General Knowledge

Red bananas are a group of varieties of bananas with reddish-purple skin. Some are smaller and plumper than the common Cavendish banana, others much larger. Ripe, raw red bananas have a flesh that is creamy to light pink. They are also softer and sweeter than the yellow Cavendish varieties, some with a slight tangy raspberry flavor and…

Milk is usually a white liquid food produced by the mammary glands of lactating mammals. It is the primary source of nutrition for young mammals before they are able to digest solid food. Milk contains many nutrients, including calcium and protein, as well as lactose and saturated fat; the enzyme lactase is needed to break down lactose.…

Diffuse sky radiation, is solar radiation reaching the Earth's surface after having been scattered from the direct solar beam by molecules or particulates in the atmosphere. It is also called sky radiation, the determinative process for changing the colors of the sky. It is normally measured on a horizontal surface, thus frequently…

An umbrella is a folding canopy supported by wooden or metal ribs that is mounted on a wooden, metal, or plastic pole. It is usually designed to protect a person against sun or rain. Initially, they were used in warmer countries for shade from the sun, but in modern times they evolved to also be used for protection from rain.…

Winter is the coldest and darkest season of the year in temperate and polar climates. It occurs after autumn and before spring, when the hemisphere is oriented away from the Sun as a result of the tilt of Earth's axis. Different cultures define different dates as the start of winter, and some use a definition based on weather.

Spherical Earth or Earth's curvature refers to the approximation of the figure of the Earth as a sphere. The earliest documented mention of the concept dates from around the 5th century BC, when it appears in the writings of Greek philosophers. In the 3rd century BC, Hellenistic astronomy established the roughly spherical shape of Earth…

A finger is a prominent digit on the forelimbs of most tetrapod vertebrate animals, especially those with prehensile extremities such as humans and other primates. Most tetrapods have five digits (pentadactyly), and short digits are typically referred to as toes, while those that are notably elongated are called fingers. In humans, the…

Snow is a form of solid atmospheric precipitation consisting of individual ice crystals that grow while suspended in the air—usually within clouds—and then fall, accumulating on the ground, where they undergo further changes. It consists of frozen crystalline water throughout its life cycle, starting when, under suitable conditions, the…

Breakfast is the first meal of the day, usually eaten in the morning. The word in English refers to breaking the fasting period of the previous night. Various "typical" or "traditional" breakfast menus exist, with food choices varying by regions and traditions worldwide.

A wing is a structure which produces both lift and drag while moving through air. Wings are defined by two shape characteristics, an airfoil section and a planform. Wing efficiency is expressed as lift-to-drag ratio, which compares the benefit of lift with the air resistance of a given wing shape, as it flies. Aerodynamics includes the…

"East of the Sun and West of the Moon" is a Norwegian fairy-tale. It was collected by Peter Christen Asbjørnsen and Jørgen Moe, who compiled it from variants they recorded in the regions of Ringerike and Telemark. The tale was first published in 1844 as No. 42 in Norske Folkeeventyr Anden Deel, before being subsequently renumbered as No. 41 in 1852.

A bicycle wheel is a wheel, most commonly a wire wheel, designed for a bicycle. A pair is often called a wheelset, especially in the context of ready built "off the shelf" performance-oriented wheels.

Smell Like a Man, Man is a television advertising campaign in the United States created by ad agency Wieden+Kennedy for the Old Spice brand of male grooming products, owned by Procter & Gamble. The campaign is commonly referred to as The Man Your Man Could Smell Like, the title of the campaign's initial 30-second commercial. The campaign…

Ice is water that is frozen into a solid state, typically forming at or below temperatures of 0 °C, 32 °F, or 273.15 K. It occurs naturally on Earth, on other planets, in Oort cloud objects, and as interstellar ice. As a naturally occurring crystalline inorganic solid with an ordered structure, ice is considered to be a mineral.…

Humans and other hominids have consumed eggs for millions of years. The most widely consumed eggs are those of fowl, especially chickens. People in Southeast Asia began harvesting chicken eggs for food around 1500 BCE. Eggs of other birds, such as ducks and ostriches, are eaten regularly but much less commonly than those of chickens.…

The Twelve-Day War was an armed conflict between Iran and Israel which lasted from 13 to 24 June 2025. It began when Israel bombed military and nuclear facilities in Iran in a surprise attack, assassinating prominent military leaders, nuclear scientists, and politicians, killing civilians, and damaging or destroying air defenses. Iran…

Owls are birds from the order Strigiformes, which includes over 200 species of mostly solitary and nocturnal birds of prey typified by an upright stance, a large, broad head, binocular vision, binaural hearing, sharp talons, and feathers adapted for silent flight. Exceptions include the diurnal northern hawk-owl and the gregarious burrowing owl.

Hail is a form of solid atmospheric precipitation. It is distinct from ice pellets, though the two are often confused. It consists of balls or irregular lumps of ice, each of which is called a hailstone. Ice pellets generally fall in cold weather, while hail growth is greatly inhibited during low surface temperatures.

In lexical semantics, opposites are words lying in an inherently incompatible binary relationship. For example, something that is even entails that it is not odd. It is referred to as a 'binary' relationship because there are two members in a set of opposites. The relationship between opposites is known as opposition. A member of a pair…

Sunlight is the portion of the electromagnetic radiation which is emitted by the Sun and received by the Earth, in particular the visible light perceptible to the human eye as well as invisible infrared and ultraviolet lights. However, according to the American Meteorological Society, there are "conflicting conventions as to whether all…

A is the first letter and the first vowel letter of the Latin alphabet, used in the modern English alphabet, and others worldwide. Its name in English is a, plural aes.

A triangle or trigon is a polygon with three corners and three sides, one of the basic shapes in geometry. The corners, also called vertices, are zero-dimensional points while the sides connecting them, also called edges, are one-dimensional line segments. A triangle has three internal angles, each one bounded by a pair of adjacent…

A shoe is an item of footwear normally found in pairs intended to protect and comfort the human foot, usually made in such a way that one is designed to fit the left foot and the other the right foot.

Milk is usually a white liquid food produced by the mammary glands of lactating mammals. It is the primary source of nutrition for young mammals before they are able to digest solid food. Milk contains many nutrients, including calcium and protein, as well as lactose and saturated fat; the enzyme lactase is needed to break down lactose.…

Sheep or domestic sheep are a domesticated, ruminant mammal typically kept as livestock. Although the term sheep can apply to other species in the genus Ovis, in everyday usage it almost always refers to domesticated sheep. Like all ruminants, sheep are members of the order Artiodactyla, the even-toed ungulates. There are around 1.2…

Emerald is a gemstone and a variety of the mineral beryl (Be3Al2(SiO3)6) colored green by trace amounts of chromium or sometimes vanadium. Beryl has a hardness of 7.5–8 on the Mohs scale. Most emeralds have many inclusions, so their toughness is classified as poor. Emerald is a cyclosilicate. It occurs mainly in association with quartz,…

An apple is the round, edible fruit of an apple tree. Fruit trees of the orchard or domestic apple, the most widely grown in the genus, are cultivated worldwide. The tree originated in Central Asia, where its wild ancestor, Malus sieversii, is still found. Apples have been grown for thousands of years in Eurasia before they were…

The Arctic is the polar region of Earth that surrounds the North Pole, lying north of the Arctic Circle. The Arctic region, from the IERS Reference Meridian travelling east, consists of parts of northern Norway, northernmost Sweden, northern Finland, Russia, the United States (Alaska), Canada, Danish Realm (Greenland), and northern…

In lexical semantics, opposites are words lying in an inherently incompatible binary relationship. For example, something that is even entails that it is not odd. It is referred to as a 'binary' relationship because there are two members in a set of opposites. The relationship between opposites is known as opposition. A member of a pair…

The chicken is the domesticated form of the red junglefowl, originally native to Southeast Asia. It was first domesticated around 8,000 years ago and is one of the most common and widespread domesticated animals in the world. Chickens are primarily kept for their meat and eggs, though they are also kept as pets.

A stop sign is a traffic sign designed to notify drivers that they must come to a complete stop and make sure the intersection is safely clear of vehicles and pedestrians before continuing past the sign. In many countries, the sign is a red octagon with the word STOP, in either English, the national language of that particular country,…

Lamb and mutton, collectively sheep meat, is one of the most common meats around the world. It is meat from the domestic sheep, Ovis aries, and generally divided into lamb, from sheep in their first year, hogget, from sheep in their second, and mutton, from older sheep.

Chalk is a soft, white, porous, sedimentary carbonate rock. It is a form of limestone composed of the mineral calcite and originally formed under the sea by the accumulation and lithification of hard parts of organisms, mostly microscopic plankton, which had settled to the sea floor. Chalk is common throughout Western Europe, where…

Tuesday is the day of the week between Monday and Wednesday. According to international standard ISO 8601, Monday is the first day of the week; thus, Tuesday is the second day of the week. According to many traditional calendars, however, Sunday is the first day of the week, so Tuesday is the third day of the week. In some Muslim…

Rain or rainfall is a form of atmospheric precipitation composed of droplets of water aerosols that have condensed from atmospheric water vapor and fall by gravity. Depending on the intensity, rain can be described as a drizzle, a shower, a cloudburst or a downpour. It is also often accompanied by other weather phenomena such as strong…

Rabbits, or bunnies, are small mammals in the family Leporidae, which is in the order Lagomorpha. They are familiar throughout the world as a small herbivore, a prey animal, a domesticated form of livestock, and a pet, having a widespread effect on ecologies and cultures. The most widespread rabbit genera are Oryctolagus and Sylvilagus.…

The lemon is a species of small evergreen tree in the Citrus genus of the flowering plant family Rutaceae. A true lemon is a hybrid of the citron and the bitter orange. Its origins are uncertain, but some evidence suggests lemons originated during the 1st millennium BC in what is now northeastern India. Some other citrus fruits are called lemon.

