petroleum 呆在那儿并逐渐长成小牡蛎。 我们称之为种子或贝
苗。 贝苗吸进海水中的微小生物作为食物从而越长越大。 不products such as waxes and lubricating oils. Petroleum was not
then used to 久之后，农夫将这些小牡蛎收
make gasoline or heating oil.
集起来，把它们移种进其他的水域加快其生长，然后再次将
炼油
它们移种进另外的水域以使其肥 壮起来。 直到最近，野生
一种重要的新兴工业--炼油业在国内战争后成长起来。 未加
的以及人工饲养的牡蛎完全能够满足人们的需要。
工的石油，或原油--一种深 色的地下的稠浆--数百年来一直
但是今天这种 可口的海味已不再大量存在。这个问题已经变
为大众所知，但是人们却很少使用过它。
得如此严重以至于一些牡蛎苗床已完全消失。 幸运的是，早
在十九世纪五十 年代，萨缪尔〃M〃科尔，宾西法尼亚西
在 20
部的一位制造商，开始从当地的溢出物中收集石油
世纪初期海洋生物学家们就意识到如果不采取新的措施，牡
并将它炼成煤油。与冶炼矿石一样，石油提炼是一个从未加
蛎将会灭绝 或至少会变为一种奢侈的食品。 因此他们建造
工的原料中除去杂质的过程。煤 油被用来点灯。
了装备良好的孵卵场所并开始工作。 但是他
它是鲸油的一种便宜的替代品，而鲸油正变得越来越难以获
们尚没有适当的装臵或技术来处理牡蛎卵。他们不知道何时、
得。 不久就产 生了对煤油的大量需求。 人们开始寻找新
用什么以及如何喂养幼贝。他 们对捕食数百万幼小牡蛎的动
的石油供应。 第一口油井为
物天敌也所知无几。
E〃L〃瑞克，一个 退休的火车检票员所钻得。 1859 年他
他们失败了，但他们顽强地坚持了下来。 终于，在 20 世纪
开始在宾西法尼亚的泰特斯维尔钻井。 整个的这项
40 年代，一个重要的突破性的进展产生了。 海洋生物学家
冒险事业看起来是如此不现实和愚蠢以致旁观者称之为\鸭
发现，升高水
子的蠢行\。 (译者注：Drake's Folly, drake
温能够诱导牡蛎不仅在夏季也在秋季、冬季和春季里产卵。
在这里意含双关，即指瑞克的名字，又指该词的本义即鸭
后来他们发展了一项技术来喂 养幼贝至其长成贝苗。
子。 )但当瑞克往下钻 至 70 英尺(21 米)的时候，他发现
他们进一步成功地培养出了新的品种，可以抵抗疾病、长得
了石油。 他的油井从此每天生产
更快、 更大并且在不同的盐度和温度的水中都能茁壮生长。
20 桶原油。 瑞克成功的 消息将石油勘探者们吸引到现场。
此外，这些培殖出的牡蛎口感更佳!
截止到 19 世纪 60 年代早期，这些冒险者为寻找\黑色的
>35 Oil Refining
An important new industry, oil refining, grew after the Civil War. 金子\钻探遍了整个宾西法尼亚西部。 这项繁荣的事业在刺
激性和粗犷的西部气氛上可与 Crude
而且它为勘探者带来了远超过oil, or petroleum -- a dark, thick ooze from the earth -- had 1848 年的加州淘金热相媲美，
been known 淘金潮的财富。 原油能被提炼 成许多产品。 多年以来煤for hundreds of years, but little use had ever been made of it. In 油一直是主要的一种产品。 the 它在杂货店中出售由人挨户推销。 19 世纪八十九十年代炼1850's Samuel M. Kier, a manufacturer in western
油者们懂得了生产其它石油产品，如蜡和润滑油。 那时石
Pennsylvania, began
油还没有被
collecting the oil from local seepages and refining it into
用来制造汽油或采暖装臵用油。 kerosene.
