Venice

Others closely associated with the city include:. Hazy conditions, atmospheric dust, and high humidity contribute to this atmospheric attenuation. For persons born in Venice, see Natives of Venice.. During sunrise and sunset, sunlight is attenuated by a particularly long passage through Earth's atmosphere, and the direct Sun is sometimes faint enough to be viewed directly without discomfort or safely with binoculars. In videogames, Venice appeared in Core Design's Tomb Raider 2. Viewing the partially eclipsed Sun with the naked eye can cause permanent localized damage to the retina, resulting in small, permanent blind spots for the viewer.^[20] This is an especially insidious hazard for inexperienced observers and for children, because there is no immediate perception of pain and it is tempting to stare at the spectacle of the eclipsing Sun, compounding any damage. Other major works involving Venice include:. Each retinal cell that is exposed to the partially-eclipsed solar image thus receives about ten times as much light as it would looking at the normal, non-eclipsed Sun.

Cooper's novel depicts Venice as a brutal dictatorship, governed through intrigue and murder, masked by the placid facade of the Repubblica Serenissima (serene republic). In the dim overall light, the pupil tends to dilate from about 2 mm to perhaps 6 mm diameter, increasing the eye's collecting area by a factor of nearly 10. A bravo is an assassin under contract to the state, typically carrying out his assignments with a stilletto. During partial eclipses, most sunlight is blocked by the Moon passing directly in front of the Sun, but the uncovered parts of the photosphere have the same surface brightness as during a normal day. A remarkable, and unflattering, portrait of Venetian politics appears in The Bravo, published in 1831 by American novelist James Fennimore Cooper. The pupil is controlled by the total amount of light in the visual field, not by the brightest object in the field. Life in 1750s Venice is illustrated by the biography A Venetian Affair, which is based on the prolific love letters between a Venetian nobleman and his illegitimate half-English lover. During partial eclipses of the Sun, another hazardous condition exists because of the way the eye responds to bright light.

They were generally rough. Even brief glances at the midday Sun through unfiltered binoculars can cause permanent blindness.^[19]. Canvases (the now almost universal surface for painting) originated in Venice during the early renaissance. Viewing the Sun through unfiltered 7x50 mm binoculars can deliver as much as 2.5 watts of sunlight into each eye, over 300 times more power than naked eye viewing. By the end of the century, Venice was famous for the splendor of its music, as exemplified in the "colossal style" of Andrea and Giovanni Gabrieli, which used multiple choruses and instrumental groups. Using a proper filter is very important as some improvised filters reduce visible light while passing either infrared or ultraviolet rays that can still damage the eye. Venice was the early center of music printing; Ottaviano Petrucci began publishing music almost as soon as this technology was available, and his publishing enterprise helped to attract composers from all over Europe, especially from France and Flanders. Suitable filters are available at welding supply shops and camera stores.

During the 16th century, Venice became one of the most important musical centers of Europe, marked by a characteristic style of composition (the Venetian school) and the development of the Venetian polychoral style under composers such as Adrian Willaert, who worked at San Marco. Viewing the Sun through light-concentrating optics such as binoculars is hazardous without an attenuating (ND) filter to dim the sunlight. Dull garments were worn over colorful ones, which then were cut to show the hidden colors — which resulted in the wide spread of men's "slashed" fashions in the 15th century. Brief viewing of the full direct Sun with the naked eye is unpleasant but generally safe.^[18]. The Senate passed sumptuary laws, but these merely resulted in changes in fashion in order to circumvent the law. Direct viewing of the Sun with the naked eye delivers about 4 milliwatts of sunlight to the retina that is in the solar image, heating it up and potentially (though not normally) damaging it. In the 14th century, many young Venetian men began wearing tight-fitting multicolored hose, the designs on which indicated the Compagnie della Calza ("Trouser Club") to which they belonged. Looking directly at the Sun when it is high in the sky causes temporary bleaching of the photosensitive pigments in the retina, which makes phosphene visual artifacts and may cause temporary partial blindness.

