How many continents are there?

Come on kids, between us we can crack this. Image: Getty.

Once upon a time, “How many continents are there” was one of those questions with straightforward answers, like “How many colours are in a rainbow” or “what is the weather like in summer”. There are seven. Of course there are seven: all those picture books I had as a kid said there were seven.

Except, it turns out that, as with so many of the things we tell our children, this number owed as much to social convention as it does to objective reality. And social conventions can differ: depending on where you are in the world, there can be anywhere between four and seven continents, and you sometimes don’t have to travel very far to get a different answer.

So, to coin a phrase: what on Earth is going on?

Rules and regulations

First define your continent. The Wikipedia page on the matter contains this helpful explanation:

By convention, “continents are understood to be large, continuous, discrete masses of land, ideally separated by expanses of water”.

Which sounds simple enough. Except the very next sentence is this:

Many of the seven most commonly recognized continents identified by convention are not discrete landmasses separated completely by water.

Which feels like an unexpected piece of dry humour from an open-sourced encyclopaedia.

But it has a point: it’s the work of all of four seconds to think of vast numbers of ways in which the seven things you almost certainly think of as continents don’t fit this rule. Off the top of my head:

  • Islands like Great Britain are considered part of continents despite not being part of continuous masses of land;

  • North and South America are not discrete masses of land, they’re connected by an isthmus;

  • Neither are Africa and Asia;

  • Europe and Asia aren’t even vaguely separated, they’re quite obviously the same bloody thing;

  • If Europe gets to be a continent because it’s separated from Asia by some mountains and some inland seas, then why is India only a sub-continent?

  • If Australia is a continent why is Greenland only an island? Okay, it’s smaller, but where’s the line? What are the rules here?

And so on and so on.

Spinning plates

There is another way of dividing the Earth up into roughly continent sized bits, which has a rather more scientific basis to it: plate tectonics, the geological theory which explains mountain ranges, volcanoes, and so on by showing how bits of the Earth’s surface have been sliding about and banging into each other for the last few billion years.

In this theory, it’s quite obvious why the Americas are two continents, why Australia is one but Greenland isn’t, and why Africa is a different thing to Asia despite being attached to it. It also highlights a very good reason for considering Britain to be part of Europe: they’re part of the same continental shelf, even if part of that shelf is submerged under water. Despite Brexit, Britain will always be in Europe.

The plates. Click to expand. Image: USGS/Wikimedia Commons.

In many other ways, though, the map of the tectonic plates doesn’t look anything like the map of the continents. For one thing there are a bunch of oceanic ones, which on maps of the world are mostly just water with a few islands in them.

For another, the Middle East and India are their own plates, so aren’t part of Asia; neither is the Russian Far East, which is actually part of the North American plate. Europe, meanwhile, very clearly is part of Asia, except for Iceland, which is half Asian, half North American.

There are good reasons why plate tectonics isn’t going to get us very far in explaining why we mostly think we have seven continents. One is that it’s a surprisingly recent theory: it wasn’t widely recognised by the scientific community until the 1960s, so there are plenty of people around now whose school text books will have laughed at the idea.

Another is that the plate boundaries are often invisible or, at least at the human scale, nonsensical: any system which splits Iceland into two separate continents is not going to be a useful categorisation.


Geography is written by the victors

The real reason we count Europe as a continent and include Britain in it, treat India as a part of Asia, and so forth is (this is where we came in) social convention: we do it because we do.

More than that, we do it because the rules on this stuff were largely formulated by the Europeans who spent much of the last five hundred years or so conquering the world. That’s why Europe is a seen as a single, diverse continent but the Indian subcontinent, with its own patchwork of languages, cultures and religions, isn’t: because the former was the imperial power that conquered the latter.

A related point is that, if you ignore plate tectonics, the entire world doesn’t divide neatly up into continents at all. The reason a huge bunch of Pacific islands get bundled together with Australia as a slightly miscellaneous category called “Oceania” is as much because people wanted to make everything fit in somewhere, as it is because of any real connection between the two.

So those lengthy explanations aside, how many continents actually are there?

Counting continents

There seem to be six different systems, helpfully portrayed in this gif:

A gif of the various models. Click to expand. Image: AlexCovarrubia/Wikimedia Commons.

The seven continent system is the one you’re probably familiar with. That’s the one that’s standard in the English-speaking world, China, south Asia, and parts of western Europe. The British Empire can probably be blamed, at least in part, for its dominance.

There’s also an ultra-stripped down four continent model which divides the world into four major landmasses: Eurasia-Africa, America, Antarctica, Australia. This, best I can tell, isn’t taught anywhere; but it is the logical end point of the definition that involves big bits of land divided by water, so it’s worth including it anyway.

In between there are four other models:

  • A six-continent system in which Europe and Asia are one continent. This, the internet tells me, is the standard in Russia and Eastern Europe (which makes sense, given that the slavic world straddles the Urals), and also Japan (although, citation needed).

  • A different six-continent system treats Europe and Asia as separate, but combines North and South America. That one seems to be favoured in France, much of southern Europe and various places colonised by those countries.

  • There’s also a five continent system which combines the Americas but ignores Antarctica because, to the first approximation, nobody lives there. This is the one favoured by the UN and the International Olympic Committee (count the rings).

  • Lastly, there’s a variant five-continent system consisting of Eurasia, America, Africa, Australia and Antarctica. I can find no reference whatsoever to anyone using this one, but it’s in the gif and also this National Geographic page, so I’m including it for the sake of completism.

So, there you go. The best we can say is that the world has “some continents”. Assuming you accept the notion that continents exist at all.

I’m still really angry at those picture books which promised me snow in winter and heat in summer, incidentally.

