研究生科技英语阅读课文翻译(1、2、4、8、10)

研究生科技英语阅读课文翻译(1、2、4、8、10) Unit 1 Genetically modified foods -- Feed the World? If you want to spark a heated debate at a dinner party, bring up the topic of genetically modified foods. For many people, the concept of genetically altered, high-tech crop production raises all kinds of environmental, health, safety and ethical questions. Particularly in countries with long agrarian traditions -- and vocal green lobbies -- the idea seems against nature. 如果你想在某次晚宴上挑起一场激烈的争论，那就提出转基因食品的话题 吧。对许多人来说，高科技的转基因作物生产的概念会带来诸如环境、健康、安 全和伦理等方面的各种问题。特别是在有悠久的农业生产传统和主张环保的游说 集团的国家里，转基因食品的主意似乎有悖自然。 In fact, genetically modified foods are already very much a part of our lives. A third of the corn and more than half the soybeans and cotton grown in the US last year were the product of biotechnology, according to the Department of Agriculture. More than 65 million acres of genetically modified crops will be planted in the US this year. The genetic is out of the bottle. 事实上，转基因食品已经成为我们生活重要的一部分。根据农业部的统计， ,3，大豆和棉花的一半以上都是生物技术的产物。今美国去年所种植玉米的1 年，美国将种植6500多万英亩的转基因作物。基因妖怪已经从瓶子里跑出来了。 Yet there are clearly some very real issues that need to be resolved. Like any new product entering the food chain, genetically modified foods must be subjected to rigorous testing. In wealthy countries, the debate about biotech is tempered by the fact that we have a rich array of foods to choose from -- and a supply that far exceeds our needs. In developing countries desperate to feed fast-growing and underfed populations; the issue is simpler and much more urgent: Do the benefits of biotech outweigh the risks? 但是，显然还有一些非常现实的问题需要解决。就像任何一种要进入食物链 的新食品一样，转基因食品必须经过严格的检验。在富裕的国家里，由于有大量 丰富的食品可供选择，而且供应远远超过需求，所以关于生物技术的争论相对缓 和一些。在迫切想要养活其迅速增长而又吃不饱的人口的发展中国家，问题比较 简单，也更加紧迫:生物技术的好处是否大于风险呢? The statistics on population growth and hunger are disturbing. Last year the world's population reached 6 billion. And by 2050, the UN estimates, it will probably near 9 billion. Almost all that growth will occur in developing countries. At the same time, the world's available cultivable land per person is declining. Arable land has 1 declined steadily since 1960 and will decease by half over the next 50 years, according to the International Service for the Acquisition of Agri-Biotech Applications (ISAAA). 关于人口增长和饥饿的统计数字读来令人感到不安。去年，世界人口达到了 60亿。联合国预测，到2D0年，这个数字很可能将接近90亿，而增加的人口几 乎都来自发展中国家。与此同时，世界人均耕地正在减少。国际农业生物 工程 路基工程安全技术交底工程项目施工成本控制工程量增项单年度零星工程技术标正投影法基本原理 应 用技术采购管理局(ISAAA)称，自1960年以来，耕地面积一直持续下降，并将 在今后50年减少一半。 The UN estimates that nearly 800 million people around the world are undernourished. The effects are devastating. About 400 million women of childbearing age are iron deficient, which means their babies are exposed to various birth defects. As many as 100 million children suffer from vitamin A deficiency, a leading cause of blindness. Tens of millions of people suffer from other major ailments and nutritional deficiencies caused by lack of food. 联合国估计，世界上有近8亿人口营养不良。它产生的效应是破坏性的。大 约有4亿的育龄妇女体内缺铁，也就是说，她们的婴儿将可能有各种天生的缺陷。 数量多达1亿的儿童缺乏维生素A，这是导致失明的主要原因。还有数千万的人 患有因食物匮乏而导致的其他严重疾病和营养不良症。 How can biotech help? Biotechnologists have developed genetically modified rice that is fortified with beta-carotene -- which the body converts into vitamin A -- and additional iron, and they are working on other kinds of nutritionally improved crops. Biotech can also improve farming productivity in places where food shortages are caused by crop damage attribution to pests, drought, poor soil and crop viruses, bacteria or fungi. 生物技术对此能做些什么呢?生物技术专家已经培育出了含有β—胡萝卜素 (身体可将之转化为维生素A)和更多铁元素的转基因水稻，目前正在研究培育其 他一些增进营养成分的农作物。生物技术还可以帮助提高因虫害、干旱、土壤贫 瘠和作物病毒、细菌或真菌导致作物减产而出现食物匮乏的地区的农业生产率。 Damage caused by pests is incredible. The European corn borer, for example, destroys 40 million tons of the world's corn crop annually, about 7% of the total. Incorporating pest-resistant genes into seeds can help restore the balance. In trials of pest-resistant cotton in Africa, yields have increased significantly. So far, fears that genetically modified, pest-resistant crops might kill good insects as well as bad appear unfounded. 虫害带来的损失令人难以置信。例如，欧洲玉米螟每年毁掉4000万吨玉米， 2 占世界玉米总产量的7,。把抗虫害的基因植入种子可以帮助避免这一损失。在 非洲进行的抗虫害棉花试验中，棉花的产量已大幅度提高。有人担心，抗虫害的 转基因作物不仅将害虫杀死，而且有可能连益虫也一起杀死，但到目前为止，这 种担心似乎没有根据。 Viruses often cause massive failure in staple crops in developing countries. Two years age, Africa lost more than half its cassava crop -- a key source of calories -- to the mosaic virus. Genetically modified, virus-resistant crops can reduce that damage, as can drought-tolerant seeds in regions where water shortages limit the amount of land under cultivation. Biotech can also help solve the problem of soil that contains excess aluminum, which can damage roots and cause many staple-crop failures. A gene that helps neutralize aluminum toxicity in rice has been identified. 