An igloo, also known as a snow house or snow hut, is a type of shelter built of suitable snow.

A sandwich is a dish typically consisting variously of meat, cheese, sauces, and vegetables used as a filling between slices of bread, or placed atop a slice of bread ; or, more generally, any dish in which bread serves as a container or wrapper for another food type. The sandwich began as a portable, convenient food in the Western…

A frog is any member of a diverse and largely semiaquatic group of short-bodied, tailless amphibian vertebrates composing the order Anura. Frog species with rough skin texture due to wart-like parotoid glands tend to be called toads, but the distinction between frogs and toads is informal and purely cosmetic, and does not reflect…

Green is the color between cyan and yellow on the visible spectrum. It has 295–350 different shades. It is evoked by light which has a dominant wavelength of roughly 495–570 nm. In subtractive color systems, used in painting and color printing, it is created by a combination of yellow and cyan; in the RGB color model, used on television…

Toes are the digits of the foot of a tetrapod. Animal species such as cats that walk on their toes are described as being digitigrade. Humans, and other animals that walk on the soles of their feet, are described as being plantigrade; unguligrade animals are those that walk on hooves at the tips of their toes.

The goldfish is a freshwater fish in the family Cyprinidae of the order Cypriniformes. It is commonly kept as a pet in indoor aquariums, and is one of the most popular aquarium fish. Goldfish released into the wild have become an invasive pest in parts of North America and Australia.

Night, or nighttime, is the period of darkness when the Sun is below the horizon. Daylight illuminates one side of the Earth, leaving the other in darkness. The opposite of nighttime is daytime. Earth's rotation causes the appearance of sunrise and sunset. Moonlight, airglow, starlight, and light pollution dimly illuminate night. The…

The garden strawberry is a widely grown hybrid plant cultivated worldwide for its fruit. The genus Fragaria, the strawberries, is in the rose family, Rosaceae. The fruit is appreciated for its aroma, bright red colour, juicy texture, and sweetness. It is eaten either fresh or in prepared foods such as jam, ice cream, and chocolates.…

Among animals which produce eggs, the yolk is the nutrient-bearing portion of the egg, the primary function of which is to supply food for the development of the embryo. Some types of egg contain no yolk, for example because they are laid in situations where the food supply is sufficient or because the embryo develops in the parent's…

In geometry, a square is a regular quadrilateral. It has four straight sides of equal length and four equal angles. Squares are special cases of rectangles, which have four equal angles, and of rhombuses, which have four equal sides. As with all rectangles, a square's angles are right angles, making adjacent sides perpendicular. The area…

The hazelnut is the fruit of the hazel tree and therefore includes any of the nuts deriving from species of the genus Corylus, especially the nuts of the species Corylus avellana. They are also known as cobnuts or filberts according to species.

Ice cream is a frozen dessert typically made from milk or cream that has been flavoured with a sweetener, either sugar or an alternative, and a spice, such as cocoa or vanilla, or with fruit, such as strawberries or peaches. Food colouring is sometimes added in addition to stabilizers. The mixture is cooled below the freezing point of…

An aircraft pilot is an individual who controls an aircraft's flight by operating its directional controls. Other aircrew members, such as navigators and flight engineers, are also considered aviators because they assist in operating the aircraft’s navigation and engine systems. Aircrew members like drone operators, flight attendants,…

In lexical semantics, opposites are words lying in an inherently incompatible binary relationship. For example, something that is even entails that it is not odd. It is referred to as a 'binary' relationship because there are two members in a set of opposites. The relationship between opposites is known as opposition. A member of a pair…

A veterinarian (vet) or veterinary surgeon is a medical professional who practices veterinary medicine. They manage a wide range of health conditions and injuries in non-human animals. Along with this, veterinarians also play a role in animal reproduction, health management, conservation, husbandry and breeding and preventive medicine…

An apple is the round, edible fruit of an apple tree. Fruit trees of the orchard or domestic apple, the most widely grown in the genus, are cultivated worldwide. The tree originated in Central Asia, where its wild ancestor, Malus sieversii, is still found. Apples have been grown for thousands of years in Eurasia before they were…

The polar bear is a large bear native to the Arctic and nearby areas. It is closely related to the brown bear, and the two species can interbreed. The polar bear is the largest extant species of bear and land carnivore by body mass, with adult males weighing 300–800 kg (660–1,760 lb). The species is sexually dimorphic, as adult females…

Duck is the common name for numerous species of waterfowl in the family Anatidae. Ducks are generally smaller and shorter-necked than swans and geese, which are members of the same family. Divided among several subfamilies, they are a form taxon; they do not represent a monophyletic group, since swans and geese are not considered ducks.…

Sugar is a class of sweet-tasting, soluble carbohydrates, many of which are used in food. Simple sugars, also called monosaccharides, include glucose, fructose and galactose. Compound sugars, also called disaccharides or double sugars, are molecules made of two bonded monosaccharides; common examples are sucrose, lactose and maltose.…

A forest is an ecosystem characterized by a dense community of trees. Hundreds of definitions of forest are used throughout the world, incorporating factors such as tree density, tree height, land use, legal standing, and ecological function. The United Nations' Food and Agriculture Organization (FAO) defines a forest as, "Land spanning…

Boiling or ebullition is the rapid phase transition from liquid to gas or vapour; the reverse of boiling is condensation. Boiling occurs when a liquid is heated to its boiling point, so that the vapour pressure of the liquid is equal to the pressure exerted on the liquid by the surrounding atmosphere. Boiling and evaporation are the two…

A library is a collection of books, and possibly other materials and media, that is accessible for use by its members and members of allied institutions. Libraries provide physical or digital materials, and may be a physical location, a virtual space, or both. A library's collection normally includes printed materials which can be…

A rainbow is an optical phenomenon caused by refraction, internal reflection and dispersion of light in water droplets resulting in a continuous spectrum of light appearing in the sky. The rainbow takes the form of a multicoloured circular arc. Rainbows caused by sunlight always appear in the section of sky directly opposite the sun.…

Ice is water that is frozen into a solid state, typically forming at or below temperatures of 0 °C, 32 °F, or 273.15 K. It occurs naturally on Earth, on other planets, in Oort cloud objects, and as interstellar ice. As a naturally occurring crystalline inorganic solid with an ordered structure, ice is considered to be a mineral.…

Bamboos are a diverse group of mostly evergreen perennial flowering plants making up the subfamily Bambusoideae of the grass family Poaceae. Giant bamboos are the largest members of the grass family, in the case of Dendrocalamus sinicus having individual stalks (culms) reaching a length of 46 meters (151 ft), up to 36 centimeters (14 in)…

A drop or droplet is a small column of liquid, bounded completely or almost completely by free surfaces. A drop may form when liquid accumulates at the end of a tube or other surface boundary, producing a hanging drop called a pendant drop. Drops may also be formed by the condensation of a vapor or by atomization of a larger mass of…

A pupa is the life stage of insects from the Holometabola clade undergoing metamorphosis between immature and mature stages. Insects that go through a pupal stage are holometabolous: they go through four distinct stages in their life cycle, the stages thereof being egg, larva, pupa and imago (adult). The processes of entering and…

A football pitch or soccer field is the playing surface for the game of association football. Its dimensions and markings are defined by Law 1 of the Laws of the Game, "The Field of Play". The pitch is typically made of natural turf or artificial turf, although amateur and recreational teams often play on dirt fields. Artificial surfaces…

Tinker Bell is a fictional character from J. M. Barrie's 1904 play Peter Pan and its 1911 novelisation Peter and Wendy. She has appeared in a variety of film and television adaptations of the Peter Pan stories, in particular the 1953 animated Walt Disney picture Peter Pan. She also appears in the official 2006 sequel Peter Pan in Scarlet…

A herbivore is an animal anatomically or physiologically evolved to feed on plants, especially upon vascular tissues such as foliage, fruits or seeds, as the main component of its diet. These more broadly also encompass animals that eat non-vascular autotrophs such as mosses, algae and lichens, but do not include those feeding on…

Superman is a superhero created by writer Jerry Siegel and artist Joe Shuster, first appearing in issue #1 of Action Comics, published in the United States on April 18, 1938. Superman has been regularly published in American comic books published by DC Comics since then, and has been adapted to other media including radio serials,…

February is the second month of the year in the Julian and Gregorian calendars. The month has 28 days in common years and 29 in leap years, with the 29th day being called the leap day. February is the third and last month of meteorological winter in the Northern Hemisphere. In the Southern Hemisphere, February is the third and last month…

Summer or summertime is the hottest and brightest of the four temperate seasons, occurring after spring and before autumn. At or centered 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 sunrises and latest…

Ants are eusocial insects of the family Formicidae and, along with the related wasps and bees, belong to the order Hymenoptera. Ants evolved from vespoid wasp ancestors in the Cretaceous period. More than 13,800 of an estimated total of 22,000 species have been described. They are easily identified by their geniculate (elbowed) antennae…

"Jack and the Beanstalk" is an English fairy tale with ancient origins. It appeared as "The Story of Jack Spriggins and the Enchanted Bean" in 1734 and as Benjamin Tabart's moralized "The History of Jack and the Bean-Stalk" in 1807. Henry Cole, publishing under pen name Felix Summerly, popularized the tale in The Home Treasury (1845),…

Baseball is a bat-and-ball sport played between two teams of nine players each, taking turns batting and fielding. The game occurs over the course of several plays, with each play beginning when a player on the fielding team, called the pitcher, throws a ball that a player on the batting team, called the batter, tries to hit with a bat.…

RMS Titanic was a British ocean liner that sank in the early hours of 15 April 1912 as a result of striking an iceberg on her maiden voyage from Southampton, England, to New York City. Of the 2,208 passengers and crew aboard, approximately 1,500 died, making the incident one of the deadliest peacetime sinkings of a single ship. Titanic,…

A day is the time period of a full rotation of the Earth with respect to the Sun. On average, this is 24 hours. As a day passes at a given location it experiences morning, afternoon, evening, and night. This daily cycle drives circadian rhythms in many organisms, which are vital to many life processes.