Refining, like smelting, is a process of removing impurities from >36 Plate Tectonics and Sea-floor Spreading
The theory of plate tectonics describes the motions of the a raw
lithosphere, the material.
Earth that includes Kerosene was used to light lamps. It was a comparatively rigid outer layer of the
all the crust cheap substitute for
and part of the underlying mantle. The lithosphere is whale oil, which was becoming harder to get. Soon there
divided into a few was a large
plates of various sizes and shapes, in general the plates demand for kerosene. People began to search for new supplies of dozen
are in petroleum.
The first oil well was drilled by E. L. Drake, a retired railroad motion with respect to one another. A mid-ocean ridge is a
boundary conductor. In 1859 he began drilling in Titusville,
between plates where new lithospheric material is injected from Pennsylvania. The whole
venture seemed so impractical and foolish that onlookers called it belows. As
the plates diverge from a mid-ocean ridge they slide on a more \
Folly\But when he had drilled down about 70 feet (21 yielding
layer at the base of the lithosphere. meters), Drake
struck oil. His well began to yield 20 barrels of crude oil a Since the size of the Earth is essentially constant, new
lithosphere can day.
News of Drake's success brought oil prospectors to the scene. By be created at the mid-ocean ridges only if an equal amount of
lithospheric the early
1860's these wildcatters were drilling for \gold\all material is consumed elsewhere. The site of this destruction is
another over western
Pennsylvania. The boom rivaled the California gold rush of kind of plate boundary: a subduction zone. There one plate
dives under the 1848 in its
Both excitement and Wild West atmosphere. And it brought far edge of another and is reincorporated into the mantle.
kinds of plate more wealth to
boundary are associated with fault systems, earthquakes and the prospectors than any gold rush.
Crude oil could be refined into many products. For some years volcanism, but
the kinds of geologic activity observed at the two boundaries kerosene
continued to be the principal one. It was sold in grocery stores are quite
different. and
door-to-door. In the 1880's refiners learned how to make other The idea of sea-floor spreading actually preceded the theory of
plate variety of shapes, they may be dazzlingly white, or they may tectonics. In its original version, in the early 1960's, it be glassy described the blue, green or purple, tinted faintly or in darker hues. They creation and destruction of the ocean floor, but it did not specify are rigid graceful, stately, inspiring -- in calm, sunlight seas.
lithospheric plates. The hypothesis was substantiated soon But they are also called frightening and dangerous, and that they afterward by the are -- in
discovery that periodic reversals of the Earth's magnetic field the night, in the fog, and in storms. Even in clear weather one is are wise to
recorded in the oceanic crust. As magma rises under the stay a safe distance away from them. Most of their bulk is mid-ocean hidden below the
ridge, ferromagnetic minerals in the magma water, so their underwater parts may extend out far beyond the become magnetized in the visible top. direction of the geomagnetic field. When the magma cools Also, they may roll over unexpectedly, churning the waters and solidifies, around them.
