童話中的科學(xué)

Kids of any age love to read fairy tales because the storyline offers the possibility that anything can happen. Curses， spells1)， and handsome princes reign in worlds beyond the reader's imagination.

But are the most magical moments from some of our favorite stories actually possible? Basic physical principles and recent scientific research suggest that what readers might mistake for fantasies2) and exaggeration3) could be rooted in4) reality.

So suspend5) your imagination for a moment， and look at the following fairy tales as a hard-core6) scientist might.

每個(gè)年齡段的孩子都愛讀童話故事，因?yàn)槠涔适虑楣?jié)從來都是天馬行空，什么都有可能發(fā)生。咒語、魔法和英俊的王子主宰著讀者想象以外的童話世界。

但是，在這些我們喜愛的童話中上演的那些最為神奇的場(chǎng)景事實(shí)上真有可能發(fā)生嗎?基礎(chǔ)物理學(xué)原理和最近的科學(xué)研究表明，一些讀者們誤認(rèn)為是虛幻和夸張的情節(jié)可能就來源于現(xiàn)實(shí)。

那么，就請(qǐng)你暫時(shí)停止想象，像一個(gè)純粹的科學(xué)家那樣來看看下面這幾個(gè)童話故事吧!

《格林童話》中有一個(gè)《長(zhǎng)發(fā)公主》的故事，說的是一個(gè)女巫將一位美麗的少女囚禁在一座塔中。長(zhǎng)發(fā)公主天生一副動(dòng)人的歌喉，長(zhǎng)著一頭金色的長(zhǎng)發(fā)。一天，一位王子經(jīng)過附近的樹林，被她的歌聲深深地迷住了。兩人墜入了愛河。長(zhǎng)發(fā)公主放下她的長(zhǎng)發(fā)，讓王子順著長(zhǎng)發(fā)爬上塔與她相會(huì)。這一連串的情節(jié)不禁使讀者心生疑竇:人類的頭發(fā)能承受另一個(gè)人的重量嗎?

一絲頭發(fā)平均能承受約3.5盎司或約兩塊糖的重量。一般來說，一絲黑色的頭發(fā)比金色的頭發(fā)更粗，因而也更結(jié)實(shí)。

但是，唉，長(zhǎng)發(fā)公主必須得靠她的金發(fā)了?？紤]到金發(fā)女子頭上有約14萬根頭發(fā)，因此她的頭發(fā)應(yīng)該可以輕而易舉地承受許多個(gè)王子的重量。然而，在這個(gè)故事里，問題沒那么簡(jiǎn)單。

如果長(zhǎng)發(fā)公主就這么簡(jiǎn)單地放下她的頭發(fā)，然后王子馬上開始攀爬，那么她的頭發(fā)不會(huì)斷，但有可能會(huì)被連“根”扯掉。而且，她身體的其他部分可能承受不了這樣的重量。值得慶幸的是，有一些辦法可以幫助減輕她頭部和身體所受到的拉力。

華盛頓特區(qū)的美國(guó)大學(xué)物理學(xué)助理教授內(nèi)森·哈什曼表示，如果長(zhǎng)發(fā)公主先把頭發(fā)綁在某個(gè)物體上，然后再垂下去，她就會(huì)更安全，也更有把握成功?！斑@樣做的原理是你可以利用頭發(fā)打上結(jié)后自身產(chǎn)生的摩擦力，而且不管頭發(fā)綁在什么物體上，這一物體都將會(huì)承受王子的重量?！陛^之于把長(zhǎng)發(fā)公主的頭皮作為支撐點(diǎn)，這個(gè)辦法要好得多。

Rapunzel《長(zhǎng)發(fā)公主》

In the Brothers Grimm story of Rapunzel， a witch holds a beautiful young woman captive7) in a tower. Rapunzel is blessed with a lovely singing voice and long， long blond hair. One day， her voice enchants8) a prince passing through a nearby forest. They fall in love， and Rapunzel lets down her hair so that the prince may use it to climb the tower to meet her. This chain of events begs9) readers to ask a question. Can human hair support the weight of another person?

On average one strand10) of hair can support about three and one-half ounces， or about the weight of two candy bars. Each strand of dark hair is generally thicker， and therefore stronger， than blond hair.

But， alas11)， Rapunzel must make do with blond locks12). Given that blondes generally have about 140，000 hairs on their heads， her hair should easily support the weight of many， many princes. However， there is more to this story.

If Rapunzel simply let down her hair and the prince started climbing immediately， her hair would not break， but it might be ripped13) out. Also， the rest of her body might not be able to support the weight. Thankfully， there are strategies that she can use to help reduce the strain14) on her head and body.

