Earth

How is the land laid out?

Earth is pre-dominantly a watery planet: oceans dominate the surface. If there were no water--as on the moon--outsiders' focus would be on the abyssal plains, the sea bottoms. Land is predominantly continental but also includes sea mountains and mid-oceanic rises that top sea level. The continental margins are, currently, below sea level, but most of these land masses are above.

The oceans are the vast Pacific, the Indian, the Atlantic and the generally shallow Arctic. (Some posit a Southern Ocean--distinct from the term Australians use for the part of the Indian Ocean south of their continent--that swirls about Antarctica, but this is more a term that accounts for temperature and biozones than one that rests on geomorphology alone.)

The continental features account for almost all of humanity. These land masses and islands within the continental margins exclude only scattered islands, most of which are small. For convenience all islands are allocated to a continent--although not everyone follows this practice--but the allocation is, understandably--arbitrary.

There are four continental landmasses: the Old World, where humans evolved; Australia, the heart of Oceania, where we moved about 50 thousand years ago; the Americas, where we moved about 30 thousand years ago; and Antarctica, where the first local baby was born in the late 20th century. The Old World divides neatly into Eurasia and Africa, with only the small argument of to which side the Sinai Peninsula belongs. The division between Europe and Asia is an entirely arbitrary line whose start originated in the history of conflicts around the Turkish Straits. The Americas divide fairly nicely into North America and South America at the Isthmus of Panama, conventionally at the Panama-Colombia border.

The world and he Eurasian land mass's high point is Mount Everest (Oomonlangma or Sagamatha) in the Himalayas, at over 8,800 meters. Europe's tallest peak is far shorter: Mt. El'brus in the Great Caucasus (Kavkaz) at around 5,400 meters. The old volcano of Kilamanjaro in east Africa, is, at 5,895 meters, only somewhat higher than the European mountain. North America boasts Mt. McKinley of the Alaska Range at more than 6,100 meters, but this is topped in its South America by Aconcagua in the Andes, which approaches 7,000 meters. While average heights in Antarctica are above the other continents, its highest point, Vinson Massif in the Ellsworth Mountains, is only 5,100 meters. Oceania's tallest is Mount Wilhelm on the island of New Guinea at less than 5,000 meters.

Mountain tops bear some resemblance to extreme latitudes: ice and tundra are found at both. Much of the Arctic Ocean and the waters near Antarctica are frozen, or contain sea ice, more in winter, less on average in recent seasons. The continent of Antarctica is mostly covered with vast ice sheets, as in most of Greenland and the more northerly parts of the Canadian Archipelago, and the waters between.

A belt of tundra is found in northern North America and Eurasia, south of which is swamped out forests--taiga. Humanly useful lands dominate the middle latitudes of both hemispheres, but belts of deserts or semi-arid lands separate these zones from the equatorial forests.

The world's ten biggest islands are:

Name	Continent	World rank
Greenland1	North America	1
New Guinea	Asia/ Oceania	2
Borneo2	Asia	3
Madagascar	Africa	4
Sumatra3	Asia	5
Baffin	North America	6
Honshu	Asia	7
Great Britain	Europe	8
Ellesmere	North America	9
Victoria	North America	10

Some other islands of great importance to humans are:

Name	Continent	Continental rank
Cuba	North America	5
Hispaniola	North America	7
Celebes4	Asia	5
Java5	Asia	6
Luzon	Asia	7
Mindinao	Asia	8

The world's ten longest rivers are:

Name	Continent	World rank
Nile	Africa	1
Amazon	South America	2
Mississippi-Missouri-Red Rock	North America	3
Chang Jiang6	Asia	4
Ob'-Irtysh	Asia	5
Yenisey-Angara	Asia	6
Huang7	Asia	7
Congo8	Africa	8
Paraná	South America	9
Mekong	Asia	10

The world's ten largest lakes are (or were):

Name	Continent	World rank
Caspian ‘Sea’	Asia/ Europe	1
Superior	North America	2
Victoria	Africa	3
Aral ‘Sea’9	Asia	4
Huron	North America	5
Michigan	North America	6
Tanganyika	Africa	7
Baykal	Asia	8
Great Bear	North America	9
Great Slave	North America	10

Who lives there?

In 2008, 6.6 billion people lived on the Earth. There are three great population centers: Europe, South Asia and East Asia, and numerous secondary ones. Antarctica has only a small number of year-round residents.

Only a few languages are spoken natively by majorities in significant sized areas lying on two or more continents.¹⁰ English is spoken on four¹¹ and is also the world's most important second language. Spanish is also spoken by these majorities on four continents, French and Russian on three, and Japanese and Portuguese on two.

Languages are grouped into hierarchies by linguists, some categories well accepted by all, some accepted in large part by all and some subject to vigorous debate. The Indo-European family is well accepted, and includes four important branches plus Greek. One of these four, the Indo-Iranian Group, splits into the Iranian and Indo-Aryan groups.

