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Actually that brings up a question, why is landmass on Earth so unevenly distributed between northern and southern hemispheres?




This definitely doesn't contain the answer but is hilarous


If you want a more serious answer, tectonic plates are the floating cooled solidified 'slag' on a spinning spherical molten furnace (that's been cooling for 4 billion years).

Distance from spin axis (equator Vs poles) plays more of a dynamic than "South" vs "North" (air quoted as that's merely a convention as to which hemisphere is the 'top' hemisphere).

Two major points are that:

* N vs S looks a bit different on a globe or non Mercator projection (chosen by European traders to maximise the parts of the world of interest to them).

* current positions are just that - they've steadily moved since formation of the planet.

https://www.youtube.com/watch?v=OGdPqpzYD4o


North and South should not be in air-quotes. They're correct, by definition.

"Top" and "bottom", however, can be air-quoted. There's nothing that says north equals "top"; north and south are arbitrary, and are just terms chosen to designate the two poles. The only reason people think north=top is because most maps are oriented that way.


North and South are arbitrary and subject to change though; at least 183 reversals over the last 83 million years [-1].

Unless you mean spin direction about axis, and even so a spinning top can also flip.

[-1] https://en.wikipedia.org/wiki/Geomagnetic_reversal


If you flip North can change from "top" to "bottom" or from "bottom" to "top" depending on your map. But it doesn't stop being North, which is a fairly well defined concept. Hence no air quotes.


> But it doesn't stop being North, which is a fairly well defined concept.

Can you cite the definition please?

My understanding, from 40 years of geodesy and cartography, was that it was a fairly recent (post 16th Century) convention and many many significant older maps orientate in quite different ways.

eg:

http://america.aljazeera.com/opinions/2014/2/maps-cartograph...


per Wikipedia "By convention, the top or upward-facing side of a map is north", so I guess I was wrong.


Huh? This doesn't make sense. Lots of modern maps even have north pointing somewhere other than up, though they use a marker to indicate which way is north.

It doesn't matter which way you point a piece of paper: the North Pole is always going to be the North Pole, and the South Pole is always going to be in Antarctica (until the continent drifts, though the pole will still be there). The names of these poles may have been originally chosen centuries ago because popular maps pointed that way, but now those names are fixed by definition.


How about a better definition and a source for it then? :)


You need a source to tell you where the north and south poles are located?

Here's a start: https://en.wikipedia.org/wiki/South_Pole https://en.wikipedia.org/wiki/North_Pole


So you link to Wikipedia. OK. You see that it defines North pole in terms of Northern hemisphere. Now if you follow the links through you will see that Wikipedia defines North as "where the up on the map is". Qed.


If I'm standing on the Moon, looking at the Earth, I can see which side is North because of the arrangement of the continents. I don't need to have a paper map with me. The whole thing doesn't make sense.

Finally, you're just plain wrong, and you're reading Wikipedia wrongly. According to the page for "North",

>The word north is related to the Old High German nord, both descending from the Proto-Indo-European unit ner-, meaning "left; below" as north is to left when facing the rising sun. Similarly, the other cardinal directions are also related to the sun's position.

So the definition is derived from the Sun's position, not some stupid paper map.

You're probably reading this part:

>By convention, the top or upward-facing side of a map is north.

That just says that maps are normally oriented with North pointing up. It doesn't say that "north" is defined* that way.


First you define North in terms of arrangements of continents (saying north is where northern continents are, cool) and then you use English etymology as definition? Lol.

> You're probably reading this part

Probably? I literally quoted it.

You claim I misinterpreted that phrase but you don't give a better option. All definitions of north are by convention or relative to space (so if it flips then "northern arrangement" of continents you see from the moon will be southern)


"North" IS by convention. I've been saying this all along. It has nothing to do with any map. The place we call "the north pole" is north because it's been defined that way for ages. Apparently the origins of the word have to do with Sun, but the effect is the same, because it points to the same place on this spinning ball.

You quoted it, but you don't understand it.


Ah but that's my point, turns out north is not a well-defined concept contrary to what I thought first.

That quote is ambiguous and could be interpreted as "north is where the up on the map is". And actually there seems to be no better definition (that eg. would stand the flip of axis). What are we arguing about again?


North IS a well-defined concept. From the most ancient times, people knew where north was: it's 90 degrees left of east, and east is where the Sun rises. Go back in time 5000 years and ask anyone where North is, and they'll point you to it, long before any modern maps of the world were ever made.

Wikipedia having one poorly-written line about it doesn't change tens of thousands of years of human history and knowledge about where north is. Wikipedia isn't even an authoritative reference on anything.


Great, so why do you link to it then?


I think it's pretty much a myth that a projection was chosen to accentuate certain countries, the simpler and less nefarious reason is that they're easier to use for navigation.


Why is it thar more landmass gets spun into the axis in the NH than in the SH? They should be the same distance from the axis, right?


The land masses are floating plates pushing and shoving against each other over a bubling mass of heat energy pushing up to escape outwards, there are more forces at play than simple centrifuging.

The linked animation shows a relatively short sequence of movement, over the last few million years, that is likely the most we'll be able to reconstruct thanks to the arrow of time.


Now you know where all the redditors moved to


BTW, looking at northern hemisphere vs southern hemisphere doesn't show just how unevenly it is distributed. To really see how unevenly land is distributed go to Google Maps (or any other online map that switches to a 3D globe view when you zoom out and search for Bora Bora in French Polynesia.

Then zoom out to the globe view. Then tweak the position to get North America to just disappear over the horizon, along with most of South America.

With sufficient tweaking you can get it down to the half of the Earth you are looking at just being ocean, Australia, Papua New Guinea, Tasmania, about 2/3 of Antartica, and parts of Argentina, Chile, Indonesia, and Philippines, plus a handful of islands.


*at the moment

You're looking at a snapshot of a process that goes on for billions of years... there's no particular reason why any snapshot would look like any sort of way.


the short answer is mantle convection. the slightly longer answer is it's constantly changing and we just happen to be alive now when it's this way




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