In geometry, an octagon is an eight-sided polygon or 8-gon.

Kangaroos are marsupials from the subfamily Macropodinae. In common use, the term is used to describe the largest species from this family, the red kangaroo, as well as the antilopine kangaroo, eastern grey kangaroo, and western grey kangaroo. Kangaroos are indigenous to Australia and New Guinea. The Australian government estimates that…

Sheriff Woody Pride is a pull-string cowboy doll who appears in the Disney–Pixar Toy Story franchise. In the films, Woody is one of the main protagonists, alongside Buzz Lightyear, Jessie, Bo Peep, and Bullseye. He is primarily voiced by Tom Hanks, who voices him in the Toy Story films, short films, and TV specials. Hanks's brother, Jim…

A twelve-string guitar is a steel-string guitar with 12 strings in six courses, which produces a thicker, more ringing tone than a standard six-string guitar. Typically, the strings of the lower four courses are tuned in octaves, with those of the upper two courses tuned in unison. The gap between the strings within each dual-string…

"Hedwig's Theme" is an orchestral piece composed by John Williams. It serves as the main theme for the Harry Potter film series, based on the series of popular fantasy novels of the same name by author J. K. Rowling. The theme first appears in the opening credits of The Philosopher's Stone in the "Prologue" track, a shortened version of…

A frog is any member of a diverse and largely semiaquatic group of short-bodied, tailless amphibian vertebrates composing the order Anura. Frog species with rough skin texture due to wart-like parotoid glands tend to be called toads, but the distinction between frogs and toads is informal and purely cosmetic, and does not reflect…

1000 or one thousand is the natural number following 999 and preceding 1001. In most English-speaking countries, it can be written with or without a comma or sometimes a period separating the thousands digit: 1,000.

Cheese is a type of dairy product produced in a range of flavors, textures, and forms by coagulation of the milk protein casein. It is composed of proteins and fat from milk, usually of cows, goats or sheep, and sometimes of water buffalo. During production, milk is usually acidified and either the enzymes of rennet or bacterial enzymes…

A circle is a shape consisting of all points in a plane that are at a given distance from a given point, the centre. The distance between any point of the circle and the centre is called the radius. The length of a line segment connecting two points on the circle and passing through the centre is called the diameter. A circle bounds a…

Buzz Lightyear is a fictional character in the Disney–Pixar Toy Story franchise. He is a superhero action figure from an in-universe media franchise. Buzz is recognizable by his lime green, purple, and white space suit. Originating as a one-man band toy named Tinny, he evolved into a space ranger action figure during the development of…

February is the second month of the year in the Julian and Gregorian calendars. The month has 28 days in common years and 29 in leap years, with the 29th day being called the leap day. February is the third and last month of meteorological winter in the Northern Hemisphere. In the Southern Hemisphere, February is the third and last month…

Water is an inorganic compound with the chemical formula H2O. It is a transparent, tasteless, odorless, and nearly colorless chemical substance. It is the main constituent of Earth's streams, lakes, and oceans. Water is also the fluid of all known living organisms, in which it acts as a solvent. Water, being a polar molecule, undergoes…

A chef is a professional cook and tradesperson who is proficient in many aspects of food preparation, often focusing on a particular cuisine. The word "chef" is derived from the term chef de cuisine, the director or head of a kitchen. Chefs can receive formal training from an institution, as well as by apprenticing with an experienced chef.

Blueberries are a widely distributed and widespread group of perennial flowering plants with blue or purple berries. They are classified in the section Cyanococcus within the genus Vaccinium. Commercial blueberries—both wild (lowbush) and cultivated (highbush)—are all native to North America. The highbush varieties were introduced into…

Tennis is a racket sport that is played either individually against a single opponent (singles) or between two teams of two players each (doubles). Each player uses a tennis racket strung with a cord to strike a hollow rubber ball covered with felt over or around a net and into the opponent's court. The objective is to manoeuvre the ball…

Bears are carnivoran mammals of the family Ursidae. They are classified as caniforms within the suborder Caniformia. Although only eight species of bears are extant, they are widespread, appearing in a wide variety of habitats throughout most of the Northern Hemisphere and partially in the Southern Hemisphere. Bears are found on the…

Coffee is a beverage brewed from roasted ground coffee beans. Darkly colored and bitter, coffee has a stimulating effect on humans due to its caffeine content, but decaffeinated coffee is also commercially available. There are also various coffee substitutes.

Egg white is the clear liquid contained within an egg. In chickens, it is formed from the layers of secretions of the anterior section of the hen's oviduct during the passage of the egg. It forms around fertilized or unfertilized egg yolks. The primary natural purpose of egg white is to protect the yolk and provide additional nutrition…

Eeyore is a fictional anthropomorphic stuffed donkey created by the English author A. A. Milne and the English illustrator E. H. Shepard. Eeyore is a character in the Winnie-the-Pooh book series, debuting in Winnie-the-Pooh (1926). The character is inspired by a stuffed toy that Milne had bought for his son Christopher Robin in Harrods department store.

A sleigh is a horse-drawn vehicle mounted on runners for travel over snow or ice and pulled by one or more horses. Sleighs are used for winter transport, agricultural work, and pleasure. They were historically used in regions with long winters as a practical means of transport, and they remain culturally associated with winter travel and…

The human skeleton is the internal framework of the human body. It is composed of around 270 bones at birth – this total decreases to around 206 bones by adulthood after some bones fuse together, not counting accessory bones. The bone mass in the skeleton makes up about 14% of the total body weight and reaches maximum mass between the…

An aurora is a natural light display in Earth's upper atmosphere caused by charged particles from the Sun colliding with atoms in the atmosphere. These collisions excite oxygen and nitrogen, which then emit light of different colors such as green, red, and purple. When observed in high-latitude regions they are called polar lights and…

Human teeth function to mechanically break down items of food by cutting and crushing them in preparation for swallowing and digesting. As such, they are considered part of the human digestive system. Humans have four types of teeth: incisors, canines, premolars, and molars, which each have a specific function. The incisors cut the food,…

Brazilian Portuguese is the set of varieties of the Portuguese language native to Brazil. It is spoken by nearly all of the 203 million inhabitants of Brazil, and widely across the Brazilian diaspora, consisting of approximately two million Brazilians who have emigrated to other countries.

Pride is a primary emotion characterized by a sense of security with one's identity, performance, and/or accomplishments. It is sometimes considered the opposite of shame. Depending on the context, pride may be viewed as either a virtue or a vice. Typically, pride arises from praise, independent self-reflection, or a fulfilled feeling of belonging.

Invertebrates are animals that neither develop nor retain a vertebral column, which evolved from the notochord. It is a paraphyletic grouping including all animals excluding the chordate subphylum Vertebrata, i.e. vertebrates. Nonetheless, almost all invertebrates belong to the monophyletic clade Protostomia, including arthropods,…

A barometer is a scientific instrument that is used to measure air pressure. Pressure tendency, which is derived from barometric readings, can forecast short term changes in the weather. Many measurements of air pressure are used within surface weather analysis to help find surface troughs, pressure systems and frontal boundaries.

In geometry, a pentagon is any five-sided polygon or 5-gon. The sum of the internal angles in a simple pentagon is 540°.

Basketball is a team sport in which two teams of five players each oppose one another on a rectangular court. Players compete with the primary objective of shooting a basketball through a hoop at each end of the court. Teams alternate between offense, and defense. A field goal is worth two points, unless made from behind the three-point…

Complementary colors are pairs of colors which, when combined or mixed, cancel each other out by producing a grayscale color like white or black. When two highly chromatic complementary colors are placed next to each other, they create a strong contrast. Complementary colors may also be called "opposite colors".

Tyrannosaurus is a genus of large theropod dinosaur. The type species Tyrannosaurus rex, 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. Tyrannosaurus had a much wider range than other…

Flour is a powder used to make many different foods, including baked goods, as well as thickening dishes. It is made by grinding grains, beans, nuts, seeds, roots, or vegetables using a mill.

An earthquake, also called a quake, tremor, or temblor, is the shaking of the Earth's surface resulting from a sudden release of energy in the lithosphere that creates seismic waves. Earthquakes can range in intensity, from those so weak they cannot be felt, to those violent enough to propel objects and people into the air, damage…

The dog is a domesticated descendant of wolves. Also called the domestic dog, it was selectively bred during the Late Pleistocene by hunter-gatherers. Dogs and the modern gray wolf share a common ancestor. Dogs were the first species to be domesticated over 14,000 years ago, before the development of agriculture, though genetic studies…

Neil Alden Armstrong was an American astronaut and aeronautical engineer who, as the commander of the 1969 Apollo 11 mission, became the first person to walk on the Moon. He was also a naval aviator, test pilot and university professor.

Botany, also called plant science, is the branch of natural science and biology that studies the growth, reproduction and evolution of plants over the last 3.5 billion years of life on earth. As with all areas of biology and medicine, plants can be studied at range of levels from their biochemistry, molecular biology, cell biology and…

The degree Celsius is the unit of temperature on the Celsius temperature scale, one of two temperature scales used in the International System of Units (SI), the other being the closely related Kelvin scale. The degree Celsius can refer to a specific point on the Celsius temperature scale or to a difference or range between two…

In geometry, a decagon is a ten-sided polygon or 10-gon. The total sum of the interior angles of a simple decagon is 1440°.

Vitamin D is a group of structurally related, fat-soluble compounds responsible for increasing intestinal absorption of calcium and phosphate, along with numerous other biological functions. In humans, the most important compounds within this group are vitamin D3 (cholecalciferol) and vitamin D2 (ergocalciferol).