病毒常常在发展中国家造成主要粮食作物的大面积歉收。两年前，花叶病 毒使非洲损失了超过一半的木薯，而这种作物是当地人的主要食物。转基因的抗 病毒作物可以减少这种损失，就像抗干旱种子在可耕地面积因缺水而受到限制的 地区起到的作用一样。含铝过高的土壤会损伤作物的根系并使许多主要作物歉 收，对于这种问题生物技术也能帮助解决。目前，研究人员已经识别出一种有助 于中和水稻里铝的毒性的基因。 Many scientists believe biotech could raise overall crop productivity in developing countries as much as 25% and help prevent the loss of those crops after they are harvested. 许多科学家认为，生物技术能够把发展中国家的农业总产量提高25,，并 且帮助防止作物收割后遭受损失。 Yet for all that promise, biotech is far from being the whole answer. In developing countries, lost crops are only one cause of hunger. Poverty plays the largest role. Today more than 1 billion people around the globe live on less than ' 1 a day. Making genetically modified crops available will not reduce hunger if farmers cannot afford to grow them or if the local population cannot afford to buy the food those farmers produce. 尽管具有这么多潜力，生物技术还远远不能解决全部问题。在发展中国家， 作物歉收只是造成饥饿的一个原因。贫穷才是罪魁祸首。今天，全世界有超过 10亿人口每天靠不到1美元维持生计。如果农民没钱种植转基因作物或当地人 买不起农民种出的粮食，培育转基因作物就无法减少饥饿。 Nor can biotech overcome the challenge of distributing food in developing countries. Taken as a whole, the world produces enough food to feed everyone -- but much of it is simply in the wrong place. Especially in countries with undeveloped 3 transport infrastructures, geography restricts food availability as dramatically as genetics promises to improve it. 此外，生物技术也无法克服在发展中国家分配粮食的难题。从整体上看，世 界生产的粮食足够养活所有人，但大部分粮食却不是在需要的地方。尤其在运输 基础设施落后的国家，地理条件对食物供给的限制正如遗传学为食物供给带来的 希望一样大。 Biotech has its own "distribution" problems. Private-sector biotech companies in the rich countries carry out much of the leading-edge research on genetically modified crops. Their products are often too costly for poor farmers in the developing world, and many of those products won't even reach the regions where they are most needed. Biotech firms have a strong financial incentive to target rich markets first in order to help them rapidly recoup the high costs of product development. But some of these companies are responding to needs of poor countries. A London-based company, for example, has announced that it will share with developing countries technology needed to produce vitamin-enriched "golden rice". 生物技术也面临自身的“分配”问题。许多转基因作物方面的尖端研究都是富 国的私营生物技术公司进行的。对发展中国家的穷苦农民来说，这些公司的产品 通常显得过于昂贵，而且这些产品中的大部分甚至无法到达最需要的地区。强大 的经济刺激促使生物技术公司把富裕国家的市场作为第一目标，以便能够尽快回 收产品开发的高额成本。不过，有些公司已开始对贫穷国家的需要做出反应。例 如，一家总部在伦敦的公司已经宣布，它愿意和发展中国家一起分享生产维生素 增强型的“金水稻”所需的技术。 More and more biotech research is being carried out in developing countries. But to increase the impact of genetic research on the food production of those countries, there is a need for better collaboration between government agencies -- both local and in developed countries -- and private biotech firms. The ISAAA, for example, is successfully partnering with the US Agency for International Development, local researches and private biotech companies to find and deliver biotech solutions for farmers in developing countries. 发展中国家正在进行越来越多的生物技术研究。但是，为扩大遗传学研究对 这些国家的粮食生产的影响，政府各部门(包括当地政府部门和发达国家的政府 部门)与私营生物技术公司之间需要更好的合作。例如，国际农业生物工程应用 技术采购管理局目前正与美国国际发展署、当地的研究人员以及私营的生物技术 公司进行成功的合作，以帮助发展中国家的农民寻求生物技术方面的解决办法。 Will "Franken foods" feed the world? Biotech is not a panacea, but it does 4 promise to transform agriculture in many developing countries. If that promise is not fulfilled, the real losers will be their people, who could suffer for years to come. “弗兰肯食品”能养活世界吗?生物技术虽不是万灵药，但它确实有希望改造许多发展中国家的农业。如果这种希望不能实现，真正的受害者将是这些国家的人民，他们可能会在未来的岁月里遭受苦难。 Unit 2 The Biology of Skin Color:Black and White 10年之前当时在西澳大学的人类学家Nina Jalonski被要求做一项关于人类皮肤的演说。作为灵长类进化研究的专家，她决定对肤色的进化史研讨一番，可是当她对课题进行文献研究时，结果却使她倍感失望。在1970年之前的较为新的理论都存在种族主义，而另外的文献则相当缺乏说服力。比如，有研究发 表 关于同志近三年现实表现材料材料类招标技术评分表图表与交易pdf视力表打印pdf用图表说话 pdf 说白色皮肤可以更好的抵御寒冷。1970年之后，研究人员渐渐认识到对于研究皮肤这样的课题变的无足轻重，因为这样的研究总是收获甚微。Jalonski说:这个事实人人皆知，只是无人再议而已。 不久之后，Jablonski和她的丈夫Geoge Chaplin(一位地理信息系统专家)发表了第一份综合性肤色论。该文章发表于人类进化日报中，该文章说明了肤色与全球光线强度之间存在强烈且可预测的关联。但同时他们的发现也产生了一个深层次且令人吃惊的结论:肤色与维他命存在密切的联系。 作为加利福尼亚学术研究部门的领导，Jablonski首先假设我们最早的人类祖先有着与大猩猩(生物学角度最密切)类似的皮肤。在450万年到200万年以前，早起人类从热带雨林中脱离，开始走向非洲东部大草原。在以前的大草原上，人们不仅仅要更多的暴露于阳光下，而且他们忙于收集食物。哺乳动物的大脑非常害怕过热，只需要5、6个级别的热量就能使他们中暑，因此我们祖先不得不发明更好的解暑办法。 答案很简单，那就是通过蒸发带走热量。早起人类可能汗腺极少就像大猩猩一样，汗腺可能主要集中于他们的手掌中和脚底。然而有时，某些个体会比通常的个体长更多汗腺。这些汗腺更多的人，他们可以在热量驱逐他们躲在阴凉下之前有更长的时间去找食物。因此他们能得到更多食物，使得他们能孕育更健康的后代，并且将发达的汗腺遗传给后代。 在几百万年的自然选择后，人类的身体上已经拥有大约200万个汗腺。人类的皮肤相对于大猩猩的毛减少许多。加利福尼亚大学的人类学家Adrienne Zihlaman说:这样使得我们人类在沐浴后毛发干燥的更快。 然而，缺少毛发的皮肤非常容易遭到紫外线的破坏。科学家提出了一种假说: 5 人类的肤色由黑色素所决定，而黑色素可以吸收或者分解紫外线。