搜尋結果
Chan Kong-sang[a] SBS MBE PMW[3] (born 7 April 1954), known professionally as Jackie Chan,[b][4][2][1] is a Hong Kong[5][6] actor, director, writer, producer, martial artist, and stuntman known for his slapstick acrobatic fighting style, comic timing, and innovative stunts, which he typically performs himself. Before entering the film industry ...
This article needs to be updated. Please help update this article to reflect recent events or newly available information. (January 2019) This article is part of a series about Meta Platforms History Instagram WhatsApp Acquisitions Products and services Facebook 2021 outage Features Dating Feed Like button Other products Instagram Threads ...
Wikipedia is written by volunteer editors and hosted by the Wikimedia Foundation, a non-profit organization that also hosts a range of other volunteer projects : Commons. Free media repository. MediaWiki. Wiki software development. Meta-Wiki. Wikimedia project coordination. Wikibooks. Free textbooks and manuals.
- Etymology
- History
- Symbols and Representations
- Mathematics
- Physics
- Computer Science
- Other Fields
- See Also
- External Links
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.
Gmail is the email service provided by Google. As of 2019,[update] it had 1.5 billion active users worldwide, making it the largest email service in the world.[1] It also provides a webmail interface, accessible through a web browser, and is also accessible through the official mobile application. Google also supports the use of third-party ...
The Hello Kitty murder case ( Chinese: Hello Kitty藏屍案; Jyutping: Hello Kitty cong4si1ngon3; lit. 'Hello Kitty hidden body case') took place in Hong Kong in the spring of 1999, when a nightclub hostess was abducted in Lai Yiu Estate, tortured and raped in an apartment in Tsim Sha Tsui, Kowloon, after stealing a wallet owned by one of her ...
Dustin Moskovitz. Dustin Aaron Moskovitz [1] ( / ˈmɒskəvɪts /; born May 22, 1984) [2] is an American billionaire internet entrepreneur who co-founded Facebook, Inc. (now known as Meta Platforms) with Mark Zuckerberg, Eduardo Saverin, Andrew McCollum and Chris Hughes. [3] In 2008, he left Facebook to co-found Asana [4] with Justin Rosenstein.
