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18236523 | https://en.wikipedia.org/wiki/Alc%C3%A1ntara%20Bridge | Alcántara Bridge | The Alcántara Bridge (also known as Trajan's Bridge at Alcantara) is a Roman bridge at Alcántara, in Extremadura, Spain. Alcántara is from the Arabic word al-Qantarah (القنطرة) meaning "the arch". The stone arch bridge was built over the Tagus River between 104 and 106 AD by an order of the Roman emperor Trajan in 9... | Technology | Bridges | null |
3367910 | https://en.wikipedia.org/wiki/Megalonyx | Megalonyx | Megalonyx (Greek, "great-claw") is an extinct genus of ground sloths of the family Megalonychidae, native to North America. It evolved during the Pliocene Epoch and became extinct at the end of the Late Pleistocene, living from ~5 million to ~13,000 years ago. The type species, M. jeffersonii (also called Jefferson's g... | Biology and health sciences | Xenarthra | Animals |
3372377 | https://en.wikipedia.org/wiki/Optical%20fiber | Optical fiber | An optical fiber, or optical fibre, is a flexible glass or plastic fiber that can transmit light from one end to the other. Such fibers find wide usage in fiber-optic communications, where they permit transmission over longer distances and at higher bandwidths (data transfer rates) than electrical cables. Fibers are us... | Technology | Basics_9 | null |
3372717 | https://en.wikipedia.org/wiki/Duality%20%28optimization%29 | Duality (optimization) | In mathematical optimization theory, duality or the duality principle is the principle that optimization problems may be viewed from either of two perspectives, the primal problem or the dual problem. If the primal is a minimization problem then the dual is a maximization problem (and vice versa). Any feasible solution... | Mathematics | Optimization | null |
3373620 | https://en.wikipedia.org/wiki/Atlantic%20hurricane | Atlantic hurricane | An Atlantic hurricane is a type of tropical cyclone that forms in the Atlantic Ocean primarily between June and November. The terms "hurricane", "typhoon", and "tropical cyclone" can be used interchangeably to describe this weather phenomenon. These storms are continuously rotating around a low pressure center, which c... | Physical sciences | Storms | Earth science |
28979 | https://en.wikipedia.org/wiki/Scopolamine | Scopolamine | Scopolamine, also known as hyoscine, or Devil's Breath, is a natural or synthetically produced tropane alkaloid and anticholinergic drug that is used as a medication to treat motion sickness and postoperative nausea and vomiting. It is also sometimes used before surgery to decrease saliva. When used by injection, effec... | Physical sciences | Alkaloids | Chemistry |
28982 | https://en.wikipedia.org/wiki/Snowball%20Earth | Snowball Earth | The Snowball Earth is a geohistorical hypothesis that proposes that during one or more of Earth's icehouse climates, the planet's surface became nearly entirely frozen with no liquid oceanic or surface water exposed to the atmosphere. The most academically mentioned period of such a global ice age is believed to have o... | Physical sciences | Events | Earth science |
29000 | https://en.wikipedia.org/wiki/Speciation | Speciation | Speciation is the evolutionary process by which populations evolve to become distinct species. The biologist Orator F. Cook coined the term in 1906 for cladogenesis, the splitting of lineages, as opposed to anagenesis, phyletic evolution within lineages. Charles Darwin was the first to describe the role of natural sele... | Biology and health sciences | Basics_4 | Biology |
29004 | https://en.wikipedia.org/wiki/SQL | SQL | Structured Query Language (SQL) (pronounced S-Q-L; or alternatively as "sequel") is a domain-specific language used to manage data, especially in a relational database management system (RDBMS). It is particularly useful in handling structured data, i.e., data incorporating relations among entities and variables.
In... | Technology | Data modeling languages | null |
29006 | https://en.wikipedia.org/wiki/Space%20telescope | Space telescope | A space telescope (also known as space observatory) is a telescope in outer space used to observe astronomical objects. Suggested by Lyman Spitzer in 1946, the first operational telescopes were the American Orbiting Astronomical Observatory, OAO-2 launched in 1968, and the Soviet Orion 1 ultraviolet telescope aboard sp... | Technology | Telescope | null |
29087 | https://en.wikipedia.org/wiki/Security%20through%20obscurity | Security through obscurity | In security engineering, security through obscurity is the practice of concealing the details or mechanisms of a system to enhance its security. This approach relies on the principle of hiding something in plain sight, akin to a magician's sleight of hand or the use of camouflage. It diverges from traditional security ... | Technology | Computer security | null |
29090 | https://en.wikipedia.org/wiki/Software%20testing | Software testing | Software testing is the act of checking whether software satisfies expectations.
Software testing can provide objective, independent information about the quality of software and the risk of its failure to a user or sponsor.
Software testing can determine the correctness of software for specific scenarios but cannot ... | Technology | Software development: General | null |
29163 | https://en.wikipedia.org/wiki/Sighthound | Sighthound | Sighthounds (also called gazehounds) are a type of hound dog that hunts primarily by sight and speed, unlike scent hounds, which rely on scent and endurance.
