How to Define Atmosphere

How to Define Atmosphere The term atmosphere has multiple meanings in science: Atmosphere Definition Atmosphere refers to the gases surrounding a star or planetary body held in place by gravity. A body is more likely to retain an atmosphere over time if gravity is high and the temperature of the atmosphere is low. The composition of the Earths atmosphere is about 78 percent nitrogen, 21 percent oxygen, 0.9 percent argon, with water vapor, carbon dioxide, and other gases. The atmospheres of other planets have a different composition. The composition of the Suns atmosphere consists of about 71.1 percent hydrogen, 27.4 percent helium, and 1.5 percent other elements. Atmosphere Unit An atmosphere is also a unit of pressure. One atmosphere (1 atm) is defined to be equal to 101,325 Pascals. A reference or standard pressure is commonly 1 atm. In other cases, Standard Temperature and Pressure or STP is used.

Portugals Global Empire

Portugal's Global Empire Portugal is a small Western European country located at the western tip of the Iberian Peninsula. Beginning in the 1400s, the Portuguese, led by famous explorers such as Bartolomeu Dias and Vasco de Gama and financed by the great Prince Henry the Navigator, sailed to, explored, and settled in South America, Africa, and Asia. Portugals empire, which survived for more than six centuries, was the first of the great European global empires. Its former possessions are now located in across 50 countries around the world. The Portuguese created colonies for numerous reasons: to trade for spices, gold, agricultural products, and other resources; to create more markets for Portuguese goods; to spread Catholicism; to civilize the natives of these distant places. Portugals colonies brought great wealth to this small country. The empire gradually declined, as it did for other colonizers because Portugal did not have enough people or resources to maintain so many overseas territories. Here are the most important former Portuguese possessions. Brazil Brazil  was by far Portugals largest colony by area and population and was reached by the Portuguese in 1500. Due to the  Treaty of Tordesillas, signed with Spain in 1494 and agreeing which nation could colonize where Portugal was allowed to claim Brazil. The Portuguese imported African slaves and forced them to grow sugar, tobacco, cotton, coffee, and other cash crops. The Portuguese also extracted brazilwood from the rainforest, which was used to dye European textiles; they also helped to explore and settle the vast interior of Brazil. In the 19th century, the royal court of Portugal lived in and governed both Portugal and Brazil from Rio de Janeiro. Brazil gained independence from Portugal in 1822. Angola, Mozambique, and Guinea-Bissau In the 1500s, Portugal colonized the present-day west African country of Guinea-Bissau and the two southern African countries of Angola and Mozambique.   The Portuguese enslaved many people from these countries and sent them to the New World. Gold and diamonds were also extracted from these colonies. In the 20th century, Portugal was under international pressure to release its colonies, but Portugals dictator, Antonio Salazar, refused to decolonize. Several independence movements in these three African countries erupted into the Portuguese Colonial War of the 1960s and 1970s, which killed tens of thousands and was associated with communism and the Cold War. In 1974, a military coup in Portugal forced Salazar out of power, and the new government of Portugal ended the unpopular, very expensive war. Angola, Mozambique, and Guinea-Bissau gained independence in 1975. All three countries were underdeveloped, and civil wars in the decades after independence took millions of lives. More than a million refugees from these three countries emigrated to Portugal after independence and strained the Portuguese economy. Cape Verde and Sao Tome and Principe Cape Verde and Sao Tome and Principe, two small archipelagos located off the western coast of Africa, were also colonized by the Portuguese. They were uninhabited before the Portuguese arrived and were important in the slave trade. They both achieved independence from Portugal in 1975. Goa, India In the 1500s, the Portuguese colonized the western Indian region of Goa. Goa, located on the Arabian Sea, was an important port in spice-rich India. In 1961, India annexed Goa from the Portuguese and it became an Indian state. Goa has many Catholic adherents in primarily Hindu India. East Timor The Portuguese also colonized the eastern half of the island of Timor in the 16th century. In 1975, East Timor declared independence from Portugal, but the island was invaded and annexed by Indonesia. East Timor became independent in 2002. Macau In the 16th century, the Portuguese colonized Macau, located on the South China Sea. Macau served as an important Southeast Asian trading port. The Portuguese empire ended when Portugal handed over control of Macau to China in 1999. The Portuguese Language Today Portuguese, a Romance language, is spoken by 260 million people, with between 215 and 220 native speakers. It is the sixth most spoken language in the world. It is the official language of Portugal, Brazil, Angola, Mozambique, Guinea-Bissau, Cape Verde, Sao Tome and Principe, and East Timor. It is also spoken in Macau and Goa. It is one of the official languages of the European Union, the African Union, and the Organization of American States. Brazil, with more than 207 million people (July 2017 estimate), is the most populated Portuguese-speaking country in the world. Portuguese is also spoken in the Azores Islands and the Madeira Islands, two archipelagos that still belong to Portugal. The Historic Portuguese Empire The Portuguese excelled in exploration and trade for centuries. The countrys former colonies, spread across continents, have varying areas, populations, geographies, histories, and cultures. The Portuguese tremendously affected their colonies politically, economically, and socially. The empire has been criticized for being exploitative, neglectful, and racist. Some colonies still suffer from high poverty and instability, but their valuable natural resources, combined with current diplomatic relations with and assistance from Portugal, may improve the living conditions of these numerous countries. The Portuguese language will always be an important connector of these countries and a reminder of how vast and significant the Portuguese empire once was.