The vestibular system, in vertebrates, is a sensory system that creates the sense of balance and spatial orientation for the function of coordinating movement with balance. Together with the cochlea, a part of the auditory system, it constitutes the labyrinth of the inner ear in most mammals.

Artificial satellites are human-made spacecraft placed into orbit around Earth or another celestial body. They are distinct from natural satellites such as moons, and from space probes that travel beyond Earth orbit or between planetary bodies. Artificial satellites operate as part of wider satellite systems that may include a satellite…

Legumes are plants in the pea family Fabaceae, or the fruit or seeds of such plants. When used as a dry grain for human consumption, the seeds are also called pulses. Legumes are grown agriculturally, primarily for human consumption, but also as livestock forage and silage, and as soil-enhancing green manure. Legumes produce a…

Chinese characters are logographs used to write the Chinese languages and others from regions historically influenced by Chinese culture, including Japan, Korea, and Vietnam. Of the four independently invented writing systems accepted by scholars, they represent the only one that has remained in continuous use. Over a documented history…

The Jolly Roger was the ensign flown by a pirate ship preceding or during an attack, during the early 18th century. The vast majority of such flags flew the motif of a human skull, or “Death's Head”, often accompanied by other elements, on a black field, sometimes called the "Death's Head flag" or just the "black flag".

Albert Einstein was a German-born theoretical physicist best known for developing the theory of relativity. Einstein also made important contributions to quantum theory. His mass–energy equivalence formula E = mc2, which arises from special relativity, has been called "the world's most famous equation". He received the 1921 Nobel Prize…

A national sport is a physical activity or sport that is culturally significant or deeply embedded in a nation, serving as a national symbol and an intrinsic element to a nation's identity and culture.

An equilateral triangle is a triangle in which all three sides have the same length, and all three angles are equal. Because of these properties, the equilateral triangle is a regular polygon, occasionally known as the regular triangle. It is the special case of an isosceles triangle by modern definition, creating more special properties.

Magma is the molten or semi-molten natural material from which all igneous rocks are formed. Magma is found beneath the surface of the Earth, and evidence of magmatism has also been discovered on other terrestrial planets and some natural satellites. Besides molten rock, magma may also contain suspended crystals and gas bubbles.

The almond 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 woody shell (endocarp) surrounding the seed.

The heart is a muscular organ found in humans and other animals. This organ pumps blood through the blood vessels. The heart and blood vessels together make up the circulatory system. The pumped blood carries oxygen and nutrients to the tissue, while carrying metabolic waste such as carbon dioxide to the lungs. In humans, the heart is…

RMS Titanic sank in the North Atlantic Ocean on 15 April 1912. The largest ocean liner in service at the time, Titanic was four days into her maiden voyage from Southampton, England, to New York City, United States, with over 2,200 people on board when she struck an iceberg at 23:40 on 14 April. She sank two hours and forty minutes later…

Mexican Spanish is the variety of dialects and sociolects of the Spanish language spoken in Mexico and its bordering regions. Mexico has the world's largest number of Spanish speakers, more than double any other country. Spanish is spoken by over 99% of the population, being the mother tongue of 93.8%, and the second language of 5.4%.

In Greek mythology, Icarus was the son of the master craftsman Daedalus, the architect of the labyrinth of Crete, and his wife Naucrate. After Theseus, king of Athens and enemy of King Minos, escaped from the labyrinth, Minos suspected that Icarus and Daedalus had revealed the labyrinth's secrets and thus imprisoned them—either in a…

California is a U.S. state in the Western United States that lies on the Pacific Coast. It borders Oregon to the north, and Nevada and Arizona to the east; it also shares an international border with the Mexican state of Baja California to the south. With over 39 million residents across an area of 163,696 square miles (423,970 km2), it…

A palindrome is a word, number, phrase, or other sequence of symbols that reads the same backwards as forwards, such as madam or racecar, the date "22/02/2022", or the sentence "A man, a plan, a canal – Panama". The 19-letter Finnish word saippuakivikauppias is the longest single-word palindrome in everyday use, while the 12-letter term…

The bishop is a piece in the game of chess. It moves and captures along diagonals without jumping over interfering pieces. Each player begins the game with two bishops. The starting squares are c1 and f1 for White's bishops, and c8 and f8 for Black's bishops.

Meteorology is the scientific study of the Earth's atmosphere and short-term atmospheric phenomena, with a focus on weather forecasting. It has applications in the military, aviation, energy production, transport, agriculture, construction, weather warnings, and disaster management.

The following list contains the largest terrestrial members of the order Carnivora, ranked in accordance to their maximum mass in the wild.

Bagatelle No. 25 in A minor for solo piano, commonly known as "Für Elise", is one of Ludwig van Beethoven's most popular compositions. It was not published during his lifetime but discovered 40 years after his death, and may be termed either a Bagatelle or an Albumblatt. The identity of "Elise" is unknown; researchers have suggested…

The violin, sometimes referred to as a fiddle, is a wooden chordophone, and is the smallest, and thus highest-pitched instrument (soprano) in regular use in the violin family. Smaller violin-type instruments exist, including the violino piccolo and the pochette, but these are virtually unused. Most violins have a hollow wooden body, and…

The Wright brothers, Orville Wright and Wilbur Wright, were American aviation pioneers generally credited with inventing, building, and flying the world's first successful airplane. They made the first controlled, sustained flight of an engine-powered, heavier-than-air aircraft with the Wright Flyer on December 17, 1903, four miles (6…

Ruby is a pinkish-red to blood-red-colored gemstone, a variety of the mineral corundum, consisting of aluminium oxide (α-Al2O3). Ruby is one of the most popular traditional jewelry gems and is very durable. Other varieties of gem-quality corundum are called sapphires, and rubies are also sometimes referred to as "red sapphires".

An earthquake, also called a quake, tremor, or temblor, is the shaking of the Earth's surface resulting from a sudden release of energy in the lithosphere that creates seismic waves. Earthquakes can range in intensity, from those so weak they cannot be felt, to those violent enough to propel objects and people into the air, damage…

Badminton is a racquet sport played using racquets to hit a shuttlecock across a net. Although it may be played with larger teams, the most common forms of the game are "singles" and "doubles". Badminton is often played as a casual outdoor activity in a yard or on a beach; professional games are played on a rectangular indoor court.…

Antonio Lucio Vivaldi was an Italian composer, virtuoso violinist and impresario of Baroque music. Regarded as one of the greatest Baroque composers, Vivaldi's influence during his lifetime was widespread across Europe, giving origin to many imitators and admirers. He pioneered many developments in orchestration, violin technique and…

The Great Wall of China is a series of fortifications in China. They were built across the historical northern borders of ancient Chinese states and Imperial China as protection against various nomadic groups from the Eurasian Steppe. The first walls date to the 7th century BC; these were joined together in the Qin dynasty. Successive…

The wolf, also known as the grey wolf or gray wolf, is a canine native to Eurasia and North America. More than thirty subspecies of Canis lupus have been recognized, including the dog and dingo, though grey wolves, as popularly understood, include only naturally occurring wild subspecies. The wolf is the largest wild extant member of the…

Angel Falls is a waterfall in Venezuela. It is the world's tallest uninterrupted waterfall, with a height of 979 metres (3,212 ft), and a plunge of 807 m (2,648 ft). The waterfall drops over the edge of the Auyán-tepui mountain in the Canaima National Park, a UNESCO World Heritage Site in the Gran Sabana region of Bolívar State. The…

A deer or true deer is a hoofed ruminant ungulate of the family Cervidae. Cervidae is divided into subfamilies Cervinae and Capreolinae. Male deer of almost all species, as well as female reindeer, grow and shed new antlers each year. These antlers are bony extensions of the skull and are often used for combat between males.

A numeral system is a writing system for expressing numbers without words; that is, a mathematical notation for representing numbers of a given set, using digits or other symbols in a consistent manner.

Cycling, also known as bicycling or biking, is the activity of riding a bicycle or other types of pedal-driven human-powered vehicles such as balance bikes, unicycles, tricycles, and quadricycles. Cycling is practised around the world for purposes including transport, recreation, exercise, and competitive sport.

Sherlock Holmes is a fictional detective created by British author Arthur Conan Doyle. Referring to himself as a "consulting detective" in his stories, Holmes is known for his proficiency with observation, deduction, forensic science and logical reasoning that borders on the fantastic, which he employs when investigating cases for a wide…

Mandarin is the largest branch of the Sinitic languages. Mandarin varieties are natively spoken by 70 percent of all Chinese speakers, spread over a large geographical area that stretches from Yunnan in the southwest to Xinjiang in the northwest and Heilongjiang in the northeast. Its spread is generally attributed to the overall greater…

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.

The Berlin Wall fell on 9 November 1989 during the Peaceful Revolution, marking the beginning of the destruction of the figurative Iron Curtain, as East Berlin transit restrictions were overwhelmed and discarded. Sections of the wall were breached, and planned deconstruction began the following June. It was one of the series of events…

The aorta is the main and largest artery in the human body, originating from the left ventricle of the heart, branching upwards immediately after, and extending down to the abdomen, where it splits at the aortic bifurcation into two smaller arteries. The aorta distributes oxygenated blood to all parts of the body through the systemic circulation.