Appearance
These dogs specialize in pursuing prey, keeping it in sight, and overpowering it by their great speed and agility. They must be able to detect motion... | Biology and health sciences | Dogs | Animals |
29181 | https://en.wikipedia.org/wiki/Spherical%20coordinate%20system | Spherical coordinate system | In mathematics, a spherical coordinate system specifies a given point in three-dimensional space by using a distance and two angles as its three coordinates. These are
the radial distance along the line connecting the point to a fixed point called the origin;
the polar angle between this radial line and a given po... | Mathematics | Geometry: General | null |
29208 | https://en.wikipedia.org/wiki/Square%20root | Square root | In mathematics, a square root of a number is a number such that ; in other words, a number whose square (the result of multiplying the number by itself, or ) is . For example, 4 and −4 are square roots of 16 because .
Every nonnegative real number has a unique nonnegative square root, called the principal square r... | Mathematics | Basics | null |
29234 | https://en.wikipedia.org/wiki/Spear | Spear | A spear is a polearm consisting of a shaft, usually of wood, with a pointed head. The head may be simply the sharpened end of the shaft itself, as is the case with fire hardened spears, or it may be made of a more durable material fastened to the shaft, such as bone, flint, obsidian, copper, bronze, iron, or steel. The... | Technology | Melee weapons | null |
29247 | https://en.wikipedia.org/wiki/Sulfuric%20acid | Sulfuric acid | Sulfuric acid (American spelling and the preferred IUPAC name) or sulphuric acid (Commonwealth spelling), known in antiquity as oil of vitriol, is a mineral acid composed of the elements sulfur, oxygen, and hydrogen, with the molecular formula . It is a colorless, odorless, and viscous liquid that is miscible with wate... | Physical sciences | Inorganic compounds | null |
29248 | https://en.wikipedia.org/wiki/Space%20colonization | Space colonization | Space colonization (or extraterrestrial colonization) is the colonization of outer space and astronomical bodies. As such it is a process of occupation or control for exploitation, such as extraterrestrial mining, and possibly extraterrestrial settlement.
Making territorial claims in space is prohibited by internation... | Technology | Basics_6 | null |
29293 | https://en.wikipedia.org/wiki/Optical%20spectrometer | Optical spectrometer | An optical spectrometer (spectrophotometer, spectrograph or spectroscope) is an instrument used to measure properties of light over a specific portion of the electromagnetic spectrum, typically used in spectroscopic analysis to identify materials. The variable measured is most often the irradiance of the light but coul... | Technology | Measuring instruments | null |
29318 | https://en.wikipedia.org/wiki/Streptococcus | Streptococcus | Streptococcus is a genus of gram-positive or spherical bacteria that belongs to the family Streptococcaceae, within the order Lactobacillales (lactic acid bacteria), in the phylum Bacillota. Cell division in streptococci occurs along a single axis, thus when growing they tend to form pairs or chains, which may appear b... | Biology and health sciences | Gram-positive bacteria | Plants |
29324 | https://en.wikipedia.org/wiki/Signal%20processing | Signal processing | Signal processing is an electrical engineering subfield that focuses on analyzing, modifying and synthesizing signals, such as sound, images, potential fields, seismic signals, altimetry processing, and scientific measurements. Signal processing techniques are used to optimize transmissions, digital storage efficiency,... | Technology | Basics_4 | null |
29341 | https://en.wikipedia.org/wiki/Superheterodyne%20receiver | Superheterodyne receiver | A superheterodyne receiver, often shortened to superhet, is a type of radio receiver that uses frequency mixing to convert a received signal to a fixed intermediate frequency (IF) which can be more conveniently processed than the original carrier frequency. It was invented by French radio engineer and radio manufacture... | Technology | Broadcasting | null |
29365 | https://en.wikipedia.org/wiki/Synthetic%20element | Synthetic element | A synthetic element is one of 24 known chemical elements that do not occur naturally on Earth: they have been created by human manipulation of fundamental particles in a nuclear reactor, a particle accelerator, or the explosion of an atomic bomb; thus, they are called "synthetic", "artificial", or "man-made". The synth... | Physical sciences | Chemical element groups | null |
29369 | https://en.wikipedia.org/wiki/Sex%20organ | Sex organ | A sex organ, also known as a reproductive organ, is a part of an organism that is involved in sexual reproduction. Sex organs constitute the primary sex characteristics of an organism. Sex organs are responsible for producing and transporting gametes, as well as facilitating fertilization and supporting the development... | Biology and health sciences | Reproductive system | null |
29370 | https://en.wikipedia.org/wiki/Snake | Snake | Snakes are elongated limbless reptiles of the suborder Serpentes (). Cladistically squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales much like other members of the group. Many species of snakes have skulls with several more joints than their lizard ancestors and relatives, enabling th... | Biology and health sciences | Reptiles | null |
29374 | https://en.wikipedia.org/wiki/Steam%20turbine | Steam turbine | A steam turbine or steam turbine engine is a machine or heat engine that extracts thermal energy from pressurized steam and uses it to do mechanical work on a rotating output shaft. Its modern manifestation was invented by Charles Parsons in 1884. Fabrication of a modern steam turbine involves advanced metalwork to for... | Technology | Electricity generation and distribution | null |
29381 | https://en.wikipedia.org/wiki/Semi-trailer%20truck | Semi-trailer truck | A semi-trailer truck (also known by a wide variety of other terms – see below) is the combination of a tractor unit and one or more semi-trailers to carry freight. A semi-trailer attaches to the tractor with a type of hitch called a fifth wheel.
