Английский язык. Арланова Т.Л - 43 стр.

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LESSON 8
Lasers
Exercise 1. What are lasers? List any applications you know for lasers.
Exercise 2. Read this text to check your answers to Exercise 1.
NOTES: to amplify –усиливать; precise – точный; welding – сварка; to
align – выравнивать, выпрямлять; tissue – здесь: ткань; gear – шестерня,
привод; lever – рычаг; throttle – дроссель.
Lasers (Light Amplification by Stimulated Emission of Radiation) are
devices which amplify light and produce beams of light which are very
intense, directional, and pure in colour. They can be solid state, gas, could be
used as 'death rays'. In the 1980s, the United States semiconductor, or liquid.
When lasers were invented in 1960, some people thought they
experimented with lasers as a defence against nuclear missiles. Nowadays,
they are used to identify targets. But apart from military uses, they have many
applications in engineering,communications, medicine, and the arts.
In engineering, powerful laser beams can be focused on a small area.
These beams can heat, melt, or vaporize material in a very precise way. They
can be used for drilling diamonds, cutting complex shapes in materials from
plastics to steel, for spot welding and for surfacing techniques, such as
hardening aircraft engine turbine blades. Laser beams can also be used to
measure and align structures.
Lasers are ideal for communications in space. Laser light can carry many
more information channels than microwaves because of its high frequency.
In addition, it can travel long distances without
losing signal strength. Lasers can also be used
for information recording and reading. Compact
discs are read by lasers.
In medicine, laser beams can treat
damaged tissue in a fraction of a second without
harming healthy tissue. They can be used in very
precise eye operations.
In the arts, lasers can provide fantastic
displays of light. Pop concerts are often
accompanied by laser displays.

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