Cricket is a bat-and-ball game that is played between two teams of eleven players on a field, at the centre of which is a 22-yard pitch with a wicket at each end, each comprising two bails balanced on three stumps. Two players from the batting team, the striker and nonstriker, stand in front of either wicket holding bats, while one…

In humans and other primates, the knee joins the thigh with the leg and consists of two joints: one between the femur and tibia, and one between the femur and patella. It is the largest joint in the human body. The knee is a modified hinge joint, which permits flexion and extension as well as slight internal and external rotation. The…

Maria Salomea Skłodowska Curie, better known as Marie Curie was a Polish and naturalised-French physicist and chemist. She shared the 1903 Nobel Prize in Physics with her husband, Pierre Curie, "for their joint researches on the radioactivity phenomena discovered by Professor Henri Becquerel". She won the 1911 Nobel Prize in Chemistry…

The liver is a major metabolic organ exclusively found in vertebrates, which performs many essential biological functions such as detoxification of the organism, and the synthesis of various proteins and various other biochemicals necessary for digestion and growth. In humans, it is located in the right upper quadrant of the abdomen,…

The Fahrenheit scale is a temperature scale based on one proposed in 1724 by the physicist Daniel Gabriel Fahrenheit (1686–1736). It uses the degree Fahrenheit as the unit. Several accounts of how he originally defined his scale exist, but the original paper suggests the lower defining point, 0 °F, was established as the freezing…

Thor is a prominent god in Germanic paganism. In Norse mythology, he is a hammer-wielding god associated with thunder, storms, strength, protection, fertility, and farmers. Besides Old Norse Þórr, the deity occurs in Old English as Thunor, in Old Frisian as Thuner, in Old Saxon as Thunar, and in Old High German as Donar, all ultimately…

Concorde is a retired Anglo-French supersonic airliner jointly developed and manufactured by Sud Aviation and the British Aircraft Corporation (BAC). Studies began in 1954 and a UK–France treaty followed in 1962, as the programme cost was estimated at £70 million . Construction of six prototypes began in February 1965, with the first…

Ludwig van Beethoven was a German composer, conductor, and pianist. Regarded as one of the greatest composers in the history of Western music, he was mentored during the Classical period, and his musical style was a key driver of the transition to Romantic music, and the expansion of instrumental forms such as the symphony, the piano…

Murder is the unlawful killing of another human without justification or valid excuse and committed with the necessary intent as defined by the law in a specific jurisdiction. This state of mind may, depending upon the jurisdiction, distinguish murder from other forms of unlawful homicide, such as manslaughter. Manslaughter is killing…

Michelangelo di Lodovico Buonarroti Simoni, known mononymously as Michelangelo, was an Italian sculptor, painter, architect, and poet of the High Renaissance. He was born in the Republic of Florence but was mostly active in Rome from his 30s onwards. His work was inspired by models from classical antiquity and had a lasting influence on…

The Bactrian camel, also known as the Mongolian camel, domestic Bactrian camel, two-humped camel or double humped camel, is a camel native to the steppes of Central Asia. It has two humps on its back, in contrast to the single-humped dromedary. Its population of 2 million exists mainly in the domesticated form. Their name comes from the…

Insects are invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have an exoskeleton, a three-part body, three pairs of jointed legs, compound eyes, and a pair of antennae. Insects are the most diverse group of animals, with more than a million described species; they represent more than…

The chickpea or chick pea is an annual legume of the family Fabaceae, subfamily Faboideae, cultivated for its edible seeds. Its different types are variously known as gram, Bengal gram, chana (চানা), garbanzo, garbanzo bean, or Egyptian pea. It is one of the earliest cultivated legumes, the oldest archaeological evidence of which was found in Syria.

Malala Yousafzai is a Pakistani female education activist, and producer of film and television. She is the youngest Nobel Prize laureate in history, receiving the Peace Prize in 2014 at age 17, and is the second Pakistani and the only Pashtun to receive a Nobel Prize. Yousafzai is a human rights advocate for the education of women and…

Origami is the art and technique of folding paper. It also refers to the two- and three-dimensional forms created in the process. The use of the term has been extended in modern times to include other materials such as metal, textiles, and it is also used in the biological sciences to describe folded structures like DNA.

Monopoly is a multiplayer economics-themed board game. In the game, players roll two standard dice to move their token clockwise around the game board, buying and trading properties and railroads and developing them with houses and hotels. Players collect rent from their opponents and aim to drive them into bankruptcy. Money can also be…

The larynx, commonly called the voice box, is an organ in the top of the neck involved in respiration, producing sound and protecting the trachea against food aspiration. The opening of the larynx into the pharynx, known as the laryngeal inlet, is about 4–5 centimeters in diameter. The larynx houses the vocal cords, and manipulates pitch…

There are 11 time zones in Russia, which currently observe times ranging from UTC+02:00 to UTC+12:00. Daylight saving time (DST) has not been used in Russia since 26 October 2014. From 27 March 2011 to 26 October 2014, permanent DST was used. About 63% of the Russian population live in MSK (UTC+03:00).

The vagus nerve, also known as the tenth cranial nerve, plays a crucial role in the autonomic nervous system, which is responsible for regulating involuntary functions within the human body. This nerve carries both sensory and motor fibers and serves as a major pathway that connects the brain to various organs, including the heart,…

Johann Sebastian Bach was a German composer and musician of the late Baroque period. He is known for his prolific output across a variety of instruments and forms, including the orchestral Brandenburg Concertos; solo instrumental works such as the Cello Suites and Sonatas and Partitas for Solo Violin; keyboard works such as the Goldberg…

Mycology is the branch of biology concerned with the study of fungi, including their taxonomy, genetics, biochemical properties, and use by humans. Fungi can be a source of tinder, food, and traditional medicine, as well as entheogens, poison, and infection. Yeasts are among the most heavily utilized members of the fungus kingdom,…

Arachnophobia is the fear of spiders and other arachnids, such as scorpions and ticks. Arachnophobia is a specific phobia and is one of the most common described anxiety disorders, despite the fact that most arachnids pose little threat to humans.

Dmitri Ivanovich Mendeleev was a Russian chemist known for formulating the periodic law and creating a version of the periodic table of elements. He used the periodic law not only to correct the then-accepted properties of some known elements, such as the valence and atomic weight of uranium, but also to predict the properties of three…

Graffiti is writing or drawings made on a wall or other surface, usually without permission and within public view. Graffiti ranges from simple written "monikers" to elaborate wall paintings, and has existed since ancient times, with examples dating back to ancient Egypt, ancient Greece, and the Roman Empire.

Vulcan is the god of fire including the fire of volcanoes, deserts, metalworking and the forge in ancient Roman religion and myth. He is often depicted with a blacksmith's hammer. The Vulcanalia was the annual festival held August 23 in his honor. His Greek counterpart is Hephaestus, the god of fire and smithery. In Etruscan religion, he…

Wiltshire is a ceremonial county in South West England. It borders Gloucestershire to the north, Oxfordshire to the north-east, Berkshire to the east, Hampshire to the south-east and south, Dorset to the south, and Somerset to the west. The largest settlement is Swindon.

Maine is a state in the New England region of the United States, and the northeasternmost state in the contiguous United States. It borders New Hampshire to the west, the Gulf of Maine to the southeast, and the Canadian provinces of New Brunswick and Quebec to the northeast and northwest, and shares a maritime border with Nova Scotia. It…

Les Misérables is a French epic historical novel by Victor Hugo, first published on 31 March 1862, that is considered one of the greatest novels of the 19th century. Les Misérables has been popularized through numerous adaptations for film, television, and the stage, including a musical.

George Gershwin was an American composer and pianist whose compositions spanned jazz, popular and classical music. Among his best-known works are the songs "Swanee" (1919) and "Fascinating Rhythm" (1924), the orchestral compositions Rhapsody in Blue (1924) and An American in Paris (1928), the jazz standards "Embraceable You" (1928) and…

Claustrophobia is a fear or anxiety of confined spaces. It is triggered by many situations or stimuli, including elevators, especially when crowded to capacity, windowless rooms, and hotel rooms with closed doors and sealed windows. Even bedrooms with a lock on the outside, small cars, and tight-necked clothing can induce a response in…

The ohm is the unit of electrical resistance in the International System of Units (SI). It is named after German physicist Georg Ohm (1789–1854). Various empirically derived standard units for electrical resistance were developed in connection with early telegraphy practice, and the British Association for the Advancement of Science…

Usain St. Leo Bolt is a Jamaican retired sprinter. Widely regarded as the greatest sprinter of all time, he is an eight-time Olympic gold medalist and the world record holder in the 100 metres, 200 metres, and 4 × 100 metres relay.

In zoology, a crepuscular animal is one that is active primarily during the twilight period: being matutinal, vespertine/vespertinal, or both. This is distinguished from diurnal and nocturnal behavior, where an animal is active during the hours of daytime and of night, respectively. Some crepuscular animals may also be active by…

Werner Karl Heisenberg was a German theoretical physicist, one of the main pioneers of the theory of quantum mechanics and a principal scientist in the German nuclear program during World War II.

Hudson Bay, sometimes called Hudson's Bay, is a large body of saltwater in northeastern Canada with a surface area of 1,230,000 km2 (470,000 sq mi). It is located north of Ontario, west of Quebec, northeast of Manitoba, and southeast of Nunavut, but politically entirely part of Nunavut. It is an inland marginal sea of the Arctic Ocean.…

HMS Beagle was a Cherokee-class 10-gun brig-sloop of the Royal Navy, one of more than 100 ships of this class. The vessel, constructed at a cost of £7,803, was launched on 11 May 1820 from the Woolwich Dockyard on the River Thames. Later reports say the ship took part in celebrations of the coronation of George IV, passing under the old…

Sake, saké , or saki, also referred to as Japanese rice wine, is an alcoholic beverage of Japanese origin made by fermenting rice that has been polished to remove the bran. Despite the name Japanese rice wine, sake, and indeed any East Asian rice wine, is produced by a brewing process more akin to that of beer, where starch is converted…

The House of Medici was an Italian banking family and political dynasty that first consolidated power in the Republic of Florence under Cosimo de' Medici and his grandson Lorenzo "the Magnificent" during the first half of the 15th century. The family originated in the Mugello region of Tuscany, and prospered gradually in trade until it…

The clavicle, collarbone, or keybone is a slender, S-shaped long bone approximately 15 centimetres (6 in) long that serves as a strut between the shoulder blade and the sternum (breastbone). There are two clavicles, one on each side of the body. The clavicle is the only long bone in the body that lies horizontally. Together with the…

Operation Overlord was the codename for the Battle of Normandy, the Allied operation that launched the successful liberation of German-occupied Western Europe during World War II. The operation was launched on 6 June 1944 (D-Day) with the Normandy landings. A 1,200-plane airborne assault preceded an amphibious assault involving more than…

Sir Andrew John Wiles is an English mathematician and a Royal Society Research Professor at the University of Oxford, specialising in number theory. He is best known for proving Fermat's Last Theorem, for which he was awarded the 2016 Abel Prize and the 2017 Copley Medal and for which he was appointed a Knight Commander of the Order of…

Japan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asian mainland, it is bordered to the west by the Sea of Japan, the Sea of Okhotsk in the north, and the East China Sea in the south. The Japanese archipelago consists of four major islands alongside 14,121 smaller islands. Japan is…

A black hole is an astronomical body so compact that its gravity prevents anything, including light, from escaping. Albert Einstein's theory of general relativity, which describes gravitation as the curvature of spacetime, predicts that any sufficiently compact mass will form a black hole. The boundary of no escape is called the event…

Chromosome 1 is the designation for the largest human chromosome. Humans have two copies of chromosome 1, as they do with all of the autosomes, which are the non-sex chromosomes. Chromosome 1 spans about 249 million nucleotide base pairs, which are the basic units of information for DNA. It represents about 8% of the total DNA in human cells.