但是紫外线是什么呢,一些研究人员只出它是皮肤癌的起因。癌症通常是由于人体的恶性增殖，是由日常生活习惯引起的。还有一些事实表明阳光晒过的乳腺将影响女性哺乳，但是较为黝黑的皮肤可以有效保护这些哺乳女性。 Jablonski在澳大利亚准备 演讲 办公室主任竞聘演讲中层竞聘演讲护士长竞聘演讲演讲比赛活动要求对演讲比赛的点评 期间，她曾做过关于紫外线对叶酸(一种维他命B的混合物)的影响的研究。研究表明如果你的皮肤白净那么强烈的阳光会使得叶酸等级减半。Jablonski发现这个关系仅用了几周的时间。在胚胎开发的高级阶段，Jablonski了解到过低的叶酸水准与神经管损伤相关，比如脊柱裂或先天无脑畸形(婴儿生来就没有健全的大脑和脊柱)。 Jablonski随后通过三篇文献得知孩子的神经管损伤与它的母亲孕期暴露于紫外线下密切相关。而且她发现叶酸与精液水平密切相关——通过抑制叶酸可以起到避孕作用。(Jablonski说:叶酸无处不在，它几乎影响我们的全身上下)。她现在发现了一些有趣的证明:叶酸让会我们慢慢进化出黑色皮肤，但是为什么有人皮肤却很白呢。 追溯到1960年，生物学家W.FarsworthLooms曾发表说肤色与人体的维生素D水平相关。而维他命D可以帮助人体吸收钙质构成坚硬的骨骼，尤其是快速发育的胚胎。(孕期需要很多的维生素D，这也就解释了为什么从世界范围来看女性的皮肤要比男性白皙。)不同于叶酸，维生素D需要紫外线的配合以发挥作用。Loomis坚信生活在北方的人由于那里光线较弱所以他们的皮肤较为白以便吸收更多的紫外线;而生活在热带地区的人们则长有黑色皮肤以便阻挡阳光，使得身体吸收较为均衡的维生素D不至于过量(过量的维生素D会有毒性)。 由于Jablonski的研究Loomis的部分研究成果已经被证明是错误的。Jablonski说:你可以永远不乏获得过量维生素D，因为只有极少数的人们会发生鱼肝油过量。但是Loomis对于皮肤白皙的论点是正确的，这个论点完美的证明了Jablonski对于叶酸和黑色皮肤的论点。接下的任务就是找到数据说明肤色与光线强度的关系。 到80年代，研究人员只能估算紫外线到达地球表面的量，但是在1978年的时候NASA启动了全球臭氧光谱绘制计划。三年后，Jablonski和Chaplin利用全球紫外线光谱数据，并且拿这些数据与他们统计的50个国家和地区的人们肤色进行对比。令他们兴奋不已的是，他们提出的结论完全正确:紫外线越弱，人们的肤色越白皙。Jablonski之后又统计了50个不同地区的严重缺少维生素D的人群。Jablonski说:这个人类历史解决维生素D缺乏是在他们学会钓鱼后，因此他们可以获得更加丰富的实物后，维生素D的问题就已经解决了。 人类的历史中绝大多数时间用来不停地移动，因为这样他们在面对各种环境中才学会了使用工具，制作衣服，解决居住问题并且产生了自己的饮食习惯。但 6 是Jablonski的论点指出我们的适应力非常强。热带的人们拥有黑色皮色以便他 们阻挡紫外线以便他们保护自己的叶酸水平。而远离赤道的人们在漫长的冬季 中，长出了白皙的皮肤以便产生足够的维生素D。 Jablonski希望她的研究可以改善人们饮食中的维生素D和叶酸的摄入量。比 如，总所周知黑色皮肤的人去阴雨地带生活会产生像佝偻病等这样由于缺少维生 素D而产生的症状。更重要的是，Jablonski希望人们可以通过她的研究改变会 不同肤色的人们的看法。Jablonski说:我们应该将这个理论传播到热带地区，让 人们去了解它，用它去解决分歧、误解等等，它完全有这个能力. Unit 4 Is Time Travel Possible? Hello. My name is Stephen Hawking. Physicist, cosmologist and something of a dreamer. Although I cannot move and I have to speak through a computer, in my mind I am free. Free to explore the universe and ask the big questions, such as: is time travel possible? Can we open a portal to the past or find a shortcut to the future? Can we ultimately use the laws of nature to become masters of time itself? 大家好，我是斯蒂芬-霍金，是物理学家、宇宙学家及梦想家，尽管身体不能 活动，只能通过电脑与大家交流，但从内心中我是自由的，自由地探索宇宙，思 考以下重大问题:时间旅行是否可行,能否打开一个回到过去的通道，或找到通 向未来的捷径,我们最终能否利用自然规律成为掌控时间的主人, To see how this might be possible, we need to look at time as physicists do - at the fourth dimension. It's not as hard as it sounds. Every attentive schoolchild knows that all physical objects, even me in my chair, exist in three dimensions. Everything has a width and a height and a length. 为了让这一切从虚幻变成现实，我们应以物理学家的角度来重新审视时间— —即第四维。这个问题没有听上去那么晦涩难懂。每个好学的孩子都知道，任何 物体都以三维形式存在，包括坐在轮椅上的我。一切物体都有宽度、高度和长度。 But there is another kind of length, a length in time. While a human may survive for 80 years, the stones at Stonehenge, for instance, have stood around for thousands of years. And the solar system will last for billions of years. Everything has a length in time as well as space. Travelling in time means travelling through this fourth dimension. 此外，还有一种长度——时间的长度。例如，虽然一个人可能活了80岁，但 巨石阵的石头却数千年屹立不倒。太阳系的运行将持续数十亿年。一切物体都有 时间以及空间的长度。时间旅行意味着我们要经过第四维。 To see what that means, let's imagine we're doing a bit of normal, everyday car travel. Drive in a straight line and you're travelling in one dimension. Turn right or left a 7 nd you add the second dimension. Drive up or down a twisty mountain road and that adds height, so that's travelling in all three dimensions. But how on Earth do we travel in time? How do we find a path through the fourth dimension? 要想搞明白这一点，我们可以想象正在从事一种日常活动，比如开车。开车 沿直线行驶，是在一维中旅行。向左转或是向右转，则是二维旅行。驱车上下山 路意味着又多增加了高度，所以是在三维空间内。那么我们怎样才能实现时间旅 行,怎样才能发现穿越第四维的通道呢, Let's indulge in a little science fiction for a moment. Time travel movies often feature a vast, energy-hungry machine. The machine creates a path through the fourth dimension, a tunnel through time. A time traveller, a brave, perhaps foolhardy individual, prepared for who knows what, steps into the time tunnel and emerges who knows when. The concept may be far-fetched, and the reality may be very different from this, but the idea itself is not so crazy. 让我们暂时从科幻电影中寻找答案吧。在此类电影中，通常会有一台巨大而 高能耗的时间机器，这台机器产生通往第四维的通道——“时光隧道”。时光旅 行者——勇敢但可能有些鲁莽的人，做好我们大家所知道的准备，然后走进时光 隧道，来到一个他们想要到达的时间里。这一概念可能有些牵强，事实可能与之 存在着天壤之别，但该想法本身不是那么的疯狂。 Physicists have been thinking about tunnels in time too, but we come at it from a different angle. We wonder if portals to the past or the future could ever be possible within the laws of nature. As it turns out, we think they are. What's more, we've even given them a name: wormholes. The truth is that wormholes are all around us, only they're too small to see. Wormholes are very tiny. They occur in nooks and crannies in space and time. You might find it a tough concept, but stay with me. 物理学家们也在思考时光隧道，但我们的角度不同。我们想搞清过去或未来 的通道是否存在于自然规律中,事实证明，我们认为确实是这样的。