VI. Найдите и переведите предложения в Present Perfect Tense, в Passive Voice . 4 страница
Venus is an extraordinary bright planet. No other planet6 is so bright as this one. Its brilliance is 13 times that of the brightest star6 in the night sky Sinus.
Since long ago 7 Venus has attracted the attention of astronomers. The fact is that. the .planet is generally shrouded in a dense layer of clouds which makes observation by means of an ordinary telescope extremely difficult. This is why Venus is sometimes called the "Planet of Mystery".
The atmosphere on Venus was discovered in 1761 by Mikhail Lomonosov. Loinonosov's discovery played an important part in the study of Venus and, as a matter of fact,8 laid the beginning for research into the physical properties of the planets of the solar system.
The study of Venus through optical telescopes which gave a visual picture has led to a number of fundamental discoveries.
The development of science and technology has considerably widened the possibilities of astronomical research. An important discovery was made after radio waves had been received from Venus. The distance from our planet to Venus has been checked with great accuracy and reliability by radar and reliable data have been obtained for the first time about the rotation of this planet. It has been found that a day on Venus is approximately 10 earth days.
Thanks to 10 the methods of planetary radio astronomy, scientists have estimated the probable temperature of the surface of Venus, and have obtained a number of other important data about its nature. The first attempt to study Venus with the aid of a rocket was undertaken in the Soviet Union on February 12. 1961, when Venera-l automatic space probe was launched from a heavy sputnik. By May 19—21, it had reached the area of Venus and passed the planet at a distance of about 100,000 kilometres.
THE MOON
By the beginning of the twentieth century the physical features of the moon had become well known, although questions about its origin and history were still unsettled. Its size, weight and density had all been accurately determined. Its motions had been precisely observed, and its location could be predicted for millions of years to come.
The basic statistics of the moon have been well established for the last 75 years. The moon swings around the earth in a nearly circular orbit that is about 382,000 kilometres away. This is not a great distance; an active executive might travel that far in less than two years.
The moon is a sphere whose diameter is 3,500 kilometres — about equal to the distance between New York and El Paso, Texas, or between St. Louis and San Francisco. The surface area of the moon is about 38 million square kilometres-nearly that of North and South America combined.
Although the diameter of the moon is about one quarter that of the earth, the moon weighs only about one-eightieth as much as the earth. The force of gravity at the moon's surface is only one-sixth that of the earth. A fully suited astronaut weighing about 350 pounds on the earth weighs only about 60 pounds on the moon.
Out of these basic statistics emerges a fundamental difference between the earth and the moon. The moon's density is 3.35 grams per cubic centimetre whereas the density of the earth is 5.5. The fact that the earth is 60 per cent denser than the moon suggests that there is some basic difference in their chemical composition — a difference hard to explain in two bodies that are so close together in space,
The moon has no atmosphere. When stars pass behind the moon they disappear sharply and suddenly with none of the gradual dimming that would be produced if their light was passing through a lunar atmosphere. More recent studies have shown that natural radio sources in the sky are cut off in the same sudden way as the moon moves in front of them. These movements show that at the lunar surface there is more complete vacuum than can be produced in any terrestrial laboratory.
The absence of a lunar atmosphere is not surprising; the moon's gravity is too weak to hold an atmosphere like the earth's. If relatively light gases like oxygen, nitrogen and water vapour were ever present on the moon, their molecules must have escaped into space long ago.
This lack of atmosphere means that, unlike the earth, the surface of the moon has no protection from continuous bombardment by tiny meteorites and from scorching by lethal X-rays, gamma rays, and cosmic rays that emanate from the sun and the rest of the universe. Fortunately for us, this dangerous matter and energy is absorbed by our atmosphere before it reaches the surface of the earth.
The moon completes one orbit around the earth in 27.3 days. However, the earth also moves along its orbit around the sun while the moon is swinging around the earth. As a result, the angle of illumination of the moon by the sun changes slightly, and a longer period
passes before the moon returns to the same phase as seen from the earth. This latter period, the time between one full moon and the next, is 29.5 days, and it has long been the basis of the lunar calendar.
The moon is also locked in its orbit, and as it moves around the earth, it turns so slowly that it always keeps the same side facing toward the earth. The moon thus rotates once on its axis in the same time that it makes one trip around the earth. To keep one face turned always to the earth, the moon must turn its back on the sun during half its orbit.
As a result of these motions, the 29.5-day month is divided on the moon into a lunar «day» and a lunar «night», each about two weeks long. Because the moon has no insulating atmosphere, the «daytime» temperature in direct sunlight .is about 134°C, well above the boiling point of water. During the lunar «night» the temperature drops suddenly to about — 170°C much colder than the freezing point of carbon dioxide ("dry ice").
