world, and Europe. In its Western form, alchemy is first attested in a number of pseudepigraphical texts written in Greco-Roman Egypt du... | Physical sciences | Chemistry: General | null |
580 | https://en.wikipedia.org/wiki/Astronomer | Astronomer | An astronomer is a scientist in the field of astronomy who focuses on a specific question or field outside the scope of Earth. Astronomers observe astronomical objects, such as stars, planets, moons, comets and galaxies – in either observational (by analyzing the data) or theoretical astronomy. Examples of topics or fi... | Physical sciences | Astronomy basics | Astronomy |
586 | https://en.wikipedia.org/wiki/ASCII | ASCII | ASCII ( ), an acronym for American Standard Code for Information Interchange, is a character encoding standard for electronic communication. ASCII codes represent text in computers, telecommunications equipment, and other devices. ASCII has just 128 code points, of which only 95 are , which severely limit its scope. Th... | Technology | Software development: General | null |
612 | https://en.wikipedia.org/wiki/Arithmetic%20mean | Arithmetic mean | In mathematics and statistics, the arithmetic mean ( ), arithmetic average, or just the mean or average (when the context is clear) is the sum of a collection of numbers divided by the count of numbers in the collection. The collection is often a set of results from an experiment, an observational study, or a survey. T... | Mathematics | Statistics | null |
621 | https://en.wikipedia.org/wiki/Amphibian | Amphibian | Amphibians are ectothermic, anamniotic, four-limbed vertebrate animals that constitute the class Amphibia. In its broadest sense, it is a paraphyletic group encompassing all tetrapods excluding the amniotes (tetrapods with an amniotic membrane, such as modern reptiles, birds and mammals). All extant (living) amphibians... | Biology and health sciences | Biology | null |
633 | https://en.wikipedia.org/wiki/Algae | Algae | Algae ( , ; : alga ) is an informal term for any organisms of a large and diverse group of photosynthetic eukaryotes, which include species from multiple distinct clades. Such organisms range from unicellular microalgae such as Chlorella, Prototheca and the diatoms, to multicellular macroalgae such as the giant kelp,... | Biology and health sciences | Biology | null |
634 | https://en.wikipedia.org/wiki/Analysis%20of%20variance | Analysis of variance | Analysis of variance (ANOVA) is a collection of statistical models and their associated estimation procedures (such as the "variation" among and between groups) used to analyze the differences between groups. It uses F-test by comparing variance between groups and taking noise, or assumed normal distribution of group, ... | Mathematics | Statistics | null |
639 | https://en.wikipedia.org/wiki/Alkane | Alkane | In organic chemistry, an alkane, or paraffin (a historical trivial name that also has other meanings), is an acyclic saturated hydrocarbon. In other words, an alkane consists of hydrogen and carbon atoms arranged in a tree structure in which all the carbon–carbon bonds are single. Alkanes have the general chemical form... | Physical sciences | Hydrocarbons | null |
655 | https://en.wikipedia.org/wiki/Abacus | Abacus | An abacus (: abaci or abacuses), also called a counting frame, is a hand-operated calculating tool which was used from ancient times in the ancient Near East, Europe, China, and Russia, until the adoption of the Hindu–Arabic numeral system. An abacus consists of a two-dimensional array of slidable beads (or similar obj... | Technology | Basics_3 | null |
656 | https://en.wikipedia.org/wiki/Acid | Acid | An acid is a molecule or ion capable of either donating a proton (i.e. hydrogen ion, H+), known as a Brønsted–Lowry acid, or forming a covalent bond with an electron pair, known as a Lewis acid.
