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.

              RAINBOW                       


A rainbow is an optical and meteorological phenomenon that causes a spectrum of light to appear in the sky when the Sun shines on to droplets of moisture in the Earth's atmosphere. It takes the form of a multicoloured arc. Rainbows caused by sunlight always appear in the section of sky directly opposite the sun.
In a so-called "primary rainbow" ,the arc of a rainbow shows red on the outeR part of the arc, and violet on the inner section. This rainbow is caused by light being refracted then reflected once in droplets of water. In a double rainbow, a second arc may be seen above and outside the primary arc and has the order of its colours reversed. This second rainbow is caused by light reflecting twice inside water droplets. The region between a double rainbow is dark and is known as "Alexander's band" or "Alexander's dark band". The reason for this dark band is that, while light below the primary rainbow comes from droplet reflection and light above the upper rainbow also comes from droplet reflection, there is no mechanism for the region between a double rainbow to show any light reflected from water drops. It is impossible for an observer to manoeuvre to see any rainbow from water droplets at any angle other than the customary one (which is 42 degrees from the direction opposite the Sun). Even if an observer sees another observer who seems "under" or "at the end" of a rainbow, the second observer will see a different rainbow further off-yet, at the same angle as seen by the first observer. Thus, a "rainbow" is not a physical object and cannot be physically approached.

A rainbow spans a continuous spectrum of colours. The distinct bands are an artefact of human colour vision and no banding of any type is seen in a black-and-white photo of a rainbow. For colours seen by a normal human eye, the most commonly cited and remembered sequence, in English, is Newton's sevenfold violet, indigo, blue, green, yellow , orange and red  (popularly memorized as VIBGYOR). However, colour-blind persons will see fewer colors. Rainbows can be caused by many forms of airborne water. These include not only rain but also mist, spray and airborne dew.

Rainbows can be observed whenever there are water drops in the air and sunlight shining from behind at a low altitude angle. The most spectacular rainbow displays happen when half the sky is still dark with raining clouds and the observer is at a spot with clear sky in the direction of the sun. The result is a luminous rainbow that contrasts with the darkened background. The rainbow effect is also commonly seen near waterfalls or fountains. In addition, the effect can be artificially created by dispersing water droplets into the air during a sunny day. Rarely, a moonbow, lunar rainbow or nighttime rainbow, can be seen on strongly moonlit nights. As human visual perception for colour is poor in low light, moonbows are often perceived to be white. It is difficult to photograph the complete semicircle of a rainbow in one frame, as this would require an angle of view of 84°. For a 35 mm camera, a lens with a focal length of 19 mm or less wide-angle lens would be required. Now that powerful software for stitching several images into a panorama is available, images of the entire arc and even secondary arcs can be created fairly easily from a series of overlapping frames. From an aeroplane, one has the opportunity to see the whole circle of the rainbow, with the plane's shadow in the centre. This phenomenon can be confused with the glory but a glory is usually much smaller, covering only 5–20°. At good visibility conditions, the second arc can be seen, with inverse order of colours. At the background of the blue sky, the second arc is barely visible.

          BIOSPHERE                         

The biosphere is the global sum of all ecosystems. It can also be called the zone of life on Earth, a closed and self-regulating system. From the broadest biophysiological point of view, the biosphere is the global ecological system integrating all living beings and their relationships, including their interaction with the elements of the lithosphere, hydros  and atmosphere. The biosphere is postulated to have evolved, beginning through a process of biogenesis or biopoesis, at least some 3.5 billion years ago. In a broader sense, biospheres are any closed, self-regulating systems containing ecosystems including artificial ones such as Biosphere 2 and BIOS-3 and potentially, ones on other planets or moons.
Some life scientists and earth scientists use biosphere in a more limited sense. For example, geochemists define the biosphere as being the total sum of living organisms. In this sense, the biosphere is but one of four separate components of the geochemical model, the other three being lithosphere, hydrosphere and atmosphere. The narrow meaning used by geochemists is one of the consequences of specialization in modern science. Some might prefer the word ecosphere, coined in the 1960s, as all encompassing of both biological and physical components of the planet.

The Second International Conference on Closed Life Systems defined biospherics as the science and technology of analogs and models of Earth's biosphere i.e. artificial Earth-like biospheres. Others may include the creation of artificial non-Earth biospheres—for example, human-centered biospheres or a native Martian biosphere—in the field of biospherics. In the early 1970s, Lynn Margulis, a microbiologist from the United States, added to the hypothesis, specifically noting the ties between the biosphere and other Earth systems. For example, when carbon dioxide levels increase in the atmosphere, plants grow more quickly. As their growth continues, they remove more and more carbon dioxide from the atmosphere.
Many scientists are now involved in new fields of study that examine interactions between biotic and abiotic factors in the biosphere, such as geo-biology and geo-microbiology. Ecosystems occur when communities and their physical environment work together as a system. The difference between this and a biosphere is simple, the biosphere is everything in general terms.