If sinking is prevented, today's engineers hope that future generations will - perhaps in thousands of years time - remember the current work being done, for saving one of the most romantic cities in the world. Sunlight is very bright, and looking directly at the Sun is painful to the eyes. A further point about the "lifting" system would be that it would be permenant - the MOSE Project is, by it very nature, a temporary system: it is expected to protect Venice for "only" 100 years. The energy stored in petroleum is thought to have been converted from sunlight by photosynthesis in the distant past. This way, some hope, it could rise above sea levels, protecting it for hundreds of years, and eventually the MOSE project may not be necessary (it will, controvertially, alter the tidal patterns in the lagoon, damaging some wildlife). Photosynthesis by plants captures the energy of sunlight and converts it to chemical form (oxygen and reduced carbon compounds), while direct heating or electrical conversion by solar cells are used by solar power equipment to generate electricity or do other useful work. Some experts say that the best way to protect Venice is to physically lift the City to a greater height above sea level - by pumping water into the soil underneath the city. This energy can be harnessed through several natural and synthetic processes.

To make things worse, however, sea levels are rising anyway, and in fact, the whole east coast of Italy is sinking (although very slowly). Sunlight on the surface of Earth is attenuated by the Earth's atmosphere, so that less power arrives at the surface — closer to 1000 watts per directly exposed square meter in clear conditions when the Sun is near the zenith. This challenging engineering work is due to be completed by 2011. near Earth. When tides are predicted to rise above 110 centimetres, the pontoons will be filled with air and block the incoming water from the Adriatic sea. from the Sun, i.e. In May 2003, Silvio Berlusconi, the Italian Prime Minister, inaugurated the MOSE project, which will lay a series of 79 inflatable pontoons across the sea bed at the three entrances to the lagoon. It is about 1370 watts per square meter of area, one A.U.

Some recent studies have suggested that the city is no longer sinking^{[citation needed]}, but this is not yet certain; therefore, a state of alert has not been revoked. The solar constant is the amount of power that the Sun deposits per unit area that is directly exposed to sunlight. Thus, many Venetians resorted to moving up to the upper floors and continue with their lives. Sunlight — that is, light radiated from the surface of the Sun — is thought to be the main source of energy near the surface of Earth. In many old houses the former staircases used by people to unload goods are now flooded, rendering the former ground floor uninhabitable. Thus, the Sun was considered by Greek astronomers to be one of the seven planets (Greek planetes "wanderer"), after which the seven days of the week are named in some languages. However, the city is still threatened by more frequent low-level floods (so-called Acqua alta, "high water") that creep to a height of several centimeters over its quays, regularly following certain tides. With respect to the fixed stars, the Sun appears from Earth to revolve once a year along the ecliptic through the zodiac.

This sinking process has slowed markedly since artesian wells were banned in the 1960s. It was only after Einstein's theory of mass-energy convertibility in the early 20th century that it was finally understood that the sun runs on nuclear fusion and is billions of years old, with several other billion to go. It was realised that extraction of the aquifer was the cause. In the early years of the modern scientific era, it was proposed that the Sun extracted its energy from friction of its gas masses, which would yield a Sun no older than a few million years, with a few more million years to go. During the 20th century, when many artesian wells were sunk into the periphery of the lagoon to draw water for local industry, Venice began to subside. For teaching this heresy he was imprisoned by the authorities and sentenced to death (though later released through the intervention of Pericles). This created an ever-deeper lagoon environment. One of the first people in the Western world to offer a scientific explanation for the sun was the Greek philosopher Anaxagoras, who reasoned that it was a giant flaming ball of metal even larger than the Peleponessus, and not the chariot of Helios.

Six hundred years ago, Venetians protected themselves from land-based attacks by diverting all the major rivers flowing into the lagoon and thus preventing sediment from filling the area around the city. In many prehistoric and ancient cultures, the Sun was thought to be a deity or other supernatural phenomenon. The buildings are often threatened by flood tides pushing in from the Adriatic between autumn and early spring. Mankind's most fundamental understanding of the Sun is as the luminous disk in the heavens whose presence above the horizon creates day, and whose absence causes night. The foundations rest on the piles, and buildings of brick or stone sit above these footings. This stellar evolution scenario is typical of low to medium mass stars. Most of these piles are still intact after centuries of submersion. The Sun will then evolve into a white dwarf, slowly cooling over eons.