Branch or language	Continent(s)	Example or location
Slavic	Europe, Asia, Antarctica	Russian
Germanic	Europe, North America, South America, Africa, Oceania, Antarctica	English
Romance	Europe, North America, South America, Antarctica	Spanish
Iranian	Asia	Persian12
Indo Aryan	Asia	Hindi
Greek	Europe	Greece

Another family is the Niger Congo.¹³ It divides into two: the Atlantic Congo and the Mande groups. The Atlantic Congo splits into the Volta Congo and the Senegambian groups. The Volta Congo splits into the Southern Bantoid and two minor groups. The important part of Southern Bantoid is Narrow Bantu, which divides into the Northwest and Central groups. The Central Narrow Bantu languages divide into many small groups, and the S group. All these languages are exclusively African.

Branch or language	Example or location
Northwest Narrow Bantu	Gabon and vicinity
S	Zulu
Other Central Narrow Bantu	Mbundu
Other Volta Congo	Burkino Faso
Senegambian	Sénégal
Mande	Mandekan

A third family is Afro-Asiatic. This has one important branch, Semitic, plus three minor branches. Semitic splits into Arabic--often regarded as one language but having several spoken forms--and Ethiopian.

Branch or language	Continent(s)	Example
Arabic	Asia, Africa	Egyptian spoken Arabic
Ethiopian	Africa	Amharic
Other Afro-Asiatic	Africa	Hausa

A fourth family is Sino-Tibetan, divided iknto Chinese--often regarded as one language but having several spoken forms--and Tibeto-Burman. These languages are Asian, except as minority languages.

Branch or language	Example
Chinese	Putonghua Chinese
Other Tibeto-Burman	Central Tibetan

A fifth family is quite controversial: Austro-Tai. Only some unite the two branches of Austronesian and Kadai. Austronesian's most important part is Malayo-Polynesian.

Branch or language	Continent(s)	Example
Malayo-Polynesian	Asia, Oceania	Malay14
Kadai	Asia	Lao

A sixth family is Altaic, divided into Turkic and Mongolian. Korean scholars believe their language belongs to the family in its own branch.

Branch or language	Continent(s)	Example or location
Turkic	Asia, Europe	Turkish
Mongolian	Asia	Mongolia
Other Altaic	Asia	possibly Korean

There are several smaller families, plus Japanese.

Family or language	Continent(s)	Example or location
Nilo-Saharan	Africa	Songhai
Amerindian15	South America16	Quechua
Uralic	Europe	Hungarian
Japanese	Asia	Japan
Austro-Asiatic	Asia	Vietnamese
Dravidian	Asia	Tamil
Trans New Guinea	Asia	Papua Province of Indonesia
Eskimo-Aleut	North America	Inuktitut

Only three religions are practiced by majorities in significant-sized areas lying on two or more continents.¹⁰

Religion	Continent(s)
Christianity17	all seven
Islam18	Europe, Asia, Africa
Buddhism19	Asia, Antarctica
Hinduism	Asia

Cities

Only Antarctica lacks settlements bigger than a base. The world has tens of metropolises with ten million or more metropolitan residents.

Beyond Earth

Three people at a time rotate through the International Space Station in orbit around the Earth as of 2014. No-one else lives off the earth. People visited the Moon's Mare Tranquillitatis, Oceanus Procellarum, Fra Mauro, the Hadley-Apennines, the Descartes area and Taurus-Littrow between 1969 and 1972. Robotic landings continued until 1976 and flybys continue. People have sent robotic probes and flybys to various parts of the solar system and beyond but haven't themselves visited beyond the Earth-Moon system as of 2014.

Footnotes

1. Kalaallit Nunaat in Inuktitut.
2. Kalamantan in Indonesian.
3. Sumatera in Indonesian.
4. Sulawesi in Indonesian.
5. Jawa in Indonesian.
6. Various parts of the river have different names. English speakers sometimes called the entire length the Yangtze.
7. Yellow in English.
8. Various parts of the river have different names.
9. This lake has split into several pieces as it dries up.
10. I divided Antarctica into wedges and looked at the relative strength of the administrative languages of the bases, using their year-round populations. Religions or religious backgrounds were inferred from the administrative languages.
11. An English creole is spoken in South America, but I did not include that continent in the count.
12. Also called Dari or Tajik or Farsi.
13. This group is well accepted. Details of the branching are argued.
14. Also called Malaysian and Indonesian.
15. This group is controversial, as are some sub-groupings within it like Quechua-Aymara. Tupi-Guarani is an accepted grouping.
16. These language are minority-only further north.
17. Often syncretic with other religious practices.
18. Sometimes syncretic with other religious practices.
19. Often syncretic with other religions not listed, such as Shintoism, Confucianism, Taoism, Chondokyo and Chinese (and other) folk religions.
20. Proper rendering creates a composite letter out of the two ल letters, with a single vertical line on the right.
21. Köln (Cologne), Essen Düsseldorf, etc.
22. Shànghăi or Shang-hai in transliterated Pŭtōnghuà Chinese. The first character means above and the second sea, so a reasonable translation is Upon-the-Sea. In the Shanghai dialect of the Wu dialect group it transliterates as Zånhae.