Proudly South African
The Proudly South African campaign is a South African'buy local' marketing campaign and logo. Proudly South African was established in 2001, born out of the 1998 Presidential Job Summit, convened by the late former President Nelson Mandela. Like all government initiatives, its purpose is to work to combat the triple challenges of poverty and above all, unemployment. Cost of membership is 0.1% of sales of those products bearing the PSA logo, but is negotiable in special circumstances. Non-commercial organisations pay a nominal fee. Rainbow Nation Official website
Sir Isaac Newton was an English mathematician, astronomer and author, recognised as one of the most influential scientists of all time, a key figure in the scientific revolution. His book Philosophiæ Naturalis Principia Mathematica, first published in 1687, laid the foundations of classical mechanics. Newton made seminal contributions to optics, shares credit with Gottfried Wilhelm Leibniz for developing the infinitesimal calculus. In Principia, Newton formulated the laws of motion and universal gravitation that formed the dominant scientific viewpoint until it was superseded by the theory of relativity. Newton used his mathematical description of gravity to prove Kepler's laws of planetary motion, account for tides, the trajectories of comets, the precession of the equinoxes and other phenomena, eradicating doubt about the Solar System's heliocentricity, he demonstrated that the motion of objects on Earth and celestial bodies could be accounted for by the same principles. Newton's inference that the Earth is an oblate spheroid was confirmed by the geodetic measurements of Maupertuis, La Condamine, others, convincing most European scientists of the superiority of Newtonian mechanics over earlier systems.
Newton built the first practical reflecting telescope and developed a sophisticated theory of colour based on the observation that a prism separates white light into the colours of the visible spectrum. His work on light was collected in his influential book Opticks, published in 1704, he formulated an empirical law of cooling, made the first theoretical calculation of the speed of sound, introduced the notion of a Newtonian fluid. In addition to his work on calculus, as a mathematician Newton contributed to the study of power series, generalised the binomial theorem to non-integer exponents, developed a method for approximating the roots of a function, classified most of the cubic plane curves. Newton was a fellow of Trinity College and the second Lucasian Professor of Mathematics at the University of Cambridge, he was a devout but unorthodox Christian who rejected the doctrine of the Trinity. Unusually for a member of the Cambridge faculty of the day, he refused to take holy orders in the Church of England.
Beyond his work on the mathematical sciences, Newton dedicated much of his time to the study of alchemy and biblical chronology, but most of his work in those areas remained unpublished until long after his death. Politically and tied to the Whig party, Newton served two brief terms as Member of Parliament for the University of Cambridge, in 1689–90 and 1701–02, he was knighted by Queen Anne in 1705 and spent the last three decades of his life in London, serving as Warden and Master of the Royal Mint, as well as president of the Royal Society. Isaac Newton was born on Christmas Day, 25 December 1642 "an hour or two after midnight", at Woolsthorpe Manor in Woolsthorpe-by-Colsterworth, a hamlet in the county of Lincolnshire, his father named Isaac Newton, had died three months before. Born prematurely, Newton was a small child; when Newton was three, his mother remarried and went to live with her new husband, the Reverend Barnabas Smith, leaving her son in the care of his maternal grandmother, Margery Ayscough.
Newton disliked his stepfather and maintained some enmity towards his mother for marrying him, as revealed by this entry in a list of sins committed up to the age of 19: "Threatening my father and mother Smith to burn them and the house over them." Newton's mother had three children from her second marriage. From the age of about twelve until he was seventeen, Newton was educated at The King's School, which taught Latin and Greek and imparted a significant foundation of mathematics, he was removed from school, returned to Woolsthorpe-by-Colsterworth by October 1659. His mother, widowed for the second time, attempted to make him an occupation he hated. Henry Stokes, master at The King's School, persuaded his mother to send him back to school. Motivated by a desire for revenge against a schoolyard bully, he became the top-ranked student, distinguishing himself by building sundials and models of windmills. In June 1661, he was admitted to Trinity College, Cambridge, on the recommendation of his uncle Rev William Ayscough, who had studied there.