The buildings of Venice are constructed on closely spaced wood piles (under water, in the absence of oxygen, wood does not decay) which penetrate alternating layers of clay and sand. Following the red giant phase, giant thermal pulsations will cause the Sun to throw off its outer layers forming a planetary nebula. The city is divided into the six districts of Cannaregio, San Polo, Dorsoduro (including the Giudecca), Santa Croce, San Marco and Castello (including San Pietro di Castello and Sant'Elena). While it is likely that the expansion of the outer layers of the Sun will reach the current position of Earth's orbit, recent research suggests that mass lost from the Sun earlier in its red giant phase will cause the Earth's orbit to move further out, preventing it from being engulfed. The sestieri are the primary traditional divisions of Venice. Helium fusion will begin when the core temperature reaches about 3×10⁸ K. Other populations include Bulgarian, Tunisian, Albanian, and Macedonian. Instead, in 4-5 billion years it will enter its red giant phase, its outer layers expanding as the hydrogen fuel in the core is consumed and the core contracts and heats up.

Istat breaks down the population as:. Our Sun does not have enough mass to explode as a supernova, and its mass is below the Chandrasekhar limit. The city is much visited by tourists, of course; but of the permanent population 3.8 % are foreigners as well: from all around the world, and especially from Asia. This is suggested by a high abundance of heavy elements such as iron, gold and uranium in the solar system: the most plausible ways that these elements could be produced are by endothermic nuclear reactions during a supernova or by transmutation via neutron absorption inside a massive first generation star. The airport is on the mainland and was rebuilt away from the coast so that visitors now need to get a bus to the pier, from which a water taxi or Aliliguna waterbus can be used. The Sun is thought to be a second-generation star, whose formation may have been triggered by shockwaves from a nearby supernova. Venice is served by the newly rebuilt Marco Polo International Airport, or Aeroporto di Venezia Marco Polo, named in honor of its famous citizen. It returned to Earth in 2004 and is undergoing analysis, but it was damaged by crash-landing when its parachute failed to deploy on reentry to Earth's atmosphere.

The only unmotorized gondolas still in common use by Venetians are the traghetti, foot passenger ferries crossing the Grand Canal at certain points without bridges. A solar wind sample return mission, Genesis, was designed to allow astronomers to directly measure the composition of solar material. The city also has many private boats. Elemental abundances in the photosphere are well known from spectroscopic studies, but the composition of the interior of the Sun is much less well known. Most Venetians now travel by motorised waterbuses ("vaporetti") which ply regular routes along the major canals and between the city's islands. It has proved so useful that a follow-on mission, the Solar Dynamics Observatory, is planned for launch in 2008. The classical Venetian boat is the gondola, although it is now mostly used for tourists, or for weddings, funerals, or other ceremonies, due to its cost. Originally a two-year mission, SOHO is now over ten years old (as of late 2005).

Venice is Europe's largest carfree area, unique in Europe in remaining a sizable functioning city in the 21st century entirely without motorcars or trucks. To obtain an uninterrupted view of the Sun, the European Space Agency and NASA cooperatively launched the Solar and Heliospheric Observatory (SOHO) on December 2, 1995. Beyond these land entrances at the northern edge of the city, transportation within the city remains, as it was in centuries past, entirely on water or on foot. The North/South swing in apparent angle is the main source of seasons on Earth. In the 19th century a causeway to the mainland brought a railway station to Venice, and an automobile causeway and parking lot was added in the 20th century. The most obvious variation in the Sun's apparent position through the year is a North/South swing over 47 degrees of angle, due to the 23.5 degree tilt of the Earth, but there is an East/West component as well. In the old center, the canals serve the function of roads, and every form of transport is on water or on foot. The shape described by the Sun's position, considered at the same time each day for a complete year, is called the analemma, and resembles a figure 8, aligned along the North/South direction.