Every part of the planet, from the polar ice caps to the Equator, supports life of some kind. Recent advances in microbiology have demonstrated that microbes live deep beneath the Earth's terrestrial surface and that the total mass of microbial life in so-called "uninhabitable zones" may, in biomass, exceed all animal and plant life on the surface. The actual thickness of the biosphere on earth is difficult to measure. Birds typically fly at altitudes of 650 to 1,800 meters and fish that live deep underwater can be found down to -8,372 meters in the Puerto Rico Trench. There are more extreme examples for life on the planet: Ruppell's Vulture has been found at altitudes of 11,300 meters. Bar-headed Geese migrate at altitudes of atleast 8,300 meters. Yaks live at elevations between 3,200 to 5,400 meters above sea level. Mountain goats live up to 3,050 meters. Herbivorous animals at these elevations depend on lichens, grasses and herbs.

Microscopic organisms live at such extremes that, taking them into consideration puts the thickness of the biosphere much greater. Culturable microbes have been found in the Earth's upper atmosphere as high as 41 km. It is unlikely, however, that microbes are active at such altitudes, where temperatures and air pressure are extremely low and ultraviolet radiation very high. More likely these microbes were brought into the upper atmosphere by winds or possibly volcanic eruptions. Barophilic marine microbes have been found at more than 10 km depth in the Marianas Trench. Microbes are not limited to the air, water or the Earth's surface. Culturable thermophilic microbes have been extracted from cores drilled more than 5 km into the Earth's crust in Sweden, from rocks between 65-75 °C. Temperature increases with increasing depth into the
Earth's crust. The speed at which the temperature increases depends on many factors, including type of crust, rock type, geographic location, etc. The upper known limit of temperature at which microbial life can exist is 122 °C and it is likely that the limit of life in the "deep biosphere" is defined by temperature rather than absolute depth.

Our biosphere is divided into a number of biomes, inhabited by broadly similar flora and Fauna. On land, biomes are separated primarily by latitude. Terrestrial biomes lying within the Arctic and Antarctic Circles are relatively barren of plant and animal life, while most of the more populous biomes lie near the equator. Terrestrial organisms in temperate and Arctic biomes have relatively small amounts of total biomass, smaller energy budgets and display prominent adaptations to cold, including world-spanning migrations, social adaptations, homeothermy, estivation and multiple layers of insulation.

      GEOMETRY

Geometry (Greek: Geo- "earth" -Metria "measurement") is a branch of mathematics concerned with questions of shape, size, relative position of figures, and the properties of space. Geometry is one of the oldest mathematical sciences. Initially a body of practical knowledge concerning lengths, areas and volumes, in the 3rd century BC geometry was put into an axiomatic form by Euclid, whose treatment—Euclidean geometry—set a standard for many centuries to follow. Archimedes developed ingenious techniques for calculating areas and volumes, in many ways anticipating modern integral calculus. The field of astronomy, especially mapping the positions of the stars and planets on the celestial sphere and describing the relationship between movements of celestial bodies, served as an important source of geometric problems during the next one and a half millennia. A mathematician who works in the field of geometry is called a geometer. The introduction of coordinates by Rene Descartes and the concurrent development of algebra marked a new stage for geometry, since geometric figures, such as plane curves, could now be represented analytically, i.e., with functions and equations. This played a key role in the emergence of infinitesimal calculus in the Th century. Furthermore, the theory of perspective showed that there is more to geometry than just the metric properties of figures: perspective is the origin of projective geometry. The subject of geometry was further enriched by the study of intrinsic structure of geometric objects that originated with Euler and Gauss and led to the creation of topology and differential geometry.

In Euclid's time there was no clear distinction between physical space and geometrical space. Since the 19th-century discovery of non-Euclidean geometry, the concept of space has undergone a radical transformation and the question arose which geometrical space best fits physical space. With the rise of formal mathematics in the 20th century, also space lost its intuitive contents, so today we have to distinguish between physical space, geometrical spaces and abstract spaces. Contemporary geometry considers manifolds, spaces that are considerably more abstract than the familiar Euclidean space, which they only approximately resemble at small scales. These spaces may be endowed with additional structure, allowing one to speak about length. Modern geometry has multiple strong bonds with physics, exemplified by the ties between pseudo-Riemannian geometry and general relativity. One of the youngest physical  theories, string theory, is also very geometric in flavour. While the visual nature of geometry makes it initially more accessible than other parts of mathematics, such as algebra or number theory, geometric language is also used in contexts far removed from its traditional, Euclidean provenance.

