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Dubai, also spelled Dubayy, city and capital of the emirate of Dubai, one of the wealthiest of the seven emirates that constitute the federation of the United Arab Emirates, which was created in 1971 following independence from Great Britain. There are several theories about the origin of the name Dubai. Pop. Area 13.5 square miles (35 square km). (2017 est.) 2,919,178. In recent years Dubai has been compared to Singapore and Hong Kong and is often regarded as the Middle East’s premier entrepôt. One associates it with the daba—a type of locust that infests the area—while another holds that it refers to a market that existed near the city.Islam is the majority religion, but churches and Hindu temples coexist with Dubai’s mosques. Because of its large expatriate population, it feels like a Middle Eastern melting pot, and the atmosphere is generally tolerant. Religious affiliations are not a prominent aspect of city life. Character of the city Dubai is a city of skyscrapers, port...

EARTH PLANET Earth, third planet from the Sun and the fifth largest planet in the solar system in terms of size and mass. Earth’s name in English, the international language of astronomy, derives from Old English and Germanic words for ground and earth, and it is the only name for a planet of the solar system that does not come from Greco-Roman mythology. It is designated by the symbol ♁. Its single most outstanding feature is that its near-surface environments are the only places in the universe known to harbour life.Concurrent sea voyages provided practical proof that Earth is a globe, just as Galileo’s use of his newly invented telescope in the early 17th century soon showed various other planets to be globes as well. The polar regions also would appear a brilliant white, because of the clouds above and the snow and ice below. Also prominent would be the growth and recession of the winter snowcap across land areas of the Northern Hemisphere. Scientists have applied th...

Rolls-Royce PLC British firm. Rolls-Royce PLC, major British manufacturer of aircraft engines, marine propulsion systems, and power-generation systems. Noted for much of the 20th century as a maker of luxury automobiles, the company was separated from its car-making operations and nationalized following bankruptcy in 1971. It returned to the private sector in 1987. Headquarters are in London.Major products include the Trent and RB211 turbofan families (see jet engine) used on Boeing, Airbus, and Tupolev aircraft and the EJ200 turbofan developed for the Eurofighter Typhoon. Other nonaerospace products include aerospace-derived gas turbines for the oil and gas industries and power-generation plants and nuclear power systems for the Royal Navy. Rolls-Royce PLC’s aerospace segment produces an extensive line of civilian and military aircraft engines, both alone and in joint ventures with companies in Europe, the United States, and Japan. Rolls-Royce is the world’s leading suppli...

sun History of observation The existence of features on the Sun was known from the records of sunspots observed by ancient astronomers with the naked eye; however, no systematic studies were made of such features until the telescope was invented in the early 17th century. Sir Isaac Newton set forth the role of the Sun as the centre of attraction of the known planetary system. Scheiner’s drawings in the Rosa Ursina are of almost modern quality, and there was little improvement in solar imaging until 1905. In the 1670s the British astronomer John Flamsteed and the French astronomer Gian Domenico Cassini calculated the distance to the Sun. The Italian scientist Galileo Galilei and the German mathematician Christoph Scheiner were among the first to make telescopic observations of sunspots.Hard X-ray data could be obtained without saturation. However, the task is not easy. By 1960 astronomers realized that these sites not only had to be clear but that they also had to have stable air. ...

history discipline. history, the discipline that studies the chronological record of events (as affecting a nation or people), based on a critical examination of source materials and usually presenting an explanation of their causes. The general articles contain many cross-references to specific historical movements and events and to biographies of significant figures. Information on any specific historical topic, such as the history of specific peoples, cultures, countries, and regions, will be found under the relevant title. For the principal treatment of the subject of historiography and the scholarly research necessary for the discipline, see historiography. For information on the historical aspects of military affairs, economics, law, literature, sciences, art, philosophy, religion, and other fields of human endeavour, the reader should also first consult the relevant title and review the subtopics in the Table of Contents. History is treated in a number of articles. Publius...

Snake Reptiles Internally, they have lost the urinary bladder. Certain burrowing lizards may have only front or hind limbs or be completely legless. The visceral organs are elongated, with reduction of the left member in relation to the right; the left lung is greatly reduced or even lost entirely. However, snakes possess increased numbers of vertebrae and have developed two novelties among vertebrates: a tracheal lung in the neck region and a venom-conducting system for subduing prey. Unlike lizards, snakes lack movable eyelids, which results in a continuous and often disconcerting stare. Classified with lizards in the order Squamata, snakes represent a lizard that, over the course of evolution, has undergone structural reduction, simplification, and loss as well as specialization. Snakes also lack external ear openings. All snakes lack external limbs, but not all legless reptiles are snakes. snake, (suborder Serpentes), also called serpent, any of more than 3,400 species of rept...

Comprising about 40 percent of Brazil’s total area, it is bounded by the Guiana Highlands to the north, the Andes Mountains to the west, the Brazilian central plateau to the south, and the Atlantic Ocean to the east. Amazon Rainforest, large tropical rainforest occupying the drainage basin of the Amazon River and its tributaries in northern South America and covering an area of 2,300,000For full treatment, see South America: Amazon River basin. Amazonia is the largest river basin in the world, and its forest stretches from the Atlantic Ocean in the east to the tree line of the Andes in the west. The forest widens from a 200-mile (320-km) front along the Atlantic to a belt 1,200 miles (1,900 km) wide where the lowlands meet the Andean foothills. A brief treatment of the Amazon Rainforest follows. The immense extent and great continuity of this rainforest is a reflection of the high rainfall, high humidity, and monotonously high temperatures that prevail in the region.Comprising abo...