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新东方精选 80 篇文章
>80 Evolution and Wheels
In the past, evolutionary biologists contemplating the absence of wheels in nature agreed that the
explanation was not undesirability: wheels would be good for animals, just as they are for us. Animals were
prevented from evolving wheels, the biologists reasoned, by the following dilemma: living cells in an animal's
body are connected to the heart by blood vessels and to the brain by nerves. Because a rotating joint is
essential to a wheel, a wheel made of living cells would twist its artery vein and nerve connections at the first
revolution, making living impracticable.
However, there is a flaw in the argument that the evolution of wheeled animals was thwarted by the
insoluble joint problem. The theory fails to explain why animals have not evolved wheels of dead tissue with
no need for arteries and nerves. Countless animals, including us, bear external structures without blood
supply or nerves - for example, our hair and fingernails, or the scales, claws, and horns of other animals. Why
have rats not evolved bony wheels, similar to roller skates? Paws might be more useful than wheels in some
situations, but cats' claws are retractable: why not retractable wheels? We thus arrive at the serious biological
paradox flippantly termed the RRR dilemma: nature's failure to produce rats with retractable roller skates.
进化与轮子
从前,研究自然界没有轮子的进化论生物学家都同意不能用无此需要来解释这种现象:轮子对于动物会像
对于我们人类一样有好处。 生物学家们推论,动物没有进化出轮子是由下述困难所致:动物身上的活细胞通过
血管与心脏相连,通过神经与大脑相连。 因为一个旋转的接头对轮子来说是至关重要的,由活的细胞构成的轮
子在第一次转动时便会扭伤其上的动脉和神经的连结,因而不现实。
不过,动物未能进化出轮子是受阻于无法解决接头问题的说法有一个缺陷。 这种理论无法解释为何动物没有
进化出由死组织构成的而无需动脉和神经的轮子。 包括人在内的无数动物都有一些没有血液供应和神经的体外
构造,例如,我们的头发和指甲,或者鳞片、爪子和其它一些动物的角。 为什么老鼠没有进化出类似于滑轮溜
冰鞋的骨质的轮子呢?在某些情况下,爪子可能比轮子更有用,但猫的爪子是可以伸缩的: 为什么不能有可以
伸缩的轮子呢?这样,我们便得出了一个被戏称为 RRR 的严肃的生物学悖论:大自然未能产生出有可伸缩的滑
轮溜冰鞋的老鼠。
>79 Population Growth
The growth of population during the past few centuries is no proof that population will continue to grow
straight upward toward infinity and doom. On the contrary, demographic history offers evidence that
population growth has not been at all constant. According to pale ecologist Edward Deevey, the past million
years show three momentous changes. The first, a rapid increase in population around one million B. C.,
followed the innovations of tool making and tool using. But when the new power from the use of tools has
been exploited, the rate of world population growth fell and became almost stable.
The next rapid jump in population started perhaps 10,000 years ago, when mankind began to keep
herds, plow and plant the earth. Once again when initial productivity gains had been absorbed, the rate of
population growth abated. These two episodes suggest that the third great change, the present rapid growth,
which began in the West between 250 and 350 years ago, may also slow down when, or if, technology begins
to yield fewer innovations. Of course, the current knowledge revolution may continue without foreseeable end.
Either way - contrary to popular belief in constant geometric growth - population can be expected in the long
run to adjust to productivity. And when one takes this view, population growth is seen to represent economic
progress and human triumph rather than social failure.