而且，我们 还给它们起了一个名字:虫洞。其实，虫洞无处不在，只是因为太小，我们肉眼 看不到罢了。虫洞非常小，存在于时空的隐蔽处和缝隙里。你或许认为这是一个 难以理解的概念，请耐心听我继续解释吧。 Nothing is flat or solid. If you look closely enough at anything you'll find holes and wrinkles in it. It's a basic physical principle, and it even applies to time. Even something as smooth as a pool ball has tiny crevices, wrinkles and voids. Now it's easy to show that this is true in the first three dimensions. But trust me, it's also true of the fourth dimension. There are tiny crevices, wrinkles and voids in time. Down at the smallest of scales, smaller even than molecules, smaller than atoms, we get to a place called t 8 he quantum foam. This is where wormholes exist. Tiny tunnels or shortcuts through space and time constantly form, disappear, and reform within this quantum world. And they actually link two separate places and two different times. 任何物质都不是平整无暇和实心的，如果仔细观察，会发现它们上面都存在 小孔和裂缝，这是一个基本的物理原理，同样适用于时间。即便是像台球一样的 东西，上面也有裂缝、褶皱或空洞。现在容易说明这种情况也存在于第一个三维 中。相信我，这一原理同样适用于第四维。时间也存在许多微小的裂缝、褶皱和 空洞。在最小的刻度下——比分子甚至原子都小，我们来到一个称为量子泡沫 (quantum foam)的地方，这是虫洞存在之处。时空中的微小隧道或捷径不停地在 这个量子世界中形成、消失和重新形成。它们可以连接两个隔离的空间以及两个 不同的时间。 Unfortunately, these real-life time tunnels are just a billion-trillion-trillionths of a centimetre across. Way too small for a human to pass through - but here's where the notion of wormhole time machines is leading. Some scientists think it may be possible to capture a wormhole and enlarge it many trillions of times to make it big enough for a human or even a spaceship to enter. 不幸的是，现实生活中这种时光隧道非常狭小，即使发现了它们，我们也不 能从这个缝隙穿过——可这正是“虫洞时间机器”概念的前进方向。部分科学家 认为，或许有一天捕捉到一个虫洞，将它放大数万亿倍，令其足够的大，能让人 甚至飞船进入。 Given enough power and advanced technology, perhaps a giant wormhole could even be constructed in space. I'm not saying it can be done, but if it could be, it would be a truly remarkable device. One end could be here near Earth, and the other far, far away, near some distant planet. 如果我们拥有足够的能量和先进的技术，将来或许甚至能在太空中建造一 个巨型虫洞。我并不是说一定可以做到，但如果真的有这种装置，那么确实很了 不起。一端在地球的附近，另一端则在遥远的星球附近。从理论上讲，虫洞或时 光隧道不仅仅能把我们带到别的星球。一端在地球的附近，另一端则在遥远的星 球附近。 Theoretically, a time tunnel or wormhole could do even more than take us to other planets. If both ends were in the same place, and separated by time instead of distance, a ship could fly in and come out still near Earth, but in the distant past. Maybe dinosaurs would witness the ship coming in for a landing. 从理论上讲，虫洞或时光隧道不仅仅能把我们带到别的星球。如果两端在同 一个地方，且由时间而非距离分离，在遥远的过去，飞船就能在地球附近自由出 9 入。或许恐龙会看到飞船登陆的场景。 The fastest manned vehicle in history was Apollo 10. It reached 25,000mph. But to travel in time we'll have to go more than 2,000 times faster. 在人类历史上，速度最快的载人飞船“阿波罗”10号，速度为每小时2.5 万英里(约合每小时4万公里)，但要实现在时间中旅行，我们的速度必须是“阿 波罗”10号速度的2000倍。 Now, I realize that thinking in four dimensions is not easy, and that wormholes are a tricky concept to wrap your head around, but hang in there. 如今，我意识到以四 维方式思考并不容易，虫洞是一个令你绞尽脑汁的概念。 A well-known problem with time travel to the past, the problem of what we call paradoxes. Paradoxes are fun to think about. The most famous one is usually called the Grandfather paradox. I have a new, simpler version I call the Mad Scientist paradox. 一个原因可能是回到过去的时间旅行所存在的问题——我们称之为悖论，一 个众所周知的问题。探讨悖论是一件很有趣的事情，最著名的悖论通常被称为“祖 父悖论”。我有一个新的简化版本——“疯狂科学家”悖论。 I don't like the way scientists in movies are often described as mad, but in this case, it's true. This chap is determined to create a paradox, even if it costs him his life. Imagine, somehow, he's built a wormhole, a time tunnel that stretches just one minute into the past. 我不喜欢一些电影中科学家被描述成疯狂的群体，但在这种情况下，确实如 此。这个家伙决心建立一个悖论，即便付出生命代价在所不惜。可以想见，他是 在建造虫洞——仅需一分钟就来到过去的时光隧道。通过虫洞，这位科学家可以 看到他一分钟以前的自我。 Through the wormhole, the scientist can see himself as he was one minute ago. But what if our scientist uses the wormhole to shoot his earlier self? He's now dead. So who fired the shot? It's a paradox. It just doesn't make sense. It's the sort of situation that gives cosmologists nightmares. 如果这位科学家利用虫洞向以前的自我开枪，会发生什么事情,他现在已经一 命呜呼。那又是谁开的枪呢,这便是一个悖论，听上去毫无意义。但这却是那种 让宇宙学家做噩梦的状况。 This kind of time machine would violate a fundamental rule that governs the entire universe - that causes happen before effects, and never the other way around. I believe things can't make themselves impossible. If they could then there'd be nothing to stop the whole universe from descending into chaos. So I think something will 10 always happen that prevents the paradox. Somehow there must be a reason why our scientist will never find himself in a situation where he could shoot himself. And in this case, I'm sorry to say, the wormhole itself is the problem. 这种时间机器会违反整个宇宙所遵循的基本规则。我认为一切皆有可能。如 果真是如此，那么就没有任何办法阻止整个宇宙陷入混乱。