In geography, the antipodes (from Greek αντίποδες, from 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 [ænˈtɪpədəl] to one another are connected by a straight line through the centre of the Earth.
In vernacular British English and Irish English, "The Antipodes" is sometimes used to refer to Australia, New Zealand and South Africa, and "Antipodeans" to their inhabitants. By contrast, under the geographical definition, the antipodes of Great Britain and Ireland are in the Pacific Ocean, south of New Zealand. The antipodes of Australia are in the North Atlantic Ocean, while parts of Spain, Portugal, and Morocco are antipodal to New Zealand.
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 Lambert azimuthal equal-area projection map of the Earth, in pink, overlaid on which is another map, in blue, 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.
If the coordinates (longitude and latitude) of a point on the Earth’s surface are (θ, φ), then the coordinates of the antipodal point can be written as (θ ± 180°,−φ). This relation holds true whether the Earth is approximated as a perfect sphere or as a reference ellipsoid.
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:(Translation: Yonder in Ethiopia are the Antipodes, men that have their feet against our feet.)
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 inhabited: 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 that since these people would have to be descended from Adam, and the equator had presumably always been impassable, no people could have come into the area.
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 earliest surviving account by a European who had visited the Southern Hemisphere is that of Marco Polo (who, on his way home in 1292, sailed south of the Malay Peninsula). 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.
Around 71% of the earth's surface is covered by oceans; thus the majority of locations on land do not have land-based antipodes.
Exact or almost exact antipodes:
To within 100 km, with at least one major city (pop ≥ 1 million):
Other major cities or capitals close to being antipodes:
Gibraltar is antipodal to a land location on Great Barrier Island about 130 km from Auckland, New Zealand. This illustrates the old bromide that the sun never set on the British Empire; the sun still does not set on the British Commonwealth.
The northern part of New Caledonia, still an overseas territory of France, is antipodal to some thinly-populated desert in Mauritania, a part of the former French West Africa. As with the British Empire, the sun never set on the French Empire at its peak, either.
The May 19th, 2008 Official Lost Audio Podcast gave credence to a theory that the Island (the setting of the show) is located at Tunisia's antipode, which is in the south Pacific east of New Zealand.