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Gimbal
A gimbal is a pivoted support that permits rotation of an object about an axis. A set of three gimbals, one mounted on the other with orthogonal pivot axes, may be used to allow an object mounted on the innermost gimbal to remain independent of the rotation of its support (e.g. vertical in the first animation). For example, on a ship, the gyroscopes, shipboard compasses, stoves, and even drink holders typically use gimbals to keep them upright with respect to the horizon despite the ship's pitching and rolling. The gimbal suspension used for mounting compasses and the like is sometimes called a Cardan suspension after Italian mathematician and physicist Gerolamo Cardano (1501–1576) who described it in detail. However, Cardano did not invent the gimbal, nor did he claim to. The device has been known since antiquity, first described in the 3rd c. BC by Philo of Byzantium, although some modern authors support the view that it may not have a single identifiable inventor. His ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gyroscope Operation
A gyroscope (from Ancient Greek γῦρος ''gŷros'', "round" and σκοπέω ''skopéō'', "to look") is a device used for measuring or maintaining orientation and angular velocity. It is a spinning wheel or disc in which the axis of rotation (spin axis) is free to assume any orientation by itself. When rotating, the orientation of this axis is unaffected by tilting or rotation of the mounting, due to the conservation of angular momentum. Gyroscopes based on other operating principles also exist, such as the microchip-packaged MEMS gyroscopes found in electronic devices (sometimes called gyrometers), solid-state ring lasers, fibre optic gyroscopes, and the extremely sensitive quantum gyroscope. Applications of gyroscopes include inertial navigation systems, such as in the Hubble Space Telescope, or inside the steel hull of a submerged submarine. Due to their precision, gyroscopes are also used in gyrotheodolites to maintain direction in tunnel mining. Gyroscopes can ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gyroscope
A gyroscope (from Ancient Greek γῦρος ''gŷros'', "round" and σκοπέω ''skopéō'', "to look") is a device used for measuring or maintaining Orientation (geometry), orientation and angular velocity. It is a spinning wheel or disc in which the axis of rotation (spin axis) is free to assume any orientation by itself. When rotating, the orientation of this axis is unaffected by tilting or rotation of the mounting, due to the angular momentum#Conservation of angular momentum, conservation of angular momentum. Gyroscopes based on other operating principles also exist, such as the microchip-packaged Vibrating structure gyroscope#MEMS gyroscopes, MEMS gyroscopes found in electronic devices (sometimes called gyrometers), solid-state ring laser gyroscope, ring lasers, fibre optic gyroscopes, and the extremely sensitive quantum gyroscope. Applications of gyroscopes include inertial navigation systems, such as in the Hubble Space Telescope, or inside the steel hull of a submer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gerolamo Cardano
Gerolamo Cardano (; also Girolamo or Geronimo; ; ; 24 September 1501– 21 September 1576) was an Italian polymath whose interests and proficiencies ranged through those of mathematician, physician, biologist, physicist, chemist, astrologer, astronomer, philosopher, music theorist, writer, and gambler. He became one of the most influential mathematicians of the Renaissance and one of the key figures in the foundation of probability; he introduced the binomial coefficients and the binomial theorem in the Western world. He wrote more than 200 works on science. Cardano partially invented and described several mechanical devices including the combination lock, the gimbal consisting of three concentric rings allowing a supported compass or gyroscope to rotate freely, and the Cardan shaft with universal joints, which allows the transmission of rotary motion at various angles and is used in vehicles to this day. He made significant contributions to hypocycloids - published in ''De prop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Compass
A compass is a device that shows the cardinal directions used for navigation and geographic orientation. It commonly consists of a magnetized needle or other element, such as a compass card or compass rose, which can pivot to align itself with North magnetic pole, magnetic north. Other methods may be used, including gyroscopes, magnetometers, and GPS receivers. Compasses often show angles in degrees: north corresponds to 0°, and the angles increase clockwise, so east is 90°, south is 180°, and west is 270°. These numbers allow the compass to show azimuths or bearing (angle), bearings which are commonly stated in degrees. If local magnetic declination, variation between magnetic north and true north is known, then direction of magnetic north also gives direction of true north. Among the Four Great Inventions, the magnetic compass was first invented as a device for divination as early as the history of science and technology in China, Chinese Han dynasty (since c. 206 BC),#Li, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Censer
A censer, incense burner, perfume burner or pastille burner is a vessel made for burning incense or perfume in some solid form. They vary greatly in size, form, and material of construction, and have been in use since ancient times throughout the world. They may consist of simple earthenware bowls or fire pots to intricately carved silver or gold vessels, small table top objects a few centimetres tall to as many as several metres high. Many designs use openwork to allow a flow of air. In many cultures, burning incense has spiritual and religious connotations, and this influences the design and decoration of the censer. Often, especially in Western contexts, the term "censer" is used for pieces made for religious use, especially those on chains that are swung through the air to spread the incense smoke widely, while the term "perfume burner" is used for objects made for secular use. The original meaning of pastille was a small compressed mixture of aromatic plant material an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Han Dynasty
