Globe

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Topography globe featuring physical features of the Earth The Great Globe, Guyot Hall, Princeton University.jpg
Topography globe featuring physical features of the Earth

A globe is a spherical model of Earth, of some other celestial body, or of the celestial sphere. Globes serve purposes similar to maps, but, unlike maps, they do not distort the surface that they portray except to scale it down. A model globe of Earth is called a terrestrial globe. A model globe of the celestial sphere is called a celestial globe .

Contents

A globe shows details of its subject. A terrestrial globe shows landmasses and water bodies. It might show nations and major cities and the network of latitude and longitude lines. Some have raised relief to show mountains and other large landforms. A celestial globe shows notable stars, and may also show positions of other prominent astronomical objects. Typically, it will also divide the celestial sphere into constellations.

The word globe comes from the Latin word globus, meaning "sphere". Globes have a long history. The first known mention of a globe is from Strabo, describing the Globe of Crates from about 150 BC. The oldest surviving terrestrial globe is the Erdapfel, made by Martin Behaim in 1492. The oldest surviving celestial globe sits atop the Farnese Atlas, carved in the 2nd century Roman Empire.

Terrestrial and planetary

Students and teacher looking at a terrestrial globe of the earth. Teacher points out a country on a map.jpg
Students and teacher looking at a terrestrial globe of the earth.

Flat maps are created using a map projection that inevitably introduces an increasing amount of distortion the larger the area that the map shows. A globe is the only representation of the Earth that does not distort either the shape or the size of large features – land masses, bodies of water, etc.

The Earth's circumference is quite close to 40 million metres. [1] [2] Many globes are made with a circumference of one metre, so they are models of the Earth at a scale of 1:40 million. In imperial units, many globes are made with a diameter of one  foot [ citation needed ] (about 30 cm), yielding a circumference of 3.14 feet (about 96 cm) and a scale of 1:42 million. Globes are also made in many other sizes.

Some globes have surface texture showing topography or bathymetry. In these, elevations and depressions are purposely exaggerated, as they otherwise would be hardly visible. For example, one manufacturer produces a three dimensional raised relief globe with a 64 cm (25 in) diameter (equivalent to a 200 cm circumference, or approximately a scale of 1:20 million) showing the highest mountains as over 2.5 cm (1 in) tall, which is about 57 times higher than the correct scale of Mount Everest. [3] [4]

Most modern globes are also imprinted with parallels and meridians, so that one can tell the approximate coordinates of a specific location. Globes may also show the boundaries of countries and their names.

Many terrestrial globes have one celestial feature marked on them: a diagram called the analemma, which shows the apparent motion of the Sun in the sky during a year.

Globes generally show north at the top, but many globes allow the axis to be swiveled so that southern portions can be viewed conveniently. This capability also permits exploring the Earth from different orientations to help counter the north-up bias caused by conventional map presentation.

Celestial

Trainer using a celestial sphere to show student a point used to see the apparent path the sun takes through the stars. 533d Training Squadron - Training.jpg
Trainer using a celestial sphere to show student a point used to see the apparent path the sun takes through the stars.

Celestial globes show the apparent positions of the stars in the sky. They omit the Sun, Moon and planets because the positions of these bodies vary relative to those of the stars, but the ecliptic, along which the Sun moves, is indicated. In their most basic form celestial globes represent the stars as if the viewer were looking down upon the sky as a globe that surrounds the earth.

History

The "Erdapfel" of Martin Beheim is the oldest surviving terrestrial globe, made between 1491 and 1493. Behaims Erdapfel.jpg
The "Erdapfel" of Martin Beheim is the oldest surviving terrestrial globe, made between 1491 and 1493.

The sphericity of the Earth was established by Greek astronomy in the 3rd century BC, and the earliest terrestrial globe appeared from that period. The earliest known example is the one constructed by Crates of Mallus in Cilicia (now Çukurova in modern-day Turkey), in the mid-2nd century BC.

No terrestrial globes from Antiquity have survived. An example of a surviving celestial globe is part of a Hellenistic sculpture, called the Farnese Atlas, surviving in a 2nd-century AD Roman copy in the Naples Archaeological Museum, Italy. [5]

Early terrestrial globes depicting the entirety of the Old World were constructed in the Islamic world. [6] [7] During the Middle Ages in Christian Europe, while there are writings alluding to the idea that the earth was spherical, no known attempts at making a globe took place before the fifteenth century. [8] The earliest extant terrestrial globe was made in 1492 by Martin Behaim (1459–1537) with help from the painter Georg Glockendon. [5] Behaim was a German mapmaker, navigator, and merchant. Working in Nuremberg, Germany, he called his globe the "Nürnberg Terrestrial Globe." It is now known as the Erdapfel. Before constructing the globe, Behaim had traveled extensively. He sojourned in Lisbon from 1480, developing commercial interests and mingling with explorers and scientists. He began to construct his globe after his return to Nürnberg in 1490.

