Antipodes

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For the related abstract mathematical concept of an antipodal point, see that article.
This world map (in red) is overlaid with an antipodal map (in yellow) showing the antipodes of each point on the Earth's surface.
This world map (in red) is overlaid with an antipodal map (in yellow) showing the antipodes of each point on the Earth's surface.

In geography, the antipodes (from Greek anti- "opposed" and pous "foot") of any place on Earth is its antipodal point; that is, the region on the Earth's surface which is diametrically opposite to it. Two points which are antipodal to one another are connected by a straight line through the centre of the Earth.

In Britain, "the Antipodes" is often used to refer to Australia and New Zealand[2] (and "Antipodeans" for their inhabitants), despite the fact that neither Australia nor New Zealand actually overlap the antipodal points of Britain. However, New Zealand (or more precisely the North Island and the northern tip of the South island) is antipodal to Iberia, as shown on the map.

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[edit] Geography

The antipodes of any place on the Earth is the place which is diametrically opposite it — so situated that a line drawn from the one to the other passes through the centre of the Earth and forms a true diameter. For example, the antipodes of New Zealand's north island lie in Spain. Most of the earth's land surfaces have ocean at its antipodes, this being a consequence of most land being in the northern hemisphere.

An antipodal point is sometimes called an antipode, a back-formation from the Greek plural antipodes, whose singular in Greek is antipous.

The antipodes of any place on Earth must be distant from it by 180° of longitude, and must be as many degrees to the north of the equator as the original is to the south; in other words, the latitudes are numerically equal, but one is north and the other south. The map shown above is based on this relationship; it shows a mercator projection map of the Earth, in red, overlaid on which is another map, in yellow, shifted horizontally by 180° of longitude and inverted about the equator with respect to latitude. This map allows the antipodes of any point on the Earth to be easily located.

Noon at the one place is midnight at the other (although daylight saving and irregularly-shaped time zones affect this in most places); seasonally, the longest day at one point corresponds to the shortest day at the other, and midwinter at one point is contemporaneous with midsummer at the other.

In the calculation of days and nights, midnight on the one side may be regarded as corresponding to the noon either of the previous or of the following day. If a voyager sails eastward, and thus anticipates the sun, his dating will be twelve hours in advance, while the reckoning of another who has been sailing westward will be as much in arrears. There will thus be a difference of twenty-four hours between the two when they meet. To avoid the confusion of dates which would thus arise, it is necessary to determine a meridian at which dates should be brought into agreement, known as the International Date Line.

[edit] Mathematical description

If the coordinates (longitude and latitude) of a point on the Earth’s surface are (x, y), then the coordinates of the antipodal point can be written as (x ± 180°, −y). This relation holds true whether the Earth is approximated as a perfect sphere or as a reference ellipsoid.

[edit] Regional usage

The term antipodes is used in the United Kingdom to refer to Australia and New Zealand, and the inhabitants of these countries are sometimes referred to as antipodeans.

This is not geographically precise: the antipodes of New Zealand lie in Spain, Portugal and the north Atlantic Ocean. The closest land to the true antipodal point of Great Britain is the Antipodes Islands, which lie off the south coast of New Zealand. Their own true antipodal point is near Cherbourg, France.

In Japan, the term antipodes (Jap: 対蹠地) refers to Brazil or Argentina.

[edit] Etymology

The Greek word is attested in Plato's dialogue Timaeus, already referring to a spherical Earth, explaining the relativity of the terms "above" and "below":

For if there were any solid body in equipoise at the centre of the universe, there would be nothing to draw it to this extreme rather than to that, for they are all perfectly similar; and if a person were to go round the world in a circle, he would often, when standing at the antipodes of his former position, speak of the same point as above and below; for, as I was saying just now, to speak of the whole which is in the form of a globe as having one part above and another below is not like a sensible man.