The islands on which the city is built are connected by about 400 bridges. Observed from Earth, the path of the Sun across the sky varies throughout the year. It is built on an archipelago of more than 100 islands (118 in total) formed by about 150 canals in a shallow lagoon. the interplanetary medium) in a magnetic field, induces electric currents which in turn generates magnetic fields, and in this respect it behaves like an MHD dynamo. Venice is famous for its canals. Magnetohydrodynamic (MHD) theory predicts that the motion of a conducting fluid (e.g. The Venetian military tradition also was notably cautious; they were more interested in achieving success with a minimum expense of lives and money than in the pursuit of glory. But satellite observations show that it is about 100 times greater at around 10^-9 tesla.

A civilian commissioner (not unlike a commissar) accompanied each army to keep an eye on things, especially the mercenaries. If space were a vacuum, then the Sun's 10^-4 tesla magnetic dipole field would reduce with the cube of the distance to about 10^-11 tesla. Not only was efficiency not degraded, this policy saved Venice from the military takeovers that other Italian city states so often experienced. The plasma in the interplanetary medium is also responsible for the strength of the Sun's magnetic field at the orbit of the Earth being over 100 times greater than originally anticipated. By ancient law, no nobleman could command more than twenty-five men (to prevent against sedition by private armies), and while the position of Captain General was introduced in the mid-14th century, he still had to answer to a civilian panel of twenty "wise men". The influence of the Sun's rotating magnetic field on the plasma in the interplanetary medium creates the largest structure in the Solar System, the Heliospheric current sheet. The command structure in the army was different from that in the fleet. The magnetic field of the sun reverses once for each 11-year sunspot cycle.

Throughout the 15th century, Venetian land forces were almost always on the offensive and were regarded as the most effective in Italy, largely because of the tradition of all classes carrying arms in defense of the city and official encouragement of general military training. The solar activity cycle includes old magnetic fields being stripped off the Sun's surface starting from one pole and ending at the other. Later in that century, uniforms were adopted that featured red-and-white stripes, and a system of honors and pensions developed. (See magnetic reconnection). In its alliance with Florence in 1426, Venice agreed to supply 8,000 cavalry and 3,000 infantry in time of war, and 3,000 and 1,000 in peacetime. The differential rotation of the Sun's latitudes causes its magnetic field lines to become twisted together over time, causing magnetic field loops to erupt from the Sun's surface and trigger the formation of the Sun's dramatic sunspots and solar prominences. Early in the 15th century, as new mainland territories were expanded, the first standing army was organized, consisting of condottieri on contract. This makes it possible for the Sun to rotate faster at its equator (about 25 days) than it does at higher latitudes (28 days near its poles).

As in other Italian cities, aristocrats and other wealthy men were cavalrymen while the city's conscripts fought as infantry. All matter in the Sun is in the form of gas and plasma due to its high temperatures. The register of 1338 estimated that 30,000 Venetian men were capable of bearing arms; many of these were skilled crossbowmen. Others suggest that cosmic rays might strongly influence the Earth's climate, and that their flux was much higher in the early history of the solar system ^[17]. In times of emergency, all males between seventeen and sixty years were registered and their weapons were surveyed, with those called to actually fight being organized into companies of twelve. Some scientists have suggested that the young Earth's atmosphere contained much larger quantities of greenhouse gases such as carbon dioxide and/or ammonia than are present today ^[16]. In the 13th century, most Italian city states already were hiring mercenaries, but Venetian troops were still recruited from the lagoon, plus feudal levies from Dalmatia and Istria. In fact, the young Earth was actually warmer than it is today.

Though Venice was famous for its navy, its army was equally effective. However, the geologic record shows that the Earth has remained at a fairly constant temperature throughout its history. The company of "Noble Bowmen" was recruited in the later 14th century from among the younger aristocracy and served aboard both war-galleys and armed merchantmen, with the privilege of sharing the captain's cabin. Such a weak star would not have been able to sustain liquid water on the Earth's surface, and thus life should not have been able to develop. As weapons became more expensive and complex to operate, professional soldiers were assigned to help work merchant sailing ships and as rowers in galleys. Theoretical models of the sun's development suggest that 3.8 to 2.5 billion years ago, during the Archean period, the Sun was only about 75 percent as bright as it is today. By 1303, crossbow practice had become compulsory in the city, with citizens training in groups. One possible candidate to explain coronal heating is continuous flaring at small scales ^[15], but this is still an open topic of investigation.

