Edmund Hillary, from New Zealand, and Tenzing Norgay, a Sherpa from from Nepal and India,

來自紐西蘭的Edmund Hillary和來自尼泊爾和印度的夏爾巴人Tenzing Norgay。

became global celebrities after reaching the summit, where Hillary snapped this photo of

在到達峰會後成為全球名人，希拉里在峰會上拍下了這張照片。

Norgay holding their national flags. Since then, many have followed in their footsteps,

諾爾蓋舉著自己的國旗。此後，許多人紛紛追隨他們的腳步。

raising their own flags at the peak. Summit bids have created a lucrative industry —

在高峰期舉起自己的旗幟。峰會競標創造了一個利潤豐厚的行業--。

and a perilous one; hundreds have died or been injured during the climb. All in the

且險象環生；在攀登過程中，已有數百人死傷。所有的人都在

pursuit of one goal: reaching the highest point on Earth. But the thing is, most of

追求一個目標：達到地球上的最高點。但問題是，大多數人

the people who have stood on top of Mt. Everest have climbed to slightly different heights—

站在珠穆朗瑪峰頂上的人，攀登的高度略有不同----。

For Hillary and Norgay, it was 8,840 meters. For this British Army officer who summited

對於希拉里和諾爾蓋來說，是8840米。對於這位登頂的英軍軍官來說

in 1976, the height was 8,848 meters. This Sherpa guide and his Swedish client climbed

1976年，高度為8848米。這名夏爾巴人嚮導和他的瑞典客人攀登的是

29,035 feet or 8,850 meters in 1999. And at the end of 2020, the height of Mount Everest

1999年為29035英尺或8850米。而在2020年底，珠穆朗瑪峰的高度。

changed again — it's now officially 8,849 meters. These changes are small — and probably

再度改變--現在官方公佈的是8849米。這些變化很小，而且可能

don't really matter to the people who've reached the summit. But the reason why Mount

對於已經登上山頂的人來說，並不重要。但山的原因

Everest's height keeps changing tells a story about how we measure mountains—and

珠穆朗瑪峰的高度不斷變化講述了一個關於我們如何測量山峰的故事------。

about who gets to do the measuring. We have only one Mt. Everest in the world.

關於誰得到做測量。我們只有一個珠穆朗瑪峰在世界上。

But the one mountain had several heights. This is the Himalayan mountain range, and

但是，一山有幾山高。這就是喜馬拉雅山脈，而。

here is Mount Everest, with one side in Tibet and another side in Nepal. In Nepal, the mountain

這裡是珠穆朗瑪峰，一面在西藏，一面在尼泊爾。在尼泊爾，這座山

is known as Sagarmatha; in Tibet, it's called Chomolungma. Everest is a colonial name, named

被稱為薩迦瑪塔；在西藏，它被稱為喬木隆瑪。珠穆朗瑪峰是一個殖民地的名字，名為

for this British official, George Everest. And that's because India, Nepal's neighbor,

對於這位英國官員，喬治-珠穆朗瑪峰。而這是因為印度，尼泊爾的鄰國。

was under British rule when Everest was first measured. British and

第一次測量珠穆朗瑪峰時，是在英國的統治下。英國和

Indian surveyors started a massive mapping project in 1802, at one point led by George

1802年，印度測量師開始了大規模的測繪工程，一度由喬治上司的

Everest. Called the Great Trigonometrical Survey. They measured as much of India's

珠穆朗瑪峰。被稱為 "大三角測量"。他們測量了儘可能多的印度

land as they could, using an instrument like this, called a theodolite.

他們儘可能地使用這樣的儀器，稱為theodolite的土地。

It's the distant ancestor of what land surveyors and engineers use today—to basically do

它是今天土地測量師和工程師使用的遠古祖先--基本上是在做... ...

the same thing —measure the angles between two horizontal points, and use basic trigonometry

同樣的事情--測量兩個水準點之間的角，並使用基本的三角學。

to measure the location and distance to a third point. But when surveyors from the Great

來測量第三點的位置和距離。但是，當來自大的測量人員

Trigonometrical Survey reached the Himalayas in the 1840s, they ran into a very tall, vertical

三角測量在19世紀40年代到達喜馬拉雅山時，他們遇到了一個非常高大的、垂直的

problem. Measuring the height of a mountain is more complicated than just measuring from

問題。測量一座山的高度，比單純的從山上測量要複雜得多。

the ground to the peak. You have to know where sea level is. Because sea level is relatively

從地面到山頂。你必須知道海平面在哪裡。因為海平面相對來說

similar throughout the globe, it's the base that most natural heights on earth are measured

世界各地都有，但地球上大多數自然高度都是以它為基準的。

from. But there is no sea or ocean immediately next to the Himalayas. So surveyors in the

從。但緊挨著喜馬拉雅山的地方沒有海和洋。所以測量人員在

mid-1800s had to walk from the Bay of Bengal to translate sea level to

19世紀中葉，人們不得不從孟加拉灣走到海平面上，將海平面換算為海平面。

the Himalayas, which took years. Surveyors couldn't enter Nepal at the time,

喜馬拉雅山，花了好幾年時間。當時測量人員無法進入尼泊爾。

so they did this from over 100 miles away, across the border in India.

