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L2A2 SUIT Sight
The SUIT sight is a 4× prism sight with tritium-powered illumination, utilised at dusk or dawn. The full name is the L2A2 Sight Unit Infantry Trilux. The sight is not designed as a sniper sight, but as a standard issue infantry sight to improve the infantryman's night fighting capability and to assist target identification at long range in daylight and in poor light conditions. The sight was mounted on the L1A1 Self-Loading Rifle or GPMG. The SUIT sight was developed in the United Kingdom by Royal Armaments Research Development Establishment (RARDE) and is manufactured by Avimo Ltd., now known as Thales UK. It was first produced in 1976 by Avimo Ltd. in London and is regarded as an early optical combat sight. The SUIT sight was an optional optical sighting system for the British Army's L1A1 Self-Loading Rifle and was also used by the Australians and New Zealanders. It was not widely issued amongst nor used in combat by the British Infantry, Royal Marines and RAF Regiment. A s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parallax
Parallax is a displacement or difference in the apparent position of an object viewed along two different sightline, lines of sight and is measured by the angle or half-angle of inclination between those two lines. Due to perspective (graphical), foreshortening, nearby objects show a larger parallax than farther objects, so parallax can be used to determine distances. To measure large distances, such as the distance of a planet or a star from Earth, astronomers use the principle of parallax. Here, the term ''Stellar parallax, parallax'' is the semi-angle of inclination between two sight-lines to the star, as observed when Earth is on opposite sides of the Sun in its orbit. These distances form the lowest rung of what is called "the cosmic distance ladder", the first in a succession of methods by which astronomers determine the distances to celestial objects, serving as a basis for other distance measurements in astronomy forming the higher rungs of the ladder. Because parallax ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prism (optics)
An optical prism is a transparent optical element with flat, polished surfaces that are designed to refract light. At least one surface must be angled—elements with two parallel surfaces are ''not'' prisms. The most familiar type of optical prism is the triangular prism, which has a triangular base and rectangular sides. Not all optical prisms are geometric prisms, and not all geometric prisms would count as an optical prism. Prisms can be made from any material that is transparent to the wavelengths for which they are designed. Typical materials include glass, acrylic and fluorite. A dispersive prism can be used to break white light up into its constituent spectral colors (the colors of the rainbow) to form a spectrum as described in the following section. Other types of prisms noted below can be used to reflect light, or to split light into components with different polarizations. Types Dispersive ''Dispersive prisms'' are used to break up light into its ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lens (optics)
A lens is a transmissive optical device that focuses or disperses a light beam by means of refraction. A simple lens consists of a single piece of transparent material, while a compound lens consists of several simple lenses (''elements''), usually arranged along a common axis. Lenses are made from materials such as glass or plastic and are ground, polished, or molded to the required shape. A lens can focus light to form an image, unlike a prism, which refracts light without focusing. Devices that similarly focus or disperse waves and radiation other than visible light are also called "lenses", such as microwave lenses, electron lenses, acoustic lenses, or explosive lenses. Lenses are used in various imaging devices such as telescopes, binoculars, and cameras. They are also used as visual aids in glasses to correct defects of vision such as myopia and hypermetropia. History The word ''lens'' comes from , the Latin name of the lentil (a seed of a lentil pla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aluminium
Aluminium (or aluminum in North American English) is a chemical element; it has chemical symbol, symbol Al and atomic number 13. It has a density lower than that of other common metals, about one-third that of steel. Aluminium has a great affinity towards oxygen, passivation (chemistry), forming a protective layer of aluminium oxide, oxide on the surface when exposed to air. It visually resembles silver, both in its color and in its great ability to reflect light. It is soft, magnetism, nonmagnetic, and ductility, ductile. It has one stable isotope, 27Al, which is highly abundant, making aluminium the abundance of the chemical elements, 12th-most abundant element in the universe. The radioactive decay, radioactivity of aluminium-26, 26Al leads to it being used in radiometric dating. Chemically, aluminium is a post-transition metal in the boron group; as is common for the group, aluminium forms compounds primarily in the +3 oxidation state. The aluminium cation Al3+ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radioactive Decay
Radioactive decay (also known as nuclear decay, radioactivity, radioactive disintegration, or nuclear disintegration) is the process by which an unstable atomic nucleus loses energy by radiation. A material containing unstable nuclei is considered ''radioactive''. Three of the most common types of decay are Alpha decay, alpha, Beta decay, beta, and Gamma ray, gamma decay. The weak force is the Fundamental interactions, mechanism that is responsible for beta decay, while the other two are governed by the electromagnetic force, electromagnetic and nuclear forces. Radioactive decay is a randomness, random process at the level of single atoms. According to quantum mechanics, quantum theory, it is impossible to predict when a particular atom will decay, regardless of how long the atom has existed. However, for a significant number of identical atoms, the overall decay rate can be expressed as a decay constant or as a half-life. The half-lives of radioactive atoms have a huge range: f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tritium