人口增长
以往几个世纪人口的增长并不能证明人口会无限地直线向上增长直到毁灭的地步。 相反地,人口统计史料
证明人口的增长完全不是稳定的。 古生态学家爱德华·狄维认为,在过去 100 万年间出现过 3 次重大的变动。
第一次在公元前 100 万年左右,随着在工具的制作和使用上的革新而出现人口迅速增长。 但当工具的使用所产
生的新动力被充分利用以后,世界人口增长率下降并且趋于稳定。
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新东方精选 80 篇文章
第二次人口剧增大约始于人类开始蓄畜、垦耕的 10,000 年前。 一旦最初的生产力增长被吸收殆尽,人口
的增长再次衰落。 以上两段说明,若技术革新的成果开始减少,从 250 到 350 年前就在西方开始出现的并且目
前还在继续的人口迅速增长可能也会放慢。 当然,当前的知识革命也许会持续下去而无法预见其未来。 无论如
何,与那种认为人口以几何级数持续增长的观点相反,从长远的观点来说,人口可望受到生产力的调节。 接受
了这一观点,人口的增长就可以被看成是经济进步和人类胜利的标志,而不是社会衰败的标志。
>78 Police and Communities
Few institutions are more important to an urban community than its police, yet there are few subjects
historians know so little about. Most of the early academic interests developed among political scientists and
sociologists, who usually examined their own contemporary problems with only a nod toward the past. Even
the public seemed concerned only during crime waves, periods of blatant corruption, or after a particularly
grisly episode. Party regulars and reformers generally viewed the institution from a political perspective;
newspapers and magazines - the nineteenth century's media - emphasized the vivid and spectacular.
Yet urban society has always vested a wide, indeed awesome, responsibility in its police. Not only were
they to maintain order, prevent crime, and protect life and property, but historically they were also to fight fires,
suppress vice, assist in health services, supervise elections, direct traffic, inspect buildings, and locate truants
and runaways. In addition, it was assumed that the police were the special guardians of the citizens' liberties
and the community's tranquility. Of course, the performance never matched expectations. The record contains
some success, but mostly failure; some effective leadership, but largely official incompetence and betrayal.
The notion of a professional police force in America is a creation of the twentieth century; not until our own
time have cities begun to take the steps necessary to produce modern departments.
警察与社区
对城市社区来说,很少有比它的警察更为重要的机构了,但少有课题像历史学家们对此了解得那样少。 早
期的学术兴趣是在政治科学家和社会学家中发展起来的,他们一般只研究他们自己当代的问题而对过去的问题
只是偶尔带过。 甚至公众似乎也仅仅在犯罪浪潮、明目张胆的贪污或特别的恐怖事件发生时才关心。 政党的忠
诚支持者和改革家们通常是从政治的前途来看待警察这个机构;而报纸和杂志-19 世纪的传播媒介-则着重活泼
生动和惊人的事件。
可是城市社会总是把广泛得可怕的责任交给警察。 他们不仅维持秩序、防止犯罪、保护生命财产,而且在
过去还要救火、镇压罪恶、协助医疗服务、监督选举、指挥交通、检查建筑物、寻找逃学学生和搜捕逃犯。 除
此以外,警察还被认为是公民自由和社会稳定的特别保护者。 自然,警察的表现并不尽如人意。 他们的记录中
有成功者,但多数是失败的;有高效率的领导,但多半的人在职务上无能和不讲信用。 专业警察部队的概念在
美国还是 20 世纪的产物;直到我们这个时代,一些城市才开始采取设立现代化部门的必要步骤。
>77 Food and Health
The food we eat seems to have profound effects on our health. Although science has made enormous
steps in making food more fit to eat, it has, at the same time, made many foods unfit to eat. Some research
has shown that perhaps eighty percent of all human illnesses are related to diet and forty percent of cancer is
related to the diet as well, especially cancer of the colon. Different cultures are more prone to contract certain
illnesses because of the food that is characteristic in these cultures. That food is related to illness is not a new
discovery. In 1945, government researchers realized that nitrates and nitrites, commonly used to preserve
color in meats, and other food additives, caused cancer.
Yet, these carcinogenic additives remain in our food, and it becomes more difficult all the time to know
which things in the packaging labels of processed food are helpful or harmful. The additives which we eat are
not all so direct. Farmers often give penicillin to beef and poultry, and because of this, penicillin has been
found in the milk of treated cows. Sometimes similar drugs are administered to animals not for medicinal
purposes, but for financial reasons. The farmers are simply trying to fatten the animals in order to obtain a
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新东方精选 80 篇文章
higher price on the market. Although the Food and Drug Administration (FDA) has tried repeatedly to control
these procedures, the practices continue.