WHY DOES THE MOON FOLLOW US WHEN WE DRIVE.
The moon doesn't look as if it's very far away, but its distance from the earth averages 239,000 miles. The diameter of the moon is 2,160 miles, or less than the distance across the United States. But when the moon is observed with a very large telescope, it looks as if it were only about 200 miles away,
Because the moon seems so close and big to us, we sometimes forget that 239,000,miles is quite a distance away. It is this great distance that explains why the moon seems to follow us when we drive in an automobile and look up at it.
To begin with, our feeling that this is happening is just that-only a feeling, a psychological reaction. When we speed along a road, we notice feat everything moves past us. Trees, houses, fences, the road - all fly past us in the opposite direction.
Now there's the moon, part at what we see as we look out, and we naturally expect it also to be flying past us, or at least to be moving backward as we speed ahead. When this doesn't happen, we have the sensation that it is "following" us.
But why doesn't it happen? Because the distance of the moon from tile earth is quite great. Compared to the distance our automobile travels in a few minutes, that distance is enormous. So as our automobile moves along, the angle at which we see the moon hardly changes.
In fact, we could go along a straight path for miles and the angle at which we would see the moon would still be basically the same. And as we notice everything else flying past, we get that feeling of me moon "following" us.
WHY IS THE SKY BLUE?
You know that the sky is blue, but have you ever thought why it isn't white, green or red? Here is the reason. Light from the sun is white. But white is composed of many colours - yellow, orange, red, green, blue and violet. Blue and violet have shorter wave lengths then the light waves of other colours.
Small particles of dust and moisture in the atmosphere bend the blue and violet waves of the sun's rays and spread them all over the atmosphere. Therefore, we see these colours more clearly than other colours in the rays, and the sky seems blue.
Try this easy experiment.
Fill a glass with water. Add a few drops of milk to represent the air filled with dust and moisture.
Take a pocket torch. Now darken the room. The beam from the pocket torch represents the light from the sun. Hold the pocket torch two inches from the glass and at a right angle to it.
The water looks blue! Why?
The particles of milk in the water have bent the blue waves which are contained in the white beam from the pocket torch. In the same way, the dust and moisture in the air bend the blue waves in the sun's rays and make the sky look blue.
WHAT IS THE MILKY WAY?
There is probably nothing more mysterious and wonderful then to observe meteoric rain. Most meteors are destroyed entirely by heat as they pass through the earth atmosphere. Only the larger meteor fragments ever reach the earth. Scientists believe that thousands of meteors fall to earth each day and night, but since most of the earth's surface is covered by water, they usually fall into oceans and lakes. Meteors may appear in the sky singly and travel in practically any direction. But meteors usually occur in swarms of thousands. As the earth travels in its path around the sun, it may come close to such swarms of meteors, and they be-come fiery hot upon contact with the upper layers of the atmosphere, and we see a "meteoric shower." Where do meteors come from? Astronomers now believe that the periodic swarms of meteors are the broken fragments of comets. When comets break up, the millions of fragments continue to move through space as a meteor swarm or stream. The swarms move in regular orbits, or paths, through space. One such swarm crosses the earth's path every 33 years.
When a piece of meteor reaches the earth, it is called "a meteorite." It has fallen to the earth because gravity has pulled it down. Far back in Roman times, in 467 B.C., a meteorite fell to the earth and its fall was considered such an important event that it was recorded by Roman historians!
COMETS.
Comets. What are they? Have you ever through about is? Where do they come from? Have you ever asked yourself about it? Of course we all know that comets consist of a body and tail, but if I ask you for much more information, you probably won't for answer me. But I also didn't know much about comets before I had read some books about them. I have always been interested in astronomy, space, and especially comets. Have you ever thought why comets don't fall on our Earth? You might say that this is a regularity, that they don't fall on Earth. It's all has been provided by scientists in facts.
In this article I would like to reveal you all the secrets about comets that were closed for you. I would to give you a key that will open the door into the strange and unknown world of comets, for better understanding of this phenomenon.
Comets appear to be very large, and they are spectacularly beautiful. They are also mysterious, because nobody knows for sure where they come from. There have been several theories of their origin. One theory claimed that comets were remnants of volcano located on one of the larger planets in our solar system. Today most scientists think comets may have created from a huge cloud of particles that surrounds our entire solar system.
Comets caused great terror amongst people in ancient times. Many thought the brilliant and mysterious light of a comet to be the warning of coming disaster - a plague, a war, an earthquake, or the death of an important person. Others feared that comets would fall directly on the Earth, causing instant destruction. Even today, some people still think that comets will hit our planet, but that is not very likely, because their orbits are so far away from the Earth.