Other terms
There are a wide variety of English-language terms for a sem... | Technology | Motorized road transport | null |
29388 | https://en.wikipedia.org/wiki/Sheffer%20stroke | Sheffer stroke | In Boolean functions and propositional calculus, the Sheffer stroke denotes a logical operation that is equivalent to the negation of the conjunction operation, expressed in ordinary language as "not both". It is also called non-conjunction, or alternative denial (since it says in effect that at least one of its operan... | Mathematics | Mathematical logic | null |
29390 | https://en.wikipedia.org/wiki/Stalactite | Stalactite | A stalactite (, ; , ) is a mineral formation that hangs from the ceiling of caves, hot springs, or man-made structures such as bridges and mines. Any material that is soluble and that can be deposited as a colloid, or is in suspension, or is capable of being melted, may form a stalactite. Stalactites may be composed of... | Physical sciences | Caves | Earth science |
29392 | https://en.wikipedia.org/wiki/Summer | Summer | Summer or summertime is the hottest and brightest of the four temperate seasons, occurring after spring and before autumn. At or centred on the summer solstice, daylight hours are the longest and darkness hours are the shortest, with day length decreasing as the season progresses after the solstice. The earliest sunris... | Physical sciences | Seasons | null |
29394 | https://en.wikipedia.org/wiki/Shrike | Shrike | Shrikes () are passerine birds of the family Laniidae. The family is composed of 34 species in two genera.
The family name, and that of the larger genus, Lanius, is derived from the Latin word for "butcher", and some shrikes are also known as butcherbirds because of the habit, particularly of males, of impaling prey o... | Biology and health sciences | Corvoidea | null |
29400 | https://en.wikipedia.org/wiki/Structural%20biology | Structural biology | Structural biology, as defined by the Journal of Structural Biology, deals with structural analysis of living material (formed, composed of, and/or maintained and refined by living cells) at every level of organization.
Early structural biologists throughout the 19th and early 20th centuries were primarily only able ... | Biology and health sciences | Biochemistry | Biology |
29409 | https://en.wikipedia.org/wiki/Spica | Spica | Spica is the brightest object in the constellation of Virgo and one of the 20 brightest stars in the night sky. It has the Bayer designation α Virginis, which is Latinised to Alpha Virginis and abbreviated Alpha Vir or α Vir. Analysis of its parallax shows that it is located 250 light-years from the Sun. It is a spectr... | Physical sciences | Notable stars | Astronomy |
29438 | https://en.wikipedia.org/wiki/Sonar | Sonar | Sonar (sound navigation and ranging or sonic navigation and ranging) is a technique that uses sound propagation (usually underwater, as in submarine navigation) to navigate, measure distances (ranging), communicate with or detect objects on or under the surface of the water, such as other vessels.
"Sonar" can refer to... | Technology | Navigation | null |
29441 | https://en.wikipedia.org/wiki/Skylab | Skylab | Skylab was the United States' first space station, launched by NASA, occupied for about 24 weeks between May 1973 and February 1974. It was operated by three trios of astronaut crews: Skylab 2, Skylab 3, and Skylab 4. Operations included an orbital workshop, a solar observatory, Earth observation and hundreds of experi... | Technology | Crewed vehicles | null |
29467 | https://en.wikipedia.org/wiki/Spinel | Spinel | Spinel () is the magnesium/aluminium member of the larger spinel group of minerals. It has the formula in the cubic crystal system. Its name comes from the Latin word , a diminutive form of spine, in reference to its pointed crystals.
