ZERO

The concept Zero played a major role in seeing the growth of higher mathematics which is a major step in the history of mankind. Zero is also a synonym of the word none. Although there are many stories that surround the invention of the number zero, studies show that the number was invented by a group of people from the Mayan civilization. At that time, the decimal system was in use just as it is today only that a space was left to indicate a zero up until the third century BC. The other version of the story is that, it was invented by the Indian mathematician and astronomer, ARYABHATTA, around 9th century C.E. There is also a claim that tracks the invention of zero back to 300 B.C in Babylon. All these inventions were independently made and were not connected. The empty space was very confusing because it was also used for the separation for numbers. That brought about the dot to stand in place of a zero. The first time the zero symbol was evidently used can be traced to the seventh century AD. The Maya made the number zero invention specifically for the calendars used during the third century AD. Evidence of number zero was not realized in the Europe civilization up until after eight hundred AD from the Arabs who were coming to trade. The Romans and Greeks used the abacus to carry out their calculations and did not therefore need the number zero. The zero name was derived from the Arabic language.


By the middle of the 2nd millennium BC, the Babylonian mathematics had a sophisticated sexagesimal positional numeral system. The lack of a positional value was indicated by a space between sexagesimal numerals. By 300 BC, a punctuation symbol was co-opted as a placeholder in the same Babylonian system. In a tablet unearthed at Kish, the scribe Bel-ban-aplu wrote his zeros with three hooks, rather than two slanted wedges. The Babylonian placeholder was not a true zero because it was not used alone. Nor was it used at the end of a number. Thus numbers like 2 and 120, 3 and 180, 4 and 240, looked the same because the larger numbers lacked a final sexagesimal placeholder. Only context could differentiate them.

Records show that the ancient Greeks seemed unsure about the status of zero as a number. They asked themselves "How can nothing be something? leading to philosophical and by the Medieval period, religious arguments about the nature and existence of zero and the vacuum. The paradoxes of Zeno of Elea depend in large part on the uncertain interpretation of zero.
The concept of zero as a number and not merely a symbol for separation is attributed to India where by the 9th century AD practical calculations were carried out using zero, which was treated like any other number, even in case of division. The Indian scholar Pingala used binary numbers in the form of short and long syllables, making it similar to Morse code. He and his contemporary Indian scholars used the Sanskrit word sunya to refer to zero or void. The Mesoamerican Long Count calendar developed in south-central Mexico and Central America required the use of zero as a place-holder within its vigesimal positional numeral system. Many different glyphs, including this partial quatrefoil——were used as a zero symbol for these Long Count dates, the earliest of which has a date of 36 BC. Since the eight earliest Long Count dates appear outside the Maya homeland, it is assumed that the use of zero in the Americas predated the Maya and was possibly the invention of the Olmecs. Many of the earliest Long Count dates were found within the Olmec heartland, although the Olmec civilization ended by the 4th century BC, several centuries before the earliest known Long Count dates.
Although zero became an integral part of Maya numerals, it did not influence Old World numeral systems.
Quipu, a knotted cord device, used in the Inca Empire and its predecessor societies in the Andean region to record accounting and other digital data, is encoded in a base ten positional system. Zero is represented by the absence of a knot in the appropriate position.The use of a blank on a counting board to represent 0 dated back in India to 4th century BC. In China, counting rods were used for decimal calculation since the 4th century BC including the use of blank spaces. Chinese mathematicians understood negative numbers and zero, some mathematicians used for the latter, until Gautama Siddha introduced the symbol 0. The Nine Chapters on the Mathematical Art, which was mainly composed in the 1st century AD, stated "subtract same signed numbers, add differently signed numbers, subtract a positive number from zero to make a negative number and subtract a negative number from zero to make a positive number.

         HOW DOES BLIND PEOPLE READ

The Braille system is a method that is widely used by people who are visually impaired to read and write and was the first digital form of writing. Braille was devised in 1825 by Louis Braille, a blind Frenchman. Each Braille character or cell is made up of six dot positions, arranged in a rectangle containing two columns of three dots each. A dot may be raised at any of the six positions to form sixty-four (26) possible subsets, including the arrangement in which no dots are raised. For reference purposes, a particular permutation may be described by naming the positions where dots are raised, the positions being universally numbered 1 to 3, from top to bottom, on the left and 4 to 6 from top to bottom on the right. For example dots 1-3-4 (⠍) would describe a cell with three dots raised, at the top and bottom in the left column and on top of the right column i.e. the letter m. The lines of horizontal Braille text are separated by a space, much like visible printed text so that the dots of one line can be differentiated from the Braille text above and below. Punctuation is represented by its own unique set of characters.