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The term is taken up by Aristotle (De caelo 308a.20), Strabo, Plutarch and Diogenes Laertius, and was adopted into Latin as antipodes. The Latin word changed its sense from the original "under the feet, opposite side" to "those with the feet opposite", i.e. a bahuvrihi referring to hypothetical people living on the opposite side of the Earth. Medieval illustrations imagine them in some way "inverted", with their feet growing out of their heads, pointing upward.

In this sense, Antipodes first entered English in 1398 in a translation of the 13th century De Proprietatibus Rerum by Bartholomeus Anglicus, translated by John of Trevisa:

Yonde in Ethiopia ben the Antipodes, men that haue theyr fete ayenst our fete.

(Translation: Yonder in Ethiopia are the Antipodes, men that have their feet against our feet.)

[edit] Historical significance

The term plays a certain role in the discussion about the shape of the Earth. The antipodes being an attribute of a spherical Earth, some authors used their perceived absurdity as an argument for a flat Earth. However, knowledge of the spherical Earth being widespread even during the Dark Ages, only occasionally disputed on theological grounds, the medieval dispute surrounding the antipodes mainly concerned the question whether they were inhabitable: since the torrid clime was considered impassable, it would have been impossible to evangelize them, posing a dilemma between two equally unacceptable possibilities that either Christ had appeared a second time in the antipodes, or that the inhabitants of the antipodes were irredeemably damned. Such an argument was forwarded by the Spanish theologian Tostatus as late as the 15th century.

Saint Augustine (354–430) argued against people inhabiting the antipodes:

But as to the fable that there are Antipodes, that is to say, men on the opposite side of the earth, where the sun rises when it sets to us, men who walk with their feet opposite ours, that is on no ground credible. And, indeed, it is not affirmed that this has been learned by historical knowledge, but by scientific conjecture, on the ground that the earth is suspended within the concavity of the sky, and that it has as much room on the one side of it as on the other: hence they say that the part which is beneath must also be inhabited. But they do not remark that, although it be supposed or scientifically demonstrated that the world is of a round and spherical form, yet it does not follow that the other side of the earth is bare of water; nor even, though it be bare, does it immediately follow that it is peopled.

– [2]

Since these people would have to be descended from Adam, they would have had to travel to the other side of the Earth at some point; Augustine continues:

... it is too absurd to say, that some men might have taken ship and traversed the whole wide ocean, and crossed from this side of the world to the other, and that thus even the inhabitants of that distant region are descended from that one first man.

The author of the Norwegian book Konungs Skuggsjá, from around 1250, discusses the existence of antipodes. He notes that they (if they exist) will see the Sun in the north in the middle of the day - and that they will have opposite seasons of the people living in the Northern Hemisphere.

The first European who actually visited the Southern Hemisphere was Marco Polo (on his way home, sailing south of the Malay Peninsula in 1292). He noted that it was impossible to see the star Polaris from there.

The idea of dry land, inhabited or not, in the Southern climes, the Terra Australis was introduced by Ptolemy, and appears on European maps as an imaginary continent from the 15th century. In spite of having been discovered relatively late by European explorers, Australia was inhabited very early in human history, the ancestors of the Indigenous Australians having reached it at least 50,000 years ago.

[edit] List of antipodes

[edit] On Earth

[edit] Other bodies

[edit] See also

[edit] References

  1. ^ Plato, Timaeus 63a, translated by Benjamin Jowett, (Indianapolis: Bobbs Merrill, 1949).[1]
  2. ^ De Civitate Dei, Book XVI, Chapter 9 — Whether We are to Believe in the Antipodes, translated by Rev. Marcus Dods, D.D.; from the Christian Classics Ethereal Library at Calvin College

[edit] External links

  • Antipodes map dual-image map to locate the antipodes of any location on Earth.
  • Latitude and Longitude converter and Antipodal calculator Includes an antipodes location point calculator and tells the antipodal location distance. Also provides a latitude and longitude converter which can convert latitude and longitude from degree, decimal form to degree, minutes, seconds form and vice versa.
  • Antipodes map Interactive maps to locate antipodal map locations
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