食品与健康
我们所吃的食物似乎对我们的健康有深远的影响。 尽管科学上已取得许多进展,使食物更适合我们食用,
但与此同时它也使许多食物不宜食用了。 一些研究已经表明,人类大概有 80%的疾病与饮食有关,40%的癌症,
特别是结肠癌,也与饮食有关。 不同的文化会使人们更易患某些疾病,这是由这些文化的人们喜好的食物所致。
食物与疾病有关并不是新发现。 1945 年,政府部门的科研工作者了解到,被广泛用于肉类以保持肉类色泽的
硝酸盐、亚硝酸盐和其他的添加剂可诱发癌症。 可是这些致癌物质依然存在于我们的食物之中。
与此同时,要想知道加工食品标签上的哪些成分对健康有利,哪些成分对健康不利,变得更加困难了。 我
们吃到的这些添加物并非都是如此直接的。 农民常给牛和家禽注射青霉素,因而在受过注射的牛所产牛奶里发
现青霉素。 有时让家禽服用这类药物并非是为了治病,而是为了经济上的缘故。 农民们只是想使家畜长得更肥
壮可以上市场上卖到好价钱。 虽然食物和药品管理局已一再设法控制这种情况的发生,但是这种行为仍在继续。
>76 MARS
According to the best evidence gathered by space probes and astronomers, Mars is an inhospitable
planet, more similar to Earth's Moon than to Earth itself - a dry, stark, seemingly lifeless world. Mars' air
pressure is equal to Earth's at an altitude of 100,000 feet. The air there is 95% carbon dioxide. Mars has no
ozone layer to screen out the Sun's lethal radiation. Daytime temperatures may reach above freezing, but
because the planet is blanketed by the mere wisp of an atmosphere, the heat radiates back into space. Even
at the equator, the temperature drops to 50 at night. Today there is no liquid water, although valleys and℃
channels on the surface show evidence of having been carved by running water. The polar ice caps are made
of frozen water and carbon dioxide, and water may be frozen in the ground as permafrost.
Despite these difficult conditions, certain scientists believe that there is a possibility of transforming Mars
into a more Earth like planet. Nuclear reactors might be used to melt frozen gases and eventually build up the
atmosphere. This in turn could create a "greenhouse effect" that would stop heat from radiating back into
space. Liquid water could be thawed to form a polar ocean. Once enough ice has melted, suitable plants
could be introduced to build up the level of oxygen in the atmosphere so that, in time, the planet would
support animal life from Earth and even permanent human colonies. "This was once thought to be so far in
the future as to be irrelevant," said Christopher McKay, a research scientist at the National Aeronautics and
Space Administration. "But now it's starting to look practical. We could begin work in four or five decades."
The idea of "terra forming" Mars, as enthusiasts call it, has its roots in science fiction. But as researchers
develop a more profound understanding of how Earth's ecology supports life, they have begun to see how it
may be possible to create similar conditions on Mars. Don't plan on homesteading on Mars any time soon,
though. The process could take hundreds or even thousands of years to complete, and the cost would be
staggering.
