When you think of Archimedes' "Eureka!" moment, you probably think of this.
当提起阿基米德定律的发现时，你想象的画面可能是这样的。
As it turns out, it may have been more like this.
但真实的故事可能是另外一个样子。
In the third century BC, Hieron, king of the Sicilian city of Syracuse,
公元前三世纪，西西里城市叙拉古的国王希伦，
chose Archimedes to supervise an engineering project of unprecedented scale.
任命阿基米德监督一项前无古人的巨大工程。
Hieron commissioned a sailing vessel 50 times bigger than a standard ancient warship, named the Syracusia after his city.
希伦下令建造一艘巨大的帆船，比当时标准大小的帆船要大上50倍，并以他统治的城市叙拉古命名。
Hieron wanted to construct the largest ship ever, which was destined to be given as a present for Egypt's ruler, Ptolemy.
希伦的目标是建造有史以来最大的帆船，并将这艘船作为礼物送给埃及法老托勒密。
But could a boat the size of a palace possibly float?
但这艘巨大的海上宫殿能浮起来吗？
In Archimedes's day, no one had attempted anything like this.
在阿基米德的时代，还没有人解决过类似的问题。
It was like asking, "Can a mountain fly?"
这就好比问“山能飞吗？”
King Hieron had a lot riding on that question.
希伦国王对此深表疑虑。
Hundreds of workmen were to labor for years on constructing the Syracusia out of beams of pine and fir from Mount Etna,
数百名工人将用许多年的时间建造叙拉古号，砍伐埃特纳火山上的松木和杉木作为船梁，
ropes from hemp grown in Spain, and pitch from France.
采用西班牙生长的大麻搓成麻绳，并使用法国生产的树脂。
The top deck, on which eight watchtowers were to stand, was to be supported not by columns,
甲板上将矗立八座瞭望塔，支撑它们的不是柱子，
but by vast wooden images of Atlas holding the world on his shoulders.
而是传说中背负整个世界的阿特拉斯像。
On the ship's bow, a massive catapult would be able to fire 180 pound stone missiles.
在船首，巨大的投石机可以投射180磅的石块。
For the enjoyment of its passengers, the ship was to feature a flower-lined promenade,
为了乘客能享受美好的旅途，船上会有装饰着美丽花纹的走廊，
a sheltered swimming pool, and bathhouse with heated water,
有遮阳的游泳池，有热水的浴池，
a library filled with books and statues, a temple to the goddess Aphrodite, and a gymnasium.
有摆满了图书和雕塑的图书室，还有供奉阿芙罗狄蒂的神庙以及一个体操馆。
And just to make things more difficult for Archimedes, Hieron intended to pack the vessel full of cargo:
最后，好像这些还不够阿基米德忙活的，希伦还要给船装满货物：
400 tons of grain, 10,000 jars of pickled fish, 74 tons of drinking water, and 600 tons of wool.
400吨的谷物，10000坛子的腌鱼，74吨的饮用水，600吨的羊毛。
It would have carried well over a thousand people on board, including 600 soldiers.
并且还有1000名乘客，其中包括600名士兵。
And it housed 20 horses in separate stalls.
还要装载20匹马，各自有单独的马厩。

To build something of this scale, only for that to sink on its maiden voyage?
建造一艘如此庞大的巨物，然后在第一次航行时就沉到水底？
Well, let's just say that failure wouldn't have been a pleasant option for Archimedes.
嗯，对阿基米德来说这应该不会是一个愉快的选项。
So he took on the problem: will it sink?
那么问题就来了：这艘船会沉吗？
Perhaps he was sitting in the bathhouse one day,
可能有那么一天，阿基米德坐在浴缸里洗澡，
wondering how a heavy bathtub can float, when inspiration came to him.
想着这么重的浴缸为什么能浮起来呢，然后灵感乍现了。
An object partially immersed in a fluid is buoyed up by a force equal to the weight of the fluid displaced by the object.
部分浸入水中的物体受到向上的浮力等于它排开水的体积。
In other words, if a 2,000 ton Syracusia displaced exactly 2,000 tons of water, it would just barely float.
也就是说，如果2000吨重的叙拉古号能排开2000吨重的水，它就刚刚能浮起来。
If it displaced 4,000 tons of water, it would float with no problem.
如果能排开4000吨重的水，那就更没有问题了。
Of course, if it only displaced 1,000 tons of water, well, Hieron wouldn't be too happy.
当然，如果只能排开1000吨的水，那么希伦国王显然就不高兴了。
This is the law of buoyancy, and engineers still call it Archimedes' Principle.
这就是浮力定理，而工程师们仍然习惯称其为阿基米德定理。
It explains why a steel supertanker can float as easily as a wooden rowboat or a bathtub.
这个定理解释了为什么万吨巨轮能和小木船一样轻而易举的浮起来，对浴缸也是同一个道理。
If the weight of water displaced by the vessel below the keel is equivalent to the vessel's weight,
如果船龙骨线以下船身排开的水的重量等于船的重量，
whatever is above the keel will remain afloat above the waterline.
那么无论在龙骨线以上的是什么，都能浮在水面上。
This sounds a lot like another story involving Archimedes and a bathtub,
这跟另一个阿基米德和浴缸的故事版本很像，
and it's possible that's because they're actually the same story, twisted by the vagaries of history.
而这很可能由于这两个故事本身就是同一回事，只是被历史的变换莫测给曲解了。
The classical story of Archimedes' Eureka!
在广为流传的故事里，阿基米德大叫着我找到了，
and subsequent streak through the streets centers around a crown, or corona in Latin.
飞奔过街道，故事的核心是一顶皇冠，皇冠在拉丁文中是corona。
At the core of the Syracusia story is a keel, or korone in Greek.
而叙拉古这个版本的核心是龙骨，在希腊文中是korone。
Could one have been mixed up for the other? We may never know.
可能是将corona与korone混淆了吗？我们永远无法知道了。
On the day the Syracusia arrived in Egypt on its first and only voyage,
当叙拉古号在完成它第一次也是唯一一次的航程抵达埃及时，
we can only imagine how residents of Alexandria thronged the harbor to marvel at the arrival of this majestic, floating castle.
我们可以想象，亚历山大城当地的居民成群结队的去港口观瞻这艘非凡的浮动的城堡，定会惊叹不已的。
This extraordinary vessel was the Titanic of the ancient world, except without the sinking, thanks to our pal, Archimedes.
这艘巨船就好比古代的泰坦尼克号一样，不同的只是它没有沉没，而这要感谢我们的阿基米德。