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Mandelbaum Effect
The Mandelbaum effect is the tendency for the eye to focus nearby in conditions of poor visibility. It was first codified by J. Mandelbaum in 1960. Because dirty glass can aggravate the effect, potentially causing a pilot or driver to miss seeing an obstacle or hazard, it is a strong safety argument for keeping windows clean. Discussion When visibility is poor, as at night during rainstorms or fog, the eye tends to relax and focus on its best distance, technically known as "empty field" or "dark focus". This distance is usually just under one meter (one yard), but varies considerably among people. The tendency is aggravated by objects close to the eye, drawing focus closer. A common synonym for the effect in FAA and Transport Canada usage is "empty-field myopia." It has been shown that the Mandelbaum effect is not a refractive error in the usual sense: it is not a structural characteristic of the eyes, but the effect arises from normal variations of perception in the brain. As ...
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Aviator
An aircraft pilot or aviator is a person who controls the flight of an aircraft by operating its directional flight controls. Some other aircrew members, such as navigators or flight engineers, are also considered aviators because they are involved in operating the aircraft's navigation and engine systems. Other aircrew members, such as drone operators, flight attendants, mechanics and ground crew, are not classified as aviators. In recognition of the pilots' qualifications and responsibilities, most militaries and many airlines worldwide award aviator badges to their pilots. Definition The first recorded use of the term ''aviator'' (''aviateur'' in French) was in 1887, as a variation of ''aviation'', from the Latin ''avis'' (meaning ''bird''), coined in 1863 by in ''Aviation Ou Navigation Aérienne'' ("Aviation or Air Navigation"). The term ''aviatrix'' (''aviatrice'' in French), now archaic, was formerly used for a female pilot. The term ''aviator'' (''aviateur'' ...
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Human Eye
The human eye is a sensory organ in the visual system that reacts to light, visible light allowing eyesight. Other functions include maintaining the circadian rhythm, and Balance (ability), keeping balance. The eye can be considered as a living optics, optical device. It is approximately spherical in shape, with its outer layers, such as the outermost, white part of the eye (the sclera) and one of its inner layers (the pigmented choroid) keeping the eye essentially stray light, light tight except on the eye's optic axis. In order, along the optic axis, the optical components consist of a first lens (the cornea, cornea—the clear part of the eye) that accounts for most of the optical power of the eye and accomplishes most of the Focus (optics), focusing of light from the outside world; then an aperture (the pupil) in a Diaphragm (optics), diaphragm (the Iris (anatomy), iris—the coloured part of the eye) that controls the amount of light entering the interior of the eye; then an ...
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Transport Canada
Transport Canada () is the Ministry (government department), department within the Government of Canada responsible for developing regulations, Policy, policies and Public services, services of road, rail, marine and air Transport in Canada, transportation in Canada. It is part of the Transportation, Infrastructure and Communities (TIC) portfolio. The current Minister of Transport (Canada), Minister of Transport is Chrystia Freeland. Transport Canada is headquartered in Ottawa, Ontario. History The Department of Transport was created in 1935 by the government of William Lyon Mackenzie King in recognition of the changing transportation environment in Canada at the time. It merged three departments: the former Department of Railways and Canals (Canada), Department of Railways and Canals, the Department of Marine, and the Civil Aviation Branch of the Department of National Defence (Canada), Department of National Defence (c. 1927 when it replaced the Air Board (Canada), Air Board) u ...
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Spatial Disorientation
Spatial disorientation is the inability to determine position or relative motion, commonly occurring during periods of challenging visibility, since visual system, vision is the dominant sense for orientation. The auditory system, vestibular system (within the inner ear), and proprioceptive system (sensory receptors located in the skin, muscles, tendons and joints) collectively work to coordinate movement with balance, and can also create illusory nonvisual sensations, resulting in spatial disorientation in the absence of strong visual cues. In aviation, spatial disorientation can result in improper perception of the Orientation (geometry), attitude of the aircraft, referring to the orientation of the aircraft relative to the horizon. If a pilot relies on this improper perception, this can result in inadvertent turning, ascending or descending. For aviators, proper recognition of aircraft attitude is most critical at night or in poor weather, when there is no visible horizon; in th ...
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Aviation Accidents And Incidents
An aviation accident is an event during aircraft operation that results serious injury, death, or significant destruction. An aviation incident is any operating event that compromises safety but does not escalate into an aviation accident. Preventing both accidents and incidents is the primary goal of aviation safety. One of the earliest recorded aviation accidents occurred on May 10, 1785, when a hot air balloon crashed in Tullamore, County Offaly, Ireland. The resulting fire seriously damaged the town, destroying over 130 homes. The first accident involving a powered aircraft occurred on September 17, 1908, when a Wright Model A crashed at Fort Myer, Virginia, USA. The pilot and co-inventor, Orville Wright, was injured, and the passenger, Signal Corps Lieutenant Thomas Selfridge, was killed. Definitions According to Annex 13 of the Convention on International Civil Aviation, an aviation accident is an occurrence associated with the operation of an aircraft, which ...
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Automobile Safety
Automotive safety is the study and practice of automotive design, construction, equipment and regulation to minimize the occurrence and consequences of traffic collisions involving motor vehicles. Road traffic safety more broadly includes roadway design. One of the first formal academic studies into improving motor vehicle safety was by Cornell Aeronautical Laboratory of Buffalo, New York. The main conclusion of their extensive report is the crucial importance of seat belts and padded dashboards. However, the primary vector of traffic-related deaths and injuries is the disproportionate mass and velocity of an automobile compared to that of the predominant victim, the pedestrian. According to the World Health Organization (WHO), 80% of cars sold in the world are not compliant with main safety standards. Only 40 countries have adopted the full set of the seven most important regulations for car safety. In the United States, a pedestrian is injured by a motor vehicle every 8 minu ...
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Accommodation (eye)
Accommodation is the process by which the vertebrate eye changes optical power to maintain a clear image or focus (optics), focus on an object as its distance varies. In this, distances vary for individuals from the far point—the maximum distance from the eye for which a clear image of an object can be seen, to the near point—the minimum distance for a clear image. Accommodation usually acts like a reflex, including part of the accommodation-convergence reflex, but it can also be consciously controlled. The main ways animals may change focus are: * Changing the shape of the lens. * Changing the position of the lens relative to the retina. * Changing the axial length of the eyeball. * Changing the shape of the cornea. Focusing mechanisms Focusing the light scattered by objects in a three dimensional environment into a two dimensional collection of individual bright points of light requires the light to be bent. To get a good image of these points of light on a defined area re ...
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Bokeh
In photography, bokeh ( or ; ) is the aesthetic quality of the blur produced in out-of-focus parts of an image, whether foreground or background or both. It is created by using a wide aperture lens. Some photographers incorrectly restrict use of the term bokeh to the appearance of bright spots in the out-of-focus area caused by circles of confusion. Bokeh has also been defined as "the way the lens renders out-of-focus points of light". Differences in lens aberrations and aperture shape cause very different bokeh effects. Some lens designs blur the image in a way that is pleasing to the eye, while others produce distracting or unpleasant blurring ("good" and "bad" bokeh, respectively). Photographers may deliberately use a shallow focus technique to create images with prominent out-of-focus regions, accentuating their lens's bokeh. Bokeh is often most visible around small background highlights, such as specular reflections and light sources, which is why it is ofte ...
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