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Clockwise And Counterclockwise
Two-dimensional rotation can occur in two possible directions or senses of rotation. Clockwise motion (abbreviated CW) proceeds in the same direction as a clock's hands relative to the observer: from the top to the right, then down and then to the left, and back up to the top. The opposite sense of rotation or revolution is (in Commonwealth English) anticlockwise (ACW) or (in North American English) counterclockwise (CCW). Three-dimensional rotation can have similarly defined senses when considering the corresponding angular velocity vector. Terminology Before clocks were commonplace, the terms "sunwise" and "deasil", "deiseil" and even "deocil" from the Scottish Gaelic language and from the same root as the Latin "dexter" ("right") were used for clockwise. "Widdershins" or "withershins" (from Middle Low German "weddersinnes", "opposite course") was used for counterclockwise. The terms clockwise and counterclockwise can only be applied to a rotational motion once a side of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Two-dimensional Rotation
In Euclidean geometry, two-dimensional rotations and reflections are two kinds of Euclidean plane isometries which are related to one another. Process A rotation in the plane can be formed by composing a pair of reflections. First reflect a point to its image on the other side of line . Then reflect to its image on the other side of line . If lines and make an angle with one another, then points and will make an angle around point , the intersection of and . I.e., angle will measure . A pair of rotations about the same point will be equivalent to another rotation about point . On the other hand, the composition of a reflection and a rotation, or of a rotation and a reflection (composition is not commutative), will be equivalent to a reflection. Mathematical expression The statements above can be expressed more mathematically. Let a rotation about the origin by an angle be denoted as . Let a reflection about a line through the origin which makes an angle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sundial
A sundial is a horology, horological device that tells the time of day (referred to as civil time in modern usage) when direct sunlight shines by the position of the Sun, apparent position of the Sun in the sky. In the narrowest sense of the word, it consists of a flat plate (the ''dial'') and a gnomon, which casts a shadow onto the dial. As the Sun diurnal motion, appears to move through the sky, the shadow aligns with different hour-lines, which are marked on the dial to indicate the time of day. The ''style'' is the time-telling edge of the gnomon, though a single point or ''nodus'' may be used. The gnomon casts a broad shadow; the shadow of the style shows the time. The gnomon may be a rod, wire, or elaborately decorated metal casting. The style must be polar alignment, parallel to the axis of the Earth's rotation for the sundial to be accurate throughout the year. The style's angle from horizontal is equal to the sundial's geographical latitude. The term ''sundial'' can r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Screw
A screw is an externally helical threaded fastener capable of being tightened or released by a twisting force (torque) to the screw head, head. The most common uses of screws are to hold objects together and there are many forms for a variety of materials. Screws might be inserted into holes in assembled parts or a screw may form its own thread. The #Differentiation between bolt and screw, difference between a screw and a bolt is that the latter is designed to be tightened or released by torquing a Nut (hardware), nut. The screw head on one end has a slot or other feature that commonly requires a tool to transfer the twisting force. Common tools for driving screws include screwdrivers, wrenches, coins and hex keys. The head is usually larger than the body, which provides a ''bearing surface'' and keeps the screw from being driven deeper than its length; an exception being the ''set screw'' (aka grub screw). The cylindrical portion of the screw from the underside of the head t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nut (hardware)
A nut is a type of fastener with a screw thread, threaded hole. Nuts are almost always used in conjunction with a mating bolt (fastener), bolt to fasten multiple parts together. The two partners are kept together by a combination of their threads' friction with slight deformation (engineering)#Elastic deformation, elastic deformation, a slight Tension (physics), stretching of the bolt, and compression (physics), compression of the parts to be held together. In applications where vibration or rotation may work a nut loose, various locking mechanisms may be employed: lock washers, jam nuts, eccentric double nuts, specialist adhesive thread-locking fluid such as Loctite, safety pins (split pins) or lockwire in conjunction with castellated nuts, nylon inserts (nyloc nut), or slightly oval-shaped threads. Square nuts, as well as bolt heads, were the first shape made and used to be the most common largely because they were much easier to manufacture, especially by hand. While rare toda ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
La Paz, Bolivia
La Paz, officially Nuestra Señora de La Paz ( Aymara: Chuqi Yapu ), is the seat of government of the Plurinational State of Bolivia. With 755,732 residents as of 2024, La Paz is the third-most populous city in Bolivia. Its metropolitan area, which is formed by La Paz, El Alto, Achocalla, Viacha, and Mecapaca makes up the second most populous urban area in Bolivia, with a population of 2.2 million, after Santa Cruz de la Sierra with a population of 2.3 million. It is also the capital of the La Paz Department. The city, in west-central Bolivia southeast of Lake Titicaca, is set in a canyon created by the Choqueyapu River. It is in a bowl-like depression, part of the Amazon basin, surrounded by the high mountains of the Altiplano. Overlooking the city is the triple-peaked Illimani. Its peaks are always snow-covered and can be seen from many parts of the city. At an elevation of roughly above sea level, La Paz is the highest capital city in the world. Due to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plaza Murillo