Athena or Athene, often given the epithet Pallas, is an ancient Greek goddess associated with wisdom, warfare, and handicraft who was later syncretised with the Roman goddess Minerva. Athena was regarded as the patron and protectress of various cities across Greece, particularly the city of Athens, from which she most likely received her…

Veryovkina Cave is a cave in Abkhazia, Georgia. With a known depth of 2,209 meters (7,247 ft) deep as of 2025, it is the second deepest-known cave on Earth after Krubera Cave. Veryovkina is in the Arabika Massif, in the Gagra mountain range of the Western Caucasus, on the pass between the Krepost and Zont mountains, close to the slopes…

The Tokugawa shogunate, also known as the Edo shogunate, was the military government of Japan during the Edo period from 1603 to 1868.

The pascal is the unit of pressure in the International System of Units (SI). It is also used to quantify internal pressure, stress, Young's modulus, and ultimate tensile strength. The unit, named after Blaise Pascal, is an SI coherent derived unit defined as one newton per square metre (N/m2). It is also equivalent to 10 barye in the…

The European Organization for Nuclear Research, known as CERN, is an intergovernmental organization that operates the largest particle physics laboratory in the world. Established in 1954, it is based in Meyrin, a western suburb of Geneva, on the France–Switzerland border. It comprises 25 member states. Israel, admitted in 2013, is the…

Half-life is the time required for a quantity to reduce to half of its initial value. The term is commonly used in nuclear physics to describe how quickly unstable atoms undergo radioactive decay or how long stable atoms survive. The term is also used more generally to characterize any type of exponential decay. For example, the medical…

Igor Fyodorovich Stravinsky was a Russian composer and conductor with French and American citizenship. He is widely considered one of the most important and influential composers of the 20th century and a pivotal figure in modernist music.

Pangaea or Pangea was a supercontinent that existed during the late Paleozoic and early Mesozoic eras. It assembled from the earlier continental units of Gondwana, Euramerica and Siberia during the Carboniferous period approximately 335 million years ago, and began to break apart about 200 million years ago, at the end of the Triassic…

Jonas Edward Salk was an American virologist and medical researcher who developed one of the first successful polio vaccines. He was born in New York City and attended the City College of New York and New York University School of Medicine.

A quarter note (AmE) or crotchet (BrE) is a musical note played for one quarter of the duration of a whole note. Quarter notes are notated with a filled-in oval note head and a straight, flagless stem. The stem usually points upwards if it is below the middle line of the staff, and downwards if it is on or above the middle line. An…

Venus is the second planet from the Sun. Similar in size and mass to Earth, Venus has no liquid water, and its atmosphere is far thicker and denser than that of any other rocky body in the Solar System. The atmosphere is composed mostly of carbon dioxide and has a thick cloud layer of sulfuric acid that spans the whole planet. At the…

In geometry, a hypotenuse is the side of a right triangle that is opposite to the right angle. It is always the longest side of the triangle. The other two sides of a right triangle are called legs or catheti.

The patella, also known as the kneecap, is a flat, rounded triangular bone which articulates with the femur and covers and protects the anterior articular surface of the knee joint. The patella is found in many tetrapods, such as mice, cats, birds, humans, and dogs, but not in whales, or most reptiles.

The Bering Strait is a strait between the Pacific and Arctic oceans, separating the Chukchi Peninsula of the Russian Far East from the Seward Peninsula of Alaska. The present Russia–United States maritime boundary is at 168° 58' 37" W longitude, slightly south of the Arctic Circle at about 65° 40' N latitude. The Strait is named after…

Sir Edward William Elgar, 1st Baronet was an English composer, many of whose works have entered the British and international classical concert repertoire. Among his best-known compositions are orchestral works including the Enigma Variations, the Pomp and Circumstance Marches, concertos for violin and cello, and two symphonies. He also…

Q is the seventeenth letter of the Latin alphabet, used in the modern English alphabet, the alphabets of other western European languages and others worldwide. Its name in English is pronounced, most commonly spelled cue, but also kew, kue, and que.

Gregor Johann Mendel was an Austrian biologist, meteorologist, mathematician, Augustinian friar and abbot of St. Thomas' Abbey in Brno (Brünn), Margraviate of Moravia. Mendel was born in a German-speaking family in the Silesian part of the Austrian Empire and gained posthumous recognition as the founder of the modern science of genetics.…

Johann Sebastian Bach was a German composer and musician of the late Baroque period. He is known for his prolific output across a variety of instruments and forms, including the orchestral Brandenburg Concertos; solo instrumental works such as the Cello Suites and Sonatas and Partitas for Solo Violin; keyboard works such as the Goldberg…

An amylase is an enzyme that catalyses the hydrolysis of starch into sugars. Amylase is present in the saliva of humans and some other mammals, where it begins the chemical process of digestion. Foods that contain large amounts of starch but little sugar, such as rice and potatoes, may acquire a sweet taste as they are chewed because…

Gian Lorenzo Bernini was an Italian sculptor, architect, painter and city planner. Bernini's creative abilities and mastery in a range of artistic arenas define him as a uomo universale or Renaissance man. While a major figure in the world of architecture, he was more prominently the leading sculptor of his age, credited with creating…

Bologna is the capital and largest city of the Emilia-Romagna region in northern Italy. It is the seventh most populous city in Italy, with 390,734 inhabitants and 150 different nationalities. Its metropolitan province is home to more than 1 million people as of 2025. Bologna is most famous for being the home to the oldest university in…

The stratosphere is the second-lowest layer of the atmosphere of Earth, located above the troposphere and below the mesosphere. Pronounced, the name originates from Ancient Greek στρωτός (strōtós) 'layer, stratum' and -sphere. The stratosphere is composed of stratified temperature zones, with the warmer layers of air located higher and…

Lava is magma that has been expelled from the interior of a terrestrial planet or a moon onto its surface. Lava may be erupted at a volcano or through a fracture in the crust, on land or underwater, usually at temperatures from 800 to 1,200 °C. Lava may be erupted directly onto the land surface or onto the sea floor or it may be ejected…

The pituitary gland or hypophysis cerebri is an endocrine gland in vertebrates. In humans, the pituitary gland is located at the base of the brain, protruding off the bottom of the hypothalamus. The pituitary gland and the hypothalamus control much of the body's endocrine system. It is seated in part of the sella turcica, a depression in…

The Atacama Desert is a desert plateau on the Pacific coast of South America, stretching along a 1,600-kilometre-long (1,000-mile) strip of land in northern Chile, west of the Andes. It covers an area of 105,000 km2 (41,000 mi2), rising to 128,000 km2 (49,000 mi2) if the barren lower slopes of the Andes are included.

Archimedes of Syracuse was an Ancient Greek mathematician, physicist, engineer, astronomer, and inventor from the city of Syracuse in Sicily. Although few details of his life are known, based on his surviving work, he is considered one of the leading scientists in classical antiquity, and one of the greatest mathematicians of all time.…

Mount Tambora, or Tomboro, is an active stratovolcano in West Nusa Tenggara, Indonesia. Located on Sumbawa in the Lesser Sunda Islands, volcanism is the result of subduction zones. The 1815 eruption was the largest in recorded history, erupting up to 150 cubic kilometers of volcanic material, making it a VEI-7 on the Volcanic Explosivity…

Precession is a change in the orientation of the rotational axis of a rotating body. In an appropriate reference frame it can be defined as a change in the first Euler angle, whereas the third Euler angle defines the rotation itself. In other words, if the axis of rotation of a body is itself rotating about a second axis, that body is…

John Archibald Wheeler was an American theoretical physicist. He was largely responsible for reviving interest in general relativity in the United States after World War II. Wheeler also worked with Niels Bohr to explain the basic principles of nuclear fission. Together with Gregory Breit, Wheeler explored positron-electron pair…

William Cuthbert Faulkner was an American writer. He is best known for his novels and short stories set in the fictional Yoknapatawpha County, Mississippi, a stand-in for Lafayette County where he spent most of his life. Winner of the 1949 Nobel Prize in Literature, Faulkner is one of the most celebrated writers of American literature,…

Vitamin C or ascorbate is a water-soluble vitamin found in citrus and other fruits, berries and vegetables. It is found as a form of ascorbic acid. It is an essential nutrient involved in the repair of tissue, the formation of collagen, and the enzymatic production of certain neurotransmitters. It is required for the functioning of…

The Tale of Ragnar's sons is an Old Norse story about Ragnar Lodbrok and his sons, written around 1300.

