1.
Fletching, East Sussex
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Fletching is a village and civil parish in the Wealden District of East Sussex, England. It is located three miles to the north-west of Uckfield, near one of the entrances to Sheffield Park, the A272 road crosses the parish. The settlement of Piltdown is part of the parish, the Piltdown Man discovery in 1912 was thought to be the missing-link between humans and apes. The significance of the specimen remained controversial until, amidst great publicity, the hamlet of Sharpsbridge lies in the south of the parish. It has a church of St. Andrew and St. Mary the Virgin dating from the twelfth century. Simon de Montfort prayed there before the Battle of Lewes, in medieval times Fletching was a major producer of bows and arrows, many of which were used at the Battle of Agincourt in 1415. The school is Fletching CE Primary school, there are two public houses in Fletching, The Griffin Inn and The Rose and Crown. Nearby is The Piltdown Man at Piltdown, the village was once the home of Jimmy Edwards
2.
Fin
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A fin is a thin component or appendage attached to a larger body or structure. Fins typically function as foils that produce lift or thrust, or provide the ability to steer or stabilize motion while traveling in water, air, fins are also used to increase surface areas for heat transfer purposes, or simply as ornamentation. Fins first evolved on fish as a means of locomotion, Fish fins are used to generate thrust and control the subsequent motion. Fish, and other animals such as cetaceans, actively propel and steer themselves with pectoral. As they swim, they use other fins, such as dorsal and anal fins to achieve stability, foil shaped fins generate thrust when moved, the lift of the fin sets water or air in motion and pushes the fin in the opposite direction. Aquatic animals get significant thrust by moving back and forth in water. Often the tail fin is used, but some aquatic animals generate thrust from pectoral fins, fins can also generate thrust if they are rotated in air or water. Turbines and propellers use a number of rotating fins, also called foils, wings, propellers use the fins to translate torquing force to lateral thrust, thus propelling an aircraft or ship. Turbines work in reverse, using the lift of the blades to generate torque, cavitation can be a problem with high power applications, resulting in damage to propellers or turbines, as well as noise and loss of power. Cavitation occurs when negative pressure causes bubbles to form in a liquid and it can cause significant damage and wear. Cavitation damage can occur to the tail fins of powerful swimming marine animals, such as dolphins. Cavitation is more likely to occur near the surface of the ocean, even if they have the power to swim faster, dolphins may have to restrict their speed because collapsing cavitation bubbles on their tail are too painful. Cavitation also slows tuna, but for a different reason, unlike dolphins, these fish do not feel the bubbles, because they have bony fins without nerve endings. Nevertheless, they cannot swim faster because the cavitation bubbles create a film around their fins that limits their speed. Lesions have been found on tuna that are consistent with cavitation damage, scombrid fishes are particularly high-performance swimmers. Along the margin at the rear of their bodies is a line of small rayless, non-retractable fins, there has been much speculation about the function of these finlets. Fish use multiple fins, so it is possible that a given fin can have an interaction with another fin. In particular, the fins immediately upstream of the fin may be proximate fins that can directly affect the flow dynamics at the caudal fin
3.