火星
据宇宙探测器和天文学家收集的有力证据,火星是一个人类不能居住的星球。 它不像地球,而更像月球--
一个干涸、荒芜,看上去没有任何生命的世界。 火星的气压相当于地球上十万英尺高空处的气压。 火星大气的
构成中有 95%是二氧化碳,而且,火星上没有能屏蔽太阳致命射线的臭氧层。 白天,那里的温度可以达到零上,
但因为包裹火星的大气层极为稀薄,热量又会辐射回宇宙中。就算是在火星赤道,夜里的温度也在 50℃。 尽
管火星上的山谷沟渠说明它曾经被流水蚀刻过,但如今那里已没有液态水了。 极地冰帽是由固态水和二氧化碳
组成的,水也有可能存在于永久冻土之中。
尽管困难重重,某些科学家依然认为有可能把火星改造成类似地球的星球。 核反应可以用来融化冰冻的气
体最终形成火星大气层。由此就可以产生温室效应,阻止热量散射回宇宙中。 液化的水可以融化成极地海洋。
足够量的冰融化后,可将地球上的植物移植上去。 植物又可以向大气层提供氧气。 久而久之火星就可以维持从
地球过去的动物生命甚至成为人类的永久居留地。 "这一切在过去看起来遥远得近乎无稽",国家航天局的一位
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新东方精选 80 篇文章
研究人员,克里斯托弗·麦克凯说,"但是现在已经开始展现出可能性。 四五十年后,我们就可以着手于这项工
作。"这种支持者们称为"移居火星"的想法最早出现在科幻小说中。 但随着研究者对地球上生态如何支持生命的
理解越来越深入,在火星上创造类似地球环境也显得越来越现实。 但千万别计划很快在火星上建造家园。 这个
历程需要几百乃至上千年,而且耗费将是惊人的。
>75 Hydrogen and Industries
Hydrogen, the lightest and simplest of the elements, has several properties that make it valuable for
many industries. It releases more heat per unit of weight than any other fuel. In rocket engines, tons of
hydrogen and oxygen are burned, and hydrogen is used with oxygen for welding torches that produce
temperatures as high as 4, 000 degrees F and can be used in cutting steel. Fuel cells to generate electricity
operate on hydrogen and oxygen.
Hydrogen also serves to prevent metals from tarnishing during heat treatments by removing the oxygen
from them. Although it would be difficult to remove the oxygen by itself, hydrogen readily combines with
oxygen to form water, which can be heated to steam and easily removed.
Hydrogen is also useful in the food industry for a process know as hydrogenation. Products such as
margarine and cooking oils are changed from liquids to semisolids by adding hydrogen to their molecules.
Soap manufacturers also use hydrogen for this purpose.
Hydrogen is also one of the coolest refrigerants. It does not become a liquid until it reaches temperatures
of -425 degrees F. Pure hydrogen gas is used in large electric generators to cool the coils. In addition, in the
chemical industry, hydrogen is used to produce ammonia, gasoline, methyl alcohol, and many other important
products.
氢与工业
氢作为最轻和最简单的元素,有几种特性对工业非常有用。 作为燃料,它每单位重量释放热量最多,在火
箭的引擎中,成吨的氢和氧被燃烧掉。 氢和氧合在一起用于焊接,能够产生高达华氏四千度的高温而可以切割
钢铁。 发电的燃料房就是使用氢和氧。
氢也可以用来在金属热处理中通过从中除去氧的方法来防锈。 虽然单独除去氧本身是困难的,氢和氧很容
易结合成水,而水是可以加热蒸发除去的。 氢在食品工业中对于所谓的氢化过程也很有用。 人造黄油和食用油
的分子中加上氢,就由液态变成半固态。 肥皂制造商也为此使用氢。
氢是温度最低的冷冻剂。 它要到华氏-425 度才会液化。 纯氢被用于大型发电机线圈的冷却。 除此之外,
在化学工业中,氢被用来制造氨、汽油、甲醇以及其它许多重要产品。
>74 The History of Chemistry
Chemistry did not emerge as a science until after the scientific revolution in the seventeenth century and
then only rather slowly and laboriously. But chemical knowledge is as old as history, being almost entirely
concerned with the practical arts of living. Cooking is essentially a chemical process; so is the melting of
metals and the administration of drugs and poisons. This basic chemical knowledge, which was applied in
most cases as a rule of thumb, was nevertheless dependent on previous experiment. It also served to
stimulate a fundamental curiosity about the processes themselves. New information was always being gained
as artisans improved techniques to gain better results.
The development of a scientific approach to chemistry was, however, hampered by several factors. The
most serious problem was the vast range of material available and the consequent difficulty of organizing it
into some system. In addition, there were social and intellectual difficulties, chemistry is nothing if not
practical; those who practice it must use their hands, they must have a certain practical flair. Yet in many
ancient civilizations, practical tasks were primarily the province of a slave population. The thinker or
philosopher stood apart from this mundane world, where the practical arts appeared to lack any intellectual
content or interest.