the direction and the polarity of the field are preserved in the Icebergs are parts of glaciers that break off, drift into the water, magnetized float
volcanic rock. Reversals of the field give rise to a series of about awhile, and finally melt. Icebergs afloat today are made of magnetic snowflakes that have fallen over long ages of time. They embody stripes running parallel to the axis of the rift. The oceanic crust snows that thus drifted down hundreds, or many thousands, or in some serves as a magnetic tape recording of the history of the cases maybe a geomagnetic field million years ago. The snows fell in polar regions and on cold that can be dated independently; the width of the stripes mountains, indicates the where they melted only a little or not at all, and so collected to rate of the sea-floor spreading. great
depths over the years and centuries. 板块结构与海床扩展
板块结构理论描述岩石圈的运动。 岩石圈是相对坚硬的地As each year's snow accumulation lay on the surface,
evaporation and 球外层，包括全部地壳和部 分地幔。
melting caused the snowflakes slowly to lose their feathery
岩石圈被划分为几十个大小不同形状各异的板块，一般而言
points and
这些板块都处于相对 运动之中。 一道中海脊是板块之间的become tiny grains of ice. When new snow fell on top of the old, 边界，在那里新的岩石圈的物质从下部注入。 it too
当板块 从中海脊脱离时，它们滑向在岩石圈基部较易变形的turned to icy grains. So blankets of snow and ice grains 地层上。 因为地球的大小本质上是不 mounted layer upon
变的，只有同等数量的岩石圈物质在其它地方被吞没，新的layer and were of such great thickness that the weight of the
upper layers 岩石圈才能生成。 销毁旧岩石
圈的地方形成另外一种板块边界：一块潜没的区域。 在这compressed the lower ones. With time and pressure from
above, the many
里，一块板块潜没到另一板块的 边缘之下并结合入地幔之
small ice grains joined and changed to larger crystals, and
中。 eventually the
两种板块边界均与地层系统、地震以及火山活动有关，但在 deeper crystals merged into a solid mass of ice.
两种边界处观察到的诸般地质活动却迥然不同。 海床扩展说冰山 冰山是大自然最壮观的创造之一，但大多数人却从未看实际上早于板块结构理论。 在 到过冰山，一种朦胧神秘的气氛
20 世纪 60 年代它的理论雏形中，描述了海底的生成和毁笼罩着它们。 冰山形成于久远的、寒冷的水体中，而且伴灭，但没有详细介绍坚硬的岩石圈 板块。 这个假定不久之随着雷声轰鸣般的嘈杂和水花汹 后为发现所证实。 涌的风暴，但却无人耳闻目睹。冰山仅存在短短的一段时间该发现表明地球磁场周期性的逆转被记录在海洋 地壳中。 就慢慢地悄无声息地融化掉。冰 山具有最纯粹的美，人们如当岩浆从中海脊下涌起的时候，岩浆中的磁铁矿物质按地磁是说。 场的方向被磁化。 岩 冰山呈现出千姿百态，可能白得耀眼，或者是闪耀着蓝 色、浆冷却并凝固下来后，地磁场的方向和磁极被保留在磁化了绿色或紫色的玻璃般的光芒，或浓或淡。 它们在平静的阳的火山岩中。 磁场的逆转形成 一系列与断层轴线平行的条光照耀的海水中显得优雅堂 形磁区。 皇，令人浮想联翩。 但是人们亦把冰山称为恐怖的和危险这样海洋壳就扮演了磁带的角色，记录下可以鉴定时 间的地的。 它们的确如此--在夜间，雾 天和风暴肆虐时。 磁场的历史。 条形磁区的宽度表明了海底扩展的速度。 即便是在晴朗的天气里，与它们保持一段安全距离也是明智>37 Icebergs 的。 冰山的 大部分体积稳藏于水下，因此其水下部分的伸Icebergs are among nature's most spectacular creations, and yet 展远远超过可见的顶部。 冰山也可能出人意 most people
料地翻滚，剧烈地搅动周围的水体。 冰山是冰川的一部分，
have never seen one. A vague air of mystery envelops them.
从冰川断裂漂流进水中，一段 时间后融化。 今天的冰山由They come into
being -- somewhere -- in faraway, frigid waters, amid thunderous 多年前降落的雪花形成。
它们的体内是数百年，或数千年，有 时甚至是数百万年前的noise and
splashing turbulence, which in most case no one hears or sees. 降雪。 这些雪花落在极地或寒冷的山上，仅有少量融化或They exist 根本不融
only a short time and then slowly waste away just as unnoticed. 化，这样经过许多年或许多世纪后积累了巨大的深度。 由Objects of sheerest beauty they have been called. Appearing in
于每年的雪花积累在表面之上， 蒸发和融化使得雪花慢慢失
an endless
去其羽状尖端而变成微小的冰粒。
当新的雪花降落到旧的表面 上，也变成了冰粒。 因而雪花this manner the
覆盖层和冰粒层层堆积起来直到如此之大的厚度以致较上层 salinity is increased, since the salts stay behind. If this is carried
to 的重量压缩较下层。
the extreme, of course, white crystals of salt would be left
在时间和压力的作用下，许多小冰粒结合到一起变成更大的
behind.
