Editing Antipodes (section)

==Geography==
Since the antipode of any place on the Earth is the place that is diametrically opposite of it, a line drawn from one to the other will pass through the centre of Earth and form a true [[diameter]].<ref name="EB1911">{{EB1911|inline=y|wstitle=Antipodes|volume=2|pages=133–134}}</ref> For example, the antipodes of New Zealand's lower North Island lie in Spain. Most of the Earth's land surfaces have ocean at their antipodes; this is a natural consequence of most of the Earth's surface being covered in water.

The antipode of any place on Earth is distant from it by 180° of [[longitude]] and as many degrees to the north of the [[Equator]] as the original is to the south (or vice versa); in other words, the [[latitude]]s are numerically equal, but one is north and the other south.<ref name="EB1911"/> The maps shown here are based on this relationship; they show a [[Lambert azimuthal equal-area projection]] of the Earth, in yellow, overlaid on which is another map, in blue, shifted horizontally by 180° of longitude and inverted about the Equator with respect to latitude.

[[Solar noon]] (i.e. the time at which the sun is highest) at one place is [[solar midnight]] at the other, the [[winter solstice]] at one place is the [[summer solstice]] at the other, and the [[Spring equinox (disambiguation)|spring equinox]] at one place is the [[Autumnal equinox (disambiguation)|fall equinox]] at the other. Sunrise and sunset do not quite oppose each other at antipodes due to refraction of sunlight.

===Mathematical description===

If the [[geographic coordinate]]s ([[latitude]] and [[longitude]]) of a point on the Earth's surface are (''φ'', ''θ''), then the coordinates of the antipodal point are (−''φ'', ''θ'' ± 180°). This relation holds true whether the Earth is approximated as a perfect [[sphere]] or as a [[reference ellipsoid]].

In terms of the usual way these geographic coordinates are given, this [[Transformation (function)|transformation]] can be expressed symbolically as

:''x''° N/S ''y''° E/W &nbsp;<big>↦</big>&nbsp; ''x''° S/N (180 − ''y'')° W/E,

that is, for the latitude (the north–south coordinate) the magnitude of the angle remains the same but N is changed to S and vice versa, and for the longitude (the East/West coordinate) the angle is replaced by its [[supplementary angle]] while E is exchanged for W. For example, the antipode of the point in China at {{nowrap|37° N 119° E}} (a few hundred kilometres from [[Beijing]]) is the point in Argentina at {{nowrap|37° S 61° W}} (a few hundred kilometres from [[Buenos Aires]]).