所以他們從100多英里外越過印度邊境做了這件事。

Only then could they measure the distance between two points at sea level then aim the

只有這樣，他們才能在海平面上測量兩點之間的距離，然後將其瞄準。

theodolite to the peak. That's how they measured the Himalayas, 100 years before anyone

他們就是這樣測量喜馬拉雅山的他們就是這樣測量喜馬拉雅山的，比任何人都早100年

reached Everest's summit. And that's how, in 1855, the first official measurement of

到達了珠穆朗瑪峰的山頂。這也是1855年，第一次正式測量珠峰的過程

Mount Everest was recorded: 8,840 meters. After that first measurement, scientists from

珠穆朗瑪峰的記錄是：8840米。在第一次測量之後，科學家們從

around the world began documenting their own heights. They were never too far off from

世界各地的人們開始記錄自己的高度。他們永遠不會離得太遠

that first one, but fluctuated anywhere from ⅓ of a meter to 72 meters. One reason those

那第一個，但波動的地方從⅓一米到72米。一個原因是這些

numbers differ is because it's still really hard to calculate sea level. The sea might

數字的不同是因為海平面的計算還真的很難。海面可能

seem relatively smooth compared to earth's erratic topography. But water is uneven too:

與地球上變化無常的地形相比，顯得相對平穩。但水也是不平的。

tides go up and down — and, thanks in part to global warming, sea levels are rising.

潮汐漲落--部分由於全球變暖，海平面正在上升。

The global mean sea level is an average of all these fluctuations. But when surveyors

全球平均海平面是所有這些波動的平均值。但當測量人員

want to measure a mountain's height, they have to be more precise. That means considering

想要測量一座山的高度，他們必須更加精確。這意味著要考慮

something called the ellipsoid — the bulge at Earth's equator due to the centrifugal

被稱為橢圓體的東西--地球赤道上由於離心力而產生的凸起。

force of its rotation. And areas of the Earth with more density, like mountain ranges, affect

其旋轉的力量。而地球上密度較大的地區，如山脈，會影響到地球的自轉。

gravity and therefore the height of sea level. Taking variations on gravity into account,

重力，是以，海平面的高度。考慮到重力的變化。

this is Earth's true sea level, called the geoid, which is full of dimples and bumps.

這就是地球的真實海平面，被稱為地殼，它充滿了凹凸不平。

When surveyors want to measure Everest, they have to precisely consider all these conversions,

當測量人員要測量珠峰時，他們必須精確地考慮所有這些轉換。

which explains some of the variations in height. But there's another reason the height of

這就解釋了一些身高的變化。但還有另一個原因是

a mountain might shift, that has to do with the origin story of the Himalayas.

一座山可能會移動，這與喜馬拉雅山的起源故事有關。

These mountains started forming 50 million years ago when the Indian continent collided

這些山脈是在5000萬年前印度大陸碰撞時開始形成的。

with the Asian continent. That collision hasn't stopped happening, even if we can't see

與亞洲大陸的碰撞。即使我們看不到，這種碰撞也沒有停止過。

it. Geologists think that the Himalayas are still rising 5 millimeters a year, or a quarter

它。地質學家認為，喜馬拉雅山每年仍在上升5毫米，或四分之一的高度。

of an inch. The tectonic shifts causing that growth also

寸的。導致這種增長的構造變化也是如此

cause earthquakes in the region, which can shift the height of mountains.

引起該地區的地震，從而使山體高度發生變化。

So when Nepal suffered a devastating earthquake in 2015,

所以，當尼泊爾在2015年遭遇毀滅性地震時。

Scientists knew Everest's height had probably changed.

科學家們知道珠穆朗瑪峰的高度可能發生了變化。

Nepalese surveyors decided to investigate. Being the Everest-lying country all responsibility

尼泊爾勘測人員決定進行調查。作為珠穆朗瑪峰的國家，所有的責任

is to clarify the question regarding the height of Mount Everest.

是為了澄清關於珠峰高度的問題。

Khim Lal Gautam, climbed to the top of Everest in 2019 to take a new measurement.