The first category of acids are the proton donors, or Brønsted–Lowry acids. In the special case of aqueous solutions, proton... | Physical sciences | Inorganic compounds | null |
657 | https://en.wikipedia.org/wiki/Bitumen | Bitumen | Bitumen ( , ) is an immensely viscous constituent of petroleum. Depending on its exact composition it can be a sticky, black liquid or an apparently solid mass that behaves as a liquid over very large time scales. In American English, the material is commonly referred to as asphalt. Whether found in natural deposits o... | Technology | Building materials | null |
662 | https://en.wikipedia.org/wiki/Apollo%2011 | Apollo 11 | Apollo 11 was a spaceflight conducted from July 16 to July 24, 1969 by the United States and launched by NASA. It marked the first time that humans landed on the Moon. Commander Neil Armstrong and Lunar Module Pilot Buzz Aldrin landed the Apollo Lunar Module Eagle on July 20, 1969, at 20:17 UTC, and Armstrong became th... | Technology | Crewed vehicles | null |
664 | https://en.wikipedia.org/wiki/Astronaut | Astronaut | An astronaut (from the Ancient Greek (), meaning 'star', and (), meaning 'sailor') is a person trained, equipped, and deployed by a human spaceflight program to serve as a commander or crew member aboard a spacecraft. Although generally reserved for professional space travelers, the term is sometimes applied to anyon... | Technology | Basics_10 | null |
666 | https://en.wikipedia.org/wiki/Alkali%20metal | Alkali metal | |-
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The alkali metals consist of the chemical elements lithium (Li), sodium (Na), potassium (K), rubidium (Rb), caesium (Cs), and francium (Fr). Together with hydrogen they constitut... | Physical sciences | Chemical element groups | null |
673 | https://en.wikipedia.org/wiki/Atomic%20number | Atomic number | The atomic number or nuclear charge number (symbol Z) of a chemical element is the charge number of its atomic nucleus. For ordinary nuclei composed of protons and neutrons, this is equal to the proton number (np) or the number of protons found in the nucleus of every atom of that element. The atomic number can be used... | Physical sciences | Basics_4 | null |
674 | https://en.wikipedia.org/wiki/Anatomy | Anatomy | Anatomy () is the branch of morphology concerned with the study of the internal structure of organisms and their parts. Anatomy is a branch of natural science that deals with the structural organization of living things. It is an old science, having its beginnings in prehistoric times. Anatomy is inherently tied to dev... | Biology and health sciences | Biology | null |
680 | https://en.wikipedia.org/wiki/Aardvark | Aardvark | Aardvarks ( ; Orycteropus afer) are medium-sized, burrowing, nocturnal mammals native to Africa. Aardvarks are the only living species of the family Orycteropodidae and the order Tubulidentata. They have a long snout, similar to that of a pig, which is used to sniff out food.
They are afrotheres, a clade that also in... | Biology and health sciences | Mammals | null |
681 | https://en.wikipedia.org/wiki/Aardwolf | Aardwolf | The aardwolf (Proteles cristatus) is an insectivorous hyaenid species, native to East and Southern Africa. Its name means "earth-wolf" in Afrikaans and Dutch. It is also called the maanhaar-jackal (Afrikaans for "mane-jackal"), termite-eating hyena and civet hyena, based on its habit of secreting substances from its an... | Biology and health sciences | Other carnivora | Animals |
682 | https://en.wikipedia.org/wiki/Adobe | Adobe | Adobe ( ; ) is a building material made from earth and organic materials. is Spanish for mudbrick. In some English-speaking regions of Spanish heritage, such as the Southwestern United States, the term is used to refer to any kind of earthen construction, or various architectural styles like Pueblo Revival or Territor... | Technology | Building materials | null |
713 | https://en.wikipedia.org/wiki/Android%20%28robot%29 | Android (robot) | An android is a humanoid robot or other artificial being, often made from a flesh-like material. Historically, androids existed only in the domain of science fiction and were frequently seen in film and television, but advances in robot technology have allowed the design of functional and realistic humanoid robots.