晶体，最 终较底层的晶体合并成庞大而坚固的冰块。
The opposite of evaporation is precipitation, such as rain,
>38 Topaz by which
Topaz is a hard, transparent mineral. It is a compound of water is added to the ocean. Here the ocean is being diluted aluminum, silica, so that the
and fluorine. Gem topaz is valuable. Jewelers call this salinity is decreased. This may occur in areas of high rainfall variety of the or in
stone \topaz\The best-known precious topaz gems coastal regions where rivers flow into the ocean. range in color Thus salinity
from rich yellow to light brown or pinkish red. Topaz is one of may be increased by the subtraction of water by evaporation, orthe hardest decreased gem minerals. In the mineral table of hardness, it has a rating by the addition of fresh water by precipitation or runoff. of 8, which Normally, in tropical regions where the sun is very strong, the means that a knife cannot cut it, and that topaz will scratch ocean quartz. salinity is somewhat higher than it is in other parts of the world The golden variety of precious topaz is quite uncommon. Most of where the world's there is not as much evaporation. Similarly, in coastal regions topaz is white or blue. The white and blue crystals of topaz where are large, rivers dilute the sea, salinity is somewhat lower than in often weighing thousands of carats. For this reason, the value of other oceanic topaz areas.
does not depend so much on its size as it does with diamonds and A third process by which salinity may be altered is associated many other with the
precious stones, where the value increases about four times formation and melting of sea ice. When sea water is frozen, with each the dissolved
doubling of weight. The value of a topaz is largely determined by materials are left behind. In this manner, sea water directly its beneath
quality. But color is also important: blue topaz, for instance, is freshly formed sea ice has a higher salinity than it did often before the ice irradiated to deepen and improve its color. appeared. Of course, when this ice melts, it will tend toBlue topaz is often sold as aquamarine and a variety of brown decrease the quartz is salinity of the surrounding water. In the Weddell Sea widely sold as topaz. The quartz is much less brilliant and more Antarctica, the plentiful densest water in the oceans is formed as a result of this freezing than true topaz. Most of it is a variety of amethyst: that heat has process, turned which increases the salinity of cold water. This heavy water sinks brown. and is 黄水晶 found in the deeper portions of the oceans of the world. 黄水晶是一种坚硬、透明的矿物质。 它是铝、硅和氟的化合海水盐度 如果我们分析海水的盐度，会发现地区间只有轻微物。 黄水晶宝石价值不菲。 珠宝商把这种石头称为\黄玉\。 的变化，然而有些小的变化是重要的。
最出名的黄玉有各种颜色如深黄色、淡棕色、浅红色等。 黄 导致海洋的盐度变化的基本过程有三个，其中之一是通过蒸水晶是最坚硬的宝石矿中的一种。 在矿石硬度表上，它的发的方式即把液态水转化为水蒸 气来减少海洋中的水分。 硬度为 8，这表明刀子不能割开 这样由于盐留了下来，所以盐度增大。 它而它可在石英上划痕。 金黄色的黄玉品种非常罕见。 世当然，如果这种方式走向 极端，将会余下白色的盐晶体。 与界上大多数的黄水晶是白色或蓝 色的。 这些白色或蓝色的蒸发相反的是降水，如降雨，由此水被加入海中，海水 被稀黄水晶晶体很大，常常有数千克拉重。 释，从而盐度降低。
由于这个原因，黄水晶的 价值不像钻石和许多其它宝石那样这种情形会发生在大量降雨的地区，或江河入海岸处。 因主要依赖于其大小，重量翻一番价值即上升约四倍。 黄 此，盐 度通过蒸发减少水分而上升或通过降水或径流增加淡水晶的价值很大程度上取决于其品质，但颜色也很重要。 举水成分而下降。 一般来说，在阳光很 例来说，蓝色的黄水晶常需放 射处理以加深和改善其颜色。 强烈的热带地区，海水的盐度略高于世界上其它没有热带那
蓝色的黄水晶常被作为海蓝宝石出售，许多种棕色石英被当 样多的蒸发的地区。 同理，在 江河稀释海水的海岸地带，作黄水晶广为贩卖。 石英光亮度远小于黄水晶，矿藏储量也海水盐度略低于其它海区。 远较黄水晶丰富。 大多数石英 第三个可以变更盐度的过程与海洋 中冰的形成和融化有关。 是一种紫水晶，高温使其变为棕色。 海水冻结时，溶于其中的物质被留了下来。 这样，在新形>39 The Salinity of Ocean Waters 成的海