Arrow
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An arrow is a shafted projectile that is shot with a bow. It predates recorded history and is common to most cultures, an arrow usually consists of a shaft with an arrowhead attached to the front end, with fletchings and a nock at the other. The oldest evidence of stone-tipped projectiles, which may or may not have been propelled by a bow, dating to c.64,000 years ago, were found in Sibudu Cave, South Africa. The oldest evidence of the use of bows to shoot arrows dates to about 10,000 years ago and they had shallow grooves on the base, indicating that they were shot from a bow. The oldest bow so far recovered is about 8,000 years old, archery seems to have arrived in the Americas with the Arctic small tool tradition, about 4,500 years ago. Arrow sizes vary greatly across cultures, ranging from eighteen inches to five feet, however, most modern arrows are 75 centimetres to 96 centimetres, most war arrows from an English ship sunk in 1545 were 76 centimetres. Very short arrows have been used, shot through a guide attached either to the bow or to the archers wrist and these may fly farther than heavier arrows, and an enemy without suitable equipment may find himself unable to return them. The shaft is the structural element of the arrow, to which the other components are attached. Traditional arrow shafts are made from wood, bamboo or reeds, while modern shafts may be made from aluminium, carbon fibre reinforced plastic. Such shafts are made from an aluminium core wrapped with a carbon fibre outer. The stiffness of the shaft is known as its spine, referring to how little the shaft bends when compressed, hence, an arrow which bends less is said to have more spine. In order to strike consistently, a group of arrows must be similarly spined, center-shot bows, in which the arrow passes through the central vertical axis of the bow riser, may obtain consistent results from arrows with a wide range of spines. Higher draw-weight bows will generally require stiffer arrows, with more spine to give the amount of flex when shot. The weight of a shaft can be expressed in GPI. The length of a shaft in inches multiplied by its GPI rating gives the weight of the shaft in grains, for example, a shaft that is 30 inches long and has a GPI of 9.5 weighs 285 grains, or about 18 grams. This does not include the elements of a finished arrow. Sometimes a shaft will be made of two different types of wood fastened together, resulting in what is known as a footed arrow, known by some as the finest of wood arrows, footed arrows were used both by early Europeans and Native Americans. Footed arrows will typically consist of a length of hardwood near the head of the arrow
4.
Crossbow bolt
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A quarrel or bolt is the arrow used in a crossbow. The name quarrel is derived from the French carré, meaning square, although their lengths vary, they are typically shorter than traditional arrows. A Glossary of the Construction, Decoration, and Use of Arms and Armor in All Countries and in All Times. Mike
5.
Dart (missile)
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Darts are missile weapons, designed to fly such that a sharp, often weighted point will strike first. They can be distinguished from javelins by fletching and a shaft that is shorter and/or more flexible, the term has been used to describe an extremely wide variety of projectiles, from heavy spear-like ammunition for siege engines or atlatls to tiny poisoned needles for use in blowguns. Plumbatae or martiobarbuli were lead-weighted darts carried by infantrymen in Antiquity, the first examples seem to have been carried by the Ancient Greeks from about 500 B. C. onwards, but the best-known users were the late Roman and Byzantine armies. Reconstructions of this system have a range of one hundred metres. This technology was used worldwide from the Upper Palaeolithic until the development of archery made it obsolete, the darts in question are much larger than arrows, but noticeably lighter than javelins. They have a point, often of stone, on a removable foreshaft. This is held by friction onto a thin, flexible main shaft a few metres in length, with fletching, since they are unlike anything in Western history, the term dart has been adopted after some debate. Some alternate terms for this missile have included the spear, but this term has fallen out of favour since in all other uses, in its function, an atlatl dart is more like a combination between a bow and an arrow. Its similarity to a bow may not be obvious. As throwing begins, a dart of this type is designed to flex in compression between the force at its nock and the inertia of its weighted point, storing energy. Late in this throw, as the point moves faster and so offers less resistance, some energy may also be recovered by the fletching as the projectile fishtails through the air. However, this energy is far less than is commonly stated, to maximize elastic energy storage and recovery, such darts should be held only by the nock and allowed to pivot freely as they are thrown. This requires a tool that is often called a spear thrower. Western culture has been able to borrow a name for this tool from the Aztec, who used it against the invading Spanish, in Europe, the atlatl was supplemented by the bow and arrow in the Epi-Paleolithic. By the Iron Age, the amentum, an attached to the shaft, was the standard European mechanism for throwing lighter javelins. The amentum gives not only range, but also spin to the projectile, archery may be easier to learn and have a faster rate of fire, yet perhaps this systems greatest advantage over the atlatl is that ammunition is easier to make and transport. Since the dart must store almost all of the elastic energy, more care, planning. For example, stone dart points from the same set tend to vary in mass by no more than a few percent, similar constraints exist for the length, diameter, and materials quality of the shaft
6.