He started as a subsizar—paying his way by performing valet's duties—until he was awarded a scholarship in 1664, guaranteeing him four more years until he could get his MA. At that time, the college's teachings were based on those of Aristotle, whom Newton supplemented with modern philosophers such as Descartes, astronomers such as Galileo and Thomas Street, through whom he learned of Kepler's work, he set down in his notebook a series of "Quaestiones" about mechanical philosophy. In 1665, he discovered the generalised binomial theorem and began to develop a mathematical theory that became calculus. Soon after Newton had obtained his BA degree in August 1665, the university temporarily closed as a precaution against the Great Plague. Although he had been undistinguished as a Cambridge student, Newton's private studies at his home in Woolsthorpe over the subsequent two years saw the development of his theories on calculus and the law of gravitation. In April 1667, he returned in October was elected as a fellow of Trinity.
Fellows were required to become ordained priests, although this was no
Mimosa is a genus of about 400 species of herbs and shrubs, in the mimosoid clade of the legume family Fabaceae. The generic name is derived from the Greek word μιμος, an "actor" or "mime," and the feminine suffix –osa, "resembling", suggesting its'sensitive leaves' which seem to'mimic conscious life'. Two species in the genus are notable. One is Mimosa pudica, because of the way it folds its leaves when exposed to heat, it is native to southern Central and South America but is cultivated elsewhere for its curiosity value, both as a houseplant in temperate areas, outdoors in the tropics. Outdoor cultivation has led to weedy invasion in some areas, notably Hawaii; the other is Mimosa tenuiflora, best known for its use in shamanic ayahuasca brews due to the psychedelic drug dimethyltryptamine found in its root bark. The taxonomy of the genus Mimosa has had a tortuous history, having gone through periods of splitting and lumping accumulating over 3,000 names, many of which have either been synonymized under other species or transferred to other genera.
In part due to these changing circumscriptions, the name "Mimosa" has been applied to several other related species with similar pinnate or bipinnate leaves, but are now classified in other genera. The most common examples of this are Acacia dealbata. Members of this genus are among the few plants capable of rapid movement; the leaves of the Mimosa pudica close when touched. Some mimosas raise their leaves in the day and lower them at night, experiments done by Jacques d'Ortous de Mairan on mimosas in 1729 provided the first evidence of biological clocks. Mimosa can be distinguished from the large related genera and Albizia, since its flowers have 10 or fewer stamens. Note that, what appears to be a single globular flower is a cluster of many individual ones. Mimosa contains some level of heptanoic acid. There are about 400 species including: Mimosa aculeaticarpa Ortega Mimosa andina Benth. Mimosa arenosa Poir. Mimosa asperata L. Mimosa borealis Gray Mimosa caesalpiniaefolia Benth. Mimosa casta L. Mimosa cupica Gray Mimosa ceratonia L. Mimosa diplotricha C.
Wright ex Sauvalle Mimosa disperma Barneby Mimosa distachya Cav. Mimosa dysocarpa Benth. Mimosa emoryana Benth. Mimosa grahamii Gray Mimosa hamata Willd. Mimosa hystricina B. L. Turner Mimosa invisa Martius ex Colla Mimosa latidens B. L. Turner Mimosa laxiflora Benth. Mimosa loxensis Barneby Mimosa malacophylla Gray Mimosa microphylla Dry. Mimosa nothacacia Barneby Mimosa nuttallii B. L. Turner Mimosa ophthalmocentra Mart. Ex Benth. 1865 Mimosa pellita Kunth ex Willd. Mimosa pigra L. Mimosa polycarpa Kunth Mimosa pudica L. Mimosa quadrivalvis L. Mimosa quadrivalvis var. hystricina Barneby Mimosa quadrivalvis var. quadrivalvis L. Mimosa roemeriana Scheele Mimosa rubicaulis Lam. Mimosa rupertiana B. L. Turner Mimosa scabrella Benth. Mimosa schomburgkii Benth. Mimosa somnians Humb. & Bonpl. Ex Willd. Mimosa strigillosa Torr. Et Gray Mimosa tenuiflora Poir. Mimosa texana Small Mimosa townsendii Barneby Mimosa turneri Barneby Mimosa verrucosa Benth; the bark and flowers have been used for centuries in traditional Chinese medicine.