China made many mapping advancements such as sophisticated land surveys and the invention of the magnetic compass. However, no record of terrestrial globes in China exists until a globe was introduced by the Persian astronomer, Jamal ad-Din, in 1276. [9]

Another early globe, the Hunt–Lenox Globe, ca. 1510, is thought to be the source of the phrase Hic Sunt Dracones, or "Here be dragons". A similar grapefruit-sized globe made from two halves of an ostrich egg was found in 2012 and is believed to date from 1504. It may be the oldest globe to show the New World. Stefaan Missine, who analyzed the globe for the Washington Map Society journal Portolan, said it was "part of an important European collection for decades." [10] After a year of research in which he consulted many experts, Missine concluded the Hunt–Lenox Globe was a copper cast of the egg globe. [10]

A facsimile globe showing America was made by Martin Waldseemüller in 1507. Another "remarkably modern-looking" terrestrial globe of the Earth was constructed by Taqi al-Din at the Constantinople observatory of Taqi ad-Din during the 1570s. [11]

The world's first seamless celestial globe was built by Mughal scientists under the patronage of Jahangir. [12]

Globus IMP, electro-mechanical devices including five-inch globes have been used in Soviet and Russian spacecraft from 1961 to 2002 as navigation instruments. In 2001, the TMA version of the Soyuz spacecraft replaced this instrument with a digital map. [13]

Manufacture

A short, 1955 Dutch film showing the traditional manufacture of globes using paper gores

Traditionally, globes were manufactured by gluing a printed paper map onto a sphere, often made from wood. [14]

The most common type has long, thin gores (strips) of paper that narrow to a point at the poles, [15] small disks cover over the inevitable irregularities at these points. The more gores there are, the less stretching and crumpling is required to make the paper map fit the sphere. This method of globe making was illustrated in 1802 in an engraving in The English Encyclopedia by George Kearsley.

Modern globes are often made from thermoplastic. Flat, plastic disks are printed with a distorted map of one of the Earth's hemispheres. This is placed in a machine which molds the disk into a hemispherical shape. The hemisphere is united with its opposite counterpart to form a complete globe.

Usually a globe is mounted so that its rotation axis is 23.5° (0.41 rad) from vertical, which is the angle the Earth's rotation axis deviates from perpendicular to the plane of its orbit. This mounting makes it easy to visualize how seasons change.

In the 1800s small pocket globes (less than 3 inches) were status symbols for gentlemen and educational toys for rich children. [16]

Examples

Eartha, the largest rotating globe Eartha, Delorme, Yarmouth ME.jpg
Eartha, the largest rotating globe

Sorted in decreasing sizes:

See also

Related Research Articles

<span class="mw-page-title-main">Celestial globe</span> Type of star chart where the map is arranged on a globe

Celestial globes show the apparent positions of the stars in the sky. They omit the Sun, Moon, and planets because the positions of these bodies vary relative to those of the stars, but the ecliptic, along which the Sun moves, is indicated.

<span class="mw-page-title-main">Celestial sphere</span> Imaginary sphere of arbitrarily large radius, concentric with the observer

In astronomy and navigation, the celestial sphere is an abstract sphere that has an arbitrarily large radius and is concentric to Earth. All objects in the sky can be conceived as being projected upon the inner surface of the celestial sphere, which may be centered on Earth or the observer. If centered on the observer, half of the sphere would resemble a hemispherical screen over the observing location.

<span class="mw-page-title-main">Map projection</span> Systematic representation of the surface of a sphere or ellipsoid onto a plane

In cartography, a map projection is any of a broad set of transformations employed to represent the curved two-dimensional surface of a globe on a plane. In a map projection, coordinates, often expressed as latitude and longitude, of locations from the surface of the globe are transformed to coordinates on a plane. Projection is a necessary step in creating a two-dimensional map and is one of the essential elements of cartography.

<span class="mw-page-title-main">Analemma</span> Diagrammatic representation of Suns position over a period of time

In astronomy, an analemma is a diagram showing the position of the Sun in the sky as seen from a fixed location on Earth at the same mean solar time, as that position varies over the course of a year. The diagram will resemble a figure eight. Globes of Earth often display an analemma as a two-dimensional figure of equation of time vs. declination of the Sun.