Te... | Technology | Machinery and tools: General | null |
734 | https://en.wikipedia.org/wiki/Actinopterygii | Actinopterygii | Actinopterygii (; ), members of which are known as ray-finned fish or actinopterygians, is a class of bony fish that comprise over 50% of living vertebrate species. They are so called because of their lightly built fins made of webbings of skin supported by radially extended thin bony spines called lepidotrichia, as op... | Biology and health sciences | Fishes | null |
748 | https://en.wikipedia.org/wiki/Amateur%20astronomy | Amateur astronomy | Amateur astronomy is a hobby where participants enjoy observing or imaging celestial objects in the sky using the unaided eye, binoculars, or telescopes. Even though scientific research may not be their primary goal, some amateur astronomers make contributions in doing citizen science, such as by monitoring variable st... | Physical sciences | Astronomy basics | Astronomy |
765 | https://en.wikipedia.org/wiki/Abortion | Abortion | Abortion is the termination of a pregnancy by removal or expulsion of an embryo or fetus. An abortion that occurs without intervention is known as a miscarriage or "spontaneous abortion"; these occur in approximately 30% to 40% of all pregnancies. When deliberate steps are taken to end a pregnancy, it is called an indu... | Biology and health sciences | Health, fitness, and medicine | null |
772 | https://en.wikipedia.org/wiki/Ampere | Ampere | The ampere ( , ; symbol: A), often shortened to amp, is the unit of electric current in the International System of Units (SI). One ampere is equal to 1 coulomb (C) moving past a point per second. It is named after French mathematician and physicist André-Marie Ampère (1775–1836), considered the father of electromagn... | Physical sciences | Electromagnetism | null |
775 | https://en.wikipedia.org/wiki/Algorithm | Algorithm | In mathematics and computer science, an algorithm () is a finite sequence of mathematically rigorous instructions, typically used to solve a class of specific problems or to perform a computation. Algorithms are used as specifications for performing calculations and data processing. More advanced algorithms can use con... | Mathematics | Mathematics: General | null |
782 | https://en.wikipedia.org/wiki/Mouthwash | Mouthwash | Mouthwash, mouth rinse, oral rinse, or mouth bath is a liquid which is held in the mouth passively or swirled around the mouth by contraction of the perioral muscles and/or movement of the head, and may be gargled, where the head is tilted back and the liquid bubbled at the back of the mouth.
Usually mouthwashes are a... | Biology and health sciences | Hygiene products | Health |
786 | https://en.wikipedia.org/wiki/Asparagales | Asparagales | 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... | Biology and health sciences | Asparagales | Plants |
789 | https://en.wikipedia.org/wiki/Asterales | Asterales | 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... | Biology and health sciences | Asterales | Plants |
791 | https://en.wikipedia.org/wiki/Asteroid | Asteroid | 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... | Physical sciences | Astronomy | null |
798 | https://en.wikipedia.org/wiki/Aries%20%28constellation%29 | Aries (constellation) | 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 ... | Physical sciences | Zodiac | Astronomy |
799 | https://en.wikipedia.org/wiki/Aquarius%20%28constellation%29 | Aquarius (constellation) | 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... | Physical sciences | Zodiac | Astronomy |
809 | https://en.wikipedia.org/wiki/Anaconda | Anaconda | 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 ... | Biology and health sciences | Snakes | Animals |
840 | https://en.wikipedia.org/wiki/Axiom%20of%20choice | Axiom of choice | 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... | Mathematics | Discrete mathematics | null |
849 | https://en.wikipedia.org/wiki/Aircraft | Aircraft | An aircraft (: aircraft) is a vehicle that is able to fly by gaining support from the air. It counters the force of gravity by using either static lift or the dynamic lift of an airfoil, or, in a few cases, direct downward thrust from its engines. Common examples of aircraft include airplanes, rotorcraft, helicopters, ... | Technology | Transportation | null |
896 | https://en.wikipedia.org/wiki/Argon | Argon | Argon is a chemical element; it has symbol Ar and atomic number 18. It is in group 18 of the periodic table and is a noble gas. Argon is the third most abundant gas in Earth's atmosphere, at 0.934% (9340 ppmv). It is more than twice as abundant as water vapor (which averages about 4000 ppmv, but varies greatly), 23 tim... | Physical sciences | Chemical elements_2 | null |
897 | https://en.wikipedia.org/wiki/Arsenic | Arsenic | Arsenic is a chemical element with the symbol As and the atomic number 33. It is a metalloid and one of the pnictogens, and therefore shares many properties with its group 15 neighbors phosphorus and antimony. Arsenic is a notoriously toxic heavy metal. It occurs naturally in many minerals, usually in combination with ... | Physical sciences | Chemical elements_2 | null |
898 | https://en.wikipedia.org/wiki/Antimony | Antimony | Antimony is a chemical element; it has symbol Sb () and atomic number 51. A lustrous grey metal or metalloid, it is found in nature mainly as the sulfide mineral stibnite (Sb2S3). Antimony compounds have been known since ancient times and were powdered for use as medicine and cosmetics, often known by the Arabic name k... | Physical sciences | Chemical elements_2 | null |
899 | https://en.wikipedia.org/wiki/Actinium | Actinium | Actinium is a chemical element; it has symbol Ac and atomic number 89. It was first isolated by Friedrich Oskar Giesel in 1902, who gave it the name emanium; the element got its name by being wrongly identified with a substance André-Louis Debierne found in 1899 and called actinium. The actinide series, a set of 15 ele... | Physical sciences | Chemical elements_2 | null |
900 | https://en.wikipedia.org/wiki/Americium | Americium | Americium is a synthetic chemical element; it has symbol Am and atomic number 95. It is radioactive and a transuranic member of the actinide series in the periodic table, located under the lanthanide element europium and was thus named after the Americas by analogy.