Throughout history, comets have been the subject of many stories.
Ancient Egyptians believed that comets were sky pictures of a woman with long, untidy hair. In ancient Greece, comets through to be orbiting planets with people on them. American Indians considered comets to be the spirits of stairs.
Comet Halley has its own share of interesting stories. The comet appeared in the year 1066, just before the Normans invaded England, and the English blamed it for the defeat of Kind Harold.
Today, we know that none of the ancient beliefs about comets is true, and that the appearance of comet during important historical events was mere coincidence.
So, in conclusion, I would like to stay to say that in this article I've given you, to my mind, only a little key to the first door of the comets world.
COMET IN OUR UNIVERSE.
Comet (Latin Stella cometa, "hairy star"), nebulous celestial body revolving around the Sun. A comet is characterized by a long, luminous tail, but only in the segment of the comet *s orbit when it passes closest to the Sun.
History
Appearances of large comets were regarded as atmospheric phenomena until 1577, when the Danish astronomer Tycho Brahe proved that they were celestial bodies. In the 17th century the British scientist Sir Isaac Newton demonstrated that the movements of comets are subject to the same laws that control the planets in their orbits.
Composition
A comet is generally considered to consist of a small, sharp nucleus embedded in a nebulous disk called the coma. American astronomer Fred L. Whipple proposed in 1949 that nucleus/ containing practically all the mass of the comet, is a "dirty snowball" conglomerate of ices and dust.
The head of a comet/ including the hazy coma, may exceed the planet Jupiter in size. The solid portion of most comets, however, is equivalent to only a few cubic kilometres. The dust-blackened nucleus of Halley's comet, for example, is about 15 by 4 km (about 9 by 2.5 miles) in size.
As a comet approaches the Sun, the solar heat evaporates, or sublimates, the ices so that the comet brightens enormously. It may develop a brilliant tail, sometimes extending many millions of kilometres into space. The tail is generally directed away from Sun, even as the comet recedes again. The great tails of comets are composed of simple ionised molecules, including carbon monoxide and dioxide.
As a comet recedes from the Sun, the loss of gas and accompanying dust decreases in quantity, and the tails disappear. Some of the comets with small orbits have tails so short that they are practically invisible. On the other hand, the tail of at least one comet has exceeded 320 million km in length. The variation in length of the tail, together with the closeness of approach to the Sun and the Earth, accounts for the variation in the visibility of comets. Of some 1400 comets on record, fewer than half the tails were visible to the naked eye, and fewer than 10 percent were conspicuous.
When several comets with different periods travel in nearly the same orbit, they are said to be members of a comet group. The most famous group includes the spectacular Sun-grazing comet, Ikeya-Seki, of 1965, and seven other having periods of nearly a thousand years.
Comets were once believed to come from interstellar space. Although no detailed theory of origin is generally accepted, many astronomers now believe that comets originated in the outer, colder part of the solar system from residual planetary matter in the early days of the solar system.
Comets have long been regarded by the superstitious as portents of calamity or important events. The appearance of a comet has also given rise to the fear of collision between the comet and the Earth. The Earth, in fact, has passed through the tails of occasional comets without measurable effect. The collision of the nucleus of a comet with a large city would probably destroy the city but the probability of such an event occurring is exceedingly small.
In 1992 Comet Shoemark-Levy 9 broke apart into 21 large fragments as it ventured into the strong gravitational field of the planet Jupiter. During a week-long bombardment in July 1994, the fragments crashed into Jupiter's dense atmosphere at speeds of about 210,000 km/hr. Upon impact, the tremendous kinetic energy of the comets was converted into heat through massive explosions, some resulting in fireballs larger than the Earth.
ECLIPSE EXPERIMENT MAY EXPLAIN WHY SUN IS SO HOT
The total eclipse of the sun, on 11 August 1999, will help scientists to understand a question that has been puzzling them for 50 years: why the sun's outer atmosphere — the corona - is so hot.
United Kingdom scientists have been investigating the corona's heat since the 1940s by using large ground-based telescopes and a spacecraft but the exact reason remains elusive. It is known that magnetic fields are involved but whether the heating process is by magnetic waves or tiny explosions called nano flares is the subject of much debate.
The experiment relies on the latest electronic digital cameras linked to a specially adapted computer. The cameras are similar to those in video camcorders but are faster and more sensitive. The computer will "grab" and process data from the camera at ultra-high rates (50 frames per second). The set-up, known as the solar eclipse coronal imaging system (Sects), will be the fastest digital astronomical camera in the world.