Feather
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Feathers are epidermal growths that form the distinctive outer covering, or plumage, on birds. They are considered the most complex integumentary structures found in vertebrates and they are among the characteristics that distinguish the extant birds from other living groups. Although feathers cover most parts of the body of birds, they arise only from certain well-defined tracts on the skin and they aid in flight, thermal insulation, and waterproofing. In addition, coloration helps in communication and protection, plumology is the name for the science that is associated with the study of feathers. Feathers are among the most complex integumentary appendages found in vertebrates and are formed in tiny follicles in the epidermis, or outer skin layer, that produce keratin proteins. There are two types of feather, vaned feathers which cover the exterior of the body. The pennaceous feathers are vaned feathers, also called contour feathers, pennaceous feathers arise from tracts and cover the entire body. In some passerines, filoplumes arise exposed beyond the contour feathers on the neck, the remiges, or flight feathers of the wing, and rectrices, the flight feathers of the tail are the most important feathers for flight. A typical vaned feather features a main shaft, called the rachis, fused to the rachis are a series of branches, or barbs, the barbs themselves are also branched and form the barbules. These barbules have minute hooks called barbicels for cross-attachment, down feathers are fluffy because they lack barbicels, so the barbules float free of each other, allowing the down to trap air and provide excellent thermal insulation. At the base of the feather, the rachis expands to form the hollow tubular calamus which inserts into a follicle in the skin, the basal part of the calamus is without vanes. This part is embedded within the follicle and has an opening at the base. Hatchling birds of species have a special kind of natal down feathers which are pushed out when the normal feathers emerge. Flight feathers are stiffened so as to work against the air in the downstroke, feathers insulate birds from water and cold temperatures. They may also be plucked to line the nest and provide insulation to the eggs, the individual feathers in the wings and tail play important roles in controlling flight. Some species have a crest of feathers on their heads, although feathers are light, a birds plumage weighs two or three times more than its skeleton, since many bones are hollow and contain air sacs. Color patterns serve as camouflage against predators for birds in their habitats, as with fish, the top and bottom colors may be different, in order to provide camouflage during flight. Striking differences in patterns and colors are part of the sexual dimorphism of many bird species and are particularly important in selection of mating pairs
7.
French language
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French is a Romance language of the Indo-European family. It descended from the Vulgar Latin of the Roman Empire, as did all Romance languages, French has evolved from Gallo-Romance, the spoken Latin in Gaul, and more specifically in Northern Gaul. Its closest relatives are the other langues doïl—languages historically spoken in northern France and in southern Belgium, French was also influenced by native Celtic languages of Northern Roman Gaul like Gallia Belgica and by the Frankish language of the post-Roman Frankish invaders. Today, owing to Frances past overseas expansion, there are numerous French-based creole languages, a French-speaking person or nation may be referred to as Francophone in both English and French. French is a language in 29 countries, most of which are members of la francophonie. As of 2015, 40% of the population is in Europe, 35% in sub-Saharan Africa, 15% in North Africa and the Middle East, 8% in the Americas. French is the fourth-most widely spoken mother tongue in the European Union, 1/5 of Europeans who do not have French as a mother tongue speak French as a second language. As a result of French and Belgian colonialism from the 17th and 18th century onward, French was introduced to new territories in the Americas, Africa, most second-language speakers reside in Francophone Africa, in particular Gabon, Algeria, Mauritius, Senegal and Ivory Coast. In 2015, French was estimated to have 77 to 110 million native speakers, approximately 274 million people are able to speak the language. The Organisation internationale de la Francophonie estimates 700 million by 2050, in 2011, Bloomberg Businessweek ranked French the third most useful language for business, after English and Standard Mandarin Chinese. Under the Constitution of France, French has been the language of the Republic since 1992. France mandates the use of French in official government publications, public education except in specific cases, French is one of the four official languages of Switzerland and is spoken in the western part of Switzerland called Romandie, of which Geneva is the largest city. French is the language of about 23% of the Swiss population. French is also a language of Luxembourg, Monaco, and Aosta Valley, while French dialects remain spoken by minorities on the Channel Islands. A plurality of the worlds French-speaking population lives in Africa and this number does not include the people living in non-Francophone African countries who have learned French as a foreign language. Due to the rise of French in Africa, the total French-speaking population worldwide is expected to reach 700 million people in 2050, French is the fastest growing language on the continent. French is mostly a language in Africa, but it has become a first language in some urban areas, such as the region of Abidjan, Ivory Coast and in Libreville. There is not a single African French, but multiple forms that diverged through contact with various indigenous African languages, sub-Saharan Africa is the region where the French language is most likely to expand, because of the expansion of education and rapid population growth
8.