Tritium () or hydrogen-3 (symbol T or H) is a rare and radioactive isotope of hydrogen with a half-life of ~12.33 years. The tritium nucleus (t, sometimes called a ''triton'') contains one proton and two neutrons, whereas the nucleus of the common isotope hydrogen-1 (''protium'') contains one proton and no neutrons, and that of non-radioactive hydrogen-2 ('' deuterium'') contains one proton and one neutron. Tritium is the heaviest particle-bound isotope of hydrogen. It is one of the few nuclides with a distinct name. The use of the name hydrogen-3, though more systematic, is much less common. Naturally occurring tritium is extremely rare on Earth. The atmosphere has only trace amounts, formed by the interaction of its gases with cosmic rays. It can be produced artificially by irradiation of lithium or lithium-bearing ceramic pebbles in a nuclear reactor and is a low-abundance byproduct in normal operations of nuclear reactors. Tritium is used as the energy source in radio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Obelisk
An obelisk (; , diminutive of (') ' spit, nail, pointed pillar') is a tall, slender, tapered monument with four sides and a pyramidal or pyramidion top. Originally constructed by Ancient Egyptians and called ''tekhenu'', the Greeks used the Greek term to describe them, and this word passed into Latin and ultimately English. Though William Thomas used the term correctly in his ''Historie of Italie'' of 1549, by the late sixteenth century (after reduced contact with Italy following the excommunication of Queen Elizabeth), Shakespeare failed to distinguish between pyramids and obelisks in his plays and sonnets. Ancient obelisks are monolithic and consist of a single stone; most modern obelisks are made of several stones. Ancient obelisks Egyptian Obelisks were prominent in the architecture of the ancient Egyptians, and played a vital role in their religion placing them in pairs at the entrance of the temples. The word "obelisk" as used in English today is of Greek rathe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reticle
A reticle or reticule, also known as a graticule or crosshair, is a pattern of fine lines or markings built into the eyepiece of an optical device such as a telescopic sight, spotting scope, theodolite, optical microscope or the electronic visual display, screen of an oscilloscope, to provide frame of reference, measurement references during visual inspections. Today, engraved lines or embedded fibers may be replaced by a digital image superimposed on a screen or eyepiece. Both terms may be used to describe any set of patterns used for aiding visual measurements and calibrations, but in modern use ''reticle'' is most commonly used for weapon sight (device), sights, while ''graticule'' is more widely used for non-weapon measuring instruments such as oscilloscope#Graticule, oscilloscope display, astronomic telescopes, microscopes and microscope slide, slides, surveying instruments and other similar devices. There are many variations of reticle pattern; this article concerns its ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Air Density
The density of air or atmospheric density, denoted '' ρ'', is the mass per unit volume of Earth's atmosphere at a given point and time. Air density, like air pressure, decreases with increasing altitude. It also changes with variations in atmospheric pressure, temperature, and humidity. According to the ISO International Standard Atmosphere (ISA), the standard sea level density of air at 101.325 kPa (abs) and is . At the non-standard sea level temperature of , the density would decrease to . This is about that of water with a density of about . Air density is a property used in many branches of science, engineering, and industry, including aeronautics;Olson, Wayne M. (2000) AFFTC-TIH-99-01, Aircraft Performance FlightICAO, Manual of the ICAO Standard Atmosphere (extended to 80 kilometres (262 500 feet)), Doc 7488-CD, Third Edition, 1993, .Grigorie, T.L., Dinca, L., Corcau J-I. and Grigorie, O. (2010) Aircraft's Altitude Measurement Using Pressure Information:Barometric Altitud ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Muzzle Velocity
Muzzle velocity is the speed of a projectile (bullet, pellet, slug, ball/ shots or shell) with respect to the muzzle at the moment it leaves the end of a gun's barrel (i.e. the muzzle). Firearm muzzle velocities range from approximately to in black powder muskets, to more than in modern rifles with high-velocity cartridges such as the .220 Swift and .204 Ruger, all the way to for tank guns firing kinetic energy penetrator ammunition. To simulate orbital debris impacts on spacecraft, NASA launches projectiles through light-gas guns at speeds up to . Several factors, including the type of firearm, the cartridge, and the barrel length, determine the bullet's muzzle velocity. Projectile velocity For projectiles in unpowered flight, its velocity is highest at leaving the muzzle and drops off steadily because of air resistance. Projectiles traveling less than the speed of sound (about in dry air at sea level) are ''subsonic'', while those traveling faster are ''super ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Projectile
A projectile is an object that is propelled by the application of an external force and then moves freely under the influence of gravity and air resistance. Although any objects in motion through space are projectiles, they are commonly found in warfare and sports (for example, a thrown baseball, kicked football, fired bullet, shot arrow, stone released from catapult). In ballistics, mathematical equations of motion are used to analyze projectile trajectories through launch, flight, and impact. Motive force Blowguns and pneumatic rifles use compressed gases, while most other guns and cannons utilize expanding gases liberated by sudden chemical reactions by propellants like smokeless powder. Light-gas guns use a combination of these mechanisms. Railguns utilize electromagnetic fields to provide acceleration along the entire length of the device, greatly increasing the muzzle velocity. Some projectiles provide propulsion during flight by means of a rocket ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
