1.
Prime meridian
–
A prime meridian is a meridian in a geographical coordinate system at which longitude is defined to be 0°. Together, a meridian and its antimeridian form a great circle. This great circle divides the sphere, e. g. the Earth, if one uses directions of East and West from a defined prime meridian, then they can be called Eastern Hemisphere and Western Hemisphere. The most widely used modern meridian is the IERS Reference Meridian and it is derived but deviates slightly from the Greenwich Meridian, which was selected as an international standard in 1884. The notion of longitude was developed by the Greek Eratosthenes in Alexandria, and Hipparchus in Rhodes, but it was Ptolemy who first used a consistent meridian for a world map in his Geographia. The main point is to be comfortably west of the tip of Africa as negative numbers were not yet in use. His prime meridian corresponds to 18°40 west of Winchester today, at that time the chief method of determining longitude was by using the reported times of lunar eclipses in different countries. Ptolemys Geographia was first printed with maps at Bologna in 1477, but there was still a hope that a natural basis for a prime meridian existed. The Tordesillas line was settled at 370 leagues west of Cape Verde. This is shown in Diogo Ribeiros 1529 map, in 1541, Mercator produced his famous 41 cm terrestrial globe and drew his prime meridian precisely through Fuertaventura in the Canaries. His later maps used the Azores, following the magnetic hypothesis, but by the time that Ortelius produced the first modern atlas in 1570, other islands such as Cape Verde were coming into use. In his atlas longitudes were counted from 0° to 360°, not 180°W to 180°E as is usual today and this practice was followed by navigators well into the 18th century. In 1634, Cardinal Richelieu used the westernmost island of the Canaries, Ferro, 19°55 west of Paris, the geographer Delisle decided to round this off to 20°, so that it simply became the meridian of Paris disguised. In the early 18th century the battle was on to improve the determination of longitude at sea, between 1765 and 1811, Nevil Maskelyne published 49 issues of the Nautical Almanac based on the meridian of the Royal Observatory, Greenwich. Maskelynes tables not only made the lunar method practicable, they made the Greenwich meridian the universal reference point. In 1884, at the International Meridian Conference in Washington, D. C.22 countries voted to adopt the Greenwich meridian as the meridian of the world. The French argued for a line, mentioning the Azores and the Bering Strait. In October 1884 the Greenwich Meridian was selected by delegates to the International Meridian Conference held in Washington, united States to be the common zero of longitude and standard of time reckoning throughout the world

2.
Metre
–
The metre or meter, is the base unit of length in the International System of Units. The metre is defined as the length of the path travelled by light in a vacuum in 1/299792458 seconds, the metre was originally defined in 1793 as one ten-millionth of the distance from the equator to the North Pole. In 1799, it was redefined in terms of a metre bar. In 1960, the metre was redefined in terms of a number of wavelengths of a certain emission line of krypton-86. In 1983, the current definition was adopted, the imperial inch is defined as 0.0254 metres. One metre is about 3 3⁄8 inches longer than a yard, Metre is the standard spelling of the metric unit for length in nearly all English-speaking nations except the United States and the Philippines, which use meter. Measuring devices are spelled -meter in all variants of English, the suffix -meter has the same Greek origin as the unit of length. This range of uses is found in Latin, French, English. Thus calls for measurement and moderation. In 1668 the English cleric and philosopher John Wilkins proposed in an essay a decimal-based unit of length, as a result of the French Revolution, the French Academy of Sciences charged a commission with determining a single scale for all measures. In 1668, Wilkins proposed using Christopher Wrens suggestion of defining the metre using a pendulum with a length which produced a half-period of one second, christiaan Huygens had observed that length to be 38 Rijnland inches or 39.26 English inches. This is the equivalent of what is now known to be 997 mm, no official action was taken regarding this suggestion. In the 18th century, there were two approaches to the definition of the unit of length. One favoured Wilkins approach, to define the metre in terms of the length of a pendulum which produced a half-period of one second. The other approach was to define the metre as one ten-millionth of the length of a quadrant along the Earths meridian, that is, the distance from the Equator to the North Pole. This means that the quadrant would have defined as exactly 10000000 metres at that time. To establish a universally accepted foundation for the definition of the metre, more measurements of this meridian were needed. This portion of the meridian, assumed to be the length as the Paris meridian, was to serve as the basis for the length of the half meridian connecting the North Pole with the Equator