Geometry originated as a practical science concerned with surveying, measurements, areas and volumes. Among the notable accomplishments one finds formulas for lengths, areas and volumes, such as Pythagorean theorem, circumference and area of a circle, area of a triangle, volume of a cylinder, sphere and a pyramid. A method of computing certain inaccessible distances or heights based on similarity of geometric figures is attributed to Thales. Development of astronomy led to emergence of trigonometry and spherical trigonometry, together with the attendant computational techniques.

                                           DEMOCRACY
     
Democracy is a form of government in which all people have an equal say in the decisions that affect their lives. Ideally, this includes equal participation in the proposal, development and passage of legislation into law. It can also encompass social, economic and cultural conditions that enable the free and equal practice of political self-determination. According to some theories of democracy, popular sovereignty is the founding principle of such a system. However, the democratic principle has also been expressed as "the freedom to call something into being which did not exist before, which was not given and which therefore, strictly speaking, could not be known." This type of freedom, which is connected to human "natality," or the capacity to begin anew, sees democracy as "not only a political system" an aspiration, really, intimately connected to and dependent upon a picture of what it is to be human—of what it is a human should be to be fully human."
While there is no universally accepted definition of 'democracy', equality and freedom have both been identified as important characteristics of democracy since ancient times. These principles are reflected in all citizens being equal before the law and having equal access to legislative processes. For example, in a representative democracy, every vote has equal weight, no unreasonable restrictions can apply to anyone seeking to become a representative and the freedom of its citizens is secured by legitimized rights and liberties which are generally protected by a constitution.

There are several varieties of democracy. Some of which provide better representation and more freedom for their citizens than others. However, if any democracy is not structured so as to prohibit the government from excluding the people from the legislative process or any branch of government from altering the separation of powers in its own favor, then a branch of the system can accumulate too much power and destroy the democracy. Representative Democracy, Consensus Democracy and Deliberative Democracy are all major examples of attempts at a form of government that is both practical and responsive to the needs and desires of citizens.
Many people use the term "democracy" as shorthand for liberal democracy, which may include elements such as political pluralism, equality before the law, the right to petition elected officials for redress of grievances, due process, civil liberties, human rights and elements of civil society outside the government. In the United States, separation of powers is often cited as a central attribute but in other countries such as the United Kingdom, the dominant principle is that of parliamentary sovereignty. In other cases, "democracy" is used to mean direct democracy. Though the term "democracy" is typically used in the context of a political state, the principles are applicable to private organizations and other groups as well.
Majority rule is often listed as a characteristic of democracy. However, it is also possible for a minority to be oppressed by a "tyranny of the majority" in the absence of governmental or constitutional protections of individual or group rights. An essential part of an "ideal" representative democracy is competitive elections that are fair both substantively and procedurally. Furthermore, freedom of political expression, freedom of speech and freedom of the press are considered to be essential, so that citizens are adequately informed and able to vote according to their own best interests as they see them. It has also been suggested that a basic feature of democracy is the capacity of individuals to participate freely and fully in the life of their society.
Democracy has its formal origins in Ancient Greece but democratic practices are evident in earlier societies including Mesopotamia, Phoenicia and India. Other cultures since Greece have significantly contributed to the evolution of democracy such as Ancient Rome, Europe and North and South America. The concept of representative democracy arose largely from ideas and institutions that developed during the European Middle Ages and the Age of Enlightenment and in the American and French Revolutions. Democracy has been called the "last form of government" and has spread considerably across the globe. The right to vote has been expanded in many jurisdictions over time from relatively narrow groups with New Zealand the first nation to grant universal suffrage for all its citizens in 1893. Democracy is often confused with the republic form of government.

Parliamentary democracy is a representative democracy where government is appointed by representatives as opposed to a 'presidential rule' wherein the President is both head of state and the head of government and is elected by the voters. Under a parliamentary democracy, government is exercised by delegation to an executive ministry and subject to ongoing review, checks and balances by the legislative parliament elected by the people. Parliamentary systems have the right to dismiss a Prime Minister at any point in time that they feel he or she is not doing their job to the expectations of the legislature. This is done through a vote of no Confidence where the legislature decides whether or not to remove the Prime Minister from office by a majority support for his or her dismissal. The Prime Minister can also call an election whenever he or she so chooses. Typically the Prime Minister will hold an election when he or she knows that they are in good favor with the public as to get re-elected.