现代大学英语精读第二册Unit16

Lesson Sixteen



Pre-class Work



Read the text a third time. Learn the new words and expressions listed below.



Glossary 1



abuse

v. to treat sth. so badly that you begin to destroy it



array

n. an ～ of: a group or collection of things, usually arranged so that you see them all



arrow

n. a sign shaped like an arrow used to show direction. Here it means the direction time moves



astronomy

n. the scientific study of the stars



atom

n. 原子



atomic

adj. the adjective of "atom"



body clock

the system in your body that controls types of behavior which happen on regular times 人体生物钟 (生物钟：biological clock)



carbon

n. 碳



cathedral

n. a very large church under the control of a bishop（主教）



cesium

n. 铯



charcoal 2

n. 木炭



chemist

n. a scientist who specializes in chemistry



Chicago

n. 芝加哥（U.S.）



chronobionics

n. 生物时间仿生学



circadian

adj. 生理节奏的



circulation

n. blood ～: the movement of blood around your body 血液循环



clockwork

adj. very regular; just like a clock



complex

adj. complicated; made up of many different parts which are closely connected



coordinated 3

adj. well-organized; organized in a way that all parts involved work well together 协调的



crude

adj. not skillfully made



decay

v. （物理）衰减



device

n. a piece of equipment, esp. one that is cleverly thought out



devise

v. to plan or invent a way of doing things



dimension

n. a measurement in space such as length, height, etc.



Egyptian

n. 埃及人



electron

n. 电子



elusive 4

adj. difficult to achieve



era

n. a long period of time in history that is different in some way from other periods



erase 5

v. to get rid of; to remove from memory



faraway

adj. distant



gear

n. a set of equipment or tools 齿轮（转动装置）



gong

n. （铜）锣



Gregorian calendar

公历；西历



Harvard

n. 哈佛大学

heartbeat

n. the action or sound of your heart as it pumps blood through your body



historian

n. a person who studies or writes history



immune

adj. ～ system: the system by which your body protects itself against disease 免疫系统



Indian

adj. Here: 印第安人的



individual

n. one person, considered separately from the rest of the group or society that he or she lives in



infinitely 6

adv. very much



internal

adj. inside your body



internalize

v. to make a pattern of behaviour part of your nature



Italy

n. 意大利



lengthy 7

adj. very long



lunar

adj. connected with the moon or the travel to the moon



mismatch

n. a combination of things that do not work well together



monastery 8

n. a building or buildings in which monks 9 （和尚；僧侣） live



Moscow

n. 莫斯科



mummy

n. a dead body preserved by being wrapped in cloth, esp. in ancient Egypt 木乃伊



nanosecond

n. one billionth of a second 纳米秒



naval 10

adj. connected with the navy 海军的



navigator

n. a person who directs or controls the course of a ship or a plane



Nobel Prize

诺贝尔奖



observatory 11

n. a special building from which scientists watch the moon, stars, weather etc. 天文台



oscillate

v. to keep moving regularly from side to side between two limits



perception

n. the way that you notice things with your senses



Pisa

n. 比萨市 (Italy)



Pope

n. the leader of the Roman Catholic Church 罗马天主教的教皇



precision

adj. (only before noun) done or made in an exact way



primordial 12

adj. existing at the beginning of time



pulse

n. 脉搏



reckon

v. to calculate



refinement 13

n. improvement



regardless of

(infml) without being affected 14 by different situations



relativity

n. theory of ～:爱因斯坦的相对论



reverse

v. to go backwards 15



rhythm

n. a regular repeated pattern of movements or sounds 节奏



riddle 16

n. a mystery; sth. one cannot understand



Roman

n. 罗马人



satellite

n. a machine that is sent into space and goes around the Earth used for radio, television or communication 卫星



signal

v. to express or indicate time 显示或表示（时间）



Sir

n. （放在姓名前）爵士



slave

n. a person completely dominated by another thing or person 奴隶



split

v. to divide into two or more parts



Sumerian

n. people in ancient Euphrates in Asia（古代幼发拉底地区）



technological 17

adj. related to technology 工艺的



tension

n. (a feeling of) nervous anxiety, worry, or pressure



theoretical

adj. based on theory



theorist

n. = theoretician; someone who develops ideas within a particular subject that explain why particular things happen or are true 理论家



therefore

adv. for that reason; as a result



tick

v. ～ away: to pass by (said of time)



timekeeping

n. the recording 18 of time



timepiece

n. a clock or watch 计时器



track

v. to follow the movement



ultimately

adv. in the end; after everything or everyone else has been done or considered



uniform

adj. being all the same in all its parts or among all its members



unified 19

adj. 统一的



variable

n. sth. that may be different in different situations so that you cannot be sure what will happen 可变因数



voyager

n. sb. who often makes long and dangerous journeys; Voyager (U.S.)探索者号（飞船）



waterwheel

n. a wheel turned by a flow of water, used to work machinery 20



width

n. size from side to side 宽度



Proper Names



Allan

艾伦



Landes

兰德斯



Ehret

埃雷特



Feynman

范曼



Gregory XIII

格雷戈里十三世



Galileo Galilei

伽利略·伽利莱伊



Gernot Winkler

格诺特·温克勒



Isaac Newton

艾萨克·牛顿



Willard Libby

威拉德·利比



Text A



The Riddle of Time



John Boslough



Read the text once for the main idea. Do not refer to the notes, dictionaries or the glossary yet.



We run our lives by clocks and calendars... but what is time?



"We physicists 22 work with time every day," said Nobel Prize winner Richard P. Feynman, "but don't ask me what it is. It's just too difficult to think about."