Nathan Harshman， Assistant Professor of Physics at American University in Washington， D.C.， suggests Rapunzel would be safer and more secure if she tied her hair around something before lowering it. \"The whole idea is that you can use the friction15) of the hair against itself in the knot， and whatever it is tied around will support the weight of the prince.\" That is a much better idea than making Rapunzel's scalp16) the anchor17) point.

The Little Mermaid《小美人魚》

In the Disney version of Hans Christian Andersen's The Little Mermaid， Ariel (the mermaid) asks a witch to make her human because she has fallen in love with a human prince. The witch bargains18) with Ariel and takes her voice in exchange for performing the transformation. For a considerable part of the story Ariel cannot speak， which is a problem because the prince can only recognize her by her incredibly beautiful singing voice. Later， she recovers her voice and wins the love of the prince.

In the story， Ariel loses her voice because of a curse. However， a less skilled witch could use a different method to silence a singing mermaid. Scientists have figured out a way to bend sound waves around an object and， can even prevent the escape19) of all sounds created inside a given area (important for keeping a transformed， singing mermaid from being heard).

Recently， Steve Cummer， Associate Professor of Electrical and Computer Engineering at Duke University announced that it is theoretically possible to create such a sound shield20). Building on research demonstrating how light waves can be bent around an object to make it appear invisible， Cummer and his collaborators21) used mathematical analysis to show how to do the same thing with sound. They established that it is possible to create a material that bends sound waves around walls， pillars， or any enclosed area， where the sound waves emerge as if nothing had been in their way. It would be like someone in the bedroom being able to hear what someone in the living room said， but as if there were no wall between them.

A side effect22) of this discovery is that sound waves generated inside the enclosed area would never escape. If the witch had been extremely clever， she could have built this material， and there would have been no need for a curse. Or maybe she did， and a transparent sound shield based on these principles was what enveloped Ariel until her love for the prince melted it away， finally releasing her melodious23) voice for the prince to hear.

在迪士尼版的安徒生童話故事《小美人魚》中，愛麗兒(小美人魚)請(qǐng)求女巫將自己變成人類，因?yàn)樗龕凵狭艘晃蝗祟惖耐踝?。女巫向愛麗兒提了要求，取走了愛麗兒的聲音作為把她變成人類的交換條件。因此在這個(gè)故事的大部分時(shí)間里，愛麗兒都不能說話，問題也由此而生，因?yàn)橥踝又挥新牭剿菬o比動(dòng)人的歌聲才能認(rèn)出她來。后來，她恢復(fù)了自己的聲音并贏得了王子的愛。

在這個(gè)故事中，愛麗兒因?yàn)橐坏乐湔Z失去了聲音。但是，如果是一個(gè)稍遜些的女巫，她還可以用另一種方法使小美人魚的歌聲“消失”?？茖W(xué)家們發(fā)現(xiàn)了一種方法，它可以讓聲波繞過物體，甚至還能使在特定區(qū)域內(nèi)發(fā)出的所有聲音絲毫不向外溢出(要使一位變?yōu)槿祟惖男∶廊唆~的歌聲不被人聽到，這一點(diǎn)非常重要)。

最近，杜克大學(xué)電氣與計(jì)算機(jī)工程副教授史蒂夫·坎默指出，制造這種聲音屏障在理論上是可行的。曾經(jīng)有研究演示了如何使光波繞過某物體，從而使該物體看上去如同消失了一樣。以此為基礎(chǔ)，坎默及其合作者運(yùn)用數(shù)學(xué)分析說明了如何使聲波也產(chǎn)生同樣的效果。他們表示，應(yīng)該可以制造出一種材料，使聲波繞過墻壁、柱子或任何封閉區(qū)域，就像未受任何阻擋一樣傳播。這就好比一個(gè)人在臥室里能聽見客廳里的人說話，就好像他們之間根本沒有墻一樣。

這一發(fā)現(xiàn)的可能后果是封閉區(qū)域內(nèi)發(fā)出的聲波完全無法外逸。如果那個(gè)女巫特別聰明，她可能已經(jīng)制造出這種材料，那也就用不著咒語了。或者也有可能她正是根據(jù)這些原理制造出的一種透明的聲音屏障將愛麗兒禁錮其中，直到愛麗兒對(duì)王子的摯愛將其消融，最終釋放出她那悅耳的聲音，使王子得以聽見。

1001 Arabian Nights 《一千零一夜》

飛毯是童話故事中最令人興奮的物品之一。在源自各種文化的眾多童話里，包括《一千零一夜》在內(nèi)，這些毯子載著人穿行千里。飛毯毫無疑問是不可能存在的，對(duì)嗎?