Properties
Spinel crystallizes in the isometric system; common crystal forms are o... | Physical sciences | Minerals | Earth science |
29468 | https://en.wikipedia.org/wiki/Speech%20recognition | Speech recognition | Speech recognition is an interdisciplinary subfield of computer science and computational linguistics that develops methodologies and technologies that enable the recognition and translation of spoken language into text by computers. It is also known as automatic speech recognition (ASR), computer speech recognition or... | Technology | Artificial intelligence concepts | null |
29469 | https://en.wikipedia.org/wiki/Sapphire | Sapphire | Sapphire is a precious gemstone, a variety of the mineral corundum, consisting of aluminium oxide () with trace amounts of elements such as iron, titanium, cobalt, lead, chromium, vanadium, magnesium, boron, and silicon. The name sapphire is derived from the Latin word , itself from the Greek word (), which referred t... | Physical sciences | Mineral gemstones | null |
29485 | https://en.wikipedia.org/wiki/Skyscraper | Skyscraper | A skyscraper is a tall continuously habitable building having multiple floors. Modern sources define skyscrapers as being at least or in height, though there is no universally accepted definition, other than being very tall high-rise buildings. Skyscrapers may host offices, hotels, residential spaces, and retail spac... | Technology | Mixed-use buildings | null |
29537 | https://en.wikipedia.org/wiki/Scientific%20misconduct | Scientific misconduct | Scientific misconduct is the violation of the standard codes of scholarly conduct and ethical behavior in the publication of professional scientific research. It is violation of scientific integrity: violation of the scientific method and of research ethics in science, including in the design, conduct, and reporting of... | Physical sciences | Science basics | Basics and measurement |
29549 | https://en.wikipedia.org/wiki/Self-replication | Self-replication | Self-replication is any behavior of a dynamical system that yields construction of an identical or similar copy of itself. Biological cells, given suitable environments, reproduce by cell division. During cell division, DNA is replicated and can be transmitted to offspring during reproduction. Biological viruses can re... | Physical sciences | Science basics | Basics and measurement |
29559 | https://en.wikipedia.org/wiki/Sienna | Sienna | Sienna (from , meaning "Earth of Siena") is an earth pigment containing iron oxide and manganese oxide. In its natural state, it is yellowish brown, and it is called raw sienna. When heated, it becomes a reddish brown, and it is called burnt sienna. It takes its name from the city-state of Siena, where it was produced ... | Physical sciences | Minerals | Earth science |
29588 | https://en.wikipedia.org/wiki/Sextant | Sextant | A sextant is a doubly reflecting navigation instrument that measures the angular distance between two visible objects. The primary use of a sextant is to measure the angle between an astronomical object and the horizon for the purposes of celestial navigation.
The estimation of this angle, the altitude, is known as si... | Technology | Navigation | null |
29638 | https://en.wikipedia.org/wiki/Sierpi%C5%84ski%20triangle | Sierpiński triangle | The Sierpiński triangle, also called the Sierpiński gasket or Sierpiński sieve, is a fractal with the overall shape of an equilateral triangle, subdivided recursively into smaller equilateral triangles. Originally constructed as a curve, this is one of the basic examples of self-similar sets—that is, it is a mathemati... | Mathematics | Other | null |
29648 | https://en.wikipedia.org/wiki/Single-lens%20reflex%20camera | Single-lens reflex camera | A single-lens reflex camera (SLR) is a camera that typically uses a mirror and prism system (hence "reflex" from the mirror's reflection) that permits the photographer to view through the lens and see exactly what will be captured. With twin lens reflex and rangefinder cameras, the viewed image could be significantly d... | Technology | Photography | null |
29657 | https://en.wikipedia.org/wiki/Salamander | Salamander | Salamanders are a group of amphibians typically characterized by their lizard-like appearance, with slender bodies, blunt snouts, short limbs projecting at right angles to the body, and the presence of a tail in both larvae and adults. All ten extant salamander families are grouped together under the order Urodela fro... | Biology and health sciences | Amphibians | null |
29816 | https://en.wikipedia.org/wiki/Technology | Technology | Technology is the application of conceptual knowledge to achieve practical goals, especially in a reproducible way. The word technology can also mean the products resulting from such efforts, including both tangible tools such as utensils or machines, and intangible ones such as software. Technology plays a critical ro... | Technology | null | null |
29831 | https://en.wikipedia.org/wiki/Television | Television | Television (TV) is a telecommunication medium for transmitting moving images and sound. Additionally, the term can refer to a physical television set rather than the medium of transmission. Television is a mass medium for advertising, entertainment, news, and sports. The medium is capable of more than "radio broadcasti... | Technology | Media and communication | null |
29952 | https://en.wikipedia.org/wiki/Thermodynamics | Thermodynamics | Thermodynamics is a branch of physics that deals with heat, work, and temperature, and their relation to energy, entropy, and the physical properties of matter and radiation. The behavior of these quantities is governed by the four laws of thermodynamics, which convey a quantitative description using measurable macrosc... | Physical sciences | Physics | null |
29954 | https://en.wikipedia.org/wiki/Topology | Topology | Topology (from the Greek words , and ) is the branch of mathematics concerned with the properties of a geometric object that are preserved under continuous deformations, such as stretching, twisting, crumpling, and bending; that is, without closing holes, opening holes, tearing, gluing, or passing through itself.