If the salinity of ocean waters is analyzed, it is found to vary only 水冰面的正下方的海水比在冰形成之前有更高的盐度。 当slightly from place to place. Nevertheless, some of these
然，当冰融化的时候，会降低周 围水中的盐度。
small changes are
在南极洲边缘的威德尔海中，结冰过程增加低温海水的盐度，important. There are three basic processes that
从而形成了 浓度最大的海水。 这些大密度的海水下沉，可cause a change in oceanic salinity.
One of these is the subtraction of water from the ocean by means 以在世界海洋的深水域发现。 of evaporation - conversion of liquid water to water vapor. In
>40 Cohesion-tension Theory
Atmospheric pressure can support a column of water up to 10 meters high.
But plants can move water much higher; the sequoia tree can pump water to
its very top more than 100 meters above the ground. Until the end of the
nineteenthcentury, the movement of water in trees and other tall plants
was a mystery. Some botanists hypothesized that theliving cells of plants
acted as pumps. But many experiments demonstrated that the stems of plants
in which all the cells are killed can still move water to appreciable
heights. Other explanations for the movement of water in plants have been
based on root pressure, a push on the water from the roots at the bottom of
the plant. But root pressure is not nearly great enough to push water to
the tops of tall trees. Furthermore, the conifers, which are among the
tallest trees, have unusually low root pressures.
If water is not pumped to the top of a tall tree, and if it is not pushed
to the top of a tall tree, then we may ask: how does it get there? According to the currently accepted cohesion-tension theory, water is
pulled there. The pull on a rising column of water in a plant results
from the evaporation of water at the top of the plant. As water is lost
from the surface of the leaves, a negative pressure, or tension, is
created. The evaporated water is replaced by water moving from inside the
plant in unbroken columns that extend from the top of a plant to its roots.
The same forces that create surface tension in any sample of water are
responsible for the maintenance of these unbroken columns of water. When
water is confined in tubes of very small bore, the forces of cohesion (the
attraction between water molecules) are so great that the strength of a
column of water compares with the strength of a steel wire of the same
diameter. This cohesive strength permits columns of water to be pulled to
great heights without being broken. 内聚压力理论
大气压能够支持 10 米高的水柱，但植物可将水送得更高。 美洲红杉就能把水泵到地面 以上 100 多米高的树顶。 直到 19
世纪末，水在树木和其它高大植物中的输送还是一个谜。 一些植物学家假定植物中的活细胞充当了水泵的角色。 但许多实验表明细胞都已死亡的植
物茎干仍能将水输送到相当可观的高度。 对于植物中输送水的其它解释都基于根压--植物 底端的根对水的推动。 但根压完全不足以将水推到树顶。
况且，最高树木中的松柏只有很 低的根压。 如果水不是被泵到高树的树顶，也不是被推到树顶，那么我们会问：它是怎样
到达树顶的呢?根据目前为人们所接受的内聚压力的理论，水是被拉到上面去的。 一株植物 中作用于一个正在升高的水
柱之上的拉力来自该植物顶部水的蒸发。
由于水从叶子表面丧 失，一个负压力，或张力就得以产生。 蒸发出去的水被植物里流动的水代替。 这些水形成
水柱从植物顶端一直延伸到根部。在任何水样中造成表面张力的力支持着这些不断的水柱。
当水被限制在内径很小的管道中时，内聚压力(水分子之间的相互吸引力)是如此之大以致一 支水柱的强度相当于一根直径相同的钢丝的强度。
这种内聚压力使得水柱被拉到非常高的 地方而不会断裂。 >41 American Black Bears
American black bears appear in a variety of colors despite their name. In
the eastern part of their range, most of these bears have shiny black fur,
but in the west they grow brown, red, or even yellow coats. To the north,
the black bear is actually gray or white in color. Even in the same litter,
both brown and black furred bears may be born.