欽-拉爾-古塔姆，在2019年登上珠峰之巔，進行新的測量。

And brought with him a tool that's been helping surveyors since the 1980s: a GPS receiver.

並帶來了一個從上世紀80年代就開始幫助測量人員的工具：GPS接收器。

Gautam lingered at the peak of Everest for nearly 2 hours in the middle of the night,

古塔姆半夜在珠峰峰頂逗留了近2個小時。

which is an eternity anywhere in the oxygen-deprived altitude above 8,000 meters, known as The

在8000米以上的缺氧高度，即所謂的 "永恆"。

Death Zone. He endured it to receive as many satellite pings as he could.

死亡地帶。他為了儘可能多地接收衛星信號而忍耐著。

GPS can accurately measure height through the time it takes a satellite signal to reach

全球定位系統可以通過衛星信號到達的時間來精確測量高度。

a receiver. But that signal gives a height based on Earth's ellipsoid, not the geoid.

一個接收器。但這個信號給出的高度是基於地球的橢圓體，而不是地球儀。

Which means it still doesn't solve for the most important part of mountain surveying:

也就是說，它仍然沒有解決山地測量中最重要的部分。

establishing the local sea level.Doing that with precision still requires surveying on

確立當地的海平面。

land. We planned for the study of 50 kilometers

土地。我們計劃研究50公里

at the east and 50 kilometers at the west, from northern border to the southern border.

東邊50公里，西邊50公里，從北部邊境到南部邊境。

This was our study area and within this region we had around 300 control points.

這是我們的研究區域，在這個區域內我們有大約300個控制點。

Susheel Dangol led the Nepalese survey from 2017 to 2019.

從2017年到2019年，Susheel Dangol上司了尼泊爾的調查。

To find the geoid height, they measured gravity through an instrument like this.

為了找到地心引力的高度，他們通過這樣的儀器測量重力。

The main motive of this... is to get the mean sea level.

主要的動機是為了得到平均海平面。

Around the same time that Susheel and Gautum were surveying, a Chinese team was, too, from

大約在蘇西爾和古圖姆勘察的同時，一支中國隊伍也，從。

the Tibetan side of Everest. And in December 2020, they made a joint announcement about

珠穆朗瑪峰的西藏一側。而在2020年12月，他們聯合宣佈了關於

their agreed-upon new measurement: 8,848.86 meters.

他們商定的新測量值：8,848.86米。

Since 1855, all official measurements of Everest from the Nepalese side were done by colonial

自1855年以來，所有從尼泊爾一側對珠峰進行的官方測量都是由殖民者完成的。

or foreign surveyors. Which makes this number significant: it's the first time in history

或外國測量師。這讓這個數字變得很有意義：這是歷史上第一次。

Nepal measured their own mountain.

尼泊爾測量自己的山。

We are very proud to be the people of the Everest country. Mount Everest country, we are the people of the Sagamartha country.

我們是珠穆朗瑪峰國的人民，我們非常自豪。珠穆朗瑪峰國，我們是薩迦瑪塔國的人民。

We feel proud to do the Everest measurement ourselves because we have not done that task ourselves.

我們覺得很自豪，因為我們自己沒有完成過這個任務，所以自己做珠峰測量。

In the future, Everest's height might still inch up or down.

未來，珠穆朗瑪峰的高度可能還會寸步難行。

but for anyone who reaches the top, they will still be on the roof of the world.

但對於任何一個到達頂峰的人來說，他們仍然會在世界屋脊上。

So we just showed you difficult it is to find mean sea level.

所以我們剛剛向你展示了尋找平均海平面的難度。

But there's actually a couple other ways you can measure the height of a mountain.

但其實還有幾種方法可以測量山的高度。

that's less universally-used but would make some mountains actually taller than Everest.

那是不太普遍使用的，但會使一些山峰實際上比珠穆朗瑪峰更高。

If you take the measurement from Earth's center instead of sea level, Mount Chimborazo in Ecuador

如果從地球中心而不是從海平面測量，厄瓜多爾的欽博拉索山。

would actually be taller than Everest.

其實會比珠穆朗瑪峰還高。

And that's because it's located closer to the Equator, so the ellipsoid would push it taller.

那是因為它的位置更靠近赤道，所以橢圓體會把它推得更高。

And if you take a simple base to peak measurement.

而如果你採取簡單的基數到峰值測量。

Mauna Kea in Hawaii would be taller than Everest

莫納克亞在夏威夷會比珠穆朗瑪峰還高。

and that's because a majority of the mountain is actually underwater, so below sea level.

而這是因為大部分的山體其實都在水下，所以低於海平面。

I included a link in the description if you want to read more about that.

如果你想閱讀更多的資訊，我在描述中加入了一個鏈接。