A to... | Mathematics | Geometry and topology | null |
29965 | https://en.wikipedia.org/wiki/Tensor | Tensor | In mathematics, a tensor is an algebraic object that describes a multilinear relationship between sets of algebraic objects related to a vector space. Tensors may map between different objects such as vectors, scalars, and even other tensors. There are many types of tensors, including scalars and vectors (which are the... | Mathematics | Geometry | null |
29967 | https://en.wikipedia.org/wiki/Tarragon | Tarragon | Tarragon (Artemisia dracunculus), also known as estragon, is a species of perennial herb in the family Asteraceae. It is widespread in the wild across much of Eurasia and North America and is cultivated for culinary and medicinal purposes.
One subspecies, Artemisia dracunculus var. sativa, is cultivated to use the lea... | Biology and health sciences | Herbs and spices | Plants |
29968 | https://en.wikipedia.org/wiki/Thyme | Thyme | Thyme () is a culinary herb consisting of the dried aerial parts of some members of the genus Thymus of flowering plants in the mint family Lamiaceae. Thymes are native to Eurasia and north Africa. Thymes have culinary, medicinal, and ornamental uses. The species most commonly cultivated and used for culinary purposes ... | Biology and health sciences | Lamiales | null |
29970 | https://en.wikipedia.org/wiki/Tank | Tank | A tank is an armoured fighting vehicle intended as a primary offensive weapon in front-line ground combat. Tank designs are a balance of heavy firepower, strong armour, and battlefield mobility provided by tracks and a powerful engine; their main armament is often mounted within a turret. They are a mainstay of modern ... | Technology | Military technology: General | null |
29973 | https://en.wikipedia.org/wiki/Turmeric | Turmeric | Turmeric (), or Curcuma longa (), is a flowering plant in the ginger family Zingiberaceae. It is a perennial, rhizomatous, herbaceous plant native to the Indian subcontinent and Southeast Asia that requires temperatures between and high annual rainfall to thrive. Plants are gathered each year for their rhizomes, some ... | Biology and health sciences | Herbs and spices | Plants |
29984 | https://en.wikipedia.org/wiki/Taurus%20%28constellation%29 | Taurus (constellation) | Taurus (Latin, 'Bull') is one of the constellations of the zodiac and is located in the northern celestial hemisphere. Taurus is a large and prominent constellation in the Northern Hemisphere's winter sky. It is one of the oldest constellations, dating back to the Early Bronze Age at least, when it marked the location ... | Physical sciences | Zodiac | Astronomy |
29989 | https://en.wikipedia.org/wiki/Triassic | Triassic | The Triassic ( ; sometimes symbolized 🝈) is a geologic period and system which spans 50.5 million years from the end of the Permian Period 251.902 million years ago (Mya), to the beginning of the Jurassic Period 201.4 Mya. The Triassic is the first and shortest period of the Mesozoic Era and the seventh period of the ... | Physical sciences | Geological periods | null |
30001 | https://en.wikipedia.org/wiki/Theory%20of%20relativity | Theory of relativity | The theory of relativity usually encompasses two interrelated physics theories by Albert Einstein: special relativity and general relativity, proposed and published in 1905 and 1915, respectively. Special relativity applies to all physical phenomena in the absence of gravity. General relativity explains the law of grav... | Physical sciences | Physics | null |
30003 | https://en.wikipedia.org/wiki/Telephone | Telephone | A telephone, colloquially referred to as a phone, is a telecommunications device that enables two or more users to conduct a conversation when they are too far apart to be easily heard directly. A telephone converts sound, typically and most efficiently the human voice, into electronic signals that are transmitted via ... | Technology | Media and communication | null |
30010 | https://en.wikipedia.org/wiki/Telegraphy | Telegraphy | Telegraphy is the long-distance transmission of messages where the sender uses symbolic codes, known to the recipient, rather than a physical exchange of an object bearing the message. Thus flag semaphore is a method of telegraphy, whereas pigeon post is not. Ancient signalling systems, although sometimes quite extensi... | Technology | Media and communication | null |
30011 | https://en.wikipedia.org/wiki/Transistor | Transistor | A transistor is a semiconductor device used to amplify or switch electrical signals and power. It is one of the basic building blocks of modern electronics. It is composed of semiconductor material, usually with at least three terminals for connection to an electronic circuit. A voltage or current applied to one pair o... | Technology | Components | null |
30012 | https://en.wikipedia.org/wiki/Time | Time | Time is the continuous progression of existence that occurs in an apparently irreversible succession from the past, through the present, and into the future. It is a component quantity of various measurements used to sequence events, to compare the duration of events (or the intervals between them), and to quantify rat... | Physical sciences | Science and medicine | null |
30040 | https://en.wikipedia.org/wiki/Titanium | Titanium | Titanium is a chemical element; it has symbol Ti and atomic number 22. Found in nature only as an oxide, it can be reduced to produce a lustrous transition metal with a silver color, low density, and high strength, resistant to corrosion in sea water, aqua regia, and chlorine.