所以，我认为有些事 情总会发生以阻止这种悖论。在某种程度上，这或许是科学家永远不会发现他面 临向自己开枪境地的原因。在这种情况下，我只能遗憾地告诉大家，虫洞本身就 是一个问题。 In the end, I think a wormhole like this one can't exist. And the reason for that is feedback. If you've ever been to a rock gig, you'll probably recognise this screeching noise. It's feedback. What causes it is simple. Sound enters the microphone. It's transmitted along the wires, made louder by the amplifier, and comes out at the speakers. But if too much of the sound from the speakers goes back into the mic it goes around and around in a loop getting louder each time. If no one stops it, feedback can destroy the sound system. 最后，我认为像这样的虫洞不能存在，原因就是反馈。如果你有到摇滚演唱 会现场观看演出的经历，你可能会辨别出这种尖利的噪音。这就是反馈，引起反 馈的原因很简单。声音进入麦克风，通过电线传播，经由扩音器令声音放大，在 一个环状物内绕来绕去，每次令声音比上一次更大。如果没人阻止，反馈能够破 坏音响系统。 The same thing will happen with a wormhole, only with radiation instead of sound. As soon as the wormhole expands, natural radiation will enter it, and end up in a loop. The feedback will become so strong it destroys the wormhole. So although tiny wormholes do exist, and it may be possible to inflate one some day, it won't last long enough to be of use as a time machine. 虫洞也会遇到这种问题，只不过声音换成了辐射。一旦虫洞变大，大自然的 辐射物会进入，最终形成一个环路。反馈变得如此强劲，最终摧毁虫洞。虽然微 型虫洞确实存在，也有可能在某一天不断膨胀，但持续时间不会太长久，所以不 能当作时间机器使用。 Any kind of time travel to the past through wormholes or any other method is probably impossible, otherwise paradoxes would occur. So sadly, it looks like time travel to the past is never going to happen. A disappointment for dinosaur hunters and a relief for historians. 任何通过虫洞和其他方式回到过去的时间旅行或许都是不可能的，否则，悖 论就会出现.因此，遗憾的是，回到过去的时间旅行应该永远不会上演。对于寻 11 找恐龙的人来说，这会令他们大失所望，但对于历史学家而言，他们可以彻底解 脱了。 Unit 8 Why We're Fat So why is obesity happening? The obvious, clichéd-but-true answer is that we eat too much high-calorie food and don't burn it off with enough exercise. If only we had more willpower, the problem would go away. But it isn't that easy. 为什么会有肥胖症,一个明显、老生常谈但又真实的答案就是我们吃太多高 热量食物并且没有进行足够的运动消耗它。要是我们的意志力更强大，这个问题 便迎刃而解了。但是，问题并不是那么简单。 When warned about the dangers of overeating, we get briefly spooked and try to do better. Then we're offered a plateful of pancakes smothered in maple syrup, our appetite overpowers our reason, and before we know it, we're at it again. Just why is appetite such a powerful driver of behavior, and, more important, how can we tame it? 当我们被警告说吃得太多的时候，一时总会被吓倒并努力做好一些。然后一 碟涂满槭糖浆的煎饼摆在面前，我们的食欲战胜了我们的理智，等到我们意识到 它的时候，我们又重蹈覆辙了。到底为什么食欲具有如此强大的推动力,更重要 的是，我们怎么才能够控制它, itWhin the past few years, science has linked our ravenous appetites to genes and hormones. Among the hormones that fuel these urges are ghrelin and leptin, known as the "hunger hormones." Ghrelin is produced mostly by cells in the stomach lining. Its job is to make you feel hungry by affecting the hypothalamus, which governs metabolism. Ghrelin levels rise in dieters who lose weight and then try to keep it off. It's almost as if their bodies are trying to regain the lost fat. This is one reason why it's hard to lose weight and maintain the loss. 近几年来，科学将我们迫不及待要吃的食欲跟基因和激素联系起来。激起这 些强烈的欲望的激素有胃促生长素和消瘦素，也被称作“饥饿激素”。胃促生长 素主要由胃保护层的细胞产生。它的职责是影响控制新陈代谢的下丘脑，让你感 到饥饿。当节食者减肥并且努力维持减肥效果，他的胃促生长素水平就会升高。 就像他们的身体要试图恢复失去的脂肪。这是为什么很难减肥并维持减肥效果的 原因之一。 Leptin turns your appetite off and is made by fat cells. Low leptin levels increase your appetite and signal your body to store more fat. High leptin levels relay the opposite signal. Many obese people have developed a resistance to the appetite-suppressing effects of leptin and never feel satisfied, no matter how much they eat. Basically, yo 12 ur body uses these hormones to help you stay at your weight and keep you from losing fat — which is another reason why dieting can be so difficult. 消瘦素消除你的食欲，它来自脂肪细胞。低消瘦素水平增加你的食欲并通知 你的身体储存更多的脂肪。高消瘦素水平传递相反的信号。很多肥胖的人已经形 成了一种对消瘦素抑制食欲效应的抵抗，不管他们吃多少也从不感到满足。从根 本上说，你的身体利用这些激素帮助你保持现在的体重，不让你的脂肪流走—— 这是节食如此之难的另外一个原因。 Lack of sleep promotes obesity by messing with these hunger hormones. If you skimp on sleep, ghrelin levels rise, making you hungry, and leptin levels dip, which signals a need for calories. During my internship, I was chronically sleep-deprived because I had to be at the hospital and stay up all night every third night. I gained a lot of weight that year; now I know why. Years later, after I gave birth to my son Alex, I put on a lot of pounds, too — twenty pounds left over from the pregnancy, and twenty pounds from being up all night with him. He had colic (fussiness) and never slept more than twenty minutes at a time the first six months of his life. My weight started coming off more easily when I got more sleep. 睡眠缺失促进肥胖，因其干扰了这些饥饿激素。如果你克扣了睡眠时间，胃 促生长素水平升高，使你饥饿，并且消瘦素下降，标志着需求热量。