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top 10 words in brain distribution (in article): water light form animal time type produce surface cause region |
top 10 words in brain distribution (in article): city build house store town home bus world term design |
top 10 words in brain distribution (not in article): ice drink rock lamp river flow wine sea state occur |
top 10 words in brain distribution (not in article): street state people Unite material country road village department type |
times more probable under eye 30 20 10 6 4 2.5 1.25 1 1.25 2.5 4 6 10 20 30 times more probable under church (words not in the model) | |
Eyes'" are organs that detect light, and send signals along the optic nerve to the visual and other areas of the brain. Complex optical systems with resolving power have come in ten fundamentally different forms, and 96% of animal species possess a complex optical system. Image-resolving eyes are present in cnidaria, mollusks, chordates, annelids and arthropods. The simplest "eyes", in even unicellular organisms, do nothing but detect whether the surroundings are light or dark, which is sufficient for the entrainment of circadian rhythms. From more complex eyes, retinal photosensitive ganglion cells send signals along the retinohypothalamic tract to the suprachiasmatic nuclei to effect circadian adjustment. Overview. Complex eyes can distinguish shapes and colors. The visual fields of many organisms, especially predators, involve large areas of binocular vision to improve depth perception; in other organisms, eyes are located so as to maximise the field of view, such as in rabbits and horses. The first proto-eyes evolved among animals 540 million years ago, about the time of the so-called Cambrian explosion. The last common ancestor of animals possessed the biochemical toolkit necessary for vision, and more advanced eyes have evolved in 96% of animal species in 6 of the thirty-something main phyla. In most vertebrates and some mollusks, the eye works by allowing light to enter it and project onto a light-sensitive panel of cells, known as the retina, at the rear of the eye. The cone cells (for color) and the rod cells (for low-light contrasts) in the retina detect and convert light into neural signals for vision. The visual signals are then transmitted to the brain via the optic nerve. Such eyes are typically roughly spherical, filled with a transparent gel-like substance called the vitreous humour, with a focusing lens and often an iris; the relaxing or tightening of the muscles around the iris change the size of the pupil, thereby regulating the amount of light that enters the eye, and reducing aberrations when there is enough light. The eyes of cephalopods, fish, amphibians and snakes usually have fixed lens shapes, and focusing vision is achieved by telescoping the lens — similar to how a camera focuses. Compound eyes are found among the arthropods and are composed of many simple facets which, depending on the details of anatomy, may give either a single pixelated image or multiple images, per eye. Each sensor has its own lens and photosensitive cell(s). Some eyes have up to 28,000 such sensors, which are arranged hexagonally, and which can give a full 360-degree field of vision. Compound eyes are very sensitive to motion. Some arthropods, including many Strepsiptera, have compound eyes of only a few facets, each with a retina capable of creating an image, creating vision. With each eye viewing a different thing, a fused image from all the eyes is produced in the brain, providing very different, high-resolution images. Possessing detailed hyperspectral color vision, the Mantis shrimp has been reported to have the world's most complex color vision system. Trilobites, which are now extinct, had unique compound eyes. They used clear calcite crystals to form the lenses of their eyes. In this, they differ from most other arthropods, which have soft eyes. The number of lenses in such an eye varied, however: some trilobites had only one, and some had thousands of lenses in one eye. In contrast to compound eyes, simple eyes are those that have a single lens. For example, jumping spiders have a large pair of simple eyes with a narrow field of view, supported by an array of other, smaller eyes for peripheral vision. Some insect larvae, like caterpillars, have a different type of simple eye (stemmata) which gives a rough image. Some of the simplest eyes, called ocelli, can be found in animals like some of the snails, which cannot actually "see" in the normal sense. They do have photosensitive cells, but no lens and no other means of projecting an image onto these cells. They can distinguish between light and dark, but no more. This enables snails to keep out of direct sunlight. In organisms dwelling near deep-sea vents, compound eyes have been secondarily simplified and adapted to spot the infra-red light produced by the hot vents in this way the bearers can spot hot springs and avoid being boiled alive. Evolution. Visual pigments appear to have a common ancestor and were probably involved in circadian rhythms or reproductive timing in simple organisms. Complex vision, associated with dedicated visual organs, or eyes, evolved many times in different lineages. Types of eye. Nature has produced ten different eye layouts — indeed every way of capturing an image has evolved at least once in nature, with the exception of zoom and Fresnel lenses. Eye types can be categorized into "simple eyes", with one concave chamber, and "compound eyes", which comprise a number of individual lenses laid out on a convex surface. Note that "simple" does not imply a reduced level of complexity or acuity. Indeed, any eye type can be adapted for almost any behaviour or environment. The only limitations specific to eye types are that of resolution — the physics of compound eyes prevents them from achieving a resolution better than 1°. Also, superposition eyes can achieve greater sensitivity than apposition eyes, so are better suited to dark-dwelling creatures. Eyes also fall into two groups on the basis of their photoreceptor's cellular construction, with the photoreceptor cells either being cilliated (as in the vertebrates) or rhabdomic. These two groups are not monophyletic; the cnidaira also possess cilliated cells, Pit eyes. Pit eyes, also known as stemma, are eye-spots which may be set into a pit to reduce the angles of light that enters and affects the eyespot, to allow the organism to deduce the angle of incoming light. Found in about 85% of phyla, these basic forms were probably the precursors to more advanced types of "simple eye". They are small, comprising up to about 100 cells covering about 100 µm. The directionality can be improved by reducing the size of the