Throughout much of history time was looked upon as a flow like a river. Even for Sir Isaac Newton, the flow of time was uniform. But with Albert Einstein's theory of relativity, time was seen as a dimension — like height and width — giving a unified picture of events in time and space. "We have given more attention to measuring time than to any other variable in nature," says Gernot Winkler of the U.S. Naval Observatory in Washington, D.C. "But time remains 23 a riddle that exists only in our minds."

Devising accurate calendars and clocks to measure the flow of time has, through history, proved to be an elusive, lengthy intellectual pursuit. The Sumerians divided the year into 360 days, then named 12 lunar months of 30 days each. The Egyptians extended the year by five days. Later changes by the Romans, plus refinements 24 by Pope Gregory XIII in 1582, gave us today's Gregorian calendar, accurate to a day in every 3323 years.

Early societies also broke the day into smaller units. The sun, arcing overhead daily, was undoubtedly 25 the first timepiece, followed perhaps by the shadow of a stick stuck in the ground — a crude sundial.

In the 11th century a Chinese scholar named Su Sung invented a huge device that was among the first mechanical water clocks. More than 30 feet high, powered by a waterwheel, his clock signaled the hours with gongs, bells and drums.

It was in the West, however, that the mechanical clock achieved its greatest glory. One of the earliest was built for an English monastery in the 13th century.

In 16th-century Italy, a young medical student named Galileo Galilei is said to have spied a newly lighted lamp swinging in the cathedral at Pisa. Timing 26 it with his pulse, he found that each swing took the same amount of time, regardless of the distance traveled. He had discovered the pendulum 27. But seven decades passed before a Dutch scientist built the first pendulum clock, starting the era of precision timekeeping.

The Western idea that past, present and future are arranged in a straight line — that time does not repeat — seems to have grown out of the Christian 28 tradition in which Christ's birth took on special meaning because it was unique and therefore unrepeatable.

In human terms, even as you watch a second tick away, it's gone. But our technological world needs the precise time. A navigator at sea or in the air, plotting location by satellite, relies on a time signal accurate to within a single millionth of a second. Spacecraft like Voyager 2 are guided by radio commands timed to billionths of a second. And physicists tracking motion inside an atom reckon in trillionths of a second.

Atomic clocks at some 50 timekeeping stations around the world from Washington to Paris to Moscow allow this remarkable 29 splitting of seconds. Since the 1940s, scientists have known that the electrons of atoms oscillate with a rhythm so regular that — like a pendulum — they could be used to tell time. First built in 1948, these clocks generally use atoms of cesium, a silvery white metal, and are accurate to within a few nanoseconds a day.

But does this give us a clue to what time is? Not really, says David Allan, a time theorist. "Clocks are very limited devices." He points out that the past does not exist except in our memory. "Nor the future, except in our expectations of it," he says. "The most a clock gives is the time an instant ago. Time is our own invention."

Nature, too, has its clocks. In 1947 American chemist Willard Libby found a natural timekeeper in everything that lived during the past 50,000 years: the carbon atom, which decays at a known rate. By determining its level of carbon-14, scientists can tell the age of an Egyptian mummy or of charcoal from an ancient Indian home.

Astronomers 30 have gazed even farther back in time. By looking at light from a faraway galaxy 31, they are actually seeing the galaxy as it was billions of years ago. The rate at which these galaxies 32 are flying away from one another tells scientists the date when all the matter in the universe set out on its journey.

"We were able to show that the matter in the universe must have been infinitely compressed about 15 billion years ago," says theoretical physicist 21 Stephen Hawking 33 of the University of Cambridge in England. And before that? "Time as we measure it simply did not exist."

But human time — the perception of our bodies and minds — has origins deep in a primordial past long before a set of gears told us when to go to bed. The body's dominant 34 time cycle is called the circadian rhythm, the control for which is believed to lie in the brain, above the roof of the mouth. For most of us a normal circadian cycle is 25 hours, give or take 15 minutes.

Why not 24? "Being slightly out of step with nature may have created a kind of tension necessary for survival," suggests Charles Ehret, president of General Chronobionics near Chicago.

A few body-clock watchers believe we may also tick to an array of weekly cycles. They are thought to regulate changes in body chemicals, the response of the immune system, and a cyclic rise and fall of heartbeat and blood circulation. Such rhythms, some scientists believe, may help explain the seven-day week as a unit of time — the only calendar measure that does not trace its origins to astronomy.

Ehret is certain that if you abuse your powerful internal rhythms, you are in for trouble. Monday-morning blues 35, sleep disorders 36 and even depression can result from the mismatch between the clock on the wall and the ones in the body.

So the human body is as much a part of the clockwork universe as any timepiece we ever built. But what of the other questions we all have about time: can we travel through it, or can it be reversed? Who has not wished to turn back clock or calendar — to erase mistakes, to return as a child with adult wisdom, and to chat with Shakespeare? But scientists say that though the laws of physics may not forbid time travel, all observed arrows of time go in only one direction.

Whatever time is, we humans have internalized it so powerfully that it has taken on a meaning all its own. We run our lives by numbers on clocks and calendars that we ourselves have created. Have we become slaves to the clock?

David Landes, a historian of timekeeping at Harvard University, thinks not. "The clock let individuals know what time belonged to their employers and what time was their own. Workers are now actually freer than ever before. Without the clock, and now the watch, there is no modern world. It is the difference between a complex, intricately coordinated society and a primitive 37 one only vaguely 38 aware of time's possibilities."

"We ultimately are still in control of how we use time and how it affects us." More than anything else time is what we make of it.