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栏目简介:《英语视频之Top5》是英语视频听力下的子栏目,栏目包含中英字幕,而且能够了解世界上5大新奇或者有意思的事物,比如美军飞行器、社交媒体、核武器等,通过简单有趣的讲述,能够提高学习英语的兴趣,积累一些英语知识,是比较生动的英语学习材料。 Article/201511/407370Suppose you want to know how long it was between the Norman invasion of England and Columbus#39;s arrival in the Caribbean;that is,what#39;s 1492 minus 1066 but you hate long subtraction with its borrowing and such.Well,we can subtract by adding:first we just need to replace each digit of the smaller number with 9 minus that digit,except the final digit gets replaced with 10 minus that digit,so 1066 becomes nine minus 1,nine minus 0,nine minus six,ten minus 6.假设你想知道,诺曼底登陆和哥伦比亚抵达加勒比海之间,相隔多久;是1429减去1066 但你又讨厌多位数减去的借位等麻烦步骤。那么,我们可以通过加法来进行减法运算:首先我们需要用9减去每个数位上的数字,得到一个较小的数字来代替它,最后一位数用10来减,那么1066就是 9减1 9减0,9减6 10减6.Adding that to 1492 gives 10426,and if we ignore the first digit,we get the answer:1492 minus 1066 is 426.You can check just to be sure.Coincidentally,it#39;s roughly 426 times farther from Portugal to the West Indies and back than from France to England.将得到的数值加上1429等于10426,然后去掉首位,我们就得到了1429减1066的426.不信,你可以计算验一下。巧的是,从葡萄牙到到西印度群岛的距离,大约是从法国到英国距离的426倍。But anyway,the subtraction-by-adding trick works for any positive numbers! 8 minus 6,or 2 is the same as 9 plus 4,ignoring the first digit.100 minus 1? is 100 plus 999,which is 99,ignoring the first digit.And 424,242 minus 333,333 is 424,242 plus666,667 or,90,909 ignoring the first digit.I#39;ll let you check that one.总之,通过加法做减法的技巧,对一切正数都管用!8减6 得2.这根8加4 忽略首位的结果是一样的。100减1? 相当于100加999.略去首位,就是99.424242减333333 相当于424242加666667等于90909再略去首位。再试试这个。This trick might seem useless,but suppose you built a machine that can add numbers together,and you wanted to make it subtract?Well,in that case it might be easier to make it subtract by adding:and matter of fact,my friend Hank Green took apart an adding machine and that#39;s exactly how it subtracts-by adding!这个计算技巧看起来似乎没什么用,但是假设你制造了一台可以进行加法计算的机器,可你却想用它做减法?在这种情况下,用加法做减法运算就很好用了:事实上,我朋友Hank Green拆解了加法机器,而这正是做减法的办法————通过相加!Basically,the machine adds numbers by rotating numbered wheels,but there aren#39;t infinitely many wheels so if you add up past the maximum possible number,you get back to zero-this is called;overflow;in computing and modular arithmetic in mathematics.But most importantly getting back to zero by adding means it#39;s possible to have positive negative numbers,since,for example,negative three is just what you add to three to get zero,and on Hank#39;s adding machine if you add 3 plus 9,997.00,you get zero,so 9,997is literally negative three!基本上,机器通过转动数字齿轮进行加法运算,问题是齿轮是有限的,因此,一旦相加的数值超过上限,你得到的数值就是0 计算机里称之为“溢出”数学运算中称之为“模运算”。最重要的是通过加法得到0 意味着,这可能是加了一个负数的结果,例如,负3加3就等于0,使用Hank的加法机器 3加9997等于0,也就是说9997相当于负3!Unfortunately,there are an infinite number of numbers when you#39;re doing regular arithmetic,so you might think that negative three is just negative three.But if you#39;re willing to fudge a little,you can just take the adding machine#39;s version of negative three,add a bunch of 9s out in front,and when you add that to stuff it#39;s basically the same as subtracting three,as long as you don#39;t look too far.不幸的是,在你进行常规计算时,存在着无数多的数字,所以你会觉得负3就只是负3.但是如果你愿意胡思乱想一番,那么负3就可以变成加法机器意义上的负3,在前面加上一大串的9,然后与某个数值相加,结果就相当于这个数值减3,就跟少几个9的时候一样。Because,you know,nine gadgillion nine hundred and ninety bajillion nine hundred and ninety seven plus three,is zero.By the way,this method of subtracting by adding is how computers subtract as well,they just do it in binary which makes it a lot easier.It#39;s called ;subtracting using the two#39;s complement,;if you want to look it up,;subtracting using the two#39;s complement;因为,你瞧99999, 99997加3 等于0.顺便说一句。计算机就是,通过这种加法,进行减法运算,只不过计算机在二进制下计算,会更简单些。 Article/201506/378046So in 1994 a small unmanned orbiter Clementine于是柯蕾曼堤号无人太空船was sent back to the moon,在1994年再度前往月球the first spacecraft to make the journey in more than 20 years.