Champagne is a sparkling wine originated and produced in the Champagne wine region of France under the AOC rules of the appellation, which demand specific vineyard practices, sourcing of grapes exclusively from designated places within it, specific grape-pressing methods and secondary fermentation of the wine in the bottle to cause carbonation.

An Inquiry into the Nature and Causes of the Wealth of Nations, usually referred to by its shortened title The Wealth of Nations, is a book by Scottish economist and moral philosopher Adam Smith. Published on 9 March 1776 as Smith's central intellectual project, the treatise sought to examine and explain the underlying political and…

Pope Urban II, otherwise known as Odo of Châtillon or Otho de Lagery, was the head of the Catholic Church and ruler of the Papal States from 12 March 1088 to his death. He is best known for convening the Council of Clermont, which ignited the series of Catholic military expeditions known as the Crusades.

Tesla, Inc. is an American multinational automotive and clean energy company. Headquartered in Austin, Texas, it designs, manufactures, and sells battery electric vehicles (BEVs), stationary battery energy storage devices from home to grid-scale, solar panels and solar shingles, and related products and services.

The Strait of Messina is a narrow strait between the eastern tip of Sicily and the western tip of Calabria in Southern Italy. It connects the Tyrrhenian Sea to the north with the Ionian Sea to the south, within the central Mediterranean. At its narrowest point, between Torre Faro and Villa San Giovanni, it is 3.1 km (1.9 mi) wide. At the…

In music, an octave (Latin: octavus: eighth) or perfect octave (sometimes called the diapason) is an interval between two tones, one having twice the frequency of vibration of the other. For instance, the interval between C4 and C5 (in scientific pitch notation) is an octave.

Eels are ray-finned fish belonging to the order Anguilliformes, which consists of eight suborders, 20 families, 164 genera, and about 1000 species. Eels undergo considerable development from the early larval stage to the eventual adult stage and are usually predators.

George Frideric Handel was a German-British Baroque composer well-known for his operas, oratorios, anthems, concerti grossi, and organ concerti.

In theories of quantum gravity, the graviton is the hypothetical elementary particle that mediates the force of gravitational interaction. It is a quantum of gravitational wave energy. There is no complete quantum field theory of gravitons due to the unsolved mathematical problem of renormalization in general relativity. This problem is…

Johann Sebastian Bach was a German composer and musician of the late Baroque period. He is known for his prolific output across a variety of instruments and forms, including the orchestral Brandenburg Concertos; solo instrumental works such as the Cello Suites and Sonatas and Partitas for Solo Violin; keyboard works such as the Goldberg…

The climate of Titan, the largest moon of Saturn, is similar in many respects to that of Earth, despite having a far lower surface temperature. Its thick atmosphere, methane rain, and possible cryovolcanism create an analogue, though with different materials, to the climatic changes undergone by Earth during the far shorter year of Earth.

This glossary of genetics and evolutionary biology is a list of definitions of terms and concepts used in the study of genetics and evolutionary biology, as well as sub-disciplines and related fields, with an emphasis on classical genetics, quantitative genetics, population biology, phylogenetics, speciation, and systematics. It has…

Kurt Friedrich Gödel was a logician, mathematician, cosmologist, and philosopher. Considered along with Aristotle and Gottlob Frege to be one of the most significant logicians in history, Gödel profoundly influenced scientific and philosophical thinking in the 20th century, building on earlier work by Frege, Richard Dedekind, and Georg Cantor.

Immanuel Kant was a German philosopher. Born in Königsberg in the Kingdom of Prussia, he is considered one of the central thinkers of the Enlightenment. His comprehensive and systematic works in epistemology, metaphysics, logic, ethics, aesthetics, political theory, and the philosophy of religion have made him one of the most influential…

Galileo di Vincenzo Bonaiuti de' Galilei, commonly referred to as Galileo Galilei or mononymously as Galileo, was an Italian astronomer, physicist, engineer and polymath. He was born in Pisa, then part of the Duchy of Florence. Galileo has been called the father of observational astronomy, classical physics, the scientific method, and modern science.

The Boomerang Nebula is a bipolar reflection young planetary nebula located approximately 5,000 light-years from Earth in the constellation Centaurus.

Mehmed II, commonly known as Mehmed the Conqueror, was the sultan of the Ottoman Empire twice, from August 1444 to September 1446 and again from February 1451 to May 1481.

Gottfried Wilhelm Leibniz was a German polymath active as a mathematician, philosopher, scientist, and diplomat who is credited, alongside Isaac Newton, with the creation of calculus in addition to many other branches of mathematics, such as binary arithmetic and statistics. Leibniz has been called the "last universal genius" due to his…

The ionosphere is the ionized part of the upper atmosphere of Earth, from about 48 km (30 mi) to 965 km (600 mi) above sea level, a region that includes the thermosphere and parts of the mesosphere and exosphere. The ionosphere is ionized by solar radiation. It plays an important role in atmospheric electricity and forms the inner edge…

The Abbasid Caliphate or Abbasid Empire was the third Islamic caliphate, ruled by the Abbasid dynasty. The dynasty was descended from Muhammad's uncle, Abbas ibn Abd al-Muttalib, after whom it is named. The Abbasids rose to power in 750, when the Abbasid Revolution overthrew the preceding Umayyad Caliphate, and they ruled as caliphs from…

Venomous mammals are mammals that produce venom, which they use to kill or disable prey, to defend themselves from predators or conspecifics or in agonistic encounters. Mammalian venoms form a heterogeneous group with different compositions and modes of action, from four orders of mammals: Eulipotyphla, Monotremata, Primates, and…

Maria Salomea Skłodowska Curie, better known as Marie Curie was a Polish and naturalised-French physicist and chemist. She shared the 1903 Nobel Prize in Physics with her husband, Pierre Curie, "for their joint researches on the radioactivity phenomena discovered by Professor Henri Becquerel". She won the 1911 Nobel Prize in Chemistry…

Hamilcar Barca or Barcas was a Carthaginian general and statesman, leader of the Barcid family, and father of Hannibal, Hasdrubal and Mago. He was also father-in-law to Hasdrubal the Fair.

Endocrinology is a branch of biology and medicine dealing with the endocrine system, its diseases, and its specific secretions known as hormones. It is also concerned with the integration of developmental events proliferation, growth and differentiation, and the psychological or behavioral activities of metabolism, growth and…

Nicolaus Copernicus was a Renaissance polymath who formulated a model of the universe that placed the Sun rather than Earth at its center. The publication of Copernicus's model in his book De revolutionibus orbium coelestium, just before his death in 1543, was a major event in the history of science, triggering the Copernican Revolution…

The Tevatron was a circular particle accelerator in the United States, at the Fermi National Accelerator Laboratory, east of Batavia, Illinois, and was the highest energy particle collider until the Large Hadron Collider (LHC) of the European Organization for Nuclear Research (CERN) was built near Geneva, Switzerland. The Tevatron was a…

Saturnalia is an ancient Roman festival and holiday in honour of the god Saturn, held on 17 December in the Julian calendar and later expanded with festivities until 19 December. By the 1st century BC, the celebration had been extended until 23 December, for a total of seven days of festivities. The holiday was celebrated with a…

Leonhard Euler was a Swiss polymath who was active as a mathematician, physicist, astronomer, logician, geographer, music theorist and engineer. He founded the studies of graph theory and topology and made influential discoveries in many other branches of mathematics, such as analytic number theory, complex analysis, and infinitesimal…

Srinivasa Ramanujan Iyengar was an Indian mathematician who worked during the early 20th century. He made substantial contributions to mathematical analysis, number theory, infinite series, and continued fractions, including solutions to mathematical problems then considered unsolvable.

Endemism is the state of a species being found only in a singular defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsewhere. For example, the Cape sugarbird is found exclusively in southwestern South Africa…

The Bahamas, officially the Commonwealth of The Bahamas, is an archipelagic country in the Caribbean located within the Lucayan Archipelago in the Atlantic Ocean. The country comprises 700 islands, and more than 2,500 cays in the Atlantic Ocean, located north of Cuba and north-west of the island of Hispaniola and the Turks and Caicos…

Paul Adrien Maurice Dirac was an English theoretical physicist who is considered to be one of the founders of quantum mechanics. Dirac laid the foundations for both quantum electrodynamics and quantum field theory, coining the former term. He was Lucasian Professor of Mathematics at the University of Cambridge from 1932 to 1969, and a…

The Afar Region, formerly known as Region 2, is a regional state in northeastern Ethiopia and the homeland of the Afar people. Its capital is the planned city of Semera, which lies on the paved Awash–Assab highway. It is bordered by Eritrea to the north and Djibouti to the northeast; it also shares regional borders with the Tigray,…

Marco Polo was a Venetian merchant, explorer, and writer who travelled through Asia along the Silk Road between 1271 and 1295. His travels are recorded in The Travels of Marco Polo, a book that described the then-mysterious culture and inner workings of the Eastern world, including the wealth and great size of the Mongol Empire and China…

Magdalena Carmen Frida Kahlo y Calderón was a Mexican painter known for her many portraits, self-portraits, and works inspired by the nature and artifacts of Mexico. Inspired by the country's popular culture, she employed a naïve folk art style to explore questions of identity, postcolonialism, gender, class, and race in Mexican society.…

The Wallace Line or Wallace's Line is a faunal boundary line drawn in 1859 by the British naturalist Alfred Russel Wallace and named by the English biologist Thomas Henry Huxley.

Ancient Egyptian literature was written with the Egyptian language from ancient Egypt's pharaonic period until the end of Roman domination. It represents the oldest corpus of Egyptian literature. Along with Sumerian literature, it is considered the world's earliest literature.