在实习期间 我长期缺觉，因为每隔三个晚上我得通宵熬夜待在医院里。那年我的体重增加了 不少，现在我明白为什么了。在那几年之后，我生了儿子亚力克斯后又增了好多 磅——怀孕期间残留的二十磅，还有夜夜无眠陪着他的二十磅。他有急性腹痛且 在他生命中的头六个月从未试过连续睡二十分钟以上。当我有了更多睡眠时间， 我的体重开始更容易降下来。 Besides ghrelin and leptin, many other hormones play a role in appetite. Scientists have been looking for ways to control all these hunger hormones, but so far nothing usable has panned out. 除了胃促生长素和消瘦素，很多其他的激素对食欲也有影响。科学家一直在 寻找控制这些饥饿激素的方法，但是目前还没有成果。 Hunger isn't the only reason people eat and eat and eat. Stress, depression, boredom, loneliness, and even joy all come into play. And some of us may just be inclined to gain weight while others are not, due to genetics. Scientists are unclear as to how much of a role genetics plays in how chubby you are, but estimates range from as low as 20 percent to as high as 90 percent. In studies of twins, researchers have found that siblings wind up with similar body weights, whether or not they are raised in different families, and that adopted children are much more likely to grow to the size of their nat 13 ural parents than their adoptive ones. Scientists speculate that part of the reason so many of us are susceptible to layering on fat is due to the "thrifty gene." Supposedly, it's a gene passed down from our prehistoric ancestors who could eat a lot and build up reserves of fat to survive frequent famines. Genetically, this made sense when you didn't know if your next meal would be tomorrow or a week from now, but when your next meal is whenever you drive by a fast-food restaurant, that's a problem. 饥饿不是人们不停地吃的唯一原因。压力，抑郁，无聊，孤独，甚至高兴都 会起作用。有些人可能就是易于发胖而另一部分人不会，这应归于遗传。科学家 不确定遗传在肥胖上面起多大的作用，但是预测它所占比例从最低20,到最高 90,。在对双胞胎的研究中，研究人员发现双胞胎兄弟(或姐妹)最终会有相似 的体重，不论他们是不是在不同的家庭中长大，而且收养的小孩的体形大小更可 能长成和他们亲生父母的一样。科学家推断我们那么多人易于堆积脂肪的部分原 因在于“节俭基因”。假设，我们的祖先食量很大，并且可以积聚脂肪来渡过频 繁发生的饥荒。从遗传学角度来看，当你不知道下一餐会在明天还是一周以后这 的确说得通，但是当你的下一餐就是在随时开车经过的快餐店，那就是一个问题 了。 Another cause of obesity, one that really fascinates me, has to do with a virus called the adenovirus-36. It comes from the family of common viruses that causes colds, pneumonia, diarrhea, and pinkeye and is present in 30 percent of obese people and 5 percent of non-obese people. Scientists found that when human stem cells are exposed to adenovirus-36, they turn into fat cells. This discovery is more evidence that our expanding waistlines are due to factors other than weak willpower and, theoretically, could lead to the development of a vaccine to prevent obesity. 肥胖的另一个起因(也是非常令我着迷的一个)就是关于一个称作腺病毒, 36的病毒。它来自引起感冒、肺炎、腹泻和红眼的普通病毒家族， 30,肥胖的 人感染了这种病毒，而非肥胖的有5,。科学家发现当人类干细胞感染了腺病毒 ,36，它们就变成脂肪细胞。这个发现更加证明了我们日益加大的腰围应归于薄 弱意志力外的其他因素，而且理论上可能促使防止肥胖疫苗的发展。 Often, hard-to-budge weight is a symptom of a hidden medical problem. You could have hypothyroidism (sluggish thyroid function), a condition that slows down your metabolism and makes it tough to lose weight, or Cushing's disease, characterized by high levels of the hormone cortisol in the blood. A glut of cortisol triggers weight gain, mostly in the trunk and face. Some women have polycystic ovary syndrome (PCOS), a treatable condition that involves a hormone imbalance. And about 30 percent of people who are obese have bingeeating disorders. Sufferers don't just munch on a few pot 14 ato chips, they inhale the whole bag, and they do this kind of thing habitually. Even certain medications, some of which may be sitting in your medicine cabinet right now, can put on pounds. Common offenders include some antidepressants like Paxil and Zoloft; mood stabilizers; diabetes drugs; blood pressure agents; steroids; antiseizure drugs; certain hormones; and antihistamines. 难以控制的体重往往是隐藏疾病的一个症状。你可能是甲状腺功能减退，它 减慢你的新陈代谢，使减肥变得困难;或者是库兴氏病，特点是血液中皮质醇水 平过高。过多的皮质醇引发体重增加，特别表现在躯干和脸上。一些女人有多囊 卵巢综合征，它包含激素不平衡，是一种可治疗的情况。大约30,肥胖的人都有 无节制狂吃失调症。患者不止吃少量薯片，他们一下子吃一整袋，而且他们习惯 性地做这类事情。甚至某些药物也能使人增重，有些可能现在就躺在你的医药箱 里。常见的祸害包括抗抑郁药如帕罗西汀和左洛复;情绪安定药;糖尿病药物; 血压药;类固醇;抗发作药物;某些激素以及抗组胺。 So perhaps there is a medical issue that spells weight trouble, or our genes and hormones may be conspiring to makes us eat more, or maybe we're infected with a virus that makes us fat. Should we throw up our hands and say, "Well, I can't do anything about it, so I'll just stay fat"? No, because obesity will affect your health, and it may kill you eventually. You will just have to work a little harder to get your weight under control. 所以，可能有些医疗问题会带来体重上的困扰，或是我们的基因和激素共谋 让我们吃更多，或是我们感染了使我们变胖的病毒。那我们是不是应该投降说“那 么，我也没有办法，我也只能保持肥胖”,不是的，因为肥胖会影响你的健康， 它最终可能会要了你的命。你只有再努力些去控制自己的体重。 Unit 10 Video Gamer Can Control Dreams, Study Suggest Playing video games before bedtime may give people an unusual level of awareness and control in their dreams, LiveScience has learned. Live Science网站获悉，在睡觉之前玩视频游戏可以让人们有一种不寻常的清 醒做梦和控制梦的水平。 