I have been taught in school that America is a single continent but I know that people from USA are taught that it's actually two: South and North America.
Some people say there are 5 continents, some say there 6 and some 7, I have also seen claims that there are 4. What constitutes a continent and what doesn't? Is the definition of "continent" as vague as the definition of "planet"?
The answer is simple: as many as we want to have. The CGPGrey video nails it, but here is my take. North and South America are two separate continents. They have different flora and fauna, are barely connected and it makes sense in the geographic sense to make them separate. Africa is its own space with its own geography and biology so it makes sense to be on its own. Antarctica, with the ice sheet, is a large landmass on its own continental plate with its own geography and biology. So it gets to be its own continent. Australia, including New Zealand and everything below the Wallace Line is its own continent. So there are the five easy ones. Now to Europe and Asia. They are not a separate continental plate, the biology on the steppes in the center is all its own and spreads from China to Hungary, and if it was anywhere else we would call it one landmass. But there is a case to be made to segregate Europe from Asia and that is culture. The forests and rivers and mountains of what we call Europe developed a different people than the steppes, so should it be its own place? If so, why is India not a continent by the same measure (different culture, geography, on its own plate, completely different biology from 'Asia')? So yes, there are 8 continents. India, Asia and Europe make the last three. Why is Greenland not its own continent then? Greenland has the same geography as Northern Canada, the same biology and the same climate. And it sits on the North American Plate. Also Greenland is big, but less than 1/2 the size of Australia. So no, it is not a continent.
I prefer to consider New Zealand (and surrounds) as a separate continent - it's heading that way anyhow, and the flora / fauna we share with Australia is mostly introduced :
Thank you for the answer, I prefer text descriptions over videos, here's an archived version of the link in the description of the video for those like me who prefer reading.
I actually Googled this just a couple days ago knowing the debate was interesting. In school in the USA I was definitely taught there were seven continents. There really isn't any good answer, sort of like how long a coastline is.
Since I was taught that America was a single continent, may I ask you what's the logic behind dividing it into two continents?
Well, originally, they were seen as only barely connected. In the 1500s or so, if Africa and Asia, or Europe and Asia were going to be seperate continents, seperating the Americas too makes sense. Now, we know that they are seperate tectonic plates (well, both are more a couple of major plates, plus dozens of minor plates), and so the seperation still makes sense.
That almost makes sense but if we are going to separate America using the tectonic plates as a reference I think that it makes more sense to have 3 Americas (South, Central and North America). Here's a map (from Wikipedia) for reference.
The Carribean Plate (I assume that's the one you mean) is largely an oceanic plate, making it geologically distinct from the more continental North and South Amercian plates. The other continents have all pretty much moved independently of each other, including the Americas, while land on the Carribean Plate is largely the result of it being 'pinched' between North and South America. Plates are more of a cause of continents than a defining factor, but they can serve to be a good indicator. In this case though, it means that sometime in the geologically near future, North and South America will no longer be connected at all, and likely most of Central Amercia will be underwater. I think most people would define continents to avoid having them disappear (though Antartica will be a different issue should all the ice melt).
Defining continents in terms of tectonic plates doesn't seem to be a viable option but I have a more philosophical question now, what's the benefit of defining continents? I understand about separating countries (there are economic and politic factors involved) but why do we try to separate different parts of land into continents when we don't even have a real definition of "continent"?
I've been taking this from a geologic standpoint because that is where my background is. For that, plates works well. But obviously, on a bigger, more holistic level, 'continent' becomes more vague. I think talking geographically and culturally, it's a historical thing largely. As Europeans developed the concept, they created these separate areas because (1) they represented a significant travel time to reach and (2) they were generally culturally different enough to be seen as distinct. Old (again, European) maps have the center in the Mediterranean, not the Atlantic. It was easy to seperate the world into Europe North of the sea, Africa South, and Asia East. Now, I think a lot of the hold over is for ease of education. It's much easier to teach kids based around readily divisible sections with obvious divisions. Africa is an easier concept to describe than say "Middle East." (Which really isn't any better defined than continent.) Also, helps with teaching geologic history, and cultural history. Other than that though, I too see little value in it, especially in a globalised world.
You are right, I completely forgot about history when I asked the question. In your opinion what number of continents is the most accurate?
I don't know too much about geography, is the canal natural or artificial? Is it really a defining factor to be used as a separation between two continents?