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Eureka (word)
Archimedes exclaiming ''Eureka''. In his excitement, he forgets to dress and runs nude in the streets straight out of his bath ''Eureka'' ( grc, εὕρηκα) is an interjection used to celebrate a discovery or invention. It is a transliteration of an exclamation attributed to Ancient Greek mathematician and inventor Archimedes. Etymology "Eureka" comes from the Ancient Greek word εὕρηκα ''heúrēka'', meaning "I have found (it)", which is the first person singular perfect indicative active of the verb εὑρίσκω ''heurískō'' "I find". It is closely related to '' heuristic'', which refers to experience-based techniques for problem-solving, learning, and discovery. Pronunciation The accent of the English word is on the second syllable, following Latin rules of accent, which require that a penult (next-to-last syllable) must be accented if it contains a long vowel. In the Greek pronunciation, the first syllable has a high pitch accent, because the Ancient ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eureka! Archimede
Eureka (often abbreviated as E!, or Σ!) is an intergovernmental organisation for research and development funding and coordination. Eureka is an open platform for international cooperation in innovation. Organisations and companies applying through Eureka programmes can access funding and support from national and regional ministries or agencies for their international R&D projects. , Eureka has 43 full members, including the European Union (represented by the European Commission) and four associated members (Argentina, Chile, South Africa, and Singapore). All 27 EU Member States are also members of Eureka. Eureka is not an EU research programme, but rather an intergovernmental organisation of national ministries or agencies, of which the EU is a member. Cooperation and synergy are sought between Eureka and the research activities of the EU proper, such as with European Union's Horizon 2020 and the European Research Area. History Founded in 1985 by prominent European politic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Catalan Language
Catalan (; autonym: , ), known in the Valencian Community and Carche as '' Valencian'' (autonym: ), is a Western Romance language. It is the official language of Andorra, and an official language of three autonomous communities in eastern Spain: Catalonia, the Valencian Community, and the Balearic Islands. It also has semi-official status in the Italian comune of Alghero. It is also spoken in the Pyrénées-Orientales department of France and in two further areas in eastern Spain: the eastern strip of Aragon and the Carche area in the Region of Murcia. The Catalan-speaking territories are often called the or "Catalan Countries". The language evolved from Vulgar Latin in the Middle Ages around the eastern Pyrenees. Nineteenth-century Spain saw a Catalan literary revival, culminating in the early 1900s. Etymology and pronunciation The word ''Catalan'' is derived from the territorial name of Catalonia, itself of disputed etymology. The main theory suggests that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
De Architectura
(''On architecture'', published as ''Ten Books on Architecture'') is a treatise on architecture written by the Roman architect and military engineer Marcus Vitruvius Pollio and dedicated to his patron, the emperor Caesar Augustus, as a guide for building projects. As the only treatise on architecture to survive from antiquity, it has been regarded since the Renaissance as the first book on architectural theory, as well as a major source on the canon of classical architecture. It contains a variety of information on Greek and Roman buildings, as well as prescriptions for the planning and design of military camps, cities, and structures both large (aqueducts, buildings, baths, harbours) and small (machines, measuring devices, instruments). Since Vitruvius published before the development of cross vaulting, domes, concrete, and other innovations associated with Imperial Roman architecture, his ten books give no information on these hallmarks of Roman building design and technolo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vitruvius
Vitruvius (; c. 80–70 BC – after c. 15 BC) was a Roman architect and engineer during the 1st century BC, known for his multi-volume work entitled '' De architectura''. He originated the idea that all buildings should have three attributes: , , and ("strength", "utility", and "beauty"). These principles were later widely adopted in Roman architecture. His discussion of perfect proportion in architecture and the human body led to the famous Renaissance drawing of the '' Vitruvian Man'' by Leonardo da Vinci. Little is known about Vitruvius' life, but by his own descriptionDe Arch. Book 1, preface. section 2. he served as an artilleryman, the third class of arms in the Roman military offices. He probably served as a senior officer of artillery in charge of ''doctores ballistarum'' (artillery experts) and ''libratores'' who actually operated the machines. As an army engineer he specialized in the construction of '' ballista'' and '' scorpio'' artillery war machines for siege ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Density
Density (volumetric mass density or specific mass) is the substance's mass per unit of volume. The symbol most often used for density is ''ρ'' (the lower case Greek letter rho), although the Latin letter ''D'' can also be used. Mathematically, density is defined as mass divided by volume: : \rho = \frac where ''ρ'' is the density, ''m'' is the mass, and ''V'' is the volume. In some cases (for instance, in the United States oil and gas industry), density is loosely defined as its weight per unit volume, although this is scientifically inaccurate – this quantity is more specifically called specific weight. For a pure substance the density has the same numerical value as its mass concentration. Different materials usually have different densities, and density may be relevant to buoyancy, purity and packaging. Osmium and iridium are the densest known elements at standard conditions for temperature and pressure. To simplify comparisons of density across different sy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Votive Crown
