Lviv vs Sun

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Lviv (Ukrainian: Львів [lʲʋiu̯] (listen); Old East Slavic: Львігород; Polish: Lwów [lvuf] (listen); Yiddish: לעמבערג‎‎, romanized: Lemberg; Russian: Львов, romanized: Lvov [lʲvof]; German: Lemberg; Latin: Leopolis; Hungarian: Ilyvó; see also other names) is the largest city in western Ukraine and the seventh-largest city in the country overall, with a population of 724,314 (2020 est.). Lviv is one of the main cultural centres of Ukraine. Named in honour of Leo, the eldest son of Daniel, King of Ruthenia, it was the capital of the Kingdom of Galicia–Volhynia from 1272 to 1349, when it was conquered by King Casimir III the Great of Poland. From 1434, it was the regional capital of the Ruthenian Voivodeship in the Kingdom of Poland. In 1772, after the First Partition of Poland, the city became the capital of the Habsburg Kingdom of Galicia and Lodomeria. In 1918, for a short time, it was the capital of the West Ukrainian People's Republic. Between the wars, the city was the centre of the Lwów Voivodeship in the Second Polish Republic.

After the German-Soviet invasion of Poland in 1939, Lviv became part of the Soviet Union, and in 1944–46 there was a population exchange between Poland and Soviet Ukraine. In 1991, it became part of the independent nation of Ukraine. Administratively, Lviv serves as the administrative centre of Lviv Oblast and has the status of city of oblast significance. Lviv was the centre of the historical regions of Red Ruthenia and Galicia. The historical heart of the city, with its old buildings and cobblestone streets, survived Soviet and German occupations during World War II largely unscathed. The city has many industries and institutions of higher education such as Lviv University and Lviv Polytechnic. Lviv is also the home of many cultural institutions, including a philharmonic orchestra and the Lviv Theatre of Opera and Ballet. The historic city centre is on the UNESCO World Heritage List.

Source: Wikipedia

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The Sun is the star at the center of the Solar System. It is a nearly perfect sphere of hot plasma, heated to incandescence by nuclear fusion reactions in its core, radiating the energy mainly as light and infrared radiation. It is by far the most important source of energy for life on Earth. Its diameter is about 1.39 million kilometres (864,000 miles), or 109 times that of Earth, and its mass is about 330,000 times that of Earth. It accounts for about 99.86% of the total mass of the Solar System. Roughly three quarters of the Sun's mass consists of hydrogen (~73%); the rest is mostly helium (~25%), with much smaller quantities of heavier elements, including oxygen, carbon, neon, and iron.The Sun is a G-type main-sequence star (G2V) based on its spectral class. As such, it is informally and not completely accurately referred to as a yellow dwarf (its light is closer to white than yellow). It formed approximately 4.6 billion years ago from the gravitational collapse of matter within a region of a large molecular cloud. Most of this matter gathered in the center, whereas the rest flattened into an orbiting disk that became the Solar System. The central mass became so hot and dense that it eventually initiated nuclear fusion in its core. It is thought that almost all stars form by this process.

In its core the Sun currently fuses about 600 million tons of hydrogen into helium every second, converting 4 million tons of matter into energy every second as a result. This energy, which can take between 10,000 and 170,000 years to escape the core, is the source of the Sun's light and heat. When hydrogen fusion in its core has diminished to the point at which the Sun is no longer in hydrostatic equilibrium, its core will undergo a marked increase in density and temperature while its outer layers expand, eventually transforming the Sun into a red giant. It is calculated that the Sun will become sufficiently large to engulf the current orbits of Mercury and Venus, and render Earth uninhabitable – but not for about five billion years. After this, it will shed its outer layers and become a dense type of cooling star known as a white dwarf, and no longer produce energy by fusion, but still glow and give off heat from its previous fusion. The enormous effect of the Sun on Earth has been recognized since prehistoric times. The Sun has been regarded by some cultures as a deity. The synodic rotation of Earth and its orbit around the Sun are the basis of solar calendars, one of which is the predominant calendar in use today.

Source: Wikipedia