这是20多年来首度展开这趟旅程的太空载具And this mission would go somewhere new.而这次的任务也不同于以往Technology had moved on since the 70s,科技自70年代后有了长足进步and so Clementine would be able to reach an area所以柯蕾曼堤号可以抵达of the moon that had never been seen in detail before.月球从未被详仔观察过的区域The lunar poles.那就是月球的两极地带Clementine spent 2 months bombarding柯蕾曼堤号花了两个月the moon with radio waves,对地球放送无线电波and in doing so,因此it made a discovery that scientists had never dreamt of.有了科学家做梦也想不到的重大发现They found what appeared to be patches of ice.他们发现了像冰层的地方Its radar was getting signals being bounced back太空船的雷达from the surface very strongly in a way收到了强大的回传讯号that was consistent with their being patches of ice down there.让人觉得下方应该是有冰层And er it#39;s not a lot of ice- it could er, could fill er,那些冰层并不大,融解的话could fill plenty of Olympic sized swimming pools,可以装满很多座标准游泳池but if you were to melt it and sp,但若将融化的水量sp it out over the lunar surface it均匀分布在月球表面would be I don#39;t know a millimetre thick or something.水的深度大概只有一公厘左右But you#39;re not going to produce oceans所以这些冰层on the moon from this ice.不可能形成海洋But enough there for humans to exploit.但是让人类利用绰绰有余The existence of water on the moon even if it was frozen月球上有冰层的事实changed everything.改变了一切The bleak and barren landscape wasn#39;t so inhospitable after all.看来荒芜贫瘠的月球,毕竟没有那么不适合人类居住Suddenly the possibilities seemed endless.突然间出现了无穷无尽的可能性With life-sustaining water,有了能维持生命的水the moon could one day be a base in space,月球未来很可能成为太空中的基地a stepping stone to the rest of the universe.征宇宙的踏脚石Humans might even live there one day.有朝一日甚至可以让人类居住The love affair was back on.熄灭的爱火重新燃起As if to drive home the renewed fascination,仿佛为了进一步撮合人类与月球的情缘45 years after President Kennedy#39;s famous pledge在肯尼迪总统承诺to take us to the moon,要让人类征月球的45年之后another US President launched a new mission.另一位美国总统推动了一项新任务Returning to the moon is an important step重返月球是我们太空计划中for our space programme.很重要的一步Establishing and extending human presence进驻月球on the moon could vastly reduce可大幅降低the cost of further space exploration.未来探索太空的成本Making possible very more ambitious missions.让我们得以推动更具企图心的任务The moon is a logical step toward further progress and achievement.追求未来的进步与成就,月球是顺理成章的下一步Human beings are headed into the cosmos.人类即将征宇宙It may have lacked some of his predecessor#39;s rhetorical flourish,布希总统的演讲也许少了甘迺迪总统的华丽辞藻but 35 years after the last man stepped off the moon,但在最后一名太空人登陆月球的35年之后we are finally going back.我们终于要回去了NASA has aly started planning the new lunar mission.航太总署已经开始规划新的登月任务And it#39;s going to be big.这次的规模将不同凡响We are planning to go to the moon in a particular,我们打算以不同于different way than what we did with Apollo Apollo was short,阿波罗计划的方式前往月球sortie missions,阿波罗计划都是短期任务and we#39;re planning to go to the moon to stay.这次我们打算长期停留 Article/201505/374276So why did the Sun#39;s spots disappear for 50-odd years?那太阳黑子为什么会消失五十几年呢To answer that question,为了回答这个问题Mike had to go back even further in time,迈克还得回到更早的时间back before the beginning of civilisation.回到文明诞生之前One of the best places to若想了解get that long view of the history of the Sun太阳的漫长历史 最好的一个地方is in ice.就是在冰里He and his fellow scientists analysed ice cores他和其他科学家分析冰芯because they contain a signature因为其上记录了of what#39;s been happening to the Sun over thousands of years.太阳数千年来的活动We can core into that effectively look back in time.我们可以取出冰芯有效地追溯到过去Roughly speaking, there are 20 to 30 grand maxima大致上 我们可以看到在九千年间and grand minima in the 9,000 years that we can look at.有二三十个太阳活动极大和极小期So what the ice showed冰芯显示的结果was something nobody could have predicted.出乎人们意料The Sun had a secret rhythm.太阳有一个秘密的周期 Article/201410/337967栏目简介:《趣味青春英语视频》是外语网络电台的精品节目,通过大讲堂的网络课堂形式,能够帮助英语学习者积累一些英语背景知识,并通过互动的教学形式,帮助有效记忆英语知识。本栏目是学习趣味青春英语的好材料。 Article/201510/398747

《谈判力》的作者威廉·尤里,提供了一种高雅,简单(但是并不容易)的方法,它使得人们在哪怕是最困难的谈判中,比如从家庭争端,也许到中东问题上达成一致。 Article/201411/341619

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