Map

A map is a graphic depiction of the interrelationships between things within a specific space. These relationships are often spatial, meaning they show where things are located in relation to one another.

While we often think of maps as tools for geography, they can represent any space. This includes real locations like a city or fictional places from a story. Maps can also represent different dimensions. They might show the two-dimensional surface of the Earth or the three-dimensional interior of the planet.

Some maps are even displayed on transitory media, such as computer screens, and can change interactively.

To create these representations, people practice a field called cartography. A person who specializes in this craft is known as a cartographer.

The process involves many complex decisions. Cartographers must use projections to translate the curved surface of the Earth onto a flat plane. Because a sphere cannot be flattened without stretching or tearing, every projection causes some level of distortion. This means that shapes, areas, or distances may not be perfectly accurate. Cartographers must decide how to apportion this distortion to best serve their specific purpose.

Maps are categorized by their function and the information they prioritize. Navigational maps are a broad category that includes many different types. Road maps are among the most common, but others include nautical charts for sailors and aeronautical charts for pilots. There are also railroad network maps and maps for hiking or bicycling. Some maps are highly specialized, such as topographic maps that use contour lines to show elevation.

Other maps, called cartograms, deliberately distort scale to represent data like population density rather than physical land area.

Humans have been mapping their surroundings since ancient times. The earliest surviving maps are quite primitive, such as cave paintings or etchings on stone.

One of the oldest known examples is an engraving on a mammoth tusk dated to 25,000 BC. As civilizations grew, so did the complexity of their maps. Ancient Babylon, Greece, Rome, China, and India all produced extensive geographic works.

In the 16th century, the Flemish geographer Gerardus Mercator developed a famous projection for two-dimensional world maps. He was also the first to popularize the atlas, which is a collection of many maps.

Orientation refers to the direction assigned to the top of a map. While the modern convention is to place north at the top, this is a relatively recent standard. Historically, orientation was often determined by cultural or religious significance. For example, many medieval European T-O maps placed east at the top to face the Garden of Eden.

Early Islamic maps often placed south at the top to orient toward Mecca. Some maps are oriented toward specific features, such as Portolan charts which follow coastlines. Others, like polar maps, are centered on the North or South Pole.

Scale is the ratio used to relate distances on a map to distances in the real world. A scale of 1:10,000 means that one unit on the map equals 10,000 units on the ground. Because of the Earth's curvature, it is impossible to maintain a constant scale across a large map. Therefore, scale is often measured as a "point scale" for a specific location. To make maps readable, cartographers use a process called generalization. This involves selecting, simplifying, and classifying information so that a map is not too crowded with unnecessary detail. This practice is sometimes called decluttering.

Maps use various symbols and design elements to communicate information clearly. A map legend, or key, explains what different colors, lines, or shapes represent.

Some cartographers use insets, which are smaller maps placed within the main map area. These might show a larger view of the globe or a zoomed-in view of a specific city. Beyond simple data, scholars of critical geography argue that maps can carry rhetorical biases. They suggest that how a map is drawn can change a person's perspective of the world. By choosing what to show and what to hide, maps can influence how we perceive global power and connections.