Titanium was discovered in Cornwall, Grea... | Physical sciences | Chemical elements_2 | null |
30041 | https://en.wikipedia.org/wiki/Technetium | Technetium | Technetium is a chemical element; it has symbol Tc and atomic number 43. It is the lightest element whose isotopes are all radioactive. Technetium and promethium are the only radioactive elements whose neighbours in the sense of atomic number are both stable. All available technetium is produced as a synthetic element.... | Physical sciences | Chemical elements_2 | null |
30042 | https://en.wikipedia.org/wiki/Tin | Tin | Tin is a chemical element; it has symbol Sn () and atomic number 50. A silvery-colored metal, tin is soft enough to be cut with little force, and a bar of tin can be bent by hand with little effort. When bent, the so-called "tin cry" can be heard as a result of twinning in tin crystals.
Tin is a post-transition metal ... | Physical sciences | Chemical elements_2 | null |
30043 | https://en.wikipedia.org/wiki/Tellurium | Tellurium | Tellurium is a chemical element; it has symbol Te and atomic number 52. It is a brittle, mildly toxic, rare, silver-white metalloid. Tellurium is chemically related to selenium and sulfur, all three of which are chalcogens. It is occasionally found in its native form as elemental crystals. Tellurium is far more common ... | Physical sciences | Chemical elements_2 | null |
30044 | https://en.wikipedia.org/wiki/Thorium | Thorium | Thorium is a chemical element; it has symbol Th and atomic number 90. Thorium is a weakly radioactive light silver metal which tarnishes olive grey when it is exposed to air, forming thorium dioxide; it is moderately soft, malleable, and has a high melting point. Thorium is an electropositive actinide whose chemistry i... | Physical sciences | Chemical elements_2 | null |
30045 | https://en.wikipedia.org/wiki/Terbium | Terbium | Terbium is a chemical element; it has the symbol Tb and atomic number 65. It is a silvery-white, rare earth metal that is malleable and ductile. The ninth member of the lanthanide series, terbium is a fairly electropositive metal that reacts with water, evolving hydrogen gas. Terbium is never found in nature as a free ... | Physical sciences | Chemical elements_2 | null |
30046 | https://en.wikipedia.org/wiki/Tungsten | Tungsten | Tungsten (also called wolfram) is a chemical element; it has symbol W and atomic number 74. It is a rare metal found naturally on Earth almost exclusively as compounds with other elements. It was identified as a distinct element in 1781 and first isolated as a metal in 1783. Its important ores include scheelite and wol... | Physical sciences | Chemical elements_2 | null |
30047 | https://en.wikipedia.org/wiki/Thulium | Thulium | Thulium is a chemical element; it has symbol Tm and atomic number 69. It is the thirteenth element in the lanthanide series of metals. It is the second-least abundant lanthanide in the Earth's crust, after radioactively unstable promethium. It is an easily workable metal with a bright silvery-gray luster. It is fairly ... | Physical sciences | Chemical elements_2 | null |
30048 | https://en.wikipedia.org/wiki/Tantalum | Tantalum | Tantalum is a chemical element; it has symbol Ta and atomic number 73. It is named after Tantalus, a figure in Greek mythology. Tantalum is a very hard, ductile, lustrous, blue-gray transition metal that is highly corrosion-resistant. It is part of the refractory metals group, which are widely used as components of str... | Physical sciences | Chemical elements_2 | null |
30056 | https://en.wikipedia.org/wiki/Trojan%20horse%20%28computing%29 | Trojan horse (computing) | In computing, a Trojan horse (or simply Trojan) is a malware that misleads users of its true intent by disguising itself as a normal program. The term is derived from the ancient Greek story of the deceptive Trojan Horse that led to the fall of the city of Troy.
Trojans are generally spread by some form of social en... | Technology | Computer security | null |
30065 | https://en.wikipedia.org/wiki/TeX | TeX | TeX (, see below), stylized within the system as , is a typesetting program which was designed and written by computer scientist and Stanford University professor Donald Knuth and first released in 1978. The term now refers to the system of extensions – which includes software programs called TeX engines, sets of TeX ... | Technology | Office and data management | null |
30075 | https://en.wikipedia.org/wiki/Tiger | Tiger | The tiger (Panthera tigris) is a large cat and a member of the genus Panthera native to Asia. It has a powerful, muscular body with a large head and paws, a long tail and orange fur with black, mostly vertical stripes. It is traditionally classified into nine recent subspecies, though some recognise only two subspecies... | Biology and health sciences | Carnivora | null |
30078 | https://en.wikipedia.org/wiki/Thyroid | Thyroid | The thyroid, or thyroid gland, is an endocrine gland in vertebrates. In humans, it is a butterfly-shaped gland located in the neck below the Adam's apple. It consists of two connected lobes. The lower two thirds of the lobes are connected by a thin band of tissue called the isthmus (: isthmi). Microscopically, the fun... | Biology and health sciences | Animal: General | null |
30284 | https://en.wikipedia.org/wiki/Statistical%20hypothesis%20test | Statistical hypothesis test | A statistical hypothesis test is a method of statistical inference used to decide whether the data sufficiently supports a particular hypothesis. A statistical hypothesis test typically involves a calculation of a test statistic. Then a decision is made, either by comparing the test statistic to a critical value or equ... | Mathematics | Statistics and probability | null |
30309 | https://en.wikipedia.org/wiki/Thallium | Thallium | Thallium is a chemical element; it has symbol Tl and atomic number 81. It is a silvery-white post-transition metal that is not found free in nature. When isolated, thallium resembles tin, but discolors when exposed to air. Chemists William Crookes and Claude-Auguste Lamy discovered thallium independently in 1861, in re... | Physical sciences | Chemical elements_2 | null |
30318 | https://en.wikipedia.org/wiki/Ton | Ton | Ton is any of several units of measure of mass, volume or force. It has a long history and has acquired several meanings and uses.