The bark is still known as'Collective Happiness Bark' and is used for cleansing the body's energetic pathways providing a spiritual boost for those who take it. The ancient Mayans used it to treat injuries and burns. Despite this, modern research remains insignificant, but the powdered bark is used by homeopaths as an anti-inflammatory, anti-septic, cough/cold relief and painkiller. Albizia julibrissin, Persian silk tree, called Mimosa in the United States Barneby, R. C. 1992. Sensitivae Censitae: A description of the genus Mimosa Linnaeus in the New World. Memoirs of the New York Botanical Garden, vol. 65. Mimosa-pudica.de Two small videos showing the plant folding its leaves
The term multiculturalism has a range of meanings within the contexts of sociology, of political philosophy, of colloquial use. In sociology and in everyday usage, it is a synonym for "ethnic pluralism", with the two terms used interchangeably, for example, a cultural pluralism in which various ethnic groups collaborate and enter into a dialogue with one another without having to sacrifice their particular identities, it can describe a mixed ethnic community area where multiple cultural traditions exist or a single country within which they do. Groups associated with an aboriginal or autochthonous ethnic group and foreigner ethnic groups are the focus. In reference to sociology, multiculturalism is the end-state of either a natural or artificial process and occurs on either a large national scale or on a smaller scale within a nation's communities. On a smaller scale this can occur artificially when a jurisdiction is established or expanded by amalgamating areas with two or more different cultures.
On a large scale, it can occur as a result of either legal or illegal migration to and from different jurisdictions around the world. Multiculturalism as a political philosophy involves policies which vary widely, it has been described as as a "cultural mosaic" -- in contrast to a melting pot. In the political philosophy of multiculturalism, ideas are focused on the ways in which societies are either believed to or should, respond to cultural and religious differences, it is associated with "identity politics", "the politics of difference", "the politics of recognition". It is a matter of economic interests and political power. In more recent times political multiculturalist ideologies have been expanding in their use to include and define disadvantaged groups such as African Americans, LGBT, with arguments focusing on ethnic and religious minorities, minority nations, indigenous peoples and the disabled, it is within this context in which the term is most understood and the broadness and scope of the definition, as well as its practical use, has been the subject of serious debate.
Most debates over multiculturalism center around whether or not multiculturalism is the appropriate way to deal with diversity and immigrant integration. The arguments regarding the perceived rights to a multicultural education include the proposition that it acts as a way to demand recognition of aspects of a group's culture subordination and its entire experience in contrast to a melting pot or non-multicultural societies; the term multiculturalism is most used in reference to Western nation-states, which had achieved a de facto single national identity during the 18th and/or 19th centuries. Multiculturalism has been official policy in several Western nations since the 1970s, for reasons that varied from country to country, including the fact that many of the great cities of the Western world are made of a mosaic of cultures; the Canadian government has been described as the instigator of multicultural ideology because of its public emphasis on the social importance of immigration. The Canadian Royal Commission on Bilingualism and Biculturalism is referred to as the origins of modern political awareness of multiculturalism.
In the Western English-speaking countries, multiculturalism as an official national policy started in Canada in 1971, followed by Australia in 1973 where it is maintained today. It was adopted as official policy by most member-states of the European Union. Right-of-center governments in several European states – notably the Netherlands and Denmark – have reversed the national policy and returned to an official monoculturalism. A similar reversal is the subject of debate in the United Kingdom, among others, due to evidence of incipient segregation and anxieties over "home-grown" terrorism. Several heads-of-state or heads-of-government have expressed doubts about the success of multicultural policies: The United Kingdom's ex-Prime Minister David Cameron, German Chancellor Angela Merkel, Australia's ex-prime minister John Howard, Spanish ex-prime minister Jose Maria Aznar and French ex-president Nicolas Sarkozy have voiced concerns about the effectiveness of their multicultural policies for integrating immigrants.
Many nation-states in Africa and the Americas are culturally diverse and are'multicultural' in a descriptive sense. In some, communalism is a major political issue; the policies adopted by these states have parallels with multiculturalist policies in the Western world, but the historical background is different, the goal may be a mono-cultural or mono-ethnic nation-building – for instance in the Malaysian government's attempt to create a'Malaysian race' by 2020. Multiculturalism is seen by its supporters as a fairer system that allows people to express who they are within a society, more tolerant and that adapts better to social issues, they argue that culture is not one definable thing based on one race or religion, but rather the result of multiple factors that change as the world changes. Support for modern multiculturalism stems from the changes in Western societies after World War II, in what Susanne Wessendorf calls the "human rights revolution", in which the horrors of institutionalized racism and ethnic cleansing became impossible to ignore in the wake of the Holocaust.