3.
Mattel
–
Mattel, Inc. is an American multinational toy manufacturing company founded in 1945 with headquarters in El Segundo, California. In 2014, it ranked #403 on the Fortune 500 list, in the early 1980s, Mattel produced video game systems, under both its own brands and under license from Nintendo. The company has presence in 40 countries and territories and sells products in more than 150 nations, the company operates through three business segments, North America, international, and American Girl. It is the worlds largest toy maker in terms of revenue, on January 17,2017 Mattel named Google executive Margaret Margo Georgiadis as its next CEO. The companys name is a portmanteau of those of Harold Matt Matson and Elliot Handler, Mattel Creations was founded in 1945 by Harold Matt Matson and Elliot Handler. The company initially sold picture frames, then dollhouse furniture, Matson soon sold his share to Handler due to poor health, and Handlers wife Ruth took over Matsons role. In 1947, the company had its first hit toy, a ukulele called Uke-A-Doodle, the company was incorporated the next year in California. Mattel became the first year-round sponsor of the Mickey Mouse Club TV series in 1955, the Barbie doll was introduced in 1959, becoming the companys best selling toy ever. In 1960, Mattel introduced Chatty Cathy, a doll that revolutionized the toy industry. The company went public in 1960 and was first listed on the New York Stock Exchange in 1963, Mattel also acquired a number of companies during the 1960s. In 1965, the built on its success with the Chatty Cathy doll to introduce the See n Say talking toy which spawned a line of products. Hot Wheels was first released to the market in 1968, in May 1970, Mattel formed a joint venture film production company, Radnitz/Mattel Productions, with producer Robert B. The Ringling Bros. and Barnum & Bailey Circus was purchased by the Mattel company in 1971 for $40 million from the Feld family, who were retained as management. Mattel had placed the circus corporation up for sale despite its profit contributions to Mattel by December 1973 as Mattel showed a $29.9 million loss in 1972. An investigation in 1974 concluded false and misleading financial reports had been issued, arthur S. Spear, a Mattel vice president was selected to run the company in 1975 and led it back to profitability in 1977. Ruth Handler sold back her stock in 1980, the Mattel Electronics line was started in 1977 with an all-electronic handheld game. The success of the led to the expansion of the line with game console then the line becoming its own corporation in 1982. Mattel Electronics forced Mattel to take a $394 million loss in 1983, in 1979, through Feld Productions, Mattel purchased the Holiday on Ice and Ice Follies for $12 million

4.
Manifold
–
In mathematics, a manifold is a topological space that locally resembles Euclidean space near each point. More precisely, each point of a manifold has a neighbourhood that is homeomorphic to the Euclidean space of dimension n. One-dimensional manifolds include lines and circles, but not figure eights, two-dimensional manifolds are also called surfaces. Although a manifold locally resembles Euclidean space, globally it may not, for example, the surface of the sphere is not a Euclidean space, but in a region it can be charted by means of map projections of the region into the Euclidean plane. When a region appears in two neighbouring charts, the two representations do not coincide exactly and a transformation is needed to pass from one to the other, Manifolds naturally arise as solution sets of systems of equations and as graphs of functions. One important class of manifolds is the class of differentiable manifolds and this differentiable structure allows calculus to be done on manifolds. A Riemannian metric on a manifold allows distances and angles to be measured, symplectic manifolds serve as the phase spaces in the Hamiltonian formalism of classical mechanics, while four-dimensional Lorentzian manifolds model spacetime in general relativity. After a line, the circle is the simplest example of a topological manifold, Topology ignores bending, so a small piece of a circle is treated exactly the same as a small piece of a line. Consider, for instance, the top part of the circle, x2 + y2 =1. Any point of this arc can be described by its x-coordinate. So, projection onto the first coordinate is a continuous, and invertible, mapping from the arc to the open interval. Such functions along with the regions they map are called charts. Similarly, there are charts for the bottom, left, and right parts of the circle, together, these parts cover the whole circle and the four charts form an atlas for the circle. The top and right charts, χtop and χright respectively, overlap in their domain, Each map this part into the interval, though differently. Let a be any number in, then, T = χ r i g h t = χ r i g h t =1 − a 2 Such a function is called a transition map. The top, bottom, left, and right charts show that the circle is a manifold, charts need not be geometric projections, and the number of charts is a matter of some choice. These two charts provide a second atlas for the circle, with t =1 s Each chart omits a single point, either for s or for t and it can be proved that it is not possible to cover the full circle with a single chart. Viewed using calculus, the transition function T is simply a function between open intervals, which gives a meaning to the statement that T is differentiable