Rowing skills were encouraged through races and regattas. Current research focus has therefore shifted towards flare heating mechanisms. Debtors generally worked off their obligations rowing the galleys. In addition, Alfven waves do not easily dissipate in the corona ^[14]. Those from the city were chosen by lot from each parish, their families being supported by the remainder of the parish while the rowers were away. All waves except Alfven waves have been found to dissipate or refract before reaching the corona (^[12], ^[13]). Galley slaves did not exist in medieval Venice, the oarsmen coming from the city itself or from its possessions, especially Dalmatia. Currently, it is unclear whether waves are an efficient heating mechanism.

A reserve of some 25 (later 100) war-galleys was maintained in the Arsenal. ^[8], ^[9], ^[10], ^[11]. The government required each merchant ship to carry a specified number of weapons (mostly crossbows and javelins) and armor; merchant passengers were also expected to be armed and to fight when necessary. The other proposed mechanism is flare heating, in which magnetic energy is continuously built up by photospheric motion and released through magnetic reconnection in the form of solar flares and waves. By 1450, more than 3,000 Venetian merchant ships were in operation, and most of these could be converted when necessary into either warships or transports. These waves travel upward and dissipate in the corona, depositing their energy in the ambient gas in the form of heat. After 1797, the city fell into a serious decline, with many of the old palaces and other buildings abandoned and falling into disrepair, although the Lido became a popular beach resort in the late 19th century. Two main mechanisms have been proposed to explain coronal heating: Wave heating, in which sound, gravitational and magnetohydrodynamic waves are produced by turbulence in the convection zone.

In 1866, along with the rest of Venetia, Venice became part of Italy. It is thought that the energy necessary to heat the corona is provided by turbulent motion in the convection zone below the photosphere. It was taken from Austria by the Treaty of Pressburg in 1805 and became part of Napoleon's Kingdom of Italy, but was returned to Austria following Napoleon's defeat in 1814. The high temperature of the corona shows that it is heated by something other than the photosphere. The Austrians took control of the city on January 18, 1798. Above it lies the solar corona with a temperature of one million kelvins. Venice became part of the Austrian-held Kingdom of Lombardy-Venetia when Napoleon signed the Treaty of Campo Formio on October 12 1797. The optical surface of the Sun (the photosphere) is known to have a temperature of about 6,000 K.

He removed the gates of the Ghetto and ended the restrictions on when and where Jews could live and travel in the city. Thus, measurement and theory have been reconciled. Napoleon was seen as something of a liberator by the city's Jewish population. It has recently been found that neutrinos have rest mass, and can therefore transform into harder-to-detect varieties of neutrinos while en route from the Sun to Earth in a process known as neutrino oscillation ^[7]. The French conqueror brought to an end the most fascinating century of its history: It was during the "Settecento" that Venice became perhaps the most elegant and refined city in Europe, greatly influencing art, architecture, and literature. Several neutrino observatories were constructed, including the Sudbury Neutrino Observatory and Kamiokande to try to measure the solar neutrino flux. After 1070 years, the Republic lost its independence when Napoleon Bonaparte on May 12, 1797, conquered Venice during the First Coalition. For some time it was thought that the number of neutrinos produced by the nuclear reactions in the Sun was only a third of the number predicted by theory, a result that was termed the solar neutrino problem.

Venetian ambassadors sent home still-extant secret reports of the politics and rumours of European courts, providing fascinating information to modern historians. The temperature of the corona is several megakelvins. The second, more famous, occasion was on April 27, 1509, by order of Pope Julius II (see League of Cambrai). The low corona, which is very near the surface of the Sun, has a particle density of 10¹¹/m³ (Earth's atmosphere near sea level has a particle density of about 2x10²⁵/m³). Venice was threatened with the interdict on a number of occasions and twice suffered its imposition. The corona merges smoothly with the solar wind that fills the solar system and heliosphere. This apparent lack of zeal contributed to its frequently coming into conflict with the Papacy. The corona is the extended outer atmosphere of the Sun, which is much larger in volume than the Sun itself.

