Speaker 1: Welcome to brain Stuff production of iHeart Radio. Hey brain Stuff,
Speaker 1: Lauren Vogelbaum. Here in elementary school, we learn some indisputable
Speaker 1: fundamental facts. Two plus two equals four. The world's round.
Speaker 1: There are seven continents on Earth, but that last one
Speaker 1: isn't quite so cut and dried. Here in the United States,
Speaker 1: students learned that there are seven continents North America, South America, Europe, Asia, Africa, Australia,
Speaker 1: and Antarctica. But that's hardly the last word on the matter.
Speaker 1: And much of Europe students learned that there are six
Speaker 1: continents Africa, America, Antarctica, Asia, Australia's slash Oceania, and Europe.
Speaker 1: There's a five continent model which lists Africa, Europe, Asia, America,
Speaker 1: and Oceanica slash Australia. And that's, by the way, why
Speaker 1: there are five rings on the Olympic flag. And some
Speaker 1: experts think that four is the way to go, using
Speaker 1: as their criteria land masses now truly separated by water
Speaker 1: rather than man made canals, so Afro, Eurasia, America, Antarctica,
Speaker 1: and Australia. As recently as the eighteen hundreds, some people
Speaker 1: said that there were just two continents, the old including Europe, Africa,
Speaker 1: and Asia, and the new encompassing North and South America.
Speaker 1: So what really makes a continent a continent? We spoke
Speaker 1: via email with Dan Montello, a geography professor at the
Speaker 1: University of California, Santa Barbara. He said, nothing really determines
Speaker 1: a continent except historical convention, a bit of an overstatement
Speaker 1: but mostly valid. Certain factors make a landmass more or
Speaker 1: less likely to be called a continent at various times
Speaker 1: in history by various people, but nothing can be said
Speaker 1: to determine continentality in a completely principled, non arbitrary way. Take,
Speaker 1: for example, the vast country of Russia six point six
Speaker 1: million square miles or seventeen million square kilometers. Why has
Speaker 1: it often been counted as part of you up rather
Speaker 1: than Asia? Montello explained. The Ural Mountains are taken to
Speaker 1: separate Asia and Europe, but only because Russians wanted their
Speaker 1: great city of Moscow to be European, so the Urals
Speaker 1: were a convenient marker for that arbitrary decision. Continents are
Speaker 1: mostly spatially contiguous collections of land masses larger than countries
Speaker 1: but smaller than hemispheres. Of course, continents do not necessarily
Speaker 1: fit entirely within single Earth hemispheres and thus cannot be
Speaker 1: defined by ranges of latitude or longitude. Okay, so how
Speaker 1: about plate tectonics. If certain land masses are constrained to
Speaker 1: one of those massive shifting hulks, can we safely call
Speaker 1: it a continent? Montello says, no quote. Plate tectonics has
Speaker 1: nothing to do with it historically, and it certainly could
Speaker 1: not provide a principal basis for continents. Now, nearly every
Speaker 1: continent includes parts of multiple plates, the same those for climate.
Speaker 1: After all, continents contain multiple climates, as evidenced by Alaska's
Speaker 1: arctic chill compared with Florida's humid heat. They're both part
Speaker 1: of North America. Mountain ranges and coastlines are useless too,
Speaker 1: as our culture and politics, Montella said. Neither ethnicity, race, culture,
Speaker 1: nor politics has ever defined continents, except by conventional theories
Speaker 1: that were largely mythical, such as old and fallacious ideas
Speaker 1: about correspondences between races and continents. Politically, Hawaii is part
Speaker 1: of the US, but is in Oceania rather than North America.
Speaker 1: Greenland is controlled by Denmark for now, but is considered
Speaker 1: part of the North American continent. So really it boils
Speaker 1: down to whom and when you ask, Montello said, no
Speaker 1: one can say, as a matter of principled fact, how
Speaker 1: many continents there are, because the decisions are largely based
Speaker 1: on convention, and convention that goes in and out of
Speaker 1: fashion over time and is still debated today. He concedes
Speaker 1: that these days many geographers would opt for a list
Speaker 1: of seven continents Africa, Antarctica, Asia, You're up, North America, Oceania,
Speaker 1: and South America, but he added that some of them
Speaker 1: would combine Asia and Europe into Eurasia, identify Oceania in
Speaker 1: other ways, or combine North and South America into the America's.
Speaker 1: He said, there is simply no BZAR or CEO of
Speaker 1: continents or any other ultimate authority, so it's pretentious for
Speaker 1: anyone to claim that they have the authoritative answer. But
Speaker 1: don't worry if you can't handle that kind of definition.
Speaker 1: It's all changing. The continents are drifting at a rate
Speaker 1: of about an inch or two point five centimeters per year.
Speaker 1: Today's episode was written by Nathan Chandler and produced by
Speaker 1: Tyler Clang. For more in this lots of other topics.
Speaker 1: Visit how stuff works dot com. Brain Stuff is production
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