GRAVITATION
Gravitation is a very important force in the universe. Every object has a gravitational pull which is like magnetism. But, unlike magnetism, gravitation is not only in iron and steel. It is in every object large or small; but large objects, such as earth, have a stronger pull than small ones.
Isaac Newton, the great scientist of the seventeenth century, first studied gravitation. When he was a boy, he often saw how apples fell to the ground. He wondered why they fell towards the earth and why they did not fly up into the sky.
According to1 the law which he later produced everything in the universe attracts everything else towards itself. The sun attracts the earth and the earth attracts the sun. The earth attracts the moon and the moon attracts the sun. Although the bigger object has the stronger attraction, all objects, in fact,2 have some attraction too but we do not notice the gravitational pull of a book because the pull of the earth is very much greater.
Why does the earth always move round the sun, and not fly off into cold space? The sun's gravitation gives the answer. The earth always tries to move away in a straight line, but the sun always pulls it back. So it continues on its journey round and round the sun.
The sun is one of the stars in the galaxy, in which there are about 100,000 million stars. It is not in the middle of the galaxy, but rather3 near one edge.
There are millions of galaxies in the universe and so there are thousands of millions of millions of suns. Many astronomers believe that some of these suns have planets as our sun does.
Gravitation is the force which holds all the atoms of a star together. It holds the sun together and it holds the atoms of the earth together. It holds us on the earth.
Einstein produced a new law of gravitation. Its main results are the same as the results of Newton's law; but in very small and fine matters Einstein's law gives different results. One of these is that gravitation bends light a little; but according to Newton's law gravitation has very little effect on light. Einstein showed this fact by means of mathematics and not by experiment. And astronomers later proved by experiments that Einstein was right.
1. according to — в соответствии с
2. in fact— на самом деле, фактически
3. but rather — а скорее
PLANET EARTH — OUR COMMON HOME
Ecology is a science which is concerned with the interrelations of organisms and their environment, that is with everything that surrounds them.
The ecologists are faced by a lot of problems in the modern world — the air we breathe, the water we drink, the food we eat, the soil we stand on, the great projects we construct...
There are about 6 billion people in the world at present. The