Black bears are the smallest of all American bears, ranging in length from
five to six feet, weighing from three hundred to five hundred pounds. Their
eyes and ears are small and their eyesight and hearing are not as good as
their sense of smell.
Like all bears, the black bear is timid, clumsy, and rarely dangerous, but
if attacked, most can climb trees and cover ground at great speeds. When
angry or frightened, it is a formidable enemy.
Black bears feed on leaves, herbs, roots, fruit, berries, insects, fish,
and even larger animals. One of the most interesting characteristics of
bears, including the black bear, is their winter sleep. Unlike squirrels,
woodchucks, and many other woodland animals, bears do not actually
hibernate. Although the bear does not eat during the winter months,
sustaining itself from body fat, its temperature remains almost normal, and
it breathes regularly four or five times per minute.
Most black bears live alone, except during mating season. They prefer
to live in caves, hollow logs, or dense thickets. A litter of one to four
cubs is born in January or February after a gestation period of six to nine
months, and they remain with their mother until they are fully grown or
about one and a half years old. Black bears can live as long as thirty
years in the wild, and even longer in game preserves set aside for them. 美国黑熊
美国黑熊虽然被叫做黑熊但却有各种各样的颜色。 在它们生活区域的东部，大部分黑 熊长有富有光泽的黑毛，但在西部，他们则长着棕色、红色甚至是黄色的毛。
在北部，黑 熊其实长着灰色或白色的毛。 就是在一胎所生的小熊中，都可能混杂棕毛和黑毛。 黑熊是 所有美洲熊中最小的，5～6 英尺长，300～500
磅重。 它们的眼睛和耳朵都很小，他们的视 力和听觉不如嗅觉那样好。 像所有的熊一样，黑熊胆小，笨拙，很少具
purely economic perspective. 有危险性。 但如果
受到攻击，大部分黑熊会以很快的速度爬上树和奔跑。 当Changes in the technological base of coal-fired power plants
could restore 发怒或受惊吓时，黑熊会成为可 怕的对手。
their attractiveness, however. Whereas some of these changes
黑熊以树叶、草、树根、水果、浆果、昆虫、鱼，甚至更大
are
的动物为食。 熊类， 包括黑熊的最有趣的一个特点是他们
evolutionary and are intended mainly to increase the
的冬眠。 productivity of 与松鼠、旱獭和其它别的林地动物不同，熊 并不真正地冬眠。 existing plants, completely new technologies for burning coal 虽然熊在冬天的几个月中不吃东西，靠体内脂肪维持生命，cleanly are
also being developed. 但它们的体
温保持正常，并有规律地一分钟呼吸 4 或 5 次。除交配季火力发电厂托马斯〃爱迪生 1879 年发明的白炽灯导致对便节外，大多数黑熊独自生活。 他 们喜欢住在洞里、空心的宜、易得、可生产大量电能 的燃料的需求。
煤似乎符合这个要求，并成为第一批电厂的燃料(正是爱迪生大木头里或茂密的树丛里。 经过 6
到 9 个月的怀孕期后一胎 1～4 个小熊在 1 月或 2 月出本人在 19 世 纪末建造了第一批电厂)。 全国到处兴建电生。 它们同母熊住在一起，直到它们完全长大，即 1 岁半厂时，对煤的依赖加深了。
自第一次世界大战 以来，美国每年约有一半的电力是以煤为左右。 黑
熊在野外可以活到长达 30 年，在专门的保护区中甚至能活燃料的电厂提供的。 1986 年这些电厂的总发电能 力达到
28，900 得更长。
千瓦并且消耗了当年全国开采的九亿吨煤的 83%。 考虑到>42 Coal-fired Power Plants
The invention of the incandescent light bulb by Thomas A. 核能发展以及石 油、天然气供应中的不确定因素，到本世纪Edison in 1879 末，火力发电厂仍可能为美国提供多达 created a demand for a cheap, readily available fuel with 70%的 电力。 然而，尽管煤长期以来一直是电力的原料之which to generate
一并且可能会继续如此(煤占美国化石燃 料储量的 80%)，它
large amounts of electric power. Coal seemed to fit the bill, and it
却不是电厂的理想燃料。
fueled
而且会 导致包括酸雨the earliest power stations (which were set up at the end of the 煤的单位能量含量低于石油和天然气，
