What is a Globe? – An insight into the Model of Earth

What is a Globe? – An insight into the Model of Earth

In simple words. We can say that a globe is a small replica of earth. But a globe does not always represent the earth. In general terms. Globe is a spherical model of a celestial body. The globe representing the Earth is called the terrestrial globe and the globe representing other celestial bodies is called a celestial globe.

Difference between Globe and Map:-

  • Globe serves the same purpose as that of maps. But globes are a three-dimensional view of the earth whereas a map is a two-dimensional view of the earth.
  • Globe represents “scaled-down” model of the entire earth whereas a map can be of the entire world or could also be of a city or a small area.
  • Since a map is a two-dimensional projection of earth it starts to project distortion as we increase the area of the map.

For example, if you observe the map of a city, you might not see any difference in the city locations compared to the map. Since the earth is very large (The Polar radius of the earth is 6357 km). We can consider a city to be a flat surface. And hence, plotting a map can be done with precision.

But when we talk about the world map, then plotting the spherical earth on a two- dimensional piece of paper has its drawbacks. In such a case, we need to distort the facts. For example, if you look at the world map, you will observe that Little Diomede Island (Alaska) and Big Diomede Island (Russia) are farthest from each other.

But in reality, the distance between the two islands is less than 4 km. In the case of Globe, since only the size of the globe changes and not its appearance, compared to the earth, we do not find such distortions in the globe.

What do Globes have?

  • Globes are a small replica of earth. They contain all the features that are needed to study the earth.
  • Globes have the axis same as the earth which does not pass perpendicular to the horizontal surface (The plane in which the earth revolves around the Sun). Instead, it passes through the center of the globe, making an angle of 23.5 degrees to the vertical (The line perpendicular to the plane in which the earth revolves around the Sun).
  • Globes also mention parallels and meridians.
  • Political globes show the countries and their borders.
  • Terrestrial globes show the landmass and water bodies. They also have raised relief to show mountains and large landforms.

There are also many ways to represent the globe depending on the necessity of the study.

Origin of Globe:-

Globes have a long history. Since this is a blog about geography. We will discuss only a few facts.

  • The word “globe” is taken from the Latin word “Globus” which means “Sphere”.
  • Globes are said to be in use since 150 BC. Most of them are destroyed or ruined.
  • The oldest available terrestrial globe is Erdapfel. It is said to be fashioned by Martin Behaim in 1492.
  •  The oldest available celestial globe was carved on the top of the Farnese Atlas in the second century Roman Empire.

Scaling of a Globe

As mentioned above, the earth has a radius of around 6357 km. We need to scale it down to a large extent to construct a globe. The scaling of the earth for a globe depends on the size of the globe.

  • Mostly, standard globes have a radius of around 16 cm. To make the entire earth fit in such a small model we need to reduce the size of the earth to a scale of nearly 1:40 million units.
  • In the case of topography, the scaling is not as precise. If we scale the mountain heights to the ratio of 1:40 million – as it is done to fit the size of the earth on the globe – we will not be able to observe the mountains on the globe due to their smaller relief. So for the sake of convenience, the topography of the globe is kept visible to us.

Types of globe:-

Broadly, there are three most common types of globes, for example, the physical globe, the political, and the celestial globe. There are also many ways to represent the globe depending on the necessity of the study.

Physical Globes:-

Physical Globes come in a way that displays the geographical features of the Earth, with a focus on the physical features of the world. For specimens, landforms, grains, animals, mountain ranges, hills, oceans, and continents, etc. Each globe shows its cartography based on climate, vegetation, or geographic features.

Political Globes:-

Political Globes depict the geographical features of the world as well as the wide political boundaries of countries on Earth. This type of globe provides a detailed view of the world’s political composition in a precise way. Political globes illuminate the boundaries of country and state with the necessary information on earth. These have names of major city locations as well.

Celestial Globes:-

Celestial Globes as a representation of stars and constellations show the apparent position of stars in the sky. This type of globe is used for scientific instruments, decorative showpieces, or astronomical calculations. They are very useful for amateur astronomers and often show the path of the Sun, Moon, and other planets as well as major constellations and important astronomical events.

Virtual Globes:-

Virtual Globes are virtual rather than real. Virtual globes offer many advantages over traditional globes with the ability to integrate large amounts of information. Some globes use global imaging system (GIS) databases and detailed country data, regional data, and even real-time weather tracking.

You can also see some other types of globes such as Spinning, Historical, Inflatable, Illuminated, Educational, Magnetic, Folding, Puzzle, Handmade, Art, and Wooden Globe.

Is Globe still relevant?

If you observe the map of a city, you might not see any difference in the city locations compared to the map. We can consider a city to be a flat surface and hence, plotting a map can be done with precision. But when we talk about the world map, then plotting the spherical earth on a two dimensional piece of paper has its drawbacks since the earth is very large (The Polar radius of the earth is 6357 km). In such a case, we need to distort the facts. For example, if you look at the world map, you will observe that Little Diomede Island (Alaska) and Big Diomede Island (Russia) are farthest from each other. But in reality, the distance between the two islands is less than 4 km.

How did it change over the period of time?

In the case of Globe, since only the size of the globe changes and not its appearance, compared to the earth, we do not find such distortions in the globe.

Uses of Globe?

Globe can be used to plot the coordinates of any location on earth. The intersection of parallels and meridians are written in coordinates which give us the precise location of any point on the earth. For example, 27.17510 N, 78.04210 E are the coordinates of the Taj Mahal (India). These are called geographical coordinates.

  • Globe can be used to locate sea route, air route, etc.
  • Globe can be used to locate continents, countries, etc. with precision.
  • Globes can be used to observe the landmass and water bodies as a replica of earth.
  • Globes give the precise replica of Earth and hence is the best way to study the entire earth at the same time. It helps us visualize the Earth accurately.