Jonn Elledge is the editor of CityMetric. He is on Twitter as @jonnelledge and also has a Facebook page now for some reason.

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12 things we learned by reading every single National Rail timetable

Some departure boards, yesterday. Image: flickr.com/photos/joshtechfission/ CC-BY-SA

A couple of weeks ago, someone on Twitter asked CityMetric’s editor about the longest possible UK train journey where the stations are all in progressive alphabetical order. Various people made suggestions, but I was intrigued as to what that definitive answer was. Helpfully, National Rail provides a 3,717 page document containing every single timetable in the country, so I got reading!

(Well, actually I let my computer read the raw data in a file provided by ATOC, the Association of Train Operating Companies. Apparently this ‘requires a good level of computer skills’, so I guess I can put that on my CV now.)

Here’s what I learned:

1) The record for stops in progressive alphabetical order within a single journey is: 10

The winner is the weekday 7.42am Arriva Trains Wales service from Bridgend to Aberdare, which stops at the following stations in sequence:

  • Barry, Barry Docks, Cadoxton, Cardiff Central, Cardiff Queen Street, Cathays, Llandaf, Radyr, Taffs Well, Trefforest

The second longest sequence possible – 8 – overlaps with this. It’s the 22:46pm from Cardiff Central to Treherbert, although at present it’s only scheduled to run from 9-12 April, so you’d better book now to avoid the rush. 

  • Cardiff Central, Cardiff Queen Street, Cathays, Llandaf, Radyr, Taffs Well, Trefforest, Trehafod

Not quite sure what you’ll actually be able to do when you get to Trehafod at half eleven. Maybe the Welsh Mining Experience at Rhondda Heritage Park could arrange a special late night event to celebrate.

Just one of the things that you probably won't be able to see in Trehafod. Image: Wikimedia/FruitMonkey.

There are 15 possible runs of 7 stations. They include:

  • Berwick Upon Tweed, Dunbar, Edinburgh, Haymarket, Inverkeithing, Kirkcaldy, Leuchars
  • Bidston, Birkenhead North, Birkenhead Park, Conway Park, Hamilton Square, James Street, Moorfields
  • Bedford, Flitwick, Harlington, Leagrave, Luton, St Albans City, St Pancras International

There is a chance for a bit of CONTROVERSY with the last one, as you could argue that the final station is actually called London St Pancras. But St Pancras International the ATOC data calls it, so if you disagree you should ring them up and shout very loudly about it, I bet they love it when stuff like that happens.

Alphabetical train journeys not exciting enough for you?

2) The longest sequence of stations with alliterative names: 5

There are two ways to do this:

  • Ladywell, Lewisham, London Bridge, London Waterloo (East), London Charing Cross – a sequence which is the end/beginning of a couple of routes in South East London.
  • Mills Hill, Moston, Manchester Victoria, Manchester Oxford Road, Manchester Piccadilly – from the middle of the Leeds-Manchester Airport route.

There are 20 ways to get a sequence of 4, and 117 for a sequence of 3, but there are no train stations in the UK beginning with Z so shut up you at the back there.

3) The longest sequence of stations with names of increasing length: 7

Two of these:

  • York, Leeds, Batley, Dewsbury, Huddersfield, Manchester Victoria, Manchester Oxford Road
  • Lewes, Glynde, Berwick, Polegate, Eastbourne, Hampden Park, Pevensey & Westham

4) The greatest number of stations you can stop at without changing trains: 50

On a veeeeery slow service that calls at every stop between Crewe and Cardiff Central over the course of 6hr20. Faster, albeit less comprehensive, trains are available.

But if you’re looking for a really long journey, that’s got nothing on:

5) The longest journey you can take on a single National Rail service: 13 hours and 58 minutes.

A sleeper service that leaves Inverness at 7.17pm, and arrives at London Euston at 9.15am the next morning. Curiously, the ATOC data appears to claim that it stops at Wembley European Freight Operations Centre, though sadly the National Rail website makes no mention of this once in a lifetime opportunity.

6) The shortest journey you can take on a National Rail service without getting off en route: 2 minutes.

Starting at Wrexham Central, and taking you all the way to Wrexham General, this service is in place for a few days in the last week of March.

7) The shortest complete journey as the crow flies: 0 miles

Because the origin station is the same as the terminating station, i.e. the journey is on a loop.

8) The longest unbroken journey as the crow flies: 505 miles

Taking you all the way from Aberdeen to Penzance – although opportunities to make it have become rarer. The only direct service in the current timetable departs at 8.20am on Saturday 24 March. It stops at 46 stations and takes 13 hours 20 minutes. Thankfully, a trolley service is available.

9) The shortest station names on the network have just 3 letters

Ash, Ayr, Ely, Lee, Lye, Ore, Par, Rye, Wem, and Wye.

There’s also I.B.M., serving an industrial site formerly owned by the tech firm, but the ATOC data includes those full stops so it's not quite as short. Compute that, Deep Blue, you chess twat.

10) The longest station name has 33 letters excluding spaces

Okay, I cheated on this and Googled it – the ATOC data only has space for 26 characters. But for completeness’ sake: it’s Rhoose Cardiff International Airport, with 33 letters.

No, I’m not counting that other, more infamous Welsh one, because it’s listed in the database as Llanfairpwll, which is what it is actually called.

 

This sign is a lie. Image: Cyberinsekt.

11) The highest platform number on the National Rail network is 22

Well, the highest platform number at which anything is currently scheduled to stop at, at least.

12) if yoU gAze lOng into an abYss the abySs alSo gazEs into yOu

Image: author's own.

“For I have seen God face to face, and my life is preserved”, said Thomas.

Ed Jefferson works for the internet and tweets as @edjeff.

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