Americium was first produced in 1944 by the group of... | Physical sciences | Chemical elements_2 | null |
901 | https://en.wikipedia.org/wiki/Astatine | Astatine | Astatine is a chemical element; it has symbol At and atomic number 85. It is the rarest naturally occurring element in the Earth's crust, occurring only as the decay product of various heavier elements. All of astatine's isotopes are short-lived; the most stable is astatine-210, with a half-life of 8.1 hours. Consequen... | Physical sciences | Chemical elements_2 | null |
902 | https://en.wikipedia.org/wiki/Atom | Atom | Atoms are the basic particles of the chemical elements. An atom consists of a nucleus of protons and generally neutrons, surrounded by an electromagnetically bound swarm of electrons. The chemical elements are distinguished from each other by the number of protons that are in their atoms. For example, any atom that co... | Physical sciences | Science and medicine | null |
903 | https://en.wikipedia.org/wiki/Arable%20land | Arable land | Arable land (from the , "able to be ploughed") is any land capable of being ploughed and used to grow crops. Alternatively, for the purposes of agricultural statistics, the term often has a more precise definition:
A more concise definition appearing in the Eurostat glossary similarly refers to actual rather than pot... | Technology | Basics_2 | null |
904 | https://en.wikipedia.org/wiki/Aluminium | Aluminium | Aluminium (or aluminum in North American English) is a chemical element; it has symbol Al and atomic number 13. Aluminium has a density lower than that of other common metals, about one-third that of steel. It has a great affinity towards oxygen, forming a protective layer of oxide on the surface when exposed to air. A... | Physical sciences | Chemistry | null |
911 | https://en.wikipedia.org/wiki/Archipelago | Archipelago | An archipelago ( ), sometimes called an island group or island chain, is a chain, cluster, or collection of islands, or a sea containing a small number of scattered islands. An archipelago may be on a lake, river, or an ocean. The list of archipelagos includes the Canadian Arctic Archipelago, the Stockholm Archipelago,... | Physical sciences | Oceanic and coastal landforms | null |
928 | https://en.wikipedia.org/wiki/Axiom | Axiom | An axiom, postulate, or assumption is a statement that is taken to be true, to serve as a premise or starting point for further reasoning and arguments. The word comes from the Ancient Greek word (), meaning 'that which is thought worthy or fit' or 'that which commends itself as evident'.
The precise definition varie... | Mathematics | Discrete mathematics | null |
956 | https://en.wikipedia.org/wiki/Asteraceae | Asteraceae | Asteraceae () is a large family of flowering plants that consists of over 32,000 known species in over 1,900 genera within the order Asterales. The number of species in Asteraceae is rivaled only by the Orchidaceae, and which is the larger family is unclear as the quantity of extant species in each family is unknown. T... | Biology and health sciences | Asterales | null |
957 | https://en.wikipedia.org/wiki/Apiaceae | Apiaceae | Apiaceae () or Umbelliferae is a family of mostly aromatic flowering plants named after the type genus Apium, and commonly known as the celery, carrot or parsley family, or simply as umbellifers. It is the 16th-largest family of flowering plants, with more than 3,800 species in about 446 genera, including such well-kno... | Biology and health sciences | Apiales | null |
958 | https://en.wikipedia.org/wiki/Axon | Axon | An axon (from Greek ἄξων áxōn, axis) or nerve fiber (or nerve fibre: see spelling differences) is a long, slender projection of a nerve cell, or neuron, in vertebrates, that typically conducts electrical impulses known as action potentials away from the nerve cell body. The function of the axon is to transmit informati... | Biology and health sciences | Nervous system | Biology |
969 | https://en.wikipedia.org/wiki/Ataxia | Ataxia | Ataxia (from Greek α- [a negative prefix] + -τάξις [order] = "lack of order") is a neurological sign consisting of lack of voluntary coordination of muscle movements that can include gait abnormality, speech changes, and abnormalities in eye movements, that indicates dysfunction of parts of the nervous system that coor... | Biology and health sciences | Symptoms and signs | Health |
991 | https://en.wikipedia.org/wiki/Absolute%20value | Absolute value | In mathematics, the absolute value or modulus of a real number , is the non-negative value without regard to its sign. Namely, if is a positive number, and if is negative (in which case negating makes positive), and For example, the absolute value of 3 and the absolute value of −3 is The absolute value of a ... | Mathematics | Specific functions | null |
994 | https://en.wikipedia.org/wiki/Arecales | Arecales | Arecales is an order of flowering plants. The order has been widely named as such only for the past few decades; until then, the accepted name for the order including these plants was Principes. The order includes palms and relatives.