Old Frankish
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Frankish, Old Franconian, or Old Frankish was the West Germanic language spoken by the Franks between the 4th and 8th century. The language itself is attested, but it gave rise to numerous loanwords in Old French. Old Dutch is the term for the Old Franconian dialects spoken in the Low Countries until about the 12th century when it evolved into Middle Dutch, during the Merovingian period, Frankish had significant influence on the Romance languages spoken in Gaul. As a result, many modern French words and placenames have a Germanic origin, France itself is still known in German as Frankreich and in Dutch as Frankrijk, i. e. the Frankish Realm. The Frankish language as spoken before the Carolingian period is mostly reconstructed from Old French loanwords, a notable exception is the Bergakker inscription, which may represent a primary record of 5th-century Frankish. In a modern context, the language is variously called Old Frankish or Old Franconian. In philology, the language spoken by the Salian Franks from around the 5th to the 10th century was called Old Dutch or, sometimes, Old Low Franconian, compare the somewhat analogous usage, in philological versus linguistic contexts, of Old English vs. Anglo-Saxon. The English term Old Frankish is, for reasons, usually not used in the context of the Ripuarian Franks. It is more used in the Salian Frank and Dutch contexts. The language spoken by the Salian Franks has sometimes referred to as Old West Low Franconian. The Germanic languages are divided into three groups, West, East and North Germanic. Their exact relation is difficult to determine, and they remained mutually intelligible throughout the Migration Period, the language spoken by the Franks was part of the West Germanic language group, which had features from Proto-Germanic in the late Jastorf culture. The West Germanic group is characterized by a number of phonological and morphological innovations not found in North, the West Germanic varieties of the time are generally split into three dialect groups, Ingvaeonic, Istvaeonic and Irminonic. While each had its own characteristics, there certainly must have still been a high degree of mutual intelligibility between these dialects. It is speculated that these tribes spoke a range of related Istvaeonic dialects in the West Germanic branch of Proto-Germanic. Sometime in the 4th or 5th centuries, it becomes appropriate to speak of Old Franconian rather than an Istvaeonic dialect of Proto-Germanic, very little is known about what the language was like during this period. One older runic sentence is on the sheath of Bergakker which is either the singular direct attestation of the Old Franconian language or the earliest attestation of Old Low Franconian language. Another early sentence from the early 6th century AD is found in the Lex Salica and this phrase was used to free a serf, Maltho thi afrio lito These are the earliest sentences yet found of Old Franconian
9.