As a unit of mass, ton can mean:
the long ton, which is
the tonne, also called the metric ton, which is ) or 1 megagram.
the short ton, which is
Its original use as a unit of volume ... | Physical sciences | Mass | null |
30325 | https://en.wikipedia.org/wiki/Transcendental%20number | Transcendental number | In mathematics, a transcendental number is a real or complex number that is not algebraic: that is, not the root of a non-zero polynomial with integer (or, equivalently, rational) coefficients. The best-known transcendental numbers are and . The quality of a number being transcendental is called transcendence.
Though... | Mathematics | Basics | null |
30330 | https://en.wikipedia.org/wiki/Total%20order | Total order | In mathematics, a total order or linear order is a partial order in which any two elements are comparable. That is, a total order is a binary relation on some set , which satisfies the following for all and in :
(reflexive).
If and then (transitive).
If and then (antisymmetric).
or (strongly connected... | Mathematics | Order theory | null |
30333 | https://en.wikipedia.org/wiki/Tetraodontiformes | Tetraodontiformes | Tetraodontiformes (), also known as the Plectognathi, is an order of ray-finned fishes which includes the pufferfishes and related taxa. This order has been classified as a suborder of the order Perciformes, although recent studies have found that it, as the Tetraodontoidei, is a sister taxon to the anglerfish order Lo... | Biology and health sciences | Acanthomorpha | Animals |
30364 | https://en.wikipedia.org/wiki/Transition%20metal | Transition metal | In chemistry, a transition metal (or transition element) is a chemical element in the d-block of the periodic table (groups 3 to 12), though the elements of group 12 (and less often group 3) are sometimes excluded. The lanthanide and actinide elements (the f-block) are called inner transition metals and are sometimes c... | Physical sciences | Chemical element groups | null |
30366 | https://en.wikipedia.org/wiki/Torr | Torr | The torr (symbol: Torr) is a unit of pressure based on an absolute scale, defined as exactly of a standard atmosphere (101325 Pa). Thus one torr is exactly (≈ ).
Historically, one torr was intended to be the same as one "millimeter of mercury", but subsequent redefinitions of the two units made the torr marginally ... | Physical sciences | Pressure | Basics and measurement |
30367 | https://en.wikipedia.org/wiki/Trigonometric%20functions | Trigonometric functions | In mathematics, the trigonometric functions (also called circular functions, angle functions or goniometric functions) are real functions which relate an angle of a right-angled triangle to ratios of two side lengths. They are widely used in all sciences that are related to geometry, such as navigation, solid mechanics... | Mathematics | Geometry | null |
30369 | https://en.wikipedia.org/wiki/Thermochemistry | Thermochemistry | Thermochemistry is the study of the heat energy which is associated with chemical reactions and/or phase changes such as melting and boiling. A reaction may release or absorb energy, and a phase change may do the same. Thermochemistry focuses on the energy exchange between a system and its surroundings in the form of ... | Physical sciences | Thermodynamics | Chemistry |
30388 | https://en.wikipedia.org/wiki/Thylacine | Thylacine | The thylacine (; binomial name Thylacinus cynocephalus), also commonly known as the Tasmanian tiger or Tasmanian wolf, is an extinct carnivorous marsupial that was native to the Australian mainland and the islands of Tasmania and New Guinea. The thylacine died out in New Guinea and mainland Australia around 3,600–3,200... | Biology and health sciences | Marsupials | Animals |
30400 | https://en.wikipedia.org/wiki/Torque | Torque | In physics and mechanics, torque is the rotational analogue of linear force. It is also referred to as the moment of force (also abbreviated to moment). The symbol for torque is typically , the lowercase Greek letter tau. When being referred to as moment of force, it is commonly denoted by . Just as a linear force is a... | Physical sciences | Classical mechanics | null |
30402 | https://en.wikipedia.org/wiki/Theory%20of%20computation | Theory of computation | In theoretical computer science and mathematics, the theory of computation is the branch that deals with what problems can be solved on a model of computation, using an algorithm, how efficiently they can be solved or to what degree (e.g., approximate solutions versus precise ones). The field is divided into three maj... | Mathematics | Discrete mathematics | null |
30403 | https://en.wikipedia.org/wiki/Turing%20machine | Turing machine | A Turing machine is a mathematical model of computation describing an abstract machine that manipulates symbols on a strip of tape according to a table of rules. Despite the model's simplicity, it is capable of implementing any computer algorithm.