Taxonomy
The APG IV system of 2016 places Dasypogonaceae in this order, after studie... | Biology and health sciences | Arecales (inc. Palms) | Plants |
1004 | https://en.wikipedia.org/wiki/April | April | April is the fourth month of the year in the Gregorian and Julian calendars. Its length is 30 days.
April is commonly associated with the season of spring in the Northern Hemisphere, and autumn in the Southern Hemisphere, where it is the seasonal equivalent to October in the Northern Hemisphere and vice versa.
Histor... | Technology | Months | null |
1005 | https://en.wikipedia.org/wiki/August | August | August is the eighth month of the year in the Julian and Gregorian calendars. Its length is 31 days.
In the Southern Hemisphere, August is the seasonal equivalent of February in the Northern Hemisphere. In the Northern Hemisphere, August falls in summer. In the Southern Hemisphere, the month falls during winter. In ma... | Technology | Months | null |
1014 | https://en.wikipedia.org/wiki/Alcohol%20%28chemistry%29 | Alcohol (chemistry) | In chemistry, an alcohol (), is a type of organic compound that carries at least one hydroxyl () functional group bound to a saturated carbon atom. Alcohols range from the simple, like methanol and ethanol, to complex, like sugars and cholesterol. The presence of an OH group strongly modifies the properties of hydrocar... | Physical sciences | Carbon–oxygen bond | null |
1032 | https://en.wikipedia.org/wiki/Abscess | Abscess | An abscess is a collection of pus that has built up within the tissue of the body, usually caused by bacterial infection. Signs and symptoms of abscesses include redness, pain, warmth, and swelling. The swelling may feel fluid-filled when pressed. The area of redness often extends beyond the swelling. Carbuncles and bo... | Biology and health sciences | Specific diseases | Health |
1064 | https://en.wikipedia.org/wiki/Almond | Almond | The almond (Prunus amygdalus, syn. Prunus dulcis) is a species of tree from the genus Prunus. Along with the peach, it is classified in the subgenus Amygdalus, distinguished from the other subgenera by corrugations on the shell (endocarp) surrounding the seed.
The fruit of the almond is a drupe, consisting of an outer... | Biology and health sciences | Rosales | null |
1134 | https://en.wikipedia.org/wiki/Analysis | Analysis | Analysis (: analyses) is the process of breaking a complex topic or substance into smaller parts in order to gain a better understanding of it. The technique has been applied in the study of mathematics and logic since before Aristotle (384–322 B.C.), though analysis as a formal concept is a relatively recent developme... | Physical sciences | Science basics | Basics and measurement |
1140 | https://en.wikipedia.org/wiki/Amplitude%20modulation | Amplitude modulation | Amplitude modulation (AM) is a modulation technique used in electronic communication, most commonly for transmitting messages with a radio wave. In amplitude modulation, the amplitude (signal strength) of the wave is varied in proportion to that of the message signal, such as an audio signal. This technique contrasts ... | Technology | Telecommunications | null |
1144 | https://en.wikipedia.org/wiki/Ardipithecus | Ardipithecus | Ardipithecus is a genus of an extinct hominine that lived during the Late Miocene and Early Pliocene epochs in the Afar Depression, Ethiopia. Originally described as one of the earliest ancestors of humans after they diverged from the chimpanzees, the relation of this genus to human ancestors and whether it is a homini... | Biology and health sciences | Australopithecines | Biology |
1146 | https://en.wikipedia.org/wiki/Assembly%20line | Assembly line | An assembly line, often called progressive assembly, is a manufacturing process where the unfinished product moves in a direct line from workstation to workstation, with parts added in sequence until the final product is completed. By mechanically moving parts to workstations and transferring the unfinished product fro... | Technology | Basics_6 | null |
1158 | https://en.wikipedia.org/wiki/Algebraic%20number | Algebraic number | An algebraic number is a number that is a root of a non-zero polynomial in one variable with integer (or, equivalently, rational) coefficients. For example, the golden ratio, , is an algebraic number, because it is a root of the polynomial . That is, it is a value for x for which the polynomial evaluates to zero. As ... | Mathematics | Basics | null |
1164 | https://en.wikipedia.org/wiki/Artificial%20intelligence | Artificial intelligence | Artificial intelligence (AI), in its broadest sense, is intelligence exhibited by machines, particularly computer systems. It is a field of research in computer science that develops and studies methods and software that enable machines to perceive their environment and use learning and intelligence to take actions tha... | Technology | Computing and information technology | null |
1176 | https://en.wikipedia.org/wiki/Antisymmetric%20relation | Antisymmetric relation | In mathematics, a binary relation on a set is antisymmetric if there is no pair of distinct elements of each of which is related by to the other. More formally, is antisymmetric precisely if for all
or equivalently,
The definition of antisymmetry says nothing about whether actually holds or not for any . An an... | Mathematics | Order theory | null |
1181 | https://en.wikipedia.org/wiki/Astrometry | Astrometry | Astrometry is a branch of astronomy that involves precise measurements of the positions and movements of stars and other celestial bodies. It provides the kinematics and physical origin of the Solar System and this galaxy, the Milky Way.