Projectile
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A projectile is any object thrown into space by the exertion of a force. Although any object in motion through space may be called a projectile, mathematical equations of motion are used to analyze projectile trajectory. Blowguns and pneumatic rifles use compressed gases, while most other guns and cannons utilize expanding gases liberated by sudden chemical reactions, light-gas guns use a combination of these mechanisms. Railguns utilize electromagnetic fields to provide a constant acceleration along the length of the device. Some projectiles provide propulsion during flight by means of an engine or jet engine. In military terminology, a rocket is unguided, while a missile is guided, note the two meanings of rocket, an ICBM is a guided missile with a rocket engine. An explosion, whether or not by a weapon, causes the debris to act as high velocity projectiles. An explosive weapon, or device may also be designed to produce high velocity projectiles by the break-up of its casing. Many projectiles, e. g. shells, may carry a charge or another chemical or biological substance. Aside from explosive payload, a projectile can be designed to cause damage, e. g. fire. Typical kinetic energy weapons are blunt projectiles such as rocks and round shots, pointed ones such as arrows, among projectiles that do not contain explosives are those launched from railguns, coilguns, and mass drivers, as well as kinetic energy penetrators. Other types of weapons are accelerated over time by a rocket engine. In either case, it is the energy of the projectile that destroys its target. Some kinetic weapons for targeting objects in spaceflight are anti-satellite weapons, since in order to reach an object in orbit it is necessary to attain an extremely high velocity, their released kinetic energy alone is enough to destroy their target, explosives are not necessary. For example, the energy of TNT is 4.6 MJ/kg, and this saves costly weight and there is no detonation to be precisely timed. This method, however, requires direct contact with the target, some hit-to-kill warheads are additionally equipped with an explosive directional warhead to enhance the kill probability. With regard to weapons, the Arrow missile and MIM-104 Patriot PAC-2 have explosives, while the Kinetic Energy Interceptor, Lightweight Exo-Atmospheric Projectile. A kinetic projectile can also be dropped from aircraft and this is applied by replacing the explosives of a regular bomb with a non-explosive material, for a precision hit with less collateral damage
10.
Aerodynamics
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Aerodynamics, from Greek ἀήρ aer + δυναμική, the study of the motion of air, particularly its interaction with a solid object, such as an airplane wing. Aerodynamics is a sub-field of fluid dynamics and gas dynamics, the term aerodynamics is often used synonymously with gas dynamics, the difference being that gas dynamics applies to the study of the motion of all gases, and is not limited to air. The formal study of aerodynamics began in the sense in the eighteenth century. Most of the efforts in aerodynamics were directed toward achieving heavier-than-air flight. Recent work in aerodynamics has focused on issues related to flow, turbulence. Fundamental concepts of continuum, drag, and pressure gradients appear in the work of Aristotle, in 1726, Sir Isaac Newton became the first person to develop a theory of air resistance, making him one of the first aerodynamicists. In 1757, Leonhard Euler published the more general Euler equations which could be applied to both compressible and incompressible flows, the Euler equations were extended to incorporate the effects of viscosity in the first half of the 1800s, resulting in the Navier-Stokes equations. The Navier-Stokes equations are the most general governing equations of fluid flow, in 1871, Francis Herbert Wenham constructed the first wind tunnel, allowing precise measurements of aerodynamic forces. Drag theories were developed by Jean le Rond dAlembert, Gustav Kirchhoff, in 1889, Charles Renard, a French aeronautical engineer, became the first person to reasonably predict the power needed for sustained flight. Otto Lilienthal, the first person to become successful with glider flights, was also the first to propose thin, curved airfoils that would produce high lift. Building on these developments as well as carried out in their own wind tunnel. During the time of the first flights, Frederick W. Lanchester, Martin Wilhelm Kutta, Kutta and Zhukovsky went on to develop a two-dimensional wing theory. Expanding upon the work of Lanchester, Ludwig Prandtl is credited with developing the mathematics behind thin-airfoil, as aircraft speed increased, designers began to encounter challenges associated with air compressibility at speeds near or greater than the speed of sound. The differences in air flows under such conditions leds to problems in control, increased drag due to shock waves. The ratio of the speed to the speed of sound was named the Mach number after Ernst Mach who was one of the first to investigate the properties of supersonic flow. Theodore von Kármán and Hugh Latimer Dryden introduced the term transonic to describe flow speeds around Mach 1 where drag increases rapidly, by the time the sound barrier was broken, aerodynamicists understanding of the subsonic and low supersonic flow had matured. The Cold War prompted the design of an line of high performance aircraft. Understanding the motion of air around an object enables the calculation of forces, in many aerodynamics problems, the forces of interest are the fundamental forces of flight, lift, drag, thrust, and weight
