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Laser

In the War of Worlds written before the turn of the last century H. Wells told a fantastic story of how Martians almost invaded our Earth. Their weapon was a mysterious sword of heat. Today Wells' sword of heat has come to reality in the laser. The name stands for light amplification by stimulated emission of radiation.

Laser, one of the most sophisticated inventions of man, produces an intensive beam of light of a very pure single colour. It represents the fulfilment of one of the mankind's oldest dreams of technology to provide1 a light beam intensive enough to vaporize the hardest and most heat-resistant materials. It can indeed make lead run like water, or, when focused, it can vaporize any substance on the earth. There is no material unamenable2 to laser treatment and laser will become one of the main technological tools quite soon.

The applications of laser in industry and science are so many and so varied as to suggest magic3. Scientists in many countries are working at a very interesting problem: combining the two big technological discoveries of the second half of the 20th century laser and thermonuclear reaction to produce a practically limitless source of energy. Physicists of this country have developed large laser installations to conduct physical experiments in heating thermonuclear fuel with laser beams. There also exists an idea to use laser for solving the problem of controlled thermonuclear reaction. The laser beam must heat the fuel to the required temperature so quickly that the plasma does not have time to disintegrate. According to current estimates, the duration of the pulse has to be approximately a billionth of a second. The light capacity of this pulse would be dozens of times greater than the capacity of all the world's power plants. To meet such demands in practice, scientists and engineers must work hard as it is clear that a lot of difficulties are to be encountered on route4.

The laser's most important potential may be its use in communications. The intensity of a laser can be rapidly changed to encode very complex signals. In principle, one laser beam, vibrating a billion times faster than ordinary radio waves, could carry the radio, TV and telephone messages of the world simultaneously. In just a


fraction of a second, for example, one laser beam could transmit the entire text of the Encyclopaedia Britannica.

Besides, there are projects to use lasers for long distance communication and for transmission of energy to space stations, to the surface of the Moon or to planets in the Solar system. Projects have also been suggested to place lasers aboard Earth satellites nearer to the Sun in order to transform the solar radiation into laser beams, with this transformed energy subsequently transmitted to the Earth or to other space bodies. These projects have not yet been put into effect5, because of the great technological difficulties to be overcome and, therefore, the great cost involved. But there is no doubt that in time6 these projects will be realized and the laser beam will begin operating in outer space as well.

Notes to the Text

1. to provide

2. unamenable

3. as to suggest magic

4. on route

5. put into effect

6. in time

8. 10 .

What is this text about? 2. What does the word laser mean? 3. What is the laser, is it a device or some phenomenon? 4. Who was the first to write about lasers? 5. What writer from this country wrote a book about a laser? 6. What can a laser do? 7. Where can it be used? 8. What other uses do you know?

9., 10. .

1. Laser means light amplification by stimulated emission of radiation. 2. Laser produces an intensive beam of light. 3. In the next few years laser will become one of the main technological tools. 4. Martians almost invaded the Earth before the turn of the last century. 5. Laser and thermonuclear reaction can produce a limited source of energy. 6. The laser beam heats the fuel so quickly that the plasma disintegrates. 7. There are projects to transform lu-


nar radiation into beams. 8. The laser beam will begin operating in outer space.

10. 10 (. 3- 5- ).

11. , .

1. design, construct and operate a laser system is a great technological achievement. 2. To protect the water resources, forests and atmosphere, several laws were passed in Russia in the 1970s. 3. A very interesting problem is to produce a practically limitless source of energy. 4. There are projects to use lasers for long distance communication. 5. Automation makes it possible to obtain and develop new sources of energy. 6. To combine laser and thermonuclear reaction is a very interesting problem for the scientists in many countries. 7. To conduct physical experiments with laser beams, Russian physicists have developed large laser installations. 8. Some Western experts consider that it is practically impossible to protect big cities from pollution. 9. Lasers to be placed on Earth satellites will transform solar radiation into laser beams. 10. A special design bureau in St. Petersburg was the first in the world to develop production of superlong escalators. 11. To put some projects with lasers in operation, great technological difficulties must be overcome. 12. One of the ways to make planes as economical as possible is to lighten the aircraft by using new composite materials. 13. Signals to be measured must be strong enough.

12., , .

