Sun vs Grenoble

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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

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Grenoble ( grə-NOH-bəl, French: [ɡʁənɔbl] (listen); Francoprovençal: Grenoblo) is the prefecture and largest city of the Isère department in the Auvergne-Rhône-Alpes region of Southeastern France. It lies at the foot of the French Alps where the river Drac joins the Isère. A significant European scientific centre, the city advertises itself as the "Capital of the Alps", due to its size and its proximity to the mountains. The population of the commune of Grenoble was 158,180 at the 2016 census, while the population of the Grenoble metropolitan area (French: aire urbaine de Grenoble or "agglomération grenobloise") was 687,985 which makes it the largest metropolis in the Alps, ahead of Innsbruck and Bolzano. The residents of the city are called "Grenoblois". The many suburb communes that make up the rest of the metropolitan area include three with populations exceeding 20,000: Saint-Martin-d'Hères, Échirolles, Fontaine and Voiron.Grenoble's history goes back over 2,000 years, to a time when it was a small Gallic village.

It became the capital of the Dauphiné in the 11th century. This status, consolidated by the annexation to France, allowed it to develop its economy. Grenoble then became a parliamentary and military city, close to the border with Savoy. Industrial development increased the prominence of Grenoble through several periods of economic expansion over the last three centuries. This started with a booming glove industry in the 18th and 19th centuries, continued with the development of a strong hydropower industry in the late 19th to early 20th centuries and ended with a post-World War II economic boom symbolized by the holding of the X Olympic Winter Games in 1968. The city has grown to be one of Europe's most important research, technology and innovation centres, with one in five inhabitants working directly in these fields. Grenoble is classified as a global city with the ranking of "sufficiency" by the Globalization and World Cities Research Network. The city will hold the title of European Green Capital in 2022.

Source: Wikipedia