Professor Ken Phillips from Rutherford Appleton Laboratory, Oxfordshire, southern England, and Peter Gallagher from Queen's University Belfast, Northern Ireland, will take the equipment to the Black Sea coast in Bulgaria, where the total eclipse will last two minutes. They will be joined there by collaborators from Poland.
The experiment will investigate what causes the sun's atmosphere to be so hot — two million degrees Celsius - far hotter than the sun's surface, which comparatively Is only 6,000 degrees. Rapid changes in the sun's magnetic field are thought to be the source of the heating and the Secis instrument should be able to detect these oscillations for the first time. It is only during an eclipse that the sun's outer atmosphere, the corona, is visible from earth; usually, the brightness of the sun obscures it.
Professor Phillips, who has just returned from testing the equipment in Poland, explained: "We only have two minutes of total eclipse to gather all the data so it is crucial that there are no hitches. We are going to the Black Sea coast because the chances of clear skies are very good but if we miss this one the next total eclipse in the world will be in Africa in 2001."
The research is funded by the Particle Physics and Astronomy Research Council PPARC), the UK's national astronomy funding body, as well as the Leverhuime Trust.
PPARC is government funded and provides researchers from UK universities with .access to world-class facilities and funds the UK membership of international bodies such as the European Laboratory for Particle Physics, CERN, and the European Space agency. More information about the eclipse and the Sects experiment is available on be national eclipse website (at: www.eclipse.org.uk).
MAN AND HIS ENVIRONMENT
The problem of man and his interaction with the environment has now become one of the difficult problems for many sciences not because it is fashionable but because of its great significance for the whole of mankind. We see at present the signs of ecological imbalance, which may cause a crisis if due measures 2 are not taken.
The air we breathe, the earth we live on and its rivers and seas are becoming polluted 3 with ever more dangerous, materials—by-products 4 of man's activities. Man depends for his life on what the biosphere provides: water, oxygen, food, etc. But the biosphere is strongly affected by all sorts of human activities. For example, man creates new compounds, new substances, pure chemical elements which are unknown to biosphere. They do not belong to the natural cycle of matter. They weaken the capacity of natural processes for self-regulation. Though not changing biologically, we change the environment in which we live. The Soviet great scientist Vladimir Vernadsky was the first in the world to realise the necessity for quite a new approach to the biosphere as early as the midforties.6
The increasing noise level is a special problem nowadays, We need silence as much as we need fresh air and unpolluted water. Noise does not only do physical damage to the hearer but can weaken his energy and break down his nerves.
Transport is a major source of environmental pollution. Every car consumes many tons of air. Its exhaust gases contain poisonous carbon dioxide which makes difficult the emission of the earth's heat into space. Many cities now are too noisy to live in. Los Angeles in the USA and Osaka in Japan are known to be the air pollution champions among major industrial cities.
Pollutants are not only harmful to health but to buildings as well. Our cities are dying physically. In most city centres some of the oldest and finest buildings are falling in pieces.7 On one hand, the foundations are being shaken by all the heavy traffic and, on the other hand, the bricks are being eaten away by fumes from the traffic. It is a slow process but it is going on even though you can't see it.
One more aspect of the problem is water pollution. Sea- and river-going ships often pollute sea and river water
with various oil products. At a rough estimate,8 no less than five million tons of oil are discharged into seas and oceans each year and one ton of oil can spread over about twelve square kilometres of the water surface as a fine film which prevents air-water oxygen exchange. One litre of oil makes one million litres of fresh water unfit for drinking. We must stop the contamination 9 of our waterways which comes from so many sources: chemical waste from factories, thermal waste from power stations, domestic waste from cities and towns and so on.
Notes
1. environment — окружающая среда
2. due measures — должные меры
3. to pollute — загрязнять;
pollution -— загрязнение!
pollutants — загрязнители
4. by-products — побочные продукты
5. man depends for his life on — в жизни человек зависит от
6. as early as the midforties —- еще в середине сороковых годов
7. are falling in pieces — разрушаются
8. at a rough estimate — по грубым подсчетам
9. contamination pollution
THE ENVIRONMENT
Why have 40% of the world's rainforests disappeared in the last 80 years?
What kind of energy will replace coal, gas and oil in the future?
How can we solve pollution problems like acid rain?
When will the hunting of animal like whales, leopards and foxes be stopped?
These are four of today's most serious "Green" issues. Ten years ago, most people knew very little about them. Now, environmental ground the world have millions of members.