1. The new system developed increased the safety and efficiency of a car. 2. The laser's most important potential use may be its long distance communication applications. 3. Provided the problems of using laser for controlled thermonuclear reaction were solved, the capacity of the pulse received would be much greater than that of all the world's power plants. 4. All a pilot needs to do is to tune to radio transmitters and he will get direction signals he needs. 5. One of the problems scientists are working at is to transmit energy to space stations by using lasers. 6. Laser provides a light beam intensive enough to vaporize the hardest and most heat-resistant materials. 7. A hypersonic aircraft will require complicated cooling measures because of the extreme temperatures involved. 8. A new electronic device to be installed in the car's panel will cal-


culate how far one can drive on the fuel left. 9. The hardest materials a laser beam is aimed at vaporize within a fraction of a second.

10. Aircraft designers are interested in all kinds of new materials that are strong enough to be used for high-speed airliners.

11. Noise and vibration are also the problems to be faced by designers of hypersonic crafts. 12. Besides, there is one more problem to be studied that of surface cooling. 13. The ordinary aircraft windows would make the future superliner structure too weak to withstand great stresses developed. 14. Every student of Cambridge is to go to his tutor once a week to discuss with him the work done.

13. .

encode, capacity, disintegrate, emission, widen, intensive, incredible, defence, stranger, reality, strengthen, fulfilment, indestructible, amplification, substance, entirely, vaporize.

14. , .

limit, transmit, approximate, success, science, relate.

15. .

installment, installation, install; , differ, difference, different; disintegrator, disintegration, disintegrate; application, applicable, apply; strong, strength, strengthen; efficient, efficiency, efficiently; amplification, amplifier, amplify.

16.:

)

rapidly, sophisticated, to conduct, demand, almost, quickly, to carry out, approximately, opportunity, requirement, also, use, to fulfill, complex, as well, to realize, application, possibility;

)

further, integrate, cooling, outside, powerless, uncontrolled, limited, disintegrate, nearer, capable, limitless, controlled, incapable, powerful, heating, inside.


17. , make light.

What makes a soap bubble ( ) rise and fall. If a soap bubble does not break at once, it will begin to fall. Why? To explain this, we must remember a balloon which is filled with hot air. It rises for some time and then it falls again. A balloon rises because the hot air inside it is lighter than the air round it, and as it is lighter, it must rise. When the air inside a balloon cools, the weight of the balloon itself makes it fall. A soap bubble is really a little balloon filled with hot air. This air is much lighter than the air outside. It can carry the weight of the water which makes the skin of the soap bubble. But this cannot last for a long time, because the skin of the soap bubble is very thin. The bubble becomes as cool as the air around it and it begins to fall. It is interesting to know that the early experiments with balloons were based on soap bubbles.

18..

There is a large garage on Seventh Street that provides work for eleven men. There is one man who meets the customers. There are two other men who take care of batteries. There is another man who washes cars. There are three other men who sell gas and oil. There is another man who repairs timers. There are two men who work with engines and there is one man who sells tires. There is no better place for automobile service.

19. to be.

I ... now in the garage on Seventh Street. There ... three cars here. One ... a Ford. There ... a man in it. He ... buying a tire. One car ... a Buick. There ... five people in it. There ... a third . A man and his wife ... in it. Their battery ... dead. The two battery men ... looking at it. I... sure you will have to rent a battery, one man says. We ... a long way from home, the man in the car answers. We .... not here often. We must buy a battery. There ... nothing else to do.

20. , .

chosen, fed, costing, put, overcome, coming, made.


21. .

understand why light from the laser is so concentrated, you must know that light travels in waves. Ordinary white light is made up of many wavelengths travelling in every direction. Laser light is essentially of one wavelength, with all the waves moving in one direction. Because the laser wavelengths intensify each other, they can remain in an unbelievably straight beam for a long distance. Almost any substance can be forced to lase if you work hard enough with it. Gas lasers give off continuous beams of light. Tiny semiconductor lasers may be especially useful in computers for transmitting signals to replace the use of cables. Many lasers can give off invisible radiation, either infrared or ultraviolet.

CONVERSATION Exercise 1.Answer the questions.

