Planisphere: what is it, images, elements that compose it

What is a planisphere?

Planisphere is a representation of the Earth's surface in the form of a map. Hence, it is also known as a world map or world map.

Planisphere is a word made up of two terms of Latin origin: planus (plane) and sphaera (sphere), which refers to the plane representation of the Earth or the celestial vault, since it is made on paper or a flat surface.

Evidence suggests that the Babylonians in approximately 2500 BC were the first to map what they then believed to be Earth: a flat surface with a river that divided the territory into two parts.

Centuries later, the Greeks began to raise the possibility that the earth's surface was spherical and created planispheres in which they located what we now know as the Mediterranean Sea as the center of the world.

In the Middle Ages, world maps were key to creating navigation routes and incorporating the new territories discovered during the process of European conquest and colonization. Today, although planispheres continue to be used (especially in schools), they have been shown to be ineffective in realistically showing the proportions of different countries and continents.

Planisphere images

Planispheres or world maps have evolved over time, not only incorporating new territories, but new graphic representation models that show the Earth's surface in a more realistic way.

Mercator world map

The Mercator World Map or Mercator Projection was an essential instrument in the 16th century, but it is imprecise.

This is, perhaps, the best known and used planisphere in the world. It was created by Gerardus Mercator in 1569 and although it was very useful for sailors in the 16th, 17th and 18th centuries, it is not a reliable model, since it represents the areas near the poles with dimensions much higher than the measurements real.

On the other hand, the territories near the equator are mapped with very small dimensions that do not correspond to reality.

Fuller's World Map

Fuller's or Dymaxion's planisphere is much more accurate than Mercator's world map.

Also known as the Fuller Projection or Dymaxion, it is a planisphere created by the American inventor Buckminster Fuller and patented in 1946, which projects the Earth's surface into a polyhedron that, when deployed as a flat surface, results in a planisphere with a minor distortion to the Mercator map.

Furthermore, the Fuller Projection also does not contemplate hierarchies with respect to the north or south (as does the Mercator planisphere) since its author associated it with a cultural bias.

Narukawa World Map

In 1999, a Japanese designer and architect named Hajime Narukawa became famous in the world of cartography for creating what, until now, is the most accurate representation of the Earth's surface.

His map, called AuthaGraph, was created from the origami technique dividing a terrestrial sphere into 96 triangles with which he built a tetrahedron (four-sided polyhedron). When unfolding the figure, a rectangle is obtained that respects the original proportions of the Earth.

Despite its usefulness in understanding the distribution of the Earth's surface in a more realistic way, this planisphere is not publicly accessible, as it is part of the project catalog of the design company of Narukawa, located in Japan.

See also Map.

Elements of a planisphere

For a planisphere or world map to be functional, it requires these elements:

Title

The planisphere must explain in a title what is shown in the cartography: if it is a political-territorial division, a river map, an ecosystem map, etc.

Geographical coordinates

Geographical coordinates are references to locate a location on the Earth's surface. Is composed of:

• Latitude: measures distances based on parallels, which are imaginary lines based on the equator. Longitude: measures the distances based on the meridians, which are imaginary lines that start from the poles. Altitude: the number of meters that a territory is above sea level.

Cardinal points

In a planisphere the cardinal points are usually marked with a compass rose, which is a universal symbol to identify east, west, north and south. In this way it is easier to understand the meaning of the map and the territories shown there.

Scale

A scale is a relationship between the measurement used on a plan or map and its actual proportion. It can be of two types:

Numerical scale

It consists of two figures: the first, on the left, shows the unit of measurement used on the map. On the right, the actual measurement. So,

1: 100,000

it means that each centimeter of the map is equivalent to a hundred thousand centimeters in reality.

Graphic scale

This type of scale is widely used in school use planispheres because it is very easy to explain and understand. In this case, just take a ruler and measure the scale of the map. With the resulting measurement a rule of three is made.

For example, if the graphical scale says that 4 centimeters corresponds to one hundred thousand kilometers, a distance of 8 cm on the map corresponds to 200,000 kilometers in reality.

Legend

Every planisphere uses different symbols to represent elements: country capitals, airports, rivers, etc. Therefore, one of the essential elements is the legend that explains what each symbol means, to make the map easier to read.

See also Types of maps