A votive crown is a votive offering in the form of a crown, normally in precious metals and often adorned with jewels. Especially in the Early Middle Ages, they are of a special form, designed to be suspended by chains at an altar, shrine or image. Later examples are more often typical crowns in the style of the period, either designed to be placed on the head of a statue, or re-used in this way after donation. Pre-Christian examples There were pagan votive crowns in the ancient world, although these are essentially known only from literary references. Vitruvius records that when Hiero II of Syracuse (died 215 BC) suspected his goldsmith of cheating him over the making of a votive crown for a statue in a temple, for which he had supplied the gold to be used, he asked Archimedes to devise a test. This led Archimedes to his famous '' eureka'' moment, after he realized he could test the crown by comparing its displacement of water to that of the same weight of pure gold; in fa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carat (purity)
The fineness of a precious metal object (coin, bar, jewelry, etc.) represents the weight of ''fine metal'' therein, in proportion to the total weight which includes alloying base metals and any impurities. Alloy metals are added to increase hardness and durability of coins and jewelry, alter colors, decrease the cost per weight, or avoid the cost of high-purity refinement. For example, copper is added to the precious metal silver to make a more durable alloy for use in coins, housewares and jewelry. Coin silver, which was used for making silver coins in the past, contains 90% silver and 10% copper, by mass. Sterling silver contains 92.5% silver and 7.5% of other metals, usually copper, by mass. Various ways of expressing fineness have been used and two remain in common use: ''millesimal fineness'' expressed in units of parts per 1,000 and '' karats'' or ''carats'' used only for gold. Karats measure the parts per 24, so that 18 karat = = 75% and 24 karat gold is considered 10 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hiero II Of Syracuse
Hiero II ( el, Ἱέρων Β΄; c. 308 BC – 215 BC) was the Greek tyrant of Syracuse from 275 to 215 BC, and the illegitimate son of a Syracusan noble, Hierocles, who claimed descent from Gelon. He was a former general of Pyrrhus of Epirus and an important figure of the First Punic War. He figures in the story of famed thinker Archimedes shouting "Eureka". Rise to power On the departure of Pyrrhus from Sicily (275 BC) the Syracusan army and citizens appointed him commander of the troops. He strengthened his position by marrying the daughter of Leptines, the leading citizen. In the meantime, the Mamertines, a body of Campanian mercenaries who had been employed by Agathocles, had seized the stronghold of Messina, and proceeded in harassing the Syracusans. They were finally defeated in a pitched battle near Mylae along the Longanus river by Hiero, who was only prevented from capturing Messina by Carthaginian interference. His grateful countrymen then made him king (275). Fir ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Syracuse, Italy
Syracuse ( ; it, Siracusa ; scn, Sarausa ), ; grc-att, Συράκουσαι, Syrákousai, ; grc-dor, Συράκοσαι, Syrā́kosai, ; grc-x-medieval, Συρακοῦσαι, Syrakoûsai, ; el, label= Modern Greek, Συρακούσες, Syrakoúses, . is a historic city on the Italian island of Sicily, the capital of the Italian province of Syracuse. The city is notable for its rich Greek and Roman history, culture, amphitheatres, architecture, and as the birthplace of the pre-eminent mathematician and engineer Archimedes. This 2,700-year-old city played a key role in ancient times, when it was one of the major powers of the Mediterranean world. Syracuse is located in the southeast corner of the island of Sicily, next to the Gulf of Syracuse beside the Ionian Sea. It is situated in a drastic rise of land with depths being close to the city offshore although the city itself is generally not so hilly in comparison. The city was founded by Ancient Greek Corinthian ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Buoyancy
Buoyancy (), or upthrust, is an upward force exerted by a fluid that opposes the weight of a partially or fully immersed object. In a column of fluid, pressure increases with depth as a result of the weight of the overlying fluid. Thus the pressure at the bottom of a column of fluid is greater than at the top of the column. Similarly, the pressure at the bottom of an object submerged in a fluid is greater than at the top of the object. The pressure difference results in a net upward force on the object. The magnitude of the force is proportional to the pressure difference, and (as explained by Archimedes' principle) is equivalent to the weight of the fluid that would otherwise occupy the submerged volume of the object, i.e. the displaced fluid. For this reason, an object whose average density is greater than that of the fluid in which it is submerged tends to sink. If the object is less dense than the liquid, the force can keep the object afloat. This can occur only in a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Archimedes' Principle
Archimedes' principle (also spelled Archimedes's principle) states that the upward buoyant force that is exerted on a body immersed in a fluid, whether fully or partially, is equal to the weight of the fluid that the body displaces. Archimedes' principle is a law of physics fundamental to fluid mechanics. It was formulated by Archimedes of Syracuse. Explanation In ''On Floating Bodies'', Archimedes suggested that (c. 246 BC): Archimedes' principle allows the buoyancy of any floating object partially or fully immersed in a fluid to be calculated. The downward force on the object is simply its weight. The upward, or buoyant, force on the object is that stated by Archimedes' principle above. Thus, the net force on the object is the difference between the magnitudes of the buoyant force and its weight. If this net force is positive, the object rises; if negative, the object sinks; and if zero, the object is neutrally buoyant—that is, it remains in place without either rising or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Displacement (fluid)
In fluid mechanics, displacement occurs when an object is largely immersed in a fluid, pushing it out of the way and taking its place. The volume of the fluid displaced can then be measured, and from this, the volume of the immersed object can be deduced: the volume of the immersed object will be exactly equal to the volume of the displaced fluid. An object that sinks displaces an amount of fluid equal to the object's volume. Thus buoyancy is expressed through Archimedes' principle, which states that the weight of the object is reduced by its volume multiplied by the density Density (volumetric mass density or specific mass) is the substance's mass per unit of volume. The symbol most often used for density is ''ρ'' (the lower case Greek letter rho), although the Latin letter ''D'' can also be used. Mathematicall ... of the fluid. If the weight of the object is less than this displaced quantity, the object floats; if more, it sinks. The amount of fluid displaced is direc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