History
The history of astrometry is linked to the history of star catalogues, w... | Physical sciences | Astrometry | null |
1187 | https://en.wikipedia.org/wiki/Alloy | Alloy | An alloy is a mixture of chemical elements of which in most cases at least one is a metallic element, although it is also sometimes used for mixtures of elements; herein only metallic alloys are described. Most alloys are metallic and show good electrical conductivity, ductility, opacity, and luster, and may have prope... | Physical sciences | Chemistry | null |
1196 | https://en.wikipedia.org/wiki/Angle | Angle | In Euclidean geometry, an angle or plane angle is the figure formed by two rays, called the sides of the angle, sharing a common endpoint, called the vertex of the angle.
Two intersecting curves may also define an angle, which is the angle of the rays lying tangent to the respective curves at their point of intersectio... | Mathematics | Geometry and topology | null |
1198 | https://en.wikipedia.org/wiki/Acoustics | Acoustics | Acoustics is a branch of physics that deals with the study of mechanical waves in gases, liquids, and solids including topics such as vibration, sound, ultrasound and infrasound. A scientist who works in the field of acoustics is an acoustician while someone working in the field of acoustics technology may be called an... | Physical sciences | Waves | null |
1200 | https://en.wikipedia.org/wiki/Atomic%20physics | Atomic physics | Atomic physics is the field of physics that studies atoms as an isolated system of electrons and an atomic nucleus. Atomic physics typically refers to the study of atomic structure and the interaction between atoms. It is primarily concerned with the way in which electrons are arranged around the nucleus and
the proces... | Physical sciences | Atomic physics | null |
1206 | https://en.wikipedia.org/wiki/Atomic%20orbital | Atomic orbital | In quantum mechanics, an atomic orbital () is a function describing the location and wave-like behavior of an electron in an atom. This function describes an electron's charge distribution around the atom's nucleus, and can be used to calculate the probability of finding an electron in a specific region around the nucl... | Physical sciences | Atomic physics | null |
1207 | https://en.wikipedia.org/wiki/Amino%20acid | Amino acid | Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although over 500 amino acids exist in nature, by far the most important are the 22 α-amino acids incorporated into proteins. Only these 22 appear in the genetic code of life.
Amino acids can be classified according to the... | Biology and health sciences | Biochemistry and molecular biology | null |
1209 | https://en.wikipedia.org/wiki/Area | Area | Area is the measure of a region's size on a surface. The area of a plane region or plane area refers to the area of a shape or planar lamina, while surface area refers to the area of an open surface or the boundary of a three-dimensional object. Area can be understood as the amount of material with a given thickness th... | Mathematics | Geometry and topology | null |
1210 | https://en.wikipedia.org/wiki/Astronomical%20unit | Astronomical unit | The astronomical unit (symbol: au or AU) is a unit of length defined to be exactly equal to . Historically, the astronomical unit was conceived as the average Earth-Sun distance (the average of Earth's aphelion and perihelion), before its modern redefinition in 2012.