5.
Cubic metre
–
The cubic metre or cubic meter is the SI derived unit of volume. It is the volume of a cube with one metre in length. An alternative name, which allowed a different usage with metric prefixes, was the stère, another alternative name, no longer widely used, was the kilolitre. A cubic metre of water at the temperature of maximum density and standard atmospheric pressure has a mass of 1000 kg. At 0 °C, the point of water, a cubic metre of water has slightly less mass,999.972 kilograms. It is sometimes abbreviated to cu m, m3, M3, m^3, m**3, CBM, abbreviated CBM and cbm in the freight business and MTQ in international trade. See Orders of magnitude for a comparison with other volumes

6.
Constant function
–
In mathematics, a constant function is a function whose value is the same for every input value. For example, the function y =4 is a constant function because the value of y is 4 regardless of the value x. As a real-valued function of an argument, a constant function has the general form y = c or just y = c. Example, The function y =2 or just y =2 is the constant function where the output value is c =2. The domain of function is the set of all real numbers ℝ. The codomain of this function is just, the independent variable x does not appear on the right side of the function expression and so its value is vacuously substituted. No matter what value of x is input, the output is 2, real-world example, A store where every item is sold for the price of 1 euro. The graph of the constant function y = c is a line in the plane that passes through the point. In the context of a polynomial in one variable x, the constant function is a polynomial of degree 0. This function has no point with the x-axis, that is. On the other hand, the polynomial f =0 is the zero function. It is the constant function and every x is a root and its graph is the x-axis in the plane. A constant function is a function, i. e. the graph of a constant function is symmetric with respect to the y-axis. In the context where it is defined, the derivative of a function is a measure of the rate of change of values with respect to change in input values. Because a constant function does not change, its derivative is 0 and this is often written, ′ =0. Namely, if y=0 for all numbers x, then y is a constant function. Example, Given the constant function y = −2, the derivative of y is the identically zero function y ′ = ′ =0. Every constant function whose domain and codomain are the same is idempotent, every constant function between topological spaces is continuous

7.
Zero morphism
–
In category theory, a branch of mathematics, a zero morphism is a special kind of morphism exhibiting properties like the morphisms to and from a zero object. Suppose C is a category, and f, X → Y is a morphism in C, the morphism f is called a constant morphism if for any object W in C and any g, h, W → X, fg = fh. Dually, f is called a coconstant morphism if for any object Z in C and any g, h, Y → Z, a zero morphism is one that is both a constant morphism and a coconstant morphism. If C is a category with zero morphisms, then the collection of 0XY is unique and this way of defining a zero morphism and the phrase a category with zero morphisms separately is unfortunate, but if each homset has a ″zero morphism, then the category has zero morphisms. In the category of groups, a morphism is a homomorphism f, G → H that maps all of G to the identity element of H. The null object in the category of groups is the trivial group 1 =, every zero morphism can be factored through 1, i. e. f, G →1 → H. More generally, suppose C is any category with a zero object 0. Then for all objects X and Y there is a sequence of morphisms 0XY. If C is a category, then every morphism set Mor is an abelian group. These zero elements form a family of zero morphisms for C making it into a category with zero morphisms. The category Set does not have an object, but it does have an initial object. The only right zero morphisms in Set are the functions ∅ → X for a set X, if C has a zero object 0, given two objects X and Y in C, there are canonical morphisms f, X →0 and g,0 → Y. Then, gf is a morphism in MorC. Thus, every category with an object is a category with zero morphisms given by the composition 0XY. If a category has zero morphisms, then one can define the notions of kernel and cokernel for any morphism in that category