<span class="mw-page-title-main">History of geodesy</span>

The history of geodesy (/dʒiːˈɒdɪsi/) began during antiquity and ultimately blossomed during the Age of Enlightenment.

<span class="mw-page-title-main">Martin Behaim</span> German cartographer

Martin Behaim, also known as Martin von Behaim and by various forms of Martin of Bohemia, was a German textile merchant and cartographer. He is served John II of Portugal as an adviser in matters of navigation and participated in a voyage to West Africa. He is now best known for his Erdapfel, the world's oldest known globe, which he produced for the Imperial City of Nuremberg in 1492.

<span class="mw-page-title-main">Voskhod (spacecraft)</span>

The Voskhod was a spacecraft built by the Soviet Union's space program for human spaceflight as part of the Voskhod programme. It was a development of and a follow-on to the Vostok spacecraft. Voskhod 1 was used for a three-man flight whereas Voskhod 2 had a crew of two. They consisted of a spherical descent module, which housed the cosmonauts, and instruments, and a conical equipment module, which contained propellant and the engine system. Voskhod was superseded by the Soyuz spacecraft in 1967.

<span class="mw-page-title-main">Vincenzo Coronelli</span>

Vincenzo Maria Coronelli was an Italian Franciscan friar, cosmographer, cartographer, publisher, and encyclopedist known in particular for his atlases and globes. He spent most of his life in Venice.

<span class="mw-page-title-main">Orthographic map projection</span> Azimuthal perspective map projection

Orthographic projection in cartography has been used since antiquity. Like the stereographic projection and gnomonic projection, orthographic projection is a perspective projection in which the sphere is projected onto a tangent plane or secant plane. The point of perspective for the orthographic projection is at infinite distance. It depicts a hemisphere of the globe as it appears from outer space, where the horizon is a great circle. The shapes and areas are distorted, particularly near the edges.

<span class="mw-page-title-main">Farnese Atlas</span> Ancient Roman statue of Greek Deity

The Farnese Atlas is a 2nd-century AD Roman marble sculpture of Atlas holding up a celestial globe. Probably a copy of an earlier work of the Hellenistic period, it is the oldest extant statue of Atlas, a Titan of Greek mythology who is represented in earlier Greek vase painting, and the oldest known representation of the celestial sphere and the classical constellations. The sculpture is at the National Archaeological Museum of Naples, in Italy.

The earliest known world maps date to classical antiquity, the oldest examples of the 6th to 5th centuries BCE still based on the flat Earth paradigm. World maps assuming a spherical Earth first appear in the Hellenistic period. The developments of Greek geography during this time, notably by Eratosthenes and Posidonius culminated in the Roman era, with Ptolemy's world map, which would remain authoritative throughout the Middle Ages. Since Ptolemy, knowledge of the approximate size of the Earth allowed cartographers to estimate the extent of their geographical knowledge, and to indicate parts of the planet known to exist but not yet explored as terra incognita.

<span class="mw-page-title-main">Erdapfel</span> Oldest surviving terrestrial globe (1490~1492)

The Erdapfel is a terrestrial globe 51 cm (20 in) in diameter, produced by Martin Behaim from 1490 to 1492. The Erdapfel is the oldest surviving terrestrial globe. It is constructed of a laminated linen ball in two halves, reinforced with wood and overlaid with a map painted on gores by Georg Glockendon. The map was drawn on paper, which was pasted on a layer of parchment around the globe.

<span class="mw-page-title-main">Hunt–Lenox Globe</span> 1504 terrestrial globe

The Hunt–Lenox Globe or Lenox Globe, dating from about 1510, is the second- or third-oldest known terrestrial globe, after the Erdapfel of Martin Behaim (1492) and the Ostrich Egg Globe. The Hunt-Lenox Globe is housed by the Rare Book Division of the New York Public Library. It is notable as one of only two known instances of a historical map actually using the phrase HC SVNT DRACONES.

<span class="mw-page-title-main">Honcheonsigye</span> South Korean astronomical clock

The Honcheonsigye is an astronomical clock made by Song Yi-Yeong (송이영), a professor of Gwansanggam in 1669. It was designated as South Korean national treasure number 230 in August 9, 1985.

<span class="mw-page-title-main">Globus Jagellonicus</span> French globe

The Jagiellonian globe, also known as the Globus Jagellonicus, is a mechanical armillary sphere made in France before 1510. It is an astronomical instrument and a universal clock tracking both local solar time and sidereal time. The central brass sphere is engraved with a map of Earth and contains the clock mechanism. It is the oldest extant globe to use the name America.