1. What is a laser? (a device producing an intensive beam of light) 2. What is its principle of operation? (light amplification by stimulated emission of radiation) 3. What light is produced by a laser? (light of pure single colour) 4. What can be done by means of a laser? (vaporizing the hardest materials) 5. What materials can be treated with a laser? (practically any material and any substance) 6. What is the most promising use of lasers? (the use in all kinds of communication) 7. What prevents putting into effect the projects to use lasers more widely in space? (great technological difficulties and great cost involved)

Exercise 2.Make a sentence out of the two parts.


1. A laser can find

2. It is very interesting to combine

3. There is an idea

4. In this case a laser beam

5. The light capacity in a laser installation should be dozens of times greater

6. To develop such a laser system in practice

7. Scientists and engineers must work


 

1. must heat the fuel to the required temperature very quickly.

2. very wide application.

3. hard to overcome numerous technological difficulties.

4. is not an easy task.

5. to use a laser for solving the problem of controlled thermonuclear reaction.

6. laser and thermonuclear reaction to produce a limitless source of energy.

7. than the capacity of all the
world's power plants.



Exercise 3. A.Read and learn.

I Want to Read Faster

Mary: I've read a detective story. It wasn't very good so I wasted (, ) much time.

Jane: Oh, it takes me now not more than an hour to read a novel.

M.: Really?

J.: Two months ago it would have taken me about two days. It is a pity you didn't join me when I was taking speed-reading course.

M.: Two things hold me back. Doubts that any system could radically and permanently increase my speed. And money for the courses.

J.: But I thought that if I could double my speed, the sum wouldn't be so much.

M.: Sure, you are right. By the way, some authorities say it isn't reading. Though a lot of unread newspapers, books and magazines about the house might fall on me. My present work day reading is 200 words per minute, it is very slow. How are those speed reading courses?

J.: Great, today 50,000 students a year take these courses.

M.: How long does this course last?

J.: Eight weeks, a 2,5 hour session a week plus an hour a day drill.

M.: What is your speed now?

J.: The final test showed that my speed was 1520 w.p.m. The book was the same we have used for our entrance exam.

M.: But you can lose the technique.

J.: It is another question. The only wide survey () of ex-students 1800 of them showed that after a year one third of the people weren't using the method at all. Another third said they use it sometimes and that probably they have kept speed. But the rest of the students said they were reading faster than a year later.

B. Answer the following questions:

1. Are you a fast or a slow reader?

2. In what situations can fast reading be useful in your opinion?

3. Would you like to improve your reading speed? Why?

4. Can all books be read quickly? Why (not)?

Exercise 4.Comment on the following statement.

Every student ought to be able to read very fast.

One point of view: Reading requires thought; one needs time for thinking, reading ought to be a kind of dialogue with the author this requires time; quality is more important than quantity.


A contrary point of view : Fast reading does not mean careless reading, nothing is left out, thinking can be very fast, fast reading is reading for meaning, it saves time () also for thinking, it is very important for a person to get a great deal of information in as little time as possible.

Exercise 5. Conduct a scientific meeting on: Laser and its applications.

Use texts 10A, 10B, and IOC as a basis for the preparation of an oral talk ( ), short abstracts ( ), summary () of the presentation and for the discussion of the theme ().

Useful Words and Phrases of Scientific Communication at a scientific meeting, conference, round-table discussion, symposium, colloquium, seminar, session, congress, etc.

 

Stages of a meeting Phrases
Opening a meeting Introducing a speaker Interrupting a speaker Opening a discussion Ending a discussion Thanking Ending a meeting Introducing the report Chairman I declare the meeting open. Right, can we start? Ladies and Gentlemen, are we ready to begin? OK then, perhaps we could make a start? I have a great pleasure to introduce Dr. (Prof.) Baker, an expert in ... Our first speaker, Dr Baker, will speak on... May I draw your attention to the fact that this point will be discussed later? And now I'd like to open the discussion on the presentation given by Dr Baker. Are there any questions to Dr Baker? May I propose that we stop there? I'm sure I'm speaking for everyone when I say how grateful we are to Dr Baker for his informative (excellent) presentation, (talk, speech, lecture). Pd like to thank everybody here. I declare the meeting closed. Speaker Mr. Chairman, Ladies and Gentlemen, it is a great honour to address this meeting (conference); I'd like to talk in my report about ... First of all (in the first place) I'd like to name the main points of my paper.


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