The Han dynasty was an Dynasties of China, imperial dynasty of China (202 BC9 AD, 25–220 AD) established by Liu Bang and ruled by the House of Liu. The dynasty was preceded by the short-lived Qin dynasty (221–206 BC) and a warring interregnum known as the Chu–Han Contention (206–202 BC), and it was succeeded by the Three Kingdoms period (220–280 AD). The dynasty was briefly interrupted by the Xin dynasty (9–23 AD) established by the usurping regent Wang Mang, and is thus separated into two periods—the #Western Han (202 BC – 9 AD), Western Han (202 BC9 AD) and the #Eastern Han (25–220 AD), Eastern Han (25–220 AD). Spanning over four centuries, the Han dynasty is considered a Golden ages of China, golden age in Chinese history, and had a permanent impact on Chinese identity in later periods. The majority ethnic group of modern China refer to themselves as the "Han people" or "Han Chinese". The spoken Chinese ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Philo Of Byzantium
Philo of Byzantium (, ''Phílōn ho Byzántios'', ), also known as Philo Mechanicus (Latin for "Philo the Engineer"), was a Greek engineer, physicist and writer on mechanics, who lived during the latter half of the 3rd century BC. Although he was from Byzantium he lived most of his life in Alexandria, Egypt. He was probably younger than Ctesibius, though some place him a century earlier. Works Philo was the author of a large work, the ''Syntaxis'' (, ''Mēkhanikḗ Sýntaxē''), which contained the following sections: * Isagoge (, ''Eisagōgḗ'') – Introduction (general mathematics) * Mochlica (, ''Mokhliká'') – Leverage (mechanics) * Limenopoeica (, ''Limenopoiiká'') – Harbour Construction * Belopoeica (, ''Belopoiiká'') – Siege Engine Construction * Pneumatica (, ''Pneumatiká'') – Pneumatics * Automatopoeica (, ''Automatopoiētiká'') – Automatons (mechanical toys and diversions) * Parasceuastica (, ''Paraskeuastiká'') – Preparations (for sieges) * Poli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sima Xiangru
Sima Xiangru ( , c. 179117BC) was a Chinese musician, poet, and politician who lived during the Han dynasty#Western Han, Western Han dynasty. Sima is a significant figure in the history of Classical Chinese poetry, and is generally regarded as the greatest of all composers of Chinese fu (poetry), ''fu'' rhapsodies. His poetry includes his invention or at least development of the ''fu'' form, applying new metrical rhythms to the lines of poetry, which he mixed with lines of prose, and provided with several of what would in ensuing centuries become among a group of common set topics for this genre. Sima Xiangru was also versatile enough to write in the ''Chu ci'' style, while it was enjoying a renaissance, and he also wrote lyrics in what would become known as the ''yuefu'' formal style. Early life and career Sima Xiangru was born in the commandery of Shu (state), Shu (now Sichuan, Sichuan Province) in the early 2nd century BC. He probably was born in 179BC, but some sources g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hellenistic
In classical antiquity, the Hellenistic period covers the time in Greek history after Classical Greece, between the death of Alexander the Great in 323 BC and the death of Cleopatra VII in 30 BC, which was followed by the ascendancy of the Roman Empire, as signified by the Battle of Actium in 31 BC and the Roman conquest of Ptolemaic Egypt the following year, which eliminated the last major Hellenistic kingdom. Its name stems from the Ancient Greek word ''Hellas'' (, ''Hellás''), which was gradually recognized as the name for Greece, from which the modern historiographical term ''Hellenistic'' was derived. The term "Hellenistic" is to be distinguished from "Hellenic" in that the latter refers to Greece itself, while the former encompasses all the ancient territories of the period that had come under significant Greek influence, particularly the Hellenized Middle East, after the conquests of Alexander the Great. After the Macedonian conquest of the Achaemenid Empire in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Andrew Wilson (classical Archaeologist)
Andrew Ian Wilson (born 29 February 1968) is a British classical archaeologist and Head of School of Archaeology at the University of Oxford. He was director of the Oxford Institute of Archaeology from 2009 to 2011. Wilson's main research interests are the Roman economy, economy of the Roman world, Ancient Greece, Greek and Ancient Rome, Roman water supply, and ancient technology. Early life and education Wilson was educated at the Perse School, Cambridge, and at Corpus Christi College, Oxford, where he studied Literae Humaniores (Classics) from 1987 to 1991. From 1991 to 1993 he worked as a computer consultant for the electronics firm Eurotherm, before returning to Oxford to study for his doctorate (1993 to 1997), a social and technological study on water management and usage in North Africa during classical antiquity#Roman era, Roman North Africa, supervised by John Lloyd (archaeologist), John Lloyd. Academic career From 1996 to 2000 he was a Fellow by Examination in Classical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wu Zetian
Wu Zetian (624 – 16 December 705), personal name Wu Zhao, was List of rulers of China#Tang dynasty, Empress of China from 660 to 705, ruling first through others and later in her own right. She ruled as queen consort , empress consort through her husband Emperor Gaozong of Tang, Emperor Gaozong and later as empress dowager through her sons Emperors Emperor Zhongzong of Tang, Zhongzong and Emperor Ruizong of Tang, Ruizong, from 660 to 690. She subsequently founded and ruled as Empress Regnant of the Wu Zhou dynasty of China from 16 October 690 to 21 February 705. She was the only female sovereign in the history of China who is widely Mandate of Heaven, regarded as legitimate. Under her 45-year reign, China grew larger, becoming one of the great powers of the world, its culture and economy were revitalized, and corruption in the court was reduced. She was eventually removed from power during a coup () and died a few months later. In early life, Wu was the concubine of Emper ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interpolation (manuscripts)
An interpolation, in relation to literature and especially ancient manuscripts, is an entry or passage in a text that was not written by the original author. As there are often several generations of copies between an extant copy of an ancient text and the original, each handwritten by different scribes, there is a natural tendency for extraneous material to be inserted into such documents over time. Overview Interpolations originally may be inserted as an authentic explanatory note (for example, ), but may also be included for fraudulent purposes. The forged passages and works attributed to the Pseudo-Isidore are an example of the latter. Similarly, the letters of Ignatius of Antioch were interpolated by Apollinarian heretics, three centuries after the originals were written. Charters and legal texts are also subject to forgery of this kind. In the 13th century, a medieval romance, the Prose ''Tristan'', inserted another prose romance, the Vulgate Cycle's ''Queste del Saint ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
