地圖為什麼是「上北下南」？

shaner

想像一下從太空來看地球。這顆星球的頂部在哪裏？說北極的大概不止你一個。嚴格來說，你錯了。

讓人有點吃驚的真相是，儘管大多數人都認為世界是上北下南，然而沒有充分的科學道理證明北方就是世界的屋頂。

至於這種方向感是如何產生的，那就是歷史、天體物理和心理學綜合作用的結果。而這又帶來了一條重要的結論：我們繪製世界地圖時所採取的方式對我們的世界觀有非常真實的影響。

導航大腦
了解你在世界中的位置是一項基本的生存技能。所以，我們人類和其他大多數物種一樣，大腦中天生就有繪製周邊地圖的專門區域。可能除了蜜蜂外，人類是唯一會彼此溝通對世界的認識的生物物種。很久以前，我們就開始繪製地圖——目前發現的最早的地圖是14000年前洞窟石壁上一些潦草的地圖。自文明出現以來，人類就在石板、莎草紙、紙張和現在的電腦屏幕上繪製地圖。

儘管人類製作地圖的歷史如此悠久，然而讓人驚訝的是，在數百年前「上北下南」的規則才確定下來。事實上，根據倫敦瑪麗王后大學（Queen Mary University）地圖歷史學家、《12幅地圖中的世界歷史》（A History of the World in Twelve Maps）一書的作者傑瑞·布羅頓（Jerry Brotton）的說法，在人類歷史的大部分時間裏，北方幾乎從未佔據過地圖的上方。他說：「北方之所以很少出現在地圖頂部，就是因為黑暗來自北方。西方出現在頂部的可能性也很小，因為日落西方。」

讓人不解的是，中國古代的地圖卻反其道而行之。但是，布羅頓說，儘管中國當時已經發明了羅盤，也無法解釋他們為什麼以北方為地圖的上部。中國古代的羅盤指向南方，而與遙遠、黑暗的北方相比，人們更加喜歡南方。但是，中國的地圖總是把居住在北方的皇帝放在地圖的頂部，這樣所有的臣民都要仰視皇帝。「在中國文化裏，皇帝面向南方，因為風來自南方，所以這是一個良好的方位。北方不是很好，但是為了表示對皇帝的臣服，你要仰視他。」布羅頓說。

shaner

由於每種文化尊崇的對象不同，古代地圖的方位自然也就不同。古埃及以東方為世界的頂部，因為那是太陽升起的地方。古代伊斯蘭文明的地圖喜歡以南方為頂部，因為早期穆斯林文化大都位於麥加的北邊，所以他們在想像中望向南方的麥加。


同時代的基督教文明的地圖（被稱為Mappa Mundi）以東方為地圖頂部，朝向伊甸園，以耶路撒冷為中心。

shaner

那麼是從什麼時候開始，全世界決定以北方為頂部呢？一個誘人的推論是克里斯托弗·哥倫布（Christopher Columbus）和斐迪南·麥哲倫（Ferdinand Megellan）等歐洲探險家因為靠北極星掌握方向而確定了地圖的方位。但是布羅頓認為，這些早期探險家眼中的世界根本不是這樣的。「哥倫布描述世界時以東方為頂部。」他說，「哥倫布說他正在前往天堂，所以他的精神世界源自中世紀的世界地圖。」布羅頓補充說，我們必須記住的一點是，當時「沒有人知道他們在做什麼，在去什麼地方。」

麥哲倫1569年的世界地圖為上北下南的方位奠定了基礎。這幅地圖第一次把地球的曲度考慮進來，這樣水手在長距離航行時就不會錯過目的地。不過，布羅頓說，這和上北下南還是不沾邊。「麥哲倫把極點定在無限遠處。他在描述這幅地圖時說，北方並不重要，因為我們沒有興趣去那裏。北方確實位於地圖上部，但是沒有人在意，因為我們不會去那裏。」

即便如此，他還是有兩種選擇。之所以選擇上北下南，是因為當時主要是歐洲人在進行探險：北半球可供探險的土地更多，人口也多得多。

shaner

不論原因是什麼，地圖上北下南的特點保留了下來。以1973年美國宇航局（Nasa）的這張著名照片為例。原本它是南半球朝上的，因為宇航員在拍照時正在打轉。美國宇航局決定把它倒轉過來，以免讓人誤會。

shaner

不過，當你從太空看地球時，任何一面朝上的想法都很難站住腳。確實，按照學校裏學到的知識，地球和太陽系其他行星一樣排列在同一個平面上，因為它們都是同一片塵埃中形成的。但是，這張照片也同樣可以反過來，太陽可以在上面，也可以在下面，這取決於你從哪個角度來看。

shaner

而與銀河的其他部分相比，整個太陽系傾斜了大約63度。

雖然天文學家發現在整個太空裏，恆星和行星以相似的方式與相鄰的天體保持在一個平面內，但是倫敦帝國學院（Imperial College London）的天體物理學家丹尼爾·莫特洛克（Daniel Mortlock）稱，與浩瀚的宇宙相比，這個規律至存在於一個微小的尺度上。「在我們天文學家來看，太空中沒有所謂的『上』或『下』。」他說。

所以，地球哪一面朝上，這個問題的答案很簡單：沒有哪一面朝上，上北下南最多不過是歷史上優勢集團的看法。

那麼，現在我們是不是應該開始接受一種與以往不同的對地球的看法？或許是的，因為心理學方面的證據顯示，上北下南的文化可能會造成我們在價值判斷方面的錯誤。

shaner

心理學上的一種著名偏見表明，大多數人有上北下南的觀念。賓夕法尼亞州蓋茨堡學院（Gettysberg College）的心理學家布萊恩·邁耶（Brian Meier）發現人們在無意識中國會把褒義詞與「上」聯繫起來，而非與「下」聯繫起來。所以，他想知道，「北=上」和「好=上」是否會影響人們對不同地區價值的判斷。

