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1989 Tiananmen Square protests and massacre. / 39.90333°N 116.39167°E / 39.90333; 116.39167. The Tiananmen Square protests, known in China as the June Fourth Incident, [1] [2] [a] were student-led demonstrations held in Tiananmen Square, Beijing, China, lasting from 15 April to 4 June 1989. After weeks of unsuccessful attempts between ...
Mount Le Conte, in the Great Smoky Mountains, viewed from Clingmans Dome.Mount Le Conte is the highest mountain entirely within Tennessee and the tallest mountain east of the Rocky Mountains, measured from base to summit. In peak bagging terminology in the United States, the Southern Sixers refers to the group of mountains in the southern states of North Carolina and Tennessee with elevations ...
South Korea,[b] officially the Republic of Korea (ROK),[c] is a country in East Asia. It constitutes the southern part of the Korean Peninsula and borders North Korea along the Korean Demilitarized Zone; though it also claims the land border with China and Russia.[d] The country's western border is formed by the Yellow Sea, while its eastern ...
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The word zero came into the English language via French zéro from the Italian zero, a contraction of the Venetian zevero form of Italian zefiro via ṣafira or ṣifr. In pre-Islamic time the word ṣifr (Arabic صفر) had the meaning "empty". Sifr evolved to mean zero when it was used to translate śūnya (Sanskrit: शून्य) from India. The first known Englis...
Ancient Near East
Ancient Egyptian numerals were of base 10. They used hieroglyphs for the digits and were not positional. In one papyrus written around 1770 BC, a scribe recorded daily incomes and expenditures for the pharaoh's court, using the nfr hieroglyph to indicate cases where the amount of a foodstuff received was exactly equal to the amount disbursed. Egyptologist Alan Gardiner suggested that the nfrhieroglyph was being used as a symbol for zero. The same symbol was also used to indicate the base leve...
Pre-Columbian Americas
The Mesoamerican Long Count calendar developed in south-central Mexico and Central America required the use of zero as a placeholder within its vigesimal (base-20) positional numeral system. Many different glyphs, including the partial quatrefoil were used as a zero symbol for these Long Count dates, the earliest of which (on Stela 2 at Chiapa de Corzo, Chiapas) has a date of 36 BC.[a] Since the eight earliest Long Count dates appear outside the Maya homeland, it is generally believed that th...
Classical antiquity
The ancient Greeks had no symbol for zero (μηδέν, pronounced 'midén'), and did not use a digit placeholder for it. According to mathematician Charles Seife, the ancient Greeks did begin to adopt the Babylonian placeholder zero for their work in astronomy after 500 BC, representing it with the lowercase Greek letter ό (όμικρον: omicron). However, after using the Babylonian placeholder zero for astronomical calculations they would typically convert the numbers back into Greek numerals. Greeks s...
Today, the numerical digit 0 is usually written as a circle or ellipse. Traditionally, many print typefaces made the capital letter O more rounded than the narrower, elliptical digit 0. Typewriters originally made no distinction in shape between O and 0; some models did not even have a separate key for the digit 0. The distinction came into promine...
The concept of zero plays multiple roles in mathematics: as a digit, it is an important part of positional notation for representing numbers, while it also plays an important role as a number in its own right in many algebraic settings.
The value zero plays a special role for many physical quantities. For some quantities, the zero level is naturally distinguished from all other levels, whereas for others it is more or less arbitrarily chosen. For example, for an absolute temperature (typically measured in kelvins), zero is the lowest possible value. (Negative temperatures can be d...
Modern computers store information in binary, that is, using an "alphabet" that contains only two symbols, usually chosen to be "0" and "1". Binary coding is convenient for digital electronics, where "0" and "1" can stand for the absence or presence of electrical current in a wire. Computer programmers typically use high-level programming languages...
Biology
In comparative zoology and cognitive science, recognition that some animals display awareness of the concept of zero leads to the conclusion that the capability for numerical abstraction arose early in the evolutionof species.
Dating systems
In the BC calendar era, the year 1BC is the first year before AD1; there is not a year zero. By contrast, in astronomical year numbering, the year 1BC is numbered 0, the year 2BC is numbered −1, and so forth.
South Africa, officially the Republic of South Africa (RSA or R.S.A.), is the southernmost country in Africa.It is bounded to the south by 2,798 kilometres (1,739 mi) of coastline that stretches along the South Atlantic and Indian Oceans; to the north by the neighbouring countries of Namibia, Botswana, and Zimbabwe; and to the east and northeast by Mozambique and Eswatini.
Mao Zedong [a] (26 December 1893 – 9 September 1976) was a Chinese politician, Marxist theorist, military strategist, poet, and revolutionary who was the founder of the People's Republic of China (PRC). He led the country from its establishment in 1949 until his death in 1976, while also serving as the chairman of the Chinese Communist Party ...
Winston Churchill. Sir Winston Leonard Spencer Churchill [a] (30 November 1874 – 24 January 1965) was a British statesman, soldier, and writer who twice served as Prime Minister of the United Kingdom, from 1940 to 1945 during the Second World War, and again from 1951 to 1955. Apart from two years between 1922 and 1924, he was a Member of ...