Though the people of Venice generally remained orthodox Roman Catholics, the state of Venice was notable for its freedom from religious fanaticism and it enacted not a single execution for religious heresy during the Counter-Reformation. It is called the chromosphere from the Greek root chroma, meaning color, because the chromosphere is visible as a colored flash at the beginning and end of total eclipses of the Sun. In practice, a number of Doges were forced by pressure from their oligarchical peers to resign the office and retire into monastic seclusion when they were felt to have been discredited by perceived political failure. Above the visible surface of the Sun is a thin layer, about 2,000km thick, that is dominated by a spectrum of emission and absorption lines. The chief executive was the Doge (duke), who, theoretically, held his elective office for life. This part of the Sun is cool enough to support simple molecules such as carbon monoxide and water which can be detected by their absorption spectra. War was regarded as a continuation of commerce by other means (hence, the city's early production of large numbers of mercenaries for service elsewhere). It is about 4,000 K.

Venice remained a republic throughout its independent period and politics and the military were kept completely separate. The coolest layer of the Sun is the temperature minimum region about 500km above the photosphere. The Cavalieri di San Marco was the only order of chivalry ever instituted in Venice, and no citizen could accept or join a foreign order without the government’s consent. They can be viewed with telescopes operating across the electromagnetic spectrum, from radio through visible light to gamma rays. Church and various private properties were tied to military service, though there was no knight tenure within the city itself. The parts of the Sun above the photosphere are referred to collectively as the solar atmosphere. The Venetian governmental structure was a mix of Byzantine and Islamic systems, but the social order was entirely feudal. The photosphere has a particle density of about 10²³/m³ (this is about 1% of the particle density of Earth's atmosphere at sea level).

Only Venetian ships could efficiently transport the men, supplies, and (especially) war horses. Sunlight has approximately a black-body spectrum that indicates its temperature is about 6,000 K, interspersed with atomic absorption lines from the tenuous layers above the photosphere. Mark, symbol of Venice. Conversely, the visible light we see is produced as electrons react with hydrogen atoms to produce H^- ions. Considerable plunder was brought back to Venice, including the Winged Lion of St. The change in opacity has to do with the decreasing amount of H^- ions, which absorb visible light easily. Though the Greeks recovered control of the ravaged city and Empire a half century later, the Byzantine Empire was effectively powerless, and existed as a ghost of it's old self until Mohammad the Conqueror took the city in 1453. Above the photosphere, sunlight is free to propagate into space and its energy escapes the Sun entirely.

Unfortunately, this seizure of Constantinople would ultimately prove to be as much a factor ending the Byzantine Empire as the loss of the Anatolian themes after Manzikert. The visible surface of the Sun, the photosphere, is the layer below which the Sun becomes opaque to visible light. Venice became an imperial power following the Fourth Crusade, which (with Venetian aid) seized Constantinople in 1204 and established the Latin Empire; Venice herself carved out a sphere of influence known as the Duchy of the Archipelago. The turbulent convection of this outer part of the solar interior gives rise to a 'small-scale' dynamo that produces magnetic north and south poles all over the surface of the Sun. By the standards of the time, Venice's stewardship of its mainland territories was relatively enlightened and the citizens of such towns as Bergamo, Brescia, and Verona rallied to the defence of Venetian sovereignty when it was threatened by invaders. The thermal columns in the convection zone form an imprint on the surface of the Sun, in the form of the solar granulation and supergranulation. In building its maritime commercial empire, the Republic acquired control of most of the islands in the Aegean, including Cyprus and Crete, and became a major power-broker in the Near East. Convective overshoot is thought to occur at the base of the convection zone, carrying turbulent downflows into the outer layers of the radiative zone.