The Plaza Murillo is the central plaza of the city of La Paz and the open space most connected to the political life of Bolivia. Prominent buildings on the plaza include the Presidential Palace, National Congress of Bolivia, and the Cathedral of La Paz (or more formally, the Cathedral Basilica of Our Lady of Peace, La Paz). It is located in the old town, or ''Casco Viejo'', of the city and is surrounded by Socabaya Street to the west, Ayacucho Street to the east, Comercio Street to the south, and a continuation of Ingavi and Ballivan Streets to the north. Names The Plaza was originally named the Plaza Mayor (''Greatest/Main Plaza'') after its construction. It was later known during the colonial period as the Plaza de Armas. Following independence, it was renamed the 16 July Plaza (Plaza 16 de Julio) on 3 February 1902, in honor of Pedro Murillo, captured and hung by Spanish troops in January 1810. History The plaza was designed in 1558 as part of the rectilinear grid of La Paz b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Evo Morales
Juan Evo Morales Ayma (; born 26 October 1959) is a Bolivian politician, trade union organizer, and former cocalero activist who served as the 65th president of Bolivia from 2006 to 2019. Widely regarded as the country's first president to come from its indigenous population, his administration worked towards the implementation of left-wing policies, focusing on the legal protections and socioeconomic conditions of Bolivia's previously marginalized indigenous population and combating the political influence of the United States and resource-extracting multinational corporations. Ideologically a socialist, he led the Movement for Socialism (MAS) party from 1998 to 2024. Born to an Aymara family of subsistence farmers in Isallawi, Orinoca Canton, Morales undertook a basic education and mandatory military service before moving to the Chapare Province in 1978. Growing coca and becoming a trade unionist, he rose to prominence in the '' campesino'' ("rural laborers") union. I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bolivia
Bolivia, officially the Plurinational State of Bolivia, is a landlocked country located in central South America. The country features diverse geography, including vast Amazonian plains, tropical lowlands, mountains, the Gran Chaco Province, warm valleys, high-altitude Andean plateaus, and snow-capped peaks, encompassing a wide range of climates and biomes across its regions and cities. It includes part of the Pantanal, the largest tropical wetland in the world, along its eastern border. It is bordered by Brazil to the Bolivia-Brazil border, north and east, Paraguay to the southeast, Argentina to the Argentina-Bolivia border, south, Chile to the Bolivia–Chile border, southwest, and Peru to the west. The seat of government is La Paz, which contains the executive, legislative, and electoral branches of government, while the constitutional capital is Sucre, the seat of the judiciary. The largest city and principal industrial center is Santa Cruz de la Sierra, located on the Geog ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hebrew Language
Hebrew (; ''ʿÎbrit'') is a Northwest Semitic language within the Afroasiatic language family. A regional dialect of the Canaanite languages, it was natively spoken by the Israelites and remained in regular use as a first language until after 200 CE and as the liturgical language of Judaism (since the Second Temple period) and Samaritanism. The language was revived as a spoken language in the 19th century, and is the only successful large-scale example of linguistic revival. It is the only Canaanite language, as well as one of only two Northwest Semitic languages, with the other being Aramaic, still spoken today. The earliest examples of written Paleo-Hebrew date back to the 10th century BCE. Nearly all of the Hebrew Bible is written in Biblical Hebrew, with much of its present form in the dialect that scholars believe flourished around the 6th century BCE, during the time of the Babylonian captivity. For this reason, Hebrew has been referred to by Jews as '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jewish Town Hall (Prague)
The Jewish Town Hall () in Josefov, Prague, was constructed adjacent to the Old New Synagogue on the corner of Maiselova and Červená Ulice in 1586 in Renaissance style under the sponsorship of Mayor Mordechai Maisel. It acquired its Rococo facade in the 18th century. The building was the main meeting house of the local Jewish community but is currently closed to the public. It is perhaps best known for its two clocks, one on a tower with Roman numeral markings, the other, lower, has Hebrew numerals, which are the same as letters in the Hebrew alphabet. The Hebrew numerals begin with aleph and continue counterclockwise around the clock dial. See also * Prague Orloj The Prague astronomical clock or Prague Orloj ( ) is a Middle Ages, medieval astronomical clock attached to the Old Town Hall (Prague), Old Town Hall in Prague, the capital of the Czech Republic. Description The Orloj is mounted on the southe ... Buildings and structures in Prague Clock towers in the Cze ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Judaism
Judaism () is an Abrahamic religions, Abrahamic, Monotheism, monotheistic, ethnic religion that comprises the collective spiritual, cultural, and legal traditions of the Jews, Jewish people. Religious Jews regard Judaism as their means of observing the Mosaic covenant, which they believe was established between God in Judaism, God and the Jewish people. The religion is considered one of the earliest monotheistic religions. Jewish religious doctrine encompasses a wide body of texts, practices, theological positions, and forms of organization. Among Judaism's core texts is the Torah—the first five books of the Hebrew Bible—and a collection of ancient Hebrew scriptures. The Tanakh, known in English as the Hebrew Bible, has the same books as Protestant Christianity's Old Testament, with some differences in order and content. In addition to the original written scripture, the supplemental Oral Torah is represented by later texts, such as the Midrash and the Talmud. The Hebrew ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
