物理学是托福听力中比较高频的一个考察题材，了解相关的背景知识可以有效助力备考。想要了解物理学，不如从物理学家开始，今天在这里给大家介绍的就是历史上比较有名一位物理学家Archimedes，没错，就是大家熟知的洗澡时发现皇冠如何称重的阿基米德。

阿基米德(Archimedes , 公元前287年 --- 公元前212年 )，伟大的古希腊哲学家、百科式科学家、数学家、物理学家、力学家，静态力学和流体静力学的奠基人，并且享有“力学之父”的美称，阿基米德和高斯(Johann Carl Friedrich Gauss)、牛顿(Isaac Newton)并列为世界三大数学家。 阿基米德曾说过：“给我一个支点，我就能撬起整个地球。”(“Give me the place to stand, and I shall move the earth.”)

接下来我们就来看一个阿基米德的(中英文)小故事。公元前1世纪，罗马作家维特鲁威记叙了一件可能是虚构的故事……

Hieron II, the King of Sicily, had ordered a new gold crown. When the crown was delivered, Hieron suspected that the crown maker had substituted silver for some of the gold, melting the silver with the remaining gold so that the color looked the same as pure gold. The King asked his chief scientist, Archimedes, to investigate.

【关键词】

Archimedes [ˌɑrkəˈmidiz] 阿基米德;

crown [kraʊn] n. 王冠;

suspect [ sʌspɛkt] vt. 怀疑;猜想;

investigate [ɪn'vɛstɪɡet] v. 调查;研究;

melt [ mɛlt] v. 融化,溶解;

传说当时的西西里国王希伦二世,新打制了一顶纯金的王冠。但是却怀疑工匠们在制作过程中以次充好，掺了一部分银子，于是命令他的首席科学家阿基米德来调查这件事。

Archimedes puzzled over the problem. The new crown was precious, and must not be damaged in any way. He went to the public baths in Syracuse to ponder the problem. The bath was full to the brim, and when he climbed in, he noticed two things: that water level rose, making some water slop over the side, and he felt weightless. He shouted “Eureka!” (I have found the answer!) and ran home stark naked.

【关键词】

puzzle ['pʌzl] vt. 使…困惑;

ponder the problem 思考问题;

brim [brɪm] n.边缘;v.溢出，满溢;

stark [stɑrk] adv. 完全;明显地

naked ['nekɪd] adj. 裸体的;无装饰的;无证据的;直率的

阿基米德受命解决这个难题，可是皇冠如此宝贵，无论如何都不能破坏。他去希腊库扎的公共浴室思考这个问题，当他进入放满水的浴缸，他注意到了两件事情：一是水位升高，还有一些水溢了出来;另外他有种失重的感觉。他高喊着“找到了”跑回了家。

Archimedes had realized that if he lowered the crown into a bucket filled to the brim with water, it would displace some water – exactly the same amount as its own volume – and he could measure how much water spilled out. This would tell him the volume of the crown. Silver is less dense than gold, so a silver crown of the same weight would be bigger than a gold crown, and would displace more water. Therefore, an adulterated crown would displace more water than a pure gold crown—and more than a lump of gold of the same weight.

【关键词】

volume ['vɑljum] n. 容量;

measure ['mɛʒɚ] v. 测量;

dense [dɛns] n.密度;

adulterated [ə'dʌltə,ret] adj. 掺入次级品的;

阿基米德意识到，如果他把皇冠放入满水中，那么有些水就会溢出来，这些水的体积等于皇冠的体积。也就能通过测量水的体积，来得到皇冠的体积。银比金密度小，因此同等重量的银子体积应该大，也就是说，会溢出更多的水。因此，掺入次级品的皇冠在同等重量下，会溢出更多的水。

Archimedes probably solved the puzzle by hanging the crown and an equal weight of pure gold on opposite ends of a stick, which he then suspended by its center so that the two weights balanced. Then he lowered the whole thing into a bath of water. If the crown was pure gold, it and the lump of gold would experience an equal upthrust, and the stick would stay horizontal. If the crown contained some silver, however, the volume of the crown would be greater than the volume of the lump of gold—the crown would displace more water, and the stick would tilt sharply.

【关键词】

puzzle ['pʌzl] n. 难题;谜;

suspend [sə'spend] v. 悬浮;暂停;

lump [lʌmp] n. 块; 团;

upthrust ['ʌpθrʌst] n. 上推;

horizontal [ˌhɔːrə'zɑːntl] adj. 水平的;

displace [dɪs'pleɪs] v.替换;

tilt [tɪlt] v.倾斜;

阿基米德可能通过以下方法解决了这个难题：他将皇冠以及相同重量的金块挂在一根木棍的两端，然后从木棍的中间悬挂起来，使得两个重物达到平衡。然后他将皇冠和金块同时浸到一盆水中，如果皇冠是纯金制成，那么它和金块将受到同样的浮力，木棍将会保持水平。如果皇冠中掺杂了银子，皇冠的体积将大于金块，皇冠会溢出更多的水，木棍就会发生倾斜。

Archimedes’ idea became known as Archimedes’ principle, which states that the upthrust on an object in a fluid is equal to the weight of the fluid the object displaces.

【关键词】

fluid ['fluːɪd] n. 液体;

阿基米德的这一想法就是我们所熟知的“阿基米德原理”，即物体在液体中受到的浮力等于溢出液体的重量。

维特鲁威告诉我们，希伦二世的皇冠确实掺杂了银，金匠也因此受到了惩罚。

好啦，故事讲完了，虽然是耳熟能详的故事，但是在用英文版陈述的时候，摇身一变，多了许多大家不太认识或者不太熟悉的单词，其中的生词你们都掌握了么?

在我们的TPO当中也提到了这位伟大的物理学家，比如TPO26-6中，就考察了有关阿基米德的重写本(Palimpsest)的内容，现在不妨放下手机，找出这篇文章仔细研究一下吧!