RAINFORESTS
Before 1900, rainforests covered 14% of the world's surface. Today they cover 7%. The reason for this is simple. They have been cut down to provide land, paper, wood, medicines, minerals, and fuel. But it's not only trees which are disappearing. Every rainforest also contains millions of animals, insects and flowers. These are destroyed, too. If man continues to cut down rainforests, more than one millions species of plants and animals will become extinct by the year 2030.
Governments in rainforest countries need to plan and work together. They should also protect certain areas and plant new forests.
ENERGY
At the moment, 94% of the world's energy comes from fossil fuels. There's enough coal for the next 300 years, but only enough gas and oil for the next 50. What happens then? Well, one answer is nuclear energy. But after the Chemobyl disaster in 1986, many people think nuclear power isn't safe
There are four Green Solutions. They all use natural energy already in the environment. Wind energy (Britain's first 'wind farm' opened in Scotland in 1988); Solar energy (from the sun); Wave energy (from the sea); Geothermal energy (from 'hot rocks' under the Earth).
ACID RAIN
One of Europe and North America's most serious pollution problems is acid rain. What happens is this. First, factories send gases and chemicals into the air. There they mix and are carried for hundreds of miles by wind. Finally, they fall back to earth when it rains. This 'acid rain' kills fish and trees. It slowly destroys buildings too.
Industrial countries should control their levels of pollution.
POLLUTION
Man has been trying to make his life easier for many centuries. In doing so, he invented machines and instruments. They have been working - and polluting the world we live in.
In this world around us, there are two things that do not belong to any one country: air and ocean water. In both the air and the water, there is much pollution. People are concerned about the air and the water used by everyone, and they are also concerned about the future of the Earth.
One of the most important pollution problems is in the oceans Many ships sail in the ocean water - fishing ships, some ships carrying people, some carrying oil. If a ship loses some of the oil in the water, or trash from the ships is put into the ocean, the water becomes dirty Many birds and fish die because of the polluted water. Many fish are dying in the sea, others are getting contaminated. Fishermen catch contaminated fish which may be sold in markets and people may get sick from eating them. Fish may also move to another part of the ocean. Lakes and rivers are getting polluted, too. Some beaches are considered dangerous for swimming.
The second important problem is air pollution. Cars and factories pollute the air we use. It also destroys the ozone layer which protects the Earth from the dangerous light of the Sun.
Another problem is that our forests are dying from acid rain. This, in turn, affects the balance of nature.
If we want our children to live in the same world we live in, or in a better and healthier world, we must learn to protect the water, the air and the earth from pollution.
Economists have long thought of the environment as an unlimited source of resources. They have thought that the atmosphere, forests, rivers and seas are capable of absorbing all the rubbish the economy throws into them. In fact, the economy and the environment are closely related. The environment supplies the economy with all its resources, such as water, timber, minerals and oil. The environment has to absorb all its waste products.
Nevertheless, some economists have always argued that pollution damages the resources. For example, pumping waste gases from a power station does not get rid of them. The waste gases cause acid rain; this leads to forest damage an therefore reduces the resources of forestry industry.
There are many consequences of damaging the environment. One of them is acid rain. Another one is water shortage resulting from abuse of arable lands in agriculture. The third one is destroying the ozone layer of the Earth through pollution from factories and plants. The fourth problem is damage to water and soils. The fifth one is damage to wildlife: numerous species of animals and plants can disappear. Lastly, the most serious danger arising from damaging the environment is the result of the above-mentioned consequences. This is the danger for the life and health of the man.
The territories of the former Soviet Union are suffering many environmental problems. Many of these problems have been caused by economic activities. Apart from the effect of the Chemobyl disaster, the worst problem is probably in the area around the Aral Sea. Cotton growing m the region has used huge quantities of water, and the sea's level has fallen by 14 yards. This destroyed fishing industry and led to a damage in soils, crops and wildlife. Many forests in the north of European Russia and the Far East are under threat. A system of dams on the Volga has caused damage to fish.
If we are unable to learn to use the environment carefully and protect it from damage caused by man's activities, very soon we'll have no world to live in.
DID DRAGONS EVER EXIST?
In the folklore and legends of countries all over the world, there are tales of great and horrible dragons.
They were pictured as huge, snakelike monsters frightful to behold. They had bulging eyes, their nostrils spouted flames, and their roar was so great they caused the earth to tremble.
One of the most famous of these ancient dragons was the Hydra, which had nine heads! it devoured many beautiful young girls before it was slain by Hercules. Another famous dragon was the Chimera, a fire-breathing monster that met its death at the hands of a young warrior, Bellerophon, who was helped by his winged steed, Pegasus.
Many dragons were supposed to be guarding great treasures. The Golden Fleece was guarded by a dragon with a hundred eyes! In other cases, great heroes always fought battles with dragons.