Worldmap browsers.svg

A world map is a map of most or all of the surface of Earth. World maps, because of their scale, must deal with the problem of projection. Maps rendered in two dimensions by necessity distort the display of the three-dimensional surface of the earth. While this is true of any map, these distortions reach extremes in a world map. Many techniques have been developed to present world maps that address diverse technical and aesthetic goals.

Charting a world map requires global knowledge of the earth, its oceans, and its continents. From prehistory through the Middle ages, creating an accurate world map would have been impossible because less than half of Earth's coastlines and only a small fraction of its continental interiors were known to any culture. With exploration that began during the European Renaissance, knowledge of the Earth's surface accumulated rapidly, such that most of the world's coastlines had been mapped, at least roughly, by the mid-1700s and the continental interiors by the twentieth century.

Maps of the world generally focus either on political features or on physical features. Political maps emphasize territorial boundaries and human settlement. Physical maps show geographical features such as mountains, soil type, or land use. Geological maps show not only the surface, but characteristics of the underlying rock, fault lines, and subsurface structures. Choropleth maps use color hue and intensity to contrast differences between regions, such as demographic or economic statistics.

Map projections

All world maps are based on one of several map projections, or methods of representing a globe on a plane. All projections distort geographic features, distances, and directions in some way. The various map projections that have been developed provide different ways of balancing accuracy and the unavoidable distortion inherent in making world maps.

Perhaps the best-known projection is the Mercator Projection, originally designed as a nautical chart.

File:Mercator projection SW.jpg, Mercator projection
(82°S and 82°N)
File:Mollweide projection SW.jpg, Mollweide projection
Image:Cahill Butterfly Map.jpg, B.J.S. Cahill Butterfly Map, 1909, from 1919 pamphlet

File:Azimuthal equidistant projection SW.jpg, Polar azimuthal equidistant projection
Image:Blank-map-world-south-up.png, A south-up map
Image:BlankMap-World-162E.svg, Pacific-centric map
(more commonly used in East Asian and Oceania countries)
File:Gall–Peters projection SW.jpg, Gall–Peters projection, an equal-area map projection
File:Robinson projection SW.jpg, Robinson projection, formerly used by National Geographic Society

Thematic maps

A thematic map shows geographical information about one or a few focused subjects. These maps "can portray physical, social, political, cultural, economic, sociological, agricultural, or any other aspects of a city, state, region, nation, or continent".

Image:Köppen-vereinfacht.svg, Clickable world map
(with climate classification)
Image:World Map (political).svg, A simple political map of the world
Image:World map.png, Topographical map of the world
File:CO2 responsibility 1950-2000.svg, Map of anthropogenic CO₂ emission by country
File:2016 UN Human Development Report.svg, United Nations Human Development Index by country as of 2016
File:Life Expectancy 2008 Estimates CIA World Factbook.png, World map showing life expectancy
File:Population density of countries 2018 world map, people per sq km.svg, 2018 population density
(people per km²) by country
Image:Volcano Map.png, Volcano map
File:Laurasia-Gondwana.svg, World map showing the continents circa 200 million years ago ( Triassic period)
File:BlackMarble20161km.jpg, Satellite image of Earth at night

Historical maps

Early world maps cover depictions of the world from the Iron Age to the Age of Discovery and the emergence of modern geography during the early modern period. Old maps provide information about places that were known in past times, as well as the philosophical and cultural basis of the map, which were often much different from modern cartography. Maps are one means by which scientists distribute their ideas and pass them on to future generations.

File:OrteliusWorldMap1570.jpg, The world, Abraham Ortelius's '' Typus Orbis Terrarum'', first published in 1564
File:Anaximander world map-en.svg, Hypothetical reconstruction of the world map of Anaximander (610–546 BC)
File:Worldmaphedo.jpg, World map according to Posidonius (150–130 BC),
drawn in 1628
File:Radkarte MKL1888.png, Ideal reconstruction of medieval T-and-O maps (from ''Meyers Konversationslexikon'', 1895)
(Asia shown on the right)
File:TabulaRogeriana.jpg, Tabula Rogeriana world map by Muhammad al-Idrisi in 1154
note that north is to the bottom
File:Leonardo da Vinci’s Mappamundi.jpg, World map in Octant projection (1514), from Leonardo da Vinci's Windsor papers
File:Mercator 1569.png, World map by Gerardus Mercator (1569), first map in the well-known Mercator projection
File:Kunyu Wanguo Quantu (坤輿萬國全圖).jpg, alt=, ''Kunyu Wanguo Quantu'' ( Ming dynasty, 1602)
File:Claes Janszoon Visscher - Nova Totius Terrarum Orbis Geographica Ac Hydrographica Tabula Autore'.jpg, 1652 world map
by Claes Janszoon Visscher
File:World Map 1689.JPG, A historical map of the world by Gerard van Schagen, 1689

See also

* Wikipedia's clickable world map
* Global Map
* Globe
* International Map of the World
* List of map projections
* List of world map changes
* Mappa mundi
* Maps of the world
* Rhumbline network
* Theorema Egregium
* Time zone

References

Further reading

* Edson, Evelyn (2011)
''The World Map, 1300–1492: The Persistence of Tradition and Transformation''
JHU Press.
* Harvey, P. D. A. (2006)
''The Hereford world map: medieval world maps and their context''
British Library.

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