The astronomical unit is used primarily for measuri... | Physical sciences | Length and distance | null |
1242 | https://en.wikipedia.org/wiki/Ada%20%28programming%20language%29 | Ada (programming language) | Ada is a structured, statically typed, imperative, and object-oriented high-level programming language, inspired by Pascal and other languages. It has built-in language support for design by contract (DbC), extremely strong typing, explicit concurrency, tasks, synchronous message passing, protected objects, and non-det... | Technology | "Historical" languages | null |
1267 | https://en.wikipedia.org/wiki/Alpha%20decay | Alpha decay | Alpha decay or α-decay is a type of radioactive decay in which an atomic nucleus emits an alpha particle (helium nucleus) and thereby transforms or "decays" into a different atomic nucleus, with a mass number that is reduced by four and an atomic number that is reduced by two. An alpha particle is identical to the nucl... | Physical sciences | Nuclear physics | Physics |
1271 | https://en.wikipedia.org/wiki/Analytical%20engine | Analytical engine | The analytical engine was a proposed digital mechanical general-purpose computer designed by English mathematician and computer pioneer Charles Babbage. It was first described in 1837 as the successor to Babbage's Difference Engine, which was a design for a simpler mechanical calculator.
The analytical engine incorpor... | Technology | Early computers | null |
1300 | https://en.wikipedia.org/wiki/Abalone | Abalone | Abalone ( or ; via Spanish , from Rumsen aulón) is a common name for any small to very large marine gastropod mollusc in the family Haliotidae, which once contained six genera but now contains only one genus, Haliotis. Other common names are ear shells, sea ears, and, now rarely, muttonfish or muttonshells in parts of... | Biology and health sciences | Gastropods | Animals |
1313 | https://en.wikipedia.org/wiki/Aromatic%20compound | Aromatic compound | Aromatic compounds or arenes are organic compounds "with a chemistry typified by benzene" and "cyclically conjugated."
The word "aromatic" originates from the past grouping of molecules based on odor, before their general chemical properties were understood. The current definition of aromatic compounds does not have an... | Physical sciences | Hydrocarbons | null |
1317 | https://en.wikipedia.org/wiki/Antimatter | Antimatter | In modern physics, antimatter is defined as matter composed of the antiparticles (or "partners") of the corresponding particles in "ordinary" matter, and can be thought of as matter with reversed charge, parity, and time, known as CPT reversal. Antimatter occurs in natural processes like cosmic ray collisions and some ... | Physical sciences | Antimatter | null |
1327 | https://en.wikipedia.org/wiki/Antiparticle | Antiparticle | In particle physics, every type of particle of "ordinary" matter (as opposed to antimatter) is associated with an antiparticle with the same mass but with opposite physical charges (such as electric charge). For example, the antiparticle of the electron is the positron (also known as an antielectron). While the electro... | Physical sciences | Antimatter | null |
1335 | https://en.wikipedia.org/wiki/Associative%20property | Associative property | In mathematics, the associative property is a property of some binary operations that means that rearranging the parentheses in an expression will not change the result. In propositional logic, associativity is a valid rule of replacement for expressions in logical proofs.
Within an expression containing two or more o... | Mathematics | Algebra | null |
1346 | https://en.wikipedia.org/wiki/Apatosaurus | Apatosaurus | Apatosaurus (; meaning "deceptive lizard") is a genus of herbivorous sauropod dinosaur that lived in North America during the Late Jurassic period. Othniel Charles Marsh described and named the first-known species, A. ajax, in 1877, and a second species, A. louisae, was discovered and named by William H. Holland in 191... | Biology and health sciences | Dinosaurs and prehistoric reptiles | null |
1347 | https://en.wikipedia.org/wiki/Allosaurus | Allosaurus | Allosaurus () is an extinct genus of large carnosaurian theropod dinosaur that lived 155 to 145 million years ago during the Late Jurassic period (Kimmeridgian to late Tithonian ages). The name "Allosaurus" means "different lizard", alluding to its unique (at the time of its discovery) concave vertebrae. It is derived ... | Biology and health sciences | Dinosaurs and prehistoric reptiles | null |
1348 | https://en.wikipedia.org/wiki/AK-47 | AK-47 | The AK-47, officially known as the Avtomat Kalashnikova (; also known as the Kalashnikov or just AK), is an assault rifle that is chambered for the 7.62×39mm cartridge. Developed in the Soviet Union by Russian small-arms designer Mikhail Kalashnikov, it is the originating firearm of the Kalashnikov (or "AK") family of ... | Technology | Specific firearms | null |
1349 | https://en.wikipedia.org/wiki/Atanasoff%E2%80%93Berry%20computer | Atanasoff–Berry computer | The Atanasoff–Berry computer (ABC) was the first automatic electronic digital computer. The device was limited by the technology of the day. The ABC's priority is debated among historians of computer technology, because it was neither programmable, nor Turing-complete. Conventionally, the ABC would be considered the fi... | Technology | Early computers | null |
1358 | https://en.wikipedia.org/wiki/Anchor | Anchor | An anchor is a device, normally made of metal, used to secure a vessel to the bed of a body of water to prevent the craft from drifting due to wind or current. The word derives from Latin , which itself comes from the Greek ().