三位科學(xué)家最近在《物理評(píng)論快報(bào)》雜志上發(fā)表的一篇論文表明，在有些情況下，毯子是可以飛行的。他們利用物理學(xué)基本原理證明，如果空氣振動(dòng)頻率合適，一塊小而薄的毯子是可以飛起來的，這就好像我們放手讓一張薄紙下落時(shí)，它會(huì)緩緩飄落到地面一樣。他們的計(jì)算表明，持續(xù)重復(fù)的快節(jié)奏小幅氣浪可以使毯子以大約每秒一英尺的速度飛行。

不能指望馬上就可以看見阿拉丁“飛”過，但這些科學(xué)家在論文中寫道，他們所說的所有條件都“在自然和技術(shù)的可能范圍之內(nèi)。讓一塊較重的毯子飛起來當(dāng)然就需要一個(gè)強(qiáng)大得多的發(fā)動(dòng)機(jī)，而我們(的計(jì)算結(jié)果)表明，飛毯仍將存在于有魔力的、神秘和虛幻的世界里，如千百年來一樣。”

One of the most exciting objects found in fairy tales is the flying carpet. In tales from a wide variety of cultures， including 1001 Arabian Nights， these tapestries24) take flight to carry people vast distances. Flying carpets are clearly impossible， right?

Three scientists recently published a paper in the journal Physical Review Letters showing that there are conditions under which a carpet could fly. They used the basic laws of physics to show that a small， thin carpet could fly if the air were vibrating25) at the right frequency， much like how a piece of tissue paper26) floats softly to the ground when it is dropped. Their calculations showed that small waves of air in repeated fast pulses could steer27) a carpet at a speed of around one foot per second.

Don't expect to see Aladdin flying by anytime soon， but the scientists write that all of their conditions \"are within the realm of possibilities in nature and in technology. Making a heavy carpet fly would， of course， require a much more powerful engine， and our [calculations] suggest it will remain in the magical， mystical， and virtual realm28) as it has existed for millennia29).\"

Perhaps some fairy tales are more grounded in reality than others. Or maybe these stories are exactly what we thought they were. An idea is fertilized by the imagination and expanded beyond what seems possible. Or maybe science has come so far over the years that scientists are looking beyond the problems of the physical world and into the imaginations of children for their inspiration.

也許有些童話比其他童話更植根于現(xiàn)實(shí)，又或許這些故事確實(shí)只是故事。由于有了想象，某一想法變得越來越豐富，最后就天馬行空到了讓人覺得不可能的地步。又或許由于這些年來科學(xué)的迅速發(fā)展，使得科學(xué)家們開始探尋物理世界以外的問題，開始在孩子們的想象中尋找靈感。

Vocabulary

1.spell [spel] n. 符咒;咒語;魔法

2.fantasy [5fAntEsI] n. 想象，幻想

3.exaggeration

[I^7zAdVE5reIFEn] n. 夸大的事例;夸張的言詞

4.root in: 起源于，起因于

5.suspend [sE5spend] vt. 暫停;中止

6.hard-core [hB:dkC:] adj. (組織或運(yùn)動(dòng)成員中)斗志最堅(jiān)定的，中堅(jiān)的，骨干的

7.captive [5kAptIv] adj. 被俘虜(或獵獲)的;被關(guān)(押)的;受控制的

8.enchant [In5tFB:nt] vt. 使陶醉，使入迷

9.beg [be^] vt. 懇求，請(qǐng)求;催促，要求

10.strand [strAnd] n. (繩、線等的)股;縷;絞

11.alas [E5lAs] int. 哎呀，唉

12.lock [lCk] n. 一綹頭發(fā)

13.rip [rIp] vt. 猛力扯掉;猛力移去

14.strain [streIn] n. 拉力，張力

15.friction [5frIkFEn] n. 摩擦，摩擦力

16.scalp [skAlp] n.【解】頭皮

17.anchor [5ANkE] n. 固定樁，系縛物

18.bargain [5bB:^In] vi. 講價(jià)，討價(jià)還價(jià);講條件，談判

19.escape [I5skeIp] n. (氣體、液體等的)泄漏，逃逸

20.shield [Fi:ld] n. 保護(hù)物，防御物

21.collaborator [kE5lAbEreItE(r)] n. 合作者

22.side effect: (事態(tài)發(fā)展等的)意外后果;意想不 到的效果

23.melodious [mI5lEudIEs] adj. 旋律優(yōu)美的，悅耳的

24.tapestry [5tApIstrI] n. 織錦，掛毯

25.vibrate [vaI5breIt] vi. 震動(dòng)，顫動(dòng);振動(dòng);抖動(dòng)

26.tissue paper: 薄紙，棉紙

27.steer [stIE(r)] vt. 為(船舶)操舵;駕駛(車、船、飛機(jī)等)

28.realm [relm] n. 界，領(lǐng)域;范圍

29.millennia [mI5lenIE] n. millennium的復(fù)數(shù)形式;millennium [mI5lenIEm] n. 一千年