Later mainland possessions, which extended across Lake Garda as far west as the Adda River, were known as "Terraferma", and were acquired partly as a buffer against belligerent neighbors, partly to guarantee Alpine trade routes, and partly to ensure the supply of mainland wheat, on which the city depended. Once the material cools off at the surface, it plunges back downward to the base of the convection zone, to receive more heat from the top of the radiative zone. The Doge already carried the titles of Duke of Dalmatia and Duke of Istria. As a result, thermal convection occurs as thermal columns carry hot material to the surface (photosphere) of the Sun. The Republic of Venice seized the eastern shores of the Adriatic before 1200, mostly for commercial reasons, because pirates based there were a menace to trade. From about 0.7 solar radii to 1.0 solar radii, the material in the Sun is not dense enough or hot enough to transfer the heat energy of the interior outward via radiation. In the 12th century the essentials for the power of Venice were laid: the Venetian Arsenal was under construction in 1104; Venice wrested control of the Brenner pass from Verona in 1178, opening a lifeline to silver from Germany; the last autocratic doge, Vitale Michiele, died in 1172. Because of this, it can take a photon nearly 1,000,000 years to reach the photosphere.

Its strategic position at head of the Adriatic made Venetian naval and commercial power almost invulnerable; and the city gave her name to the surrounding region, Venetia. Heat is transferred by ions of hydrogen and helium emitting photons, which travel a brief distance before being re-absorbed by other ions. Venice was a city state (an Italian thalassocracy or Repubblica Marinara, the other three being Genoa, Pisa, and Amalfi). In this zone, there is no thermal convection: while the material grows cooler with altitude, this temperature gradient is slower than the adiabatic lapse rate and hence cannot drive convection. As the community continued to develop and as Byzantine power waned, an increasingly anti-Eastern character emerged, leading to the growth of autonomy and eventual independence under the rulership of elected doges. From about 0.2 to about 0.7 solar radii, the material is hot and dense enough that thermal radiation is sufficient to transfer the intense heat of the core outward. In the mid-8th century, the Venetians resisted the empire-building efforts of Pepin III and remained subject to the Byzantine Empire, at least theoretically. Neutrinos are also released in the fusion reactions in the core, but unlike photons they very rarely interact with matter, and so almost all are able to escape the Sun immediately.

The city was founded as a result of the influx of refugees into the marshes of the Po estuary following the invasion of northern Italy by the Lombards in 568. Upon reaching the surface after a final trip through the convective outer layer, the photons escape as visible light. . 65) to as little as 17,000 years [6]. The Venetian Republic was a major sea power and a staging area for the Crusades, as well as a very important centre of commerce (especially the spice trade) and art in the Renaissance. Lewis, The Illustrated Encyclopedia of the Universe, Harmony Books, New York, 1983, p. [1]. Estimates of the "photon travel time" range from as much as 50 million years (Richard S.

The population estimate of 272,000 inhabitants includes the population of the whole Comune of Venezia; the historic city of Venice (Centro storico) inhabitants are nearly 62,000, while approximately 176,000 people live in Terraferma (literal dry land, it means the extra-lagoon areas) and 31,000 live in other islands of the lagoon. The high-energy photons (gamma and X rays) released in fusion reactions take a long time to reach the Sun's surface, slowed down by the indirect path taken, as well as constant absorption and re-emission at lower energies in the solar mantle (see below). The saltwater lagoon stretches along the shoreline between the mouths of the Po (south) and the Piave (north) Rivers. All of the energy of the interior fusion must travel through the successive layers to the solar photosphere, before it escapes to space. The city stretches across numerous small islands in the marshy Venetian Lagoon along the Adriatic Sea in northeast Italy. The core extends from the center of the Sun to about 0.2 solar radii, and is the only part of the Sun where an appreciable amount of heat is produced by fusion: the rest of the star is heated by energy that is transferred outward. The city is included, with Padua (Padova), in the Padua-Venice Metropolitan Area, population 1,600,000. About 8.9×10³⁷ protons (hydrogen nuclei) are converted to helium nuclei every second, releasing energy at the matter-energy conversion rate of 4.26 million tonnes per second or 383 yottawatts (9.15×10¹⁶ tons of TNT per second).