That ability to shape the alternate reality of dream worlds might not match mind-bending Hollywood films such as "The Matrix," but it could provide an edge when fighting nightmares or even mental trauma. 尽管这种塑造现实品梦境的能力与让令人费神才能理解的好莱坞电影《黑客 帝国》不同，但它还是能为与噩梦和心理创伤斗争的提供一点优势。 Dreams and video games both represent alternate realities, according to Jayne Ga 15 ckenbach, a psychologist at Grant MacEwan University in Canada. But she pointed out that dreams arise biologically from the human mind, while video games are technologically driven by computers and gaming consoles. 据加拿大Grant MacEwan大学的心理学家Jayne Gackenbach说，梦和视频游 戏都代表另一种现实。但是，她指出从生物学上讲梦来自于人的思维，而视频游 戏在技术角度上由电脑和游戏终端来驱动的。 "If you're spending hours a day in a virtual reality, if nothing else it's practice," said Jayne Gackenbach, a psychologist at Grant MacEwan University in Canada. "Gamers are used to controlling their game environments, so that can translate into dreams." “如果你每天把数小时花在虚拟现实中，如果没有做别的事情，那么这种情 况就发生”Jayne Gackenbach说，“游戏者一直在控制游戏环境，这样就会转移 成梦”。 Gackenbach first became interested in video games in the 1990s, when she watched her son repeatedly kiss a new Nintendo gaming console on the way home from a Toys "R" Us. She had previously focused on studying lucid dreams, in which people have awareness of being in a dream. 1990年代Gackenbach第一次开始关心视频游戏，那时候她看着她的儿子从游 戏店Toys "R" Us回家的路上不断的亲吻一台新的”任天堂“游戏机。她之前已 经在清醒的梦方面有集中研究，在清醒的梦里，人们能认识得到他们在梦里。 The last decade of game-related research has since yielded several surprises, although the findings represent suggestive associations rather than definitive proof, Gackenbach cautioned. She is scheduled to discuss her work as a featured speaker at the Sixth Annual Games for Health Conference in Boston this week. Gackenbach警告说，过去十年的游戏相关研究已经产生了许多惊喜，尽管这 些发现是暗示性的关联，而不是明确的证明。 她计划在本周在波士顿举行的第 六届健康大会年会上作为特邀演讲者讨论她的工作。 What dreams may come 会做什么样的梦 Several intriguing parallels between lucid dreams and video games first emerged when Gackenbach examined past research on games. Both lucid dreamers and gamers seemed to have better spatial skills and were less prone to motion sickness. 当Gackenbach检查她先前研究后，第一次提出清醒睡梦和视频游戏之间几个 关键的相似之处，清醒做梦的人和游戏玩家人似乎都有更好的空间技能且不容易 晕车。 The two groups have also demonstrated a high level of focus or concentration, w 16 hether honed through lucidity-training activities, such as meditation, or through hours spent fighting virtual enemies to reach the next level in a game. 无论是在如冥想这种清醒训练活动中还是在为升级而花几小时打游戏里的 虚拟敌人时，这两组对象都表现出很高的关注和集中注意力的能力。 That encouraged Gackenbach to survey the dreams of both non-gamers and hardcore gamers, beginning with two studies published in 2006. She had prepared by conducting larger surveys in-class and online to get a sense of where to focus questions. 这极大的鼓舞了Gackenbach去调查非游戏玩家和专家玩家的梦，2006开始时 就发表了两篇文章。通过在班级和网上更大的调查她已经准备好了，知道问题集 中在什么地方。 The first study suggested that people who frequently played video games were more likely to report lucid dreams, observer dreams where they viewed themselves from outside their bodies, and dream control that allowed people to actively influence or change their dream worlds – qualities suggestive of watching or controlling the action of a video-game character. 第一个研究表明:经常玩视频游戏的人更可能 报告 软件系统测试报告下载sgs报告如何下载关于路面塌陷情况报告535n,sgs报告怎么下载竣工报告下载 说有清醒的梦境、可以脱 离其身体看自己的观察者梦境，以及允许其主动影响或改变其梦境的梦境控制— —这也是观看和控制视频游戏中角色行动的能力。 A second study tried to narrow down the uncertainties by examining dreams that participants experienced from the night before, and focused more on gamers. It found that lucid dreams were common, but that the gamers never had dream control over anything beyond their dream selves. 第二个研究试图通过检查参与者之前的梦来缩小前一结论的不确定性，同时 更多的关注于游戏玩家。发现清醒梦境很普遍，但是游戏者从来没有控制其梦境 本身以外东西的梦。 The gamers also frequently flipped between a first person view from within the body and a third person view of themselves from outside, except never with the calm detachment of a distant witness. 游戏者也经常在居于自己身体的第一人称视角与身体之外的第三人称之间 转换，但从未与梦境中远处的见证者有平静的分离。 "The first time we simply asked people how often they had lucid dreams, looking back over their life and making judgment calls," Gackenbach told LiveScience. "That's open to all kinds of bias, [such as] certain memory biases, self-reported biases." 第一次我简单的问他们多久有一次清醒梦境，他们回顾过去做出一个判断”， Gackenbach向LiveScience说，“这意味着会有各种各样的偏见，像是特定记忆 17 的偏见，自己报告的偏见”。 Gackenbach eventually replicated her findings about lucid dreaming and video games several times with college students as subjects, and refined her methods by controlling for factors such as frequency of recalling dreams. Gackenbach最终多次以大学学生为研究对象重复了关于清醒梦境和视频游 戏的发现，通过控制诸如回忆梦的频率等因素的方法来进行改进。 