Anchors can either be temporary or permanent. Permanent anchors are used in the creation o... | Technology | Naval transport | null |
1365 | https://en.wikipedia.org/wiki/Ammonia | Ammonia | Ammonia is an inorganic chemical compound of nitrogen and hydrogen with the formula . A stable binary hydride and the simplest pnictogen hydride, ammonia is a colourless gas with a distinctive pungent smell. Biologically, it is a common nitrogenous waste, and it contributes significantly to the nutritional needs of ter... | Physical sciences | Inorganic compounds | null |
1366 | https://en.wikipedia.org/wiki/Amethyst | Amethyst | Amethyst is a violet variety of quartz. The name comes from the Koine Greek from - , "not" and (Ancient Greek) / (Modern Greek), "intoxicate", a reference to the belief that the stone protected its owner from drunkenness. Ancient Greeks wore amethyst and carved drinking vessels from it in the belief that it would... | Physical sciences | Silicate minerals | Earth science |
1368 | https://en.wikipedia.org/wiki/Assembly%20language | Assembly language | In computer programming, assembly language (alternatively assembler language or symbolic machine code), often referred to simply as assembly and commonly abbreviated as ASM or asm, is any low-level programming language with a very strong correspondence between the instructions in the language and the architecture's ma... | Technology | Programming | null |
1372 | https://en.wikipedia.org/wiki/Amber | Amber | Amber is fossilized tree resin. Examples of it have been appreciated for its color and natural beauty since the Neolithic times, and worked as a gemstone since antiquity. Amber is used in jewelry and as a healing agent in folk medicine.
There are five classes of amber, defined on the basis of their chemical constituen... | Physical sciences | Organic gemstones | null |
1383 | https://en.wikipedia.org/wiki/Alder | Alder | Alders are trees of the genus Alnus in the birch family Betulaceae. The genus includes about 35 species of monoecious trees and shrubs, a few reaching a large size, distributed throughout the north temperate zone with a few species extending into Central America, as well as the northern and southern Andes.
Description... | Biology and health sciences | Fagales | null |
1394 | https://en.wikipedia.org/wiki/Algol | Algol | Algol , designated Beta Persei (β Persei, abbreviated Beta Per, β Per), known colloquially as the Demon Star, is a bright multiple star in the constellation of Perseus and one of the first non-nova variable stars to be discovered.
Algol is a three-star system, consisting of Beta Persei Aa1, Aa2, and Ab – in which the ... | Physical sciences | Notable stars | Astronomy |
1400 | https://en.wikipedia.org/wiki/Anno%20Domini | Anno Domini | The terms (AD) and before Christ (BC) are used when designating years in the Gregorian and Julian calendars. The term is Medieval Latin and means "in the year of the Lord" but is often presented using "our Lord" instead of "the Lord", taken from the full original phrase "anno Domini nostri Jesu Christi", which transl... | Technology | Calendars | null |
1412 | https://en.wikipedia.org/wiki/Amine | Amine | In chemistry, amines (, ) are compounds and functional groups that contain a basic nitrogen atom with a lone pair. Formally, amines are derivatives of ammonia ((in which the bond angle between the nitrogen and hydrogen is 170°), wherein one or more hydrogen atoms have been replaced by a substituent such as an alkyl or... | Physical sciences | Carbon–nitrogen bond | null |
1418 | https://en.wikipedia.org/wiki/Absolute%20zero | Absolute zero | Absolute zero is the lowest limit of the thermodynamic temperature scale; a state at which the enthalpy and entropy of a cooled ideal gas reach their minimum value. The fundamental particles of nature have minimum vibrational motion, retaining only quantum mechanical, zero-point energy-induced particle motion. The theo... | Physical sciences | Thermodynamics | null |
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