Venice (Italian: Venezia, Venetian: Venexia), the "city of canals", is the capital of the region of Veneto and of the province of Venice, 45°26′N 12°19′E, population 271,663 (census estimate January 1, 2004). At the center of the Sun, where its density reaches up to 150,000 kg/m³ (150 times the density of water on Earth), thermonuclear reactions (nuclear fusion) convert hydrogen into helium, producing the energy that keeps the Sun in a state of equilibrium. "Venezuela" means "little Venice". Computer modeling of the Sun is also used as a theoretical tool to investigate its deep layers. arsenal, ciao, ghetto, gondola, lagoon, lido, Montenegro. However, just as the study of the waves generated by earthquakes (seismology) can be used to study the interior structure of the Earth, helioseismology, the study of sound waves that travel through the Sun's interior, has also contributed greatly to our understanding of the Sun's structure. Veronica Franco (1546-1591), poet and courtesan during the Renaissance. The solar interior is not directly observable and the Sun itself is opaque to electromagnetic radiation.

Titian (1477–1576), painter. Most of the mass is within about 0.7 radii. Venice and its lagoon are listed as World Heritage Sites by UNESCO. This is simply the layer above which the gases are too cool or too thin to radiate a significant amount of light. Venice is also famous world-wide for its unique carnival (1). The Sun's radius is measured from centre to the edges of the photosphere. Mark the Evangelist. Nevertheless, the Sun has a well-defined interior structure, described below.

The city's patron is St. The Sun does not have a definite boundary as rocky planets do, as the density of its gases drops off following an approximately exponential relationship with distance from the centre of the Sun. Casanova (2005 film loosely based on the life of Giacomo Casanova). The mass of the Sun is so comparatively great that the center of mass of the solar system is generally within the bounds of the Sun itself. The Italian Job (in its 2003 remake incarnation). Tidal effects from the planets do not significantly affect the shape of the Sun, although the Sun itself orbits the center of mass of the solar system, which is offset from the Sun's center mostly because of the large mass of Jupiter. Indiana Jones and the Last Crusade (1989 film). This is because the centrifugal effect of the Sun's slow rotation is 18 million times weaker than its surface gravity (at the equator).

Nicolas Roeg's 1973 film Don't Look Now, based on a story by Daphne du Maurier. The Sun is a near-perfect sphere, with an oblateness estimated at about 9 millionths, which means the polar diameter differs from the equatorial by about 10 km. From Russia with Love, a James Bond novel and film. The astronomical symbol for the Sun is a circle with a point at its centre: . Morgenstern. Compared to the average movement of other stars in the area, the Sun is moving with a speed of 20 km/s toward the star Vega. The Silent Gondoliers a fable told by William Goldman's S. The orbital speed is 217 km/s, equivalent to one light year every 1400 years, and one AU every 8 days.

Orhan Pamuk's short stories "Batsin Bu Dünya" (1983) and "Emrah Gülle Gel de Gülme" (1983). The Sun orbits the center of the Milky Way galaxy at a distance of about 25,000 to 28,000 light-years from the galactic centre, completing one revolution in about 226 million years. Death in Venice, a 1912 novel by Thomas Mann. Its current age is thought to be about 4.5 billion years, a figure which is determined using computer models of stellar evolution, and nucleocosmochronology ^[5]. Friedrich Schiller's Der Geisterseher (The Ghost-Seer). The Sun has a predicted main sequence lifetime of about 10 billion years. William Shakespeare's Othello and The Merchant of Venice. The Sun has a spectral class of G2V, with the G2 meaning that its color is yellow and its spectrum contains spectral lines of ionized and neutral metals as well as very weak hydrogen lines [3], and the V signifying that it, like most stars, is a "main sequence" star [4].

Giudecca. The Sun is classified as a main sequence star, which means it is in a state of "hydrostatic balance", neither contracting nor expanding, and is generating its energy through nuclear fusion of hydrogen nuclei into helium. Vignole. . Torcello. See below for details. San Lazzaro degli Armeni. Looking directly at the Sun can damage the retina and one's eyesight.