Mastering the nightmare world 掌控噩梦 Finding awareness and some level of control in gamer dreams was one thing. But Gackenbach also wondered if video games affected nightmares, based on the "threat simulation" theory proposed by Finnish psychologist Antti Revonsuo. 在游戏玩家的梦中寻找清醒意识和一定程度的控制力是一回事，但是 Gackenbach也想知道基于芬兰心理学家Antti Rvonsuo提出的“威胁模拟”理论 下，视频游戏是否对噩梦产生影响。 Revonsuo suggested that dreams might mimic threatening situations from real life, except in the safe environment of dream world. Such nightmares would help organisms hone their avoidance skills in a protective environment, and ideally prepare organisms for a real-life situation. Revonsuo认为梦很可能模仿来自真实生活的威胁，在安全梦环境里却并不如 此。这样的噩梦将帮助生物在安全环境中磨炼他们的躲避能力，并让生物为真实 情况做最好的准备。 To test that theory, Gackenbach conducted a 2008 study with 35 males and 63 females, and used independent assessments that coded threat levels in after-dream reports. She found that gamers experienced less or even reversed threat simulation (in which the dreamer became the threatening presence), with fewer aggression dreams overall. 为证明这一理论，Gackenbach在2008年进行了有35男63女的研究，并使用了 独立评估，评估在梦醒后报告里为威胁水平进行编码。她发现，游戏玩家经历的 威胁模拟(在威胁模拟中，做梦的人变成了威胁者)更少，甚至是相反的，总体 上有侵略性的梦也更少。 In other words, a scary nightmare scenario turned into something "fun" for a gamer. 换句话说，可怕的噩梦轩变成了对于玩家“有意思”的事情。 "What happens with gamers is that something inexplicable happens," Gackenbach explained. "They don't run away, they turn and fight back. They're more aggressive than the norms." 18 “玩家身上发生的事情是令人费解的”，Gackenbach解释说，“他们不会逃跑， 而是转过来反击。他们比其它人更具侵略性”。 Levels of aggression in gamer dreams also included hyper-violence not unlike that of an R-rated movie, as opposed to a non-gamer PG-13 dream. 玩家梦里的侵略水平也包括与R级电影(译注:美国电影分级R级:限制级， 17岁以下必须由父母或者监护陪伴才能观看。该级别的影片包含成人 内容 财务内部控制制度的内容财务内部控制制度的内容人员招聘与配置的内容项目成本控制的内容消防安全演练内容 ，里面 有较多的性爱、暴力、吸毒等场面和脏话。)里的不同高暴力，也与非游戏玩家 的PG-13(译注:美国电影分级PG-13 级:特别辅导级，13岁以下儿童尤其要有 父母陪同观看，一些内容对儿童很不适宜——粗口、毒品及部分性内容)梦不同。 "If you look at the actual overall amount of aggression, gamers have less aggression in dreams," Gackenbach said. "But when they're aggressive, oh boy, they go off the top." “如果你看侵略的实际总量，游戏玩家梦里的侵略更少”，Gackenbach说，“但 是当他们有侵略性的时候，天呐，他们会达到极高的程度。” No fear 没有恐惧 The gamer dream experience of high aggression levels matched with little or no fear inspired Gackenbach to pursue a new study with Athabasca University in Canada. If gaming can act as a semi-protective function against nightmares, she reasoned, maybe it could help war veterans who experience post-traumatic stress disorder (PTSD) after enduring combat. 游戏玩家高侵略水平梦里面恐惧微小或者没有恐惧的经验启发了 Gackenbach在加拿大Athabasca大学进行一个新的研究。她推理，如果玩游戏可 以作为防止噩梦的半保护机能，也许玩游戏可以帮助在长期战争后承受“创伤后 应激障碍”(post-traumatic stress disorder (PTSD))痛苦的的老兵。 "I don't think anyone has looked at whether there's been a protective function," Gackenbach said. "It makes a lot of sense, but it's a hypothesis." “我认为大家还没看到是不是有保护功能”，Gackenbach说，“尽管感觉上是， 但那也只是假设”。 Psychologists consider nightmares as one of the symptoms of PTSD, and studies have shown incredibly high rates of nightmares ranging from 71 to 96 percent among PTSD patients. By contrast, just 3 to 5 percent of civilians reported the same levels of nightmares. 心理学家把噩梦看成是PTSD的症状之一，且研究表明在PTSD病人中有极 高的噩梦率，从71%到96%。相反的是，在平民中有相同噩梦水平的仅有3%到 19 5%。 Virtual reality simulators have already been used to help PTSD patients gradually adjust to the threatening situations that plague their waking and sleeping thoughts. If Gackenbach's hunch is correct, perhaps video games could also help relieve the need for nightmares. 虚拟现实模拟器已经用于帮助PTSD病人逐步适应受威胁的状态，那些状况 困扰着他们清醒和睡眠时的思绪。如果Gackenbach的直觉是对的，也许视频游 戏也可以帮助减少做噩梦。 Finding the balance 寻找平衡点 Gackenbach hopes to someday get a sleep lab and perhaps a virtual reality lab to verify her results, even if studies about video games and dreams have not proven the highest priority for receiving funds. Yet studying video games has attracted more interest and respect from colleagues than studying just dreams alone, she has noticed. Gackenbach希望有一天搞一个睡眠实验室或者一个虚拟现实实验室来验证 她的结果，尽管关于视频游戏和梦的研究还未证明其在接受基金资助上的的最高 优先性。但她注意到，视频游戏的研究比单独研究梦吸引了更多同事的兴趣和尊 重。 Some of Gackenbach's latest work includes studying the violence levels in games, based upon the video game ratings given out by the Entertainment Software Rating Board, and seeing what effect they have upon aggression within dreams. Gackenbach最新的一些工作包括，根据“娱乐软件分级委员会”给出的视频 游戏分级来研究梦里的暴力水平，看看在梦中的侵略对他们有什么影响。 "I'm not saying [gamers] don't get more aggressive, not saying there's not more problems with addiction, and not saying there's not obesity issues," Gackenbach said. "As with everything else, there's a balance." Gackenbach说:“我并不是说，游戏玩家没有更具侵略性;也不是说，游戏 成瘾没造成更多问题;也不是说，没有过度肥胖的问题，有一个在这所有问题中 的平衡点”。 20