you probably think of this.

你或許會想阿基米德定律是在這樣的情況下發現的。

As it turns out, it may have been more like this.

真實的故事，可能是另外一回事。

In the third century BC, Hieron, king of the Sicilian city of Syracuse,

西元前三世紀，赫農王是西拉克斯西西里城的國王，

chose Archimedes to supervise

指定阿基米德監督

an engineering project of unprecedented scale.

一個史無前例的工程專案。

Hieron commissioned a sailing vessel

赫農王要求阿基米德建造一艘

50 times bigger than a standard ancient warship,

比戰艦還要大 50 倍的帆船，

named the Syracusia after his city.

並以其城市命名為西拉克斯。

Hieron wanted to construct the largest ship ever,

赫農王要建造一艘前所未有的大船，

which was destined to be given as a present

要作為埃及統治者

for Egypt's ruler, Ptolemy.

托勒密的禮物。

But could a boat the size of a palace possibly float?

但像宮殿一樣大的船浮得起來嗎？

In Archimedes's day, no one had attempted anything like this.

在阿基米德那個年代，沒有人解決過這樣的問題。

It was like asking, "Can a mountain fly?"

這就像是在問「能讓一座山飛起來嗎？」

King Hieron had a lot riding on that question.

赫農王對這個問題也感到疑問。

Hundreds of workmen were to labor for years on constructing the Syracusia

數百名工人花了好幾年的時間建造西拉克斯

out of beams of pine and fir from Mount Etna,

以埃特納火山的松樹和杉木來作船樑。

ropes from hemp grown in Spain,

使用西班牙的大麻作成麻繩，

and pitch from France.

使用來自法國的樹脂。

The top deck, on which eight watchtowers were to stand,

甲板上有八座瞭望臺，

was to be supported not by columns,

不是以圓柱撐起來，

but by vast wooden images of Atlas holding the world on his shoulders.

而是傳說中將世界扛在肩上的阿特拉斯的巨大木製人像。

On the ship's bow,

船頭上，

a massive catapult would be able to fire 180 pound stone missiles.

巨大的彈射器能夠發射 180 磅的石彈。

For the enjoyment of its passengers,

為了讓乘客享受搭乘的樂趣，

the ship was to feature a flower-lined promenade,

這帆船特別作一條雕花長廊步道，

a sheltered swimming pool,

一座室內游泳池，

and bathhouse with heated water,

提供熱水浴的澡堂，

a library filled with books and statues,

一座充满書籍和雕像的圖書館，

a temple to the goddess Aphrodite,

一座供奉女神愛芙羅黛蒂的神殿，

and a gymnasium.

和一座健身房。

And just to make things more difficult for Archimedes,

除此之外，還要找一些更加困難的差事給阿基米德，

Hieron intended to pack the vessel full of cargo:

赫農王想要將帆船裝滿貨物：

400 tons of grain,

四百噸的穀物，

10,000 jars of pickled fish,

一萬罐的醃魚，

74 tons of drinking water,

七十四噸的飲用水，

and 600 tons of wool.

六百噸的羊毛。

It would have carried well over a thousand people on board,

這船必須能夠搭載一千位以上的乘客，

including 600 soldiers.

其中包括六百位士兵。

And it housed 20 horses in separate stalls.

可在不同的馬廄安置二十匹馬。

To build something of this scale,

為了建造一艘龐大的船，

only for that to sink on its maiden voyage?

因為如此，它的處女航就沈沒在大海裡？

Well, let's just say that failure

嗯，也就是說失敗的結果

wouldn't have been a pleasant option for Archimedes.

對阿基米德來說並不是他想要的作法。

So he took on the problem: will it sink?

他提出了問題：這艘船會沈嗎？

Perhaps he was sitting in the bathhouse one day,

有一天他坐在澡堂裡，

wondering how a heavy bathtub can float,

很想知道如何讓一個浴缸浮起來，

when inspiration came to him.

一個靈感突然浮現腦海。

An object partially immersed in a fluid is buoyed up by a force

一個物體的一部分浸入液體會有浮力

equal to the weight of the fluid displaced by the object.

這浮力等於物體排出的液體的重量。

In other words, if a 2,000 ton Syracusia displaced exactly 2,000 tons of water,

換句話說，如果一艘二千噸的西拉克斯所排出的水量也正好是二千噸，

it would just barely float.

它剛好可以浮起來。

If it displaced 4,000 tons of water, it would float with no problem.

如果可以排出四千噸的水，要船浮起來是沒問題的。

Of course, if it only displaced 1,000 tons of water,

如果只排出一千噸的水是浮不起來的，

well, Hieron wouldn't be too happy.

當然，赫農王對此結果會不高興。

This is the law of buoyancy,

這就是浮力定律，

and engineers still call it Archimedes' Principle.

工程師仍然稱它為阿基米德定律。

It explains why a steel supertanker can float as easily as a wooden rowboat

它解釋為何一艘超級鋼製油輪能夠像木造划艇般容易浮起來

or a bathtub.

浴缸也是相同的道理。

If the weight of water displaced by the vessel below the keel

若船龍骨線以下所排出的水的重量

is equivalent to the vessel's weight,

等於船的重量，

whatever is above the keel will remain afloat above the waterline.

船龍骨線以上的地方將保持浮在船的吃水線之上。

This sounds a lot like another story involving Archimedes and a bathtub,

這聽起來像是另一個故事，有別於阿基米德和浴缸的故事，

and it's possible that's because they're actually the same story,

也可能是因為它們是同一個故事，

twisted by the vagaries of history.

卻被異想天開的歷史故事所扭曲。

The classical story of Archimedes' Eureka! and subsequent streak through the streets

大家所知的阿基米德靈機一動的故事！「大喊我發現了」然後裸奔穿過

centers around a crown, or corona in Latin.

圍繞著皇冠的街道中心，皇冠的拉丁文是"corona"。

At the core of the Syracusia story is a keel, or korone in Greek.

西拉克斯故事的主旨是船龍骨，其西臘文是"korone"。

Could one have been mixed up for the other?

是因為把 "corona"和 "korone" 混淆了嗎？

We may never know.

我們不得而知。

On the day the Syracusia arrived in Egypt on its first and only voyage,

當西拉克斯在它的第一次也是唯一一次的航行抵達埃及時，

we can only imagine how residents of Alexandria thronged the harbor

我們只能想像亞歷山大的居民蜂擁至港口

to marvel at the arrival of this majestic, floating castle.

看到這雄偉的，飄浮的城堡的到來而感到驚訝。

This extraordinary vessel was the Titanic of the ancient world,

這艘特別的船是古文明世界的鐵達尼號，

except without the sinking, thanks to our pal, Archimedes.

但這艘船並未沈入大海，這要歸功於阿基米德。