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新东方精选 80 篇文章
The final problem for early chemical science was the element of secrecy. Experts in specific trades had
developed their own techniques and guarded their knowledge to prevent others from stealing their livelihood.
Another factor that contributed to secrecy was the esoteric nature of the knowledge of a alchemists, who were
trying to transform base metals into gold or were concerned with the hunt for the elixir that would bestow the
blessing of eternal life. In one sense, the second of these was the more serious impediment because the
records of the chemical processes that early alchemists had discovered were often written down in symbolic
language intelligible to very few or in symbols that were purposely obscure.
化学的历史
化学在 17 世纪的科技革命后才成为一门科学,其发展是缓慢而艰难的。 但化学知识却像人类历史一样古
老,与人们实际生活密切相关。 做饭基本上是一个化学过程。 同样,金属熔炼、使用药品或毒剂也是如此。
人们在大多数情况下只是粗糙地运用这些基本化学知识,但这些基本知识的确是来自于前人的实验。 它们同时
也激发了人们对化学本身的兴趣。 匠人们利用新技术来改良工艺,就增加了对化学的了解。
但是,化学科学方法的发展却有许多阻碍的因素。 其中最严重的问题就是要把浩如烟海的物质归纳为若干
系统确实很困难。 此外,还有社会和知识的原因。 离开实际用途,化学就毫无价值;研究化学的人必须亲自动
手,这就要求他们要有很强的动手能力。但在许多古代文明中,动手的活都是奴隶的行当。 思想家与哲学家与
此劳碌决不沾边,因为在他们看来,实际操作技能低智而乏味。
最后,还有一个原因妨碍早期化学的发展,那就是保密。 某个行家一旦发现了新技术,就竭力保密以防被
人偷了饭碗。 另一个原因加剧了知识封锁这是因为炼金术士的知识的神秘性。 这些术士们要么想他便宜的金属
变成黄金,要么期望找到一种长生不老药。从某种意义上说,这第二个因素带来了更严重的阻碍,因为早期术
士们的研究成果记载于鲜为人知的或故意让人不懂的符号中。
>73 The Microscopic Technique
Each advance in microscopic technique has provided scientists with new perspectives on the function of
living organisms and the nature of matter itself. The invention of the visible light microscope late in the
sixteenth century introduced a previously unknown realm of single celled plants and animals. In the twentieth
century, electron microscopes have provided direct views of viruses and minuscule surface structures. Now
another type of microscope, one that utilizes x rays rather than light or electrons, offers a different way of
examining tiny details; it should extend human perception still farther into the natural world. The dream of
building an x ray microscope dates to back 1895; its development, however was virtually halted in the 1940's
because the development of the electron microscope was progressing rapidly. During the 1940's, electron
microscopes routinely achieved resolution better than that possible with a visible light microscope, while the
performance of x ray microscopes resisted improvement. In recent years, however, interest in x ray
microscopes has revived, largely because of advances such as the development t of new sources of x ray
illumination. As a result, the brightness available today is millions of times that of x ray tubes, which, for most
of the century, were the only available sources of soft x rays. The new x ray microscopes considerably
improve on the resolution provided by optical microscopes. They can also be used to map the distribution of
certain chemical elements. Some can form pictures in extremely short times; others hold the promise of
special capabilities such as three dimensional imaging. Unlike conventional electron microscope, x ray
microscope enables specimens to be kept in air and in water, which means that biological samples can be
studied under conditions similar to their natural state. The illumination used, so called soft x rays in the
wavelength range of twenty to forty angstroms (an angstrom is one ten billionth of a meter), is also sufficiently
penetrating to image intact biological cells in many cases. Because of the wavelength of the x rays used, soft
x ray microscopes will never match the highest resolution possible with electron microscopes. Rather, their
special properties will make possible investigations that will complement those performed with light and
electron based instruments.
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