The machine operates on an infinite memory tape divided into discrete c... | Mathematics | Computability theory | null |
30426 | https://en.wikipedia.org/wiki/Total%20internal%20reflection | Total internal reflection | In physics, total internal reflection (TIR) is the phenomenon in which waves arriving at the interface (boundary) from one medium to another (e.g., from water to air) are not refracted into the second ("external") medium, but completely reflected back into the first ("internal") medium. It occurs when the second medium... | Physical sciences | Optics | Physics |
30436 | https://en.wikipedia.org/wiki/Theory%20of%20everything | Theory of everything | A theory of everything (TOE), final theory, ultimate theory, unified field theory, or master theory is a hypothetical singular, all-encompassing, coherent theoretical framework of physics that fully explains and links together all aspects of the universe. Finding a theory of everything is one of the major unsolved prob... | Physical sciences | Particle physics: General | Physics |
30448 | https://en.wikipedia.org/wiki/Taylor%20series | Taylor series | In mathematics, the Taylor series or Taylor expansion of a function is an infinite sum of terms that are expressed in terms of the function's derivatives at a single point. For most common functions, the function and the sum of its Taylor series are equal near this point. Taylor series are named after Brook Taylor, who... | Mathematics | Calculus and analysis | null |
30450 | https://en.wikipedia.org/wiki/Topological%20space | Topological space | In mathematics, a topological space is, roughly speaking, a geometrical space in which closeness is defined but cannot necessarily be measured by a numeric distance. More specifically, a topological space is a set whose elements are called points, along with an additional structure called a topology, which can be defin... | Mathematics | Geometry | null |
30461 | https://en.wikipedia.org/wiki/Transfinite%20induction | Transfinite induction | Transfinite induction is an extension of mathematical induction to well-ordered sets, for example to sets of ordinal numbers or cardinal numbers. Its correctness is a theorem of ZFC.
Induction by cases
Let be a property defined for all ordinals . Suppose that whenever is true for all , then is also true. Then tra... | Mathematics | Set theory | null |
30462 | https://en.wikipedia.org/wiki/Triple%20point | Triple point | In thermodynamics, the triple point of a substance is the temperature and pressure at which the three phases (gas, liquid, and solid) of that substance coexist in thermodynamic equilibrium. It is that temperature and pressure at which the sublimation, fusion, and vaporisation curves meet. For example, the triple point ... | Physical sciences | Phase transitions | null |
30463 | https://en.wikipedia.org/wiki/Taxonomy%20%28biology%29 | Taxonomy (biology) | In biology, taxonomy () is the scientific study of naming, defining (circumscribing) and classifying groups of biological organisms based on shared characteristics. Organisms are grouped into taxa (singular: taxon), and these groups are given a taxonomic rank; groups of a given rank can be aggregated to form a more inc... | Biology and health sciences | Biology | null |
30467 | https://en.wikipedia.org/wiki/Tyrannosaurus | Tyrannosaurus | Tyrannosaurus () is a genus of large theropod dinosaur. The type species Tyrannosaurus rex ( meaning 'king' in Latin), often shortened to T. rex or colloquially T-Rex, is one of the best represented theropods. It lived throughout what is now western North America, on what was then an island continent known as Laramidia... | Biology and health sciences | Dinosaurs and prehistoric reptiles | null |
30500 | https://en.wikipedia.org/wiki/Thiamine | Thiamine | Thiamine, also known as thiamin and vitamin B1, is a vitamin – an essential micronutrient for humans and animals. It is found in food and commercially synthesized to be a dietary supplement or medication. Phosphorylated forms of thiamine are required for some metabolic reactions, including the breakdown of glucose and... | Biology and health sciences | Vitamins | Health |
30531 | https://en.wikipedia.org/wiki/Toxicology | Toxicology | Toxicology is a scientific discipline, overlapping with biology, chemistry, pharmacology, and medicine, that involves the study of the adverse effects of chemical substances on living organisms and the practice of diagnosing and treating exposures to toxins and toxicants. The relationship between dose and its effects o... | Biology and health sciences | Fields of medicine | null |
30538 | https://en.wikipedia.org/wiki/Transmission%20Control%20Protocol | Transmission Control Protocol | The Transmission Control Protocol (TCP) is one of the main protocols of the Internet protocol suite. It originated in the initial network implementation in which it complemented the Internet Protocol (IP). Therefore, the entire suite is commonly referred to as TCP/IP. TCP provides reliable, ordered, and error-checked d... | Technology | Internet | null |
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