How Light is Analysed

The efforts of ancient philosophers to analyse matter begin with an understanding that matter can be separated into its elementary constituents.

The concept that light can be analysed was much less obvious. We know men to have looked at rainbows without devising any kind of rational explanation for them.

Even when Rene Descartes noted the colours of a rainbow to be like those produced by a prism he couldn’t give an explanation to this phenomenon.

It was Newton who formulated the basic concept that light from ordinary sources is complex. By “complex” he meant that such light could be analysed into colours and the colours could be used to synthesize light.

Ex. 20. Listen to the following tape-recorded text:

The first ruby laser beam flashed on in a laboratory at the Physics Institute many years ago.

This marked the birth of one of the remarkable creations of the scientific and technological revolution.

In the short time since it appeared the laser beam has become a wide-ranging indispensable scientific and indus­trial tool. We know lasers to be able to monitor continental drift, measure air pollution and detect deep-lying mineral

N deposits, follow the movement of artificial satellites, study the structure of matter.

By using a laser beam it is possible to develop a commu- itjleation line which can carry simultaneous conversation fby thousands of millions of people.

We are sure lasers to enter the homes during the lifetime

fl the present generations. People will use the all-powerful earn in their life.

’ Bk. 21. Listen to the tape-recorded text and answer the questions that follow:

Everybody knows our country to have pioneered lasers, we manufacture laser devices of several dozen types jobth for domestic needs and for export. Medals won at the International fairs testify to the reliable performance by ^oviet lasers. By using a laser beam it is possible to develop (Bommunication lines.

I It would be interesting to note that the research project [by Soviet scientists that was awarded a State Prize will 'become more important than ever, it is connected with Using the laser to amplify weak light for the projection mi- jqfpscope. A series of laser radars, developed by Siberian en­gineers and scientists also contribute to environmental pro­tection. They are used to monitor air cleanliness, to detect sources of contamination and to analyse smells.

1. 

   jtofr

   What country was the first to have pioneered lasers?

2. What laser devices are manufactured in our country?

3. What do medals won at the international fairs testify

4. What is the research project connected with?

Б. What did Siberian engineers and scientists develop?

6. Where are laser devices used?

LESSON 24

;

Grammar: 1. The Subjective Infinitive Construction,

2, Review of the ing-forms.

Text: Mercury in the Environment.

Ex. 1. Pronounce the following words:

lithosphere ['liOosfia] disinfect [,dism'fekt]

hydrosphere f'haidrosfia] threat [0ret|

biosphere ['baiasfiaj health [hel0J

tissue ['tisju:] injurious [in'dsuarias]

marine [ma'rkn] tarnish ['tamj]

algae ['aeldsi-.j coefficient [,koui'fiJant]

Substantial [sab'etaenjal] ultraviolet j'Altra'vaialit]

sublimate ['sAblimeit]

Ex. 2. Read the following word combinations fluentlyi

sensitive methods; throughout the lithosphere; a threat tp health; per million; on a substantial scale; chemical in­dustry; ordinary temperature.

Study and remember the following chart: . .

t. He is known to work in the field of nuclear physics.

2. He is believed to have carried out a number of tests.

3. This problem is expected to have been solved.