aperture, by incorporating a reflective layer behind the receptor cells, or by filling the pit with a refractile material. Pinhole eye. The pinhole eye is an "advanced" form of pit eye incorporating these improvements, most notably a small aperture (which may be adjustable) and deep pit. It is only found in the | Pisgah Baptist Church, a typical Protestant church in rural America. Førde Church, a typical Protestant church in Norway. Interior of church in Malancrav, Romania The First Baptist Church of Austell. Located in Austell, G.A., U.S.A. A church in France being fired at during the First World War A church building'" is a building or structure whose primary purpose is to facilitate the meeting of a church. Originally, Christians met in synagogues and in one another's homes. As Christianity grew and became more accepted by governments, rooms, and eventually entire buildings, were set aside for the explicit purpose of Christian worship. Traditional church buildings are often in the shape of a cross, and frequently have a tower or dome. More modern church buildings have a variety of architectural styles and layouts; many buildings that were designed for other purposes have now been converted for church use, and similarly many original church buildings have been put to other uses. Early development. The church of Saint Simon in Aleppo, Syria is considered to be one of the oldest surviving church buildings in the world. The first Christians were, like Jesus, Jews resident in Israel who worshiped on occasion in the Temple in Jerusalem and weekly in local synagogues. Temple worship was a ritual involving sacrifice, occasionally including the sacrifice of animals in atonement for sin, offered to Yahweh. The New Testament includes many references to Jesus visiting the Temple, the first time as an infant with his parents.The early history of the synagogue is obscure, but it seems to be an institution developed for public Jewish worship during the Babylonian captivity when the Jews did not have access to the Jerusalem Temple for ritual sacrifice. Instead, they developed a daily and weekly service of readings from the Torah or the prophets followed by commentary. This could be carried out in a house if the attendance was small enough, and in many towns of the Diaspora that was the case. In others, more elaborate architectural settings developed, sometimes by converting a house and sometimes by converting a previously public building. The minimum requirements seem to have been a meeting room with adequate seating, a case for the Torah scrolls, and a raised platform for the reader and preacher. Jesus himself participated in this sort of service as a reader and commentator (see Gospel of Luke 4: 16-24) and his followers probably remained worshipers in synagogues in some cities. However, following the destruction of the Temple in Jerusalem in 70, the new Christian movement and Judaism increasingly parted ways. The Church became overwhelmingly Gentile sometime in the 4th century. The Syrian city of Dura-Europos on the West bank of the Euphrates was an outpost town between the Roman and Parthian empires. During a siege by Parthian troops in A.D. 257 the buildings in the outermost blocks of the city grid were partially destroyed and filled with rubble to reinforce the city wall. Thus were preserved and securely dated the earliest decorated church and a synagogue decorated with extensive wall paintings. Both had been converted from earlier private buildings. The church at Dura Europos has a special room dedicated for baptisms with a large baptismal font. Churches in medieval Europe. During the 11th through 14th centuries, a wave of building of cathedrals and smaller parish churches occurred across Western Europe. In addition to being a place of worship, the cathedral or parish church was used by the community in other ways. It could serve as a meeting place for guilds or a hall for banquets. Mystery plays were sometimes performed in cathedrals, and cathedrals might also be used for fairs. The church could be used as a place to thresh and store grain. Architecture. A common architecture for churches is the shape of a cross (a long central rectangle, with side rectangles, and a rectangle in front for the altar space or sanctuary). These churches also often have a dome or other large vaulted space in the interior to represent or draw attention to the heavens. Other common shapes for churches include a circle, to represent eternity, or an octagon or similar star shape, to represent the church's bringing light to the world. Another common feature is the spire, a tall tower on the "west" end of the church or over the crossing. Basilica. The Latin word basilica (derived from Greek, "Basiliké Stoà", Royal "Stoa"), was originally used to describe a Roman public building (as in Greece, mainly a tribunal), usually located in the forum of a Roman town. After the Roman Empire became officially Christian, the term came by extension to refer to a large and important church that has been given special ceremonial rites by the Pope. Thus the word retains two senses today, one architectural and the other ecclesiastical. Cathedral. Cathedral of Christ the Saviour (Moscow, Russia). The Cathedral of Saint Sava in Belgrade, Serbia. The largest Orthodox church and one of the largest Cathedrals in the world. A cathedral is a church, usually Roman Catholic, Anglican, or Eastern Orthodox, housing the seat of a bishop. The word cathedral takes its name from the word "cathedra", or Bishop's Throne (In Latin: "ecclesia cathedralis"). The term is sometimes (improperly) used to refer to any church of great size. The church that has the function of cathedral is not of necessity a large building. It might be as small as Christ Church Cathedral, Oxford or Chur Cathedral, Switzerland. But frequently, the cathedral, along with some of the abbey churches, was the largest building in any region. Alternative buildings. Barnabas Community Church, a former army centre now used by a church in Shrewsbury, England. Wasserkirche in Zürich (Switzerland), used as public library (1634-1917) Old and disused church buildings can be seen as an interesting proposition for developers as the architecture and location often provide for attractive homes or city centre entertainment venues On the other hand, many newer Churches have decided to host meetings in public buildings such as schools, universities, cinemas or theatres. There is another trend to convert old buildings for worship use rather than face the construction costs and planning difficulties of a new build. Unusual venues in the UK include an old Tram power station, a former bus garage, an old cinema and bingo hall, a former Territorial Army Drill Hall, a former synagogue and a windmill. |