A rainbow is a meteorological phenomenon, caused by reflection and dispersion of light in water droplets resulting in a spectrum of light appearing in the sky. It takes the form of a multicoloured circular arc. Rainbows caused by sunlight always appear in the section of sky directly opposite the sun. Rainbows can be full circles. However, the observer sees only an arc formed by illuminated droplets above the ground, centered on a line from the sun to the observer's eye. In a primary rainbow, the arc shows red on the outer violet on the inner side; this rainbow is caused by light being refracted when entering a droplet of water reflected inside on the back of the droplet and refracted again when leaving it. In a double rainbow, a second arc is seen outside the primary arc, has the order of its colours reversed, with red on the inner side of the arc; this is caused by the light being reflected twice on the inside of the droplet before leaving it. A rainbow is not located at a specific distance from the observer, but comes from an optical illusion caused by any water droplets viewed from a certain angle relative to a light source.
Thus, a rainbow can not be physically approached. Indeed, it is impossible for an observer to see a rainbow from water droplets at any angle other than the customary one of 42 degrees from the direction opposite the light source. If an observer sees another observer who seems "under" or "at the end of" a rainbow, the second observer will see a different rainbow—farther off—at the same angle as seen by the first observer. Rainbows span a continuous spectrum of colours. Any distinct bands perceived are an artefact of human colour vision, no banding of any type is seen in a black-and-white photo of a rainbow, only a smooth gradation of intensity to a maximum fading towards the other side. For colours seen by the human eye, the most cited and remembered sequence is Newton's sevenfold red, yellow, blue and violet, remembered by the mnemonic Richard Of York Gave Battle In Vain. Rainbows can be caused by many forms of airborne water; these include not only rain, but mist and airborne dew. Rainbows can be observed whenever there are water drops in the air and sunlight shining from behind the observer at a low altitude angle.
Because of this, rainbows are seen in the western sky during the morning and in the eastern sky during the early evening. 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. During such good visibility conditions, the larger but fainter secondary rainbow is visible, it appears about 10° outside of the primary rainbow, with inverse order of colours. The rainbow effect is 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. A moonbow, lunar rainbow or nighttime rainbow, can be seen on moonlit nights; as human visual perception for colour is poor in low light, moonbows are 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 wide-angle lens with a focal length of 19 mm or less would be required.
Now that software for stitching several images into a panorama is available, images of the entire arc and secondary arcs can be created easily from a series of overlapping frames. From above the earth such as in an aeroplane, it is sometimes possible to see a rainbow as a full circle; this phenomenon can be confused with the glory phenomenon, but a glory is much smaller, covering only 5–20°. The sky inside a primary rainbow is brighter than the sky outside of the bow; this is because each raindrop is a sphere and it scatters light over an entire circular disc in the sky. The radius of the disc depends on the wavelength of light, with red light being scattered over a larger angle than blue light. Over most of the disc, scattered light at all wavelengths overlaps, resulting in white light which brightens the sky. At the edge, the wavelength dependence of the scattering gives rise to the rainbow. Light of primary rainbow arc is 96% polarised tangential to the arch. Light of second arc is 90% polarised.
A spectrum obtained using a glass prism and a point source is a continuum of wavelengths without bands. The number of colours that the human eye is able to distinguish in a spectrum is in the order of 100. Accordingly, the Munsell colour system distinguishes 100 hues; the apparent discreteness of main colours is an artefact of human perception and the exact number of main colours is a somewhat arbitrary choice. Newton, who admitted his eyes were not critical in distinguishing colours divided the spectrum into five main colours: red, green and violet, he included orange and indigo, giving seven main colours by analogy to the number of notes in a musical scale. Newton chose to divide the visible spectrum into seven colours out of a belief derived from the beliefs of the ancient Greek sophists, who thought there was a connection between the colours, the musical notes, the known objects in the Solar System, the days of the week. Scholars have noted that what Newton regarded at the time as "blue" would today be regarded as cyan, what Newton called "indigo" would today be considered blue.
According to Isaac Asimov, "It is customary to list indigo as a colour lying between blue and violet, but it ha