<span class="mw-page-title-main">Globe of Gottorf</span> Planetarium built in the 1650s

The Globe of Gottorf is a 17th-century, large, walk-in globe of the Earth and the celestial sphere. It measures 3.1 meters in diameter. Conceived and constructed at Gottorf Castle near Schleswig, it was later transferred to the Kunstkamera museum in Saint Petersburg in Russia. Following a fire in 1747 most of the globe had to be reconstructed. A modern replica was constructed in 2005 at the original location near Schleswig.

Planetary cartography, or cartography of extraterrestrial objects (CEO), is the cartography of solid objects outside of the Earth. Planetary maps can show any spatially mapped characteristic for extraterrestrial surfaces. Some well-known examples of these maps have been produced by the USGS, such as the latest Geologic Map of Mars, but many others are published in specialized scientific journals.

<span class="mw-page-title-main">Globe Museum</span>

The Globe Museum is a museum in the Palais Mollard, Vienna, Austria, part of the Austrian National Library. It was opened in 1956, and is the only public museum in the world devoted to globes, being three-dimensional models of Earth or other celestial bodies, or spherical representations of the celestial sphere.

<span class="mw-page-title-main">Voskhod Spacecraft "Globus" IMP navigation instrument</span>

Globus IMP instruments were spacecraft navigation instruments used in Soviet and Russian crewed spacecraft. The IMP acronym stems from the Russian expression Indicator of position in flight, but the instrument is informally referred to as the Globus. It displays the nadir of the spacecraft on a rotating terrestrial globe. It functions as an onboard, autonomous indicator of the spacecraft's location relative to Earth coordinates. An electro-mechanical device in the tradition of complex post-World War II clocks such as master clocks, the Globus IMP instrument incorporates hundreds of mechanical components common to horology. This instrument is a mechanical computer for navigation akin to the Norden bombsight. It mechanically computes complex functions and displays its output through mechanical displacements of the globe and other indicator components. It also modulates electric signals from other instruments.

A variety of symbols or iconographic conventions are used to represent Earth, whether in the sense of planet Earth, or the inhabited world, or as a classical element. A circle representing the round world, with the rivers of Garden of Eden separating the four corners of the world, or rotated 45° to suggest the four continents, remains a common pictographic convention to express the notion of "worldwide". The current astronomical symbol for the planet is a circle with an intersecting cross, . Although the International Astronomical Union (IAU) now discourages the use of planetary symbols, this is an exception, being used in abbreviations such as M🜨 for Earth mass.

References

  1. ↑ The Earth’s circumference is 40 million m because the metre was originally defined to be one 10-millionth of the distance between the poles and the equator.
  2. ↑ Arc length#Arcs of great circles on the Earth
  3. ↑ MapScaping på Twitter: "3D topographic globe at Stanford's Branner Library."
  4. ↑ The GEO One 25" Extreme Raised Relief Classroom Floor Globe
  5. 1 2 Microsoft Encarta Encyclopedia 2003.
  6. ↑ Medieval Islamic Civilization By Josef W. Meri, Jere L Bacharach, pages 138–139
  7. ↑ Covington, Richard (2007), "The Third Dimension", Saudi Aramco World, May–June 2007: 17–21, archived from the original on 2008-05-12, retrieved 2008-07-06
  8. ↑ David Woodward (1989), "The Image of the Spherical Earth", Perspecta , 25, MIT Press: 3–15 [9], doi:10.2307/1567135, JSTOR   1567135
  9. ↑ David Woodward (1989), "The Image of the Spherical Earth", Perspecta , 25, MIT Press: 3–15 [9], doi:10.2307/1567135, JSTOR   1567135
  10. 1 2 Kim, Meeri (2018-01-27). "Oldest globe to depict the New World may have been discovered". Washington Post .
  11. ↑ Soucek, Svat (1994), "Piri Reis and Ottoman Discovery of the Great Discoveries", Studia Islamica , 79 (79), Maisonneuve & Larose: 121–142 [123 & 134–6], doi:10.2307/1595839, JSTOR   1595839
  12. ↑ Society, National Geographic (2011-01-21). "globe". National Geographic Society. Retrieved 2017-01-23.
  13. ↑ Tiapchenko, Yurii. "Information Display Systems for Russian Spacecraft: An Overview". Computing in the Soviet Space Program (Translation from Russian: Slava Gerovitch).
  14. ↑ "Globe making". Heritage Crafts. 2017-04-30. Retrieved 2024-02-08.
  15. ↑ "Image: globe.jpg, (450 × 100 px)". netpbm.sourceforge.net. Retrieved 2015-09-01.
  16. ↑ Bliss, Laura (13 October 2014). "These tiny glass globes were all the rage in London 200 years ago". Quartz (publication) . Retrieved 2014-10-14.
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