當向人出示一幅假想的城市地圖，並問他們想居住在哪個位置時，他們當然更有可能會選擇北部。問另一組人，假想的不同社會階層會住在哪個位置，他們的回答是富人住在北邊，窮人住在南邊。

不難想像，人們較少在意地圖上靠「下」的國家或地區所發生的事情。

好消息是邁耶的實驗中，「北」與「好」的關係被輕鬆消除了——只需把地圖倒過來。所以，假如我們把地圖倒過來看，可能世界就會更加公平一點。網上很容易找到南方朝上的地圖。這也是莫特洛克大力推崇的一件事：「作為一個澳大利亞人，我覺得人們應該多做一些這樣的事。」

即使沒有其他的作用，這也一定會讓世界再次變得新鮮又神秘。地球上留給我們這代人的探險地點已經很少了，我們只能——按照馬塞爾·普魯斯特（Marcel Proust）的說法——再次審視我們的地球，但這次要用不同的眼光。

shaner

Imagine looking at the Earth from space. What is at the top of the planet? If you said the North Pole, you probably wouldn’t be alone. Strictly speaking, you wouldn’t be right either.

The uncomfortable truth is that despite almost everybody imagining that the world is this way up, there is no good, scientific reason to think of north as being the roof of the world.

The story of how it came to be considered to be that way is heady mix of history, astrophysics and psychology. And it leads to an important conclusion: it turns out that the way we have decided to map the world has very real consequences for how we feel about it.

Navigating brain

Understanding where you are in the world is a basic survival skill, which is why we, like most species come hard-wired with specialised brain areas to create cognitive maps of our surroundings. Where humans are unique, though, with the possible exception of honeybees, is that we try to communicate this understanding of the world with others. We have a long history of doing this by drawing maps – the earliest versions yet discovered were scrawled on cave walls 14,000 years ago. Human cultures have been drawing them on stone tablets, papyrus, paper and now computer screens ever since.

Given such a long history of human map-making, it is perhaps surprising that it is only within the last few hundred years that north has been consistently considered to be at the top. In fact, for much of human history, north almost never appeared at the top, according to Jerry Brotton, a map historian from Queen Mary University, London and author of A History of the World in Twelve Maps. “North was rarely put at the top for the simple fact that north is where darkness comes from,” he says. “West is also very unlikely to be put at the top because west is where the sun disappears.”

Confusingly, early Chinese maps seem to buck this trend. But, Brotton, says, even though they did have compasses at the time, that isn’t the reason that they placed north at the top. Early Chinese compasses were actually oriented to point south, which was considered to be more desirable than deepest darkest north. But in Chinese maps, the Emperor, who lived in the north of the country was always put at the top of the map, with everyone else, his loyal subjects, looking up towards him.  “In Chinese culture the Emperor looks south because it’s where the winds come from, it’s a good direction. North is not very good but you are in a position of subjection to the emperor, so you look up to him,” says Brotton.

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Given that each culture has a very different idea of who, or what, they should look up to it’s perhaps not surprising that there is very little consistency in which way early maps pointed. In ancient Egyptian times the top of the world was east, the position of sunrise. Early Islamic maps favoured south at the top because most of the early Muslim cultures were north of Mecca, so they imagined looking up (south) towards it:

Christian maps from the same era (called Mappa Mundi) put east at the top, towards the Garden of Eden and with Jerusalem in the centre.

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So when did everyone get together and decide that north was the top? It’s tempting to put it down to European explorers like Christopher Columbus and Ferdinand Megellan, who were navigating by the North Star. But Brotton argues that these early explorers didn’t think of the world like that at all. “When Columbus describes the world it is in accordance with east being at the top,” he says. “Columbus says he is going towards paradise, so his mentality is from a medieval mappa mundi.” We’ve got to remember, adds Brotton, that at the time, “no one knows what they are doing and where they are going”.
When you start looking at the Earth from space though, the idea of it being any particular way up starts to make even less sense. It’s true that, as we all learned in school, the Earth lines up along the same plane as all of the other planets in the solar system because they all formed out of the same cloud of spinning dust. It is also true, though, that this picture could just as easily be put upside down or with the Sun at the top or bottom, depending on where in space you happen to be looking from.

And compared to the rest of the Milky Way, our entire solar system is off kilter by about 63 degrees.

While astronomers have found that stars and planets align with their neighbours in similar ways all over space, Daniel Mortlock, an astrophysicist at Imperial College London, says that this is only true at a tiny scale compared to the vastness of the Universe. “As far as we astronomers can tell, there really is no ‘up’ or ‘down’ in space,” he says.

So the answer to the question of which way up is the Earth is simple: it is not any particular way up and there is no good reason other than a historical superiority complex to think of north as being the top of the world.

Yet is it time to start embracing a different view of the planet from the one we are used to? Perhaps, because evidence from psychology suggests that our north-up culture might be polluting the way we think of what is valuable in the world.


It isn’t too much of a stretch to think that people are less likely to care what happens in countries or regions that are ‘lower’ than them on the map or globe.

The good news is that in Meier’s experiments the relationship between ‘north’ and ‘good’ was eliminated by one simple thing – turning the map upside down. So perhaps the world might get a little fairer if we just took a look at it another way up now and again. South-up maps are easily available online. It is also something that Mortlock is very much in favour of: “As an Australian, I think it should be done more often,” he says.

If nothing else, it’s a sure-fire way to make the world seem fresh, and unexplored, once more. With so few earthbound discoveries left for our generation to make, all we can do is – to paraphrase Marcel Proust – look again at the world we’ve got, but this time, through different eyes.