Themistocles was an Athenian politician and general. He was one of a new breed of non-aristocratic politicians who rose to prominence in the early years of the Athenian democracy. As a politician, Themistocles was a populist, having the support of lower-class Athenians, and generally being at odds with the Athenian nobility. Elected…

A mold or mould is one of the structures that certain fungi can form. The dust-like, colored appearance of molds is due to the formation of spores containing fungal secondary metabolites. The spores are the dispersal units of the fungi. Not all fungi form molds. Some fungi form mushrooms or ascomata; others grow as single cells and are called yeasts.

The Harvard College Observatory (HCO) is an institution managing a complex of buildings and multiple instruments used for astronomical research by the Harvard University Department of Astronomy. It is located in Cambridge, Massachusetts, United States, and was founded in 1839. With the Smithsonian Astrophysical Observatory, it forms part…

James Watt was a Scottish inventor, engineer and chemist who improved on Thomas Newcomen's 1712 Newcomen steam engine with his Watt steam engine in 1776, which was fundamental to the changes brought by the Industrial Revolution in both his native Great Britain and the rest of the world.

Basque is a language spoken by Basques and other residents of the Basque Country, a region that straddles the westernmost Pyrenees in adjacent parts of southwestern France and northern Spain. Basque is the only known language isolate in all of Europe. The Basques are indigenous to and primarily inhabit the Basque Country. Basque has…

Tip of the tongue is the phenomenon of failing to retrieve a word or term from memory, combined with partial recall and the feeling that retrieval is imminent. The phenomenon's name comes from the saying, "It's on the tip of my tongue." The tip of the tongue phenomenon reveals that lexical access occurs in stages.

Timur, also known as Tamerlane, was a Turco-Mongol conqueror, first ruler of the Timurid dynasty, and the founder of the Timurid Empire, which ruled over modern-day Afghanistan, Iran, and Central Asia. He was undefeated in battle and is widely regarded as one of the greatest military leaders and tacticians in history, as well as one of…

Grigori Yakovlevich Perelman is a Russian mathematician and geometer who is known for his contributions to the fields of geometric analysis, Riemannian geometry, and geometric topology. In 2005, Perelman resigned from his research post in Steklov Institute of Mathematics and in 2006 stated that he had quit professional mathematics, owing…

James Watson Cronin was an American particle physicist.

The Etruscans created a civilization in Etruria in ancient Italy, with a common language and culture, and formed a federation of city-states. After adjacent lands had been conquered, its territory covered, at its greatest extent, roughly what is now Tuscany, western Umbria and northern Lazio, as well as what are now the Po Valley,…

The sorites paradox, sometimes known as the paradox of the heap, is a paradox that results from vague predicates. A typical formulation involves a heap of sand, from which grains are removed individually. With the assumption that removing a single grain does not cause a heap not to be considered a heap anymore, the paradox is to consider…

Eurythenes plasticus is a species of amphipod of the genus Eurythenes, first described in 2020. It was named in reference to the PET plastic found in its stomach, after researchers wanted to highlight the impact of plastic pollution.

The number e is a mathematical constant, approximately equal to 2.71828, that is the base of the natural logarithm and exponential function. It is sometimes called Euler's number, after the Swiss mathematician Leonhard Euler, though this can invite confusion with Euler numbers, or with Euler's constant, a different constant typically…

The Antikythera mechanism is an ancient Greek hand-powered orrery built in the 2nd century BC and discovered in 1901. It is the oldest known example of an analogue computer. It could be used to predict astronomical positions and eclipses decades in advance. It could also be used to track the four-year cycle of athletic games similar to…

The Inca Empire, officially known as the Realm of the Four Parts, was the largest empire in pre-Columbian America. The administrative, political, and military center of the empire was in the city of Cusco. The Inca civilisation rose from the Peruvian highlands sometime in the early 13th century. The Portuguese explorer Aleixo Garcia was…

General Henry Seymour Rawlinson, 1st Baron Rawlinson,, known as Sir Henry Rawlinson, 2nd Baronet between 1895 and 1919, was a senior British Army officer in the First World War who commanded the Fourth Army of the British Expeditionary Force at the battles of the Somme (1916) and Amiens (1918) as well as the breaking of the Hindenburg…

Sapphire is a precious gemstone, a variety of the mineral corundum, consisting of aluminium oxide (α-Al2O3) 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 sapphirus, itself from the Greek word sappheiros (σάπφειρος,…

A metric prefix is a unit prefix that precedes a basic unit of measure to indicate a multiple or submultiple of the unit. All metric prefixes used today are decimal. Each prefix has a unique symbol that is prepended to any unit symbol. The prefix kilo, for example, may be added to gram to indicate multiplication by one thousand: one…

Theseus was a divine hero in Greek mythology, famous for slaying the Minotaur. The myths surrounding Theseus, his journeys, exploits, and friends, have provided material for storytelling throughout the ages.

Silk is a natural protein fiber, some forms of which can be woven or knitted into textiles. The protein fiber of silk is composed mainly of fibroin (75-80%) and a smaller coating of sericin (20-25%). It is most commonly produced from the cocoons of certain insect larvae. The best-known silk is obtained from the cocoons of the larvae of…

The cosmic microwave background, or relic radiation, is microwave radiation that fills all space in the observable universe. With a standard optical telescope, the background space between stars and galaxies is almost completely dark. However, a sufficiently sensitive radio telescope detects a faint background glow that is almost uniform…

Robert Recorde was a Welsh physician and mathematician. He invented the equals sign (=) and also introduced the pre-existing plus (+) and minus (−) signs to English speakers in 1557.

Kublai Khan, also known by his temple name as the Emperor Shizu of Yuan and his regnal name Setsen Khan, was the founder and first emperor of the Mongol-led Yuan dynasty of China. He proclaimed the dynastic name "Great Yuan" in 1271, and ruled Yuan China until his death in 1294.

Évariste Galois was a French mathematician and political activist. While still in his teens, he was able to determine a necessary and sufficient condition for a polynomial to be solvable by radicals, thereby solving a problem that had been open for 350 years. His work laid the foundations for Galois theory and group theory, two major…

Capsaicin (8-methyl-N-vanillyl-6-nonenamide) is a toxin that is the main active component of chili peppers and gives them their distinct pungent, "spicy" or "hot" taste. It is a potent irritant for mammals for which it produces a sensation of burning in any tissue with which it comes into contact. Capsaicin and several related amides…

In celestial mechanics, the Lagrange points, also called the Lagrangian points or libration points, are points of equilibrium for small-mass objects under the gravitational influence of two massive orbiting bodies. Mathematically, this involves the solution of the restricted three-body problem.

Artemisia Lomi Gentileschi was an Italian Baroque painter. Gentileschi is considered among the most accomplished 17th-century artists, initially working in the style of Caravaggio. She was producing professional work by the age of 15. In an era when women had few opportunities to pursue artistic training or work as professional artists,…

Entropy is a thermodynamic state variable that quantifies the probabilistic distribution of accessible microstates in a system. The term and the concept are used in diverse fields, from classical thermodynamics, to the microscopic description of nature in statistical physics, and the principles of information theory. It has found…

Lactase (EC 3.2.1.108) is an enzyme produced by many organisms and is essential to the complete digestion of whole milk. It breaks down the sugar lactose into its component parts, galactose and glucose, simple sugars that can be absorbed into the bloodstream through an animal's intestines. A lactase is a type of β-galactosidase because…

The Khmer Empire was an empire in mainland Southeast Asia, centred on hydraulic cities in what is now northern Cambodia. Known as Kambuja by its inhabitants, it grew out of the former civilisation of Chenla and lasted from 802 to 1431 AD. Historians call this period of Cambodian history the Angkor period, after the empire's most…

The Georgian scripts are the three writing systems used to write the Georgian language: Asomtavruli, Nuskhuri and Mkhedruli. Although the systems differ in appearance, their letters share the same names and alphabetical order and are written horizontally from left to right. Of the three scripts, Mkhedruli, once the official script of the…

Cape Horn is the southernmost headland of the Tierra del Fuego archipelago of southern Chile, and is located on the small Hornos Island. Although not the most southerly point of South America, Cape Horn marks both the northern boundary of the Drake Passage and where the Atlantic and Pacific Oceans meet.

Phobos is the innermost and larger of the two natural satellites of Mars, the other being Deimos. The two moons were discovered in 1877 by American astronomer Asaph Hall. Phobos is named after the Greek god of fear and panic, who is the twin brother of Deimos and son of Ares (Mars).

The Enigma machine is a cipher device developed and used in the early- to mid-20th century to protect commercial, diplomatic, and military communication. It was employed extensively by Nazi Germany during World War II, in all branches of the German military. The Enigma machine was considered so secure that it was used to encipher the…

Muhammad ibn Musa al-Khwarizmi, or simply al-Khwarizmi was a mathematician active during the Islamic Golden Age, who produced Arabic-language works in mathematics, astronomy, and geography. Around 820, he worked at the House of Wisdom in Baghdad, the contemporary capital city of the Abbasid Caliphate. One of the most prominent scholars…

A pigment is a chemical compound that gives a substance or organism color, or is used by humans to add or alter color or change visual appearance. Pigments are nearly or completely insoluble and chemically unreactive in water or another medium; in contrast, dyes are colored substances which are soluble or go into solution at some stage…

The Tao Te Ching or Dào Dé Jīng, or Laozi in Chinese and scholarship, is an ancient Chinese classic text and the foundational work of Taoism. Central to both philosophical and religious Taoism, it has been highly influential on Chinese philosophy and religious practice.

Monocrystalline silicon, often referred to as single-crystal silicon or simply mono-Si, is a critical material widely used in modern electronics and photovoltaics. As the foundation for silicon-based discrete components and integrated circuits, it plays a vital role in virtually all modern electronic equipment, from computers to…

Zeno of Elea was a pre-Socratic Greek philosopher from Elea, in Southern Italy. He was a student of Parmenides and one of the Eleatics. Zeno defended his instructor's belief in monism, the idea that only one single entity exists that makes up all of reality. He rejected the existence of space, time, and motion. To disprove these…