在内的一系列环境问题。 从 1960 年以来，排放控制和垃圾nineteenth
century by Edison himself). As more power plants were 处理的问题极大地 constructed 削弱了燃煤电厂的魅力。 由于减轻这些环境问题需要大量throughout the country, the reliance on coal increased. Since the 资金，而且建造庞大复杂的燃煤 电厂的费用不断上涨，也使First 得这些电厂从经济角度上不具备吸引力。 World War, coal-fired power plants have accounted for about
改变火力发电厂的基 础技术却可能恢复它们的吸引力。 虽
half of the
其目的只是提高现有电厂 的生产electricity produced in the United States each year. In 1986 such 然某些技术改进是渐进的，
率，但人们正在开发全新的清洁燃煤的技术。 plants
had a combined generating capacity of 289, 000 megawatts and >43 Statistics
There were two widely divergent influences on the early consumed 83
percent of the nearly 900 million tons of coal mined in the development of
statistical methods. Statistics had a mother who was dedicated to country that
year. Given the uncertainty in the future growth of nuclearkeeping
orderly records of governmental units (state and statistics come power and in
the supply of oil and natural gas, coal-fired power plants could from the
same Latin root status) and a gentlemanly gambling father well
provide up to 70 percent of the electric power in the United who relied on
mathematics to increase his skill at playing the odds in games of States by the
chance. end of the century.
Yet, in spite of the fact that coal has long been a source of The influence of the mother on the offspring, statistics, is
represented electricity
and may remain one for many years (coal represents by counting, measuring, describing, tabulating, ordering,
and the about 80 percent
of United States fossil-fuel reserves), it has actually taking of censuses -- all of which led to modern
descriptive never been
the most desirable fossil fuel for power plants. Coal contains statistics. From the influence of the father came modern
inferential less energy
per unit of weight than natural gas or oil; it is difficult to statistics, which is based squarely on theories of probability.
Descriptive statistics involves tabulating, depicting and transport,
and it is associated with a host of environmental issues, among describing
collections of data. These data may be quantitative such as them acid
rain. Since the late 1960's problems of emission control and measures of
height, intelligence or grade level -- variables that are waste disposal
have sharply reduced the appeal of coal-fired power plants. Thecharacterized by
an underlying continuum -- or the data may represent cost of
ameliorating these environmental problems along with the rising qualitative variables,
such as sex, college major or personality type. Large masses of cost of
building a facility as large and complex as a coal-fired data must
generally undergo a process of summarization or reduction power plant,
before they are have also made such plants less attractive from a
comprehensible. Descriptive statistics is a tool for describing