Throughout the years, many people pointed out inaccuracies in our original source. I finally decided to calculate the coastline myself. It is now my belief that the CIA World Factbook data is deeply flawed, and that my new original source is the most accurate compilation of country coastlines available anywhere.
great quiz. well done quizmaster. From the alternative source (wiki) it looks like Denmark would just about make the top 20 even without Greenland. Is the same true on your list?
I am not trying to be difficult, but instead of just stating that someone is wrong, how about offering the correct answer. That way we can all learn something.
@Hlodowig - Cuba is an archipelago of islands. From a distance, on a map Cuba looks like one land mass, but actually there are several small islands surrounding the island nation. Adding up the coastline of all of these islands plus the coastline of mainland Cuba gives you a larger distance than that of Madagascar.
Like people above said. Also, a big factor is how "detailed" the coastline is.
If you take two coastlines that are nominally the same length (i.e.: from one end to the other, the distance is the same), but one is relatively smooth, while the other has lots of bays, inlets, fjords and the like, that second one can be many, many, many times longer than the first. Even when measuring at the same level of granularity.
As a matter of fact there is no such thing as the length of a coastline. Mathematically, the length of a curve is the limit of smaller and smaller linearizations of the curve. This procedure however is senseless when it comes to a coast: The length will just go towards infinity, because eventually you will have to take into account every small stone that sticks out of the water.
Every data on lengths of coastlines is the result of arbitrarily setting the 'fineness' of the linearization.
Thought some more of the islands nations would appear like Micronesia, Solomon Islands or Marshall Islands. Still got them all, but took some thinking.
The wikipedia article https://en.wikipedia.org/wiki/List_of_countries_by_length_of_coastline is very interesting with its two lists from different sources. the numbers are totally different. For example, Finland is 70th on one list with 1700 km and 10th on the other with 30000+.
My guess (based on being a Finnish person, not an online source). The first one, with 1700km, is calculating only the coastline of the mainland, and possibly even that one by cutting some corners. The 30000+ includes coasts of all the islands, of which there are a LOT.
There is no accurate way to measure coastline arbitrarily well from a map. Because of that, many paradoxes will be inevitable. How is Madagascar absent, when Papua New Guinea is present, for example? One would think Argentina or South Africa surely have as much coastline as Sweden, but it's a weird thing, measuring length of a curve that doesn't have statically defined position or curvature. Anyway, fun quiz nonetheless.
So, there is a very clear difference between "contradictory" and "seemingly contradictory." If you don't like the definition, and you don't like my word usage, provide your own definition and we can go from there, otherwise you are not really making a convincing point.
As a matter of fact there is no such thing as the length of a coastline. Mathematically, the length of a curve is the limit of smaller and smaller linearizations of the curve. This procedure however is senseless when it comes to a coast: The length will just go towards infinity, because eventually you will have to take into account every small stone that sticks out of the water.
Every data on lengths of coastlines is the result of arbitrarily setting the 'fineness' of the linearization.
Quite amazing what a difference having many islands makes to ‘distance’ of a coastline. Countries that are apparently pretty small have huge coastlines while much larger nations like Saudi Arabia, which despite bordering both the Red and Arabian seas has a smaller coastline even though it looks pretty big on a map.
I wish you'd make your mind up whether Australia is a country or a continental landmass, because I've just now done a quiz where it wasn't counted as a country...
Australia is both a country and the continental landmass of Oceania. Not that hard to understand. In the same way that Iceland is both a country and an island in the North Atlantic. What quiz are you talking about? Is it one where you're required to name islands or countries on islands? Giving you Australia as a gimme on that quiz doesn't negate the fact that it's a country. There are no quizzes on the site that don't count Australia as a country.
I am not trying to be difficult, but instead of just stating that someone is wrong, how about offering the correct answer. That way we can all learn something.
If you take two coastlines that are nominally the same length (i.e.: from one end to the other, the distance is the same), but one is relatively smooth, while the other has lots of bays, inlets, fjords and the like, that second one can be many, many, many times longer than the first. Even when measuring at the same level of granularity.
Every data on lengths of coastlines is the result of arbitrarily setting the 'fineness' of the linearization.
I got Papua New Guinea and Philippines but forgot Russia.
How could I forget it's the biggest country in the world.
surprising ≠ contradictory
I think it's surprising that PNG has more coastline than Madagascar (was that the original thing?) but it's not paradoxical.
p.s. I take issue with that Google definition of paradox - we could rename the interesting facts as "paradoxes" if that were right!
Every data on lengths of coastlines is the result of arbitrarily setting the 'fineness' of the linearization.
For example Norways coastline is actually 100 915km and not 27 400km.
Russia
United States
Indonesia
Denmark
(includes Greenland)
Australia
Chile
Norway
Brazil
Philippines
China
United Kingdom
Mexico
Japan
France
Papua New Guinea
India
New Zealand
Greece
Sweden