The Braille system was based on a method of communication originally developed by Charles Barbier in response to Napoleon's demand for a code that soldiers could use to communicate silently and without light at night called night writing. Barbier's system of sets of 12 embossed dots encoding 36 different sounds was too difficult for soldiers to perceive by touch and was rejected by the military. In 1821 he visited the National Institute for the Blind in Paris where he met Louis Braille. Braille identified the two major defects of the code: First, by representing only sounds, the code was unable to give the orthography of the words and Second, the human finger could not encompass the whole symbol without moving and so could not move rapidly from one symbol to another. His modification was to use a 6 dot cell — the Braille system — representing all the letters of the alphabet. At first the system was a one-to-one transliteration of French but soon various abbreviations and contractions were developed, creating a system much more like shorthand.

People who are totally blind are absolutely not able to interact with the computer without assistive technologies. In order to overcome this barrier, they mostly use screen reader software and Braille displays. In simple terms, a screen reader system speaks all the information in a human voice which comes on the screen as well as the text which is typed on the keyboard. A Braille display makes the same information appear on a Braille line which blind people can read with their fingers. However a screen reader is much more complicated in practice. It is also important that blind people are able to navigate quickly on the screen and find information as they need it. Therefore, screen reader systems are loaded with functionality which read a portion of the screen according to certain different criteria. The more simple ones would read the current character, the current word or the current line. More complex ones would read the status line of an application, the title bar, a certain window or the current item on the menu as the user navigates.

 A Braille display is usually an addition to a screen reader. It is a small unit which lays by the keyboard and displays one line of information in Braille, mostly the same which the screen read announces with speech. This helps blind people understand the layout of the screen better and read texts which is more difficult to understand with speech. For example more complex tablets or texts which contain words in more than one language, such as dictionaries. The effectiveness of a screen reader greatly determines the effectiveness of blind people on the computer. Long ago screen readers only allowed to read the screen line by line, so people had to hunt for information they needed. Today, practically any piece of information can be assigned with a hotkey. Different hotkeys would announce different information in different applications. For example one hotkey would announce the misspelled word in a Microsoft Application, another would read the current table cell in Internet Explorer etc.

                  


The World Wide Web is a system of interlinked hypertext documents accessed via Internet. With a web browser, one can view web pages that may contain text, images, videos, and other multimedia and navigate between them via hyperlinks.


Using concepts from his earlier hypertext systems like ENQUIRE, British engineer and computer scientist Sir Tim Berners-Lee, now Director of the World Wide Web Consortium, wrote a proposal in March 1989 for what would eventually become the World Wide Web. At CERN in Geneva, Switzerland, Berners-Lee and Belgian computer scientist Robert Cailliau proposed in 1990 to use hypertext " to link and access information of various kinds as a web of nodes in which the user can browse at will" and they publicly introduced the project in December.
In the June 1970 issue of Popular Science magazine Arthur C. Clarke was reported to have predicted that satellites would one day "bring the accumulated knowledge of the world to your fingertips" using a console that would combine the functionality of the Xerox, telephone, television and a small computer, allowing data transfer and video conferencing around the globe. In March 1989, Tim Berners-Lee wrote a proposal that referenced ENQUIRE, a database and software project he had built in 1980 and described a more elaborate information management system.


With help from Robert Cailliau, he published a more formal proposal on November 12 1990 to build a "Hypertext project" called "WorldWideWeb" of "hypertext documents" to be viewed by "browsers" using a client–server architecture. This proposal estimated that a read-only web would be developed within three months and that it would take six months to achieve "the creation of new links and new material by readers, authorship becomes universal" as well as "the automatic notification of a reader when new material of interest to him has become available." While the read-only goal was met, accessible authorship of web content took longer to mature, with the wiki concept, blogs, Web 2.0 and RSS.


The proposal was modeled after the Dynatext SGML reader by Electronic Book Technology, a spin-off from the Institute for Research in Information and Scholarship at Brown University. The Dynatext system, licensed by CERN, was technically advanced and was a key player in the extension of SGML ISO 8879:1986 to Hypermedia within HIGH Time but it was considered too expensive and had an inappropriate licensing policy for use in the general high energy physics community, namely a fee for each document and each document alteration.The terms Internet and World Wide Web are often used in everyday speech without much distinction. However, the Internet and the World Wide Web are not one and the same. The Internet is a global system of interconnected computer networks. In contrast, the Web is one of the services that runs on the Internet. It is a collection of text documents and other resources, linked by hyperlinks and URLs, usually accessed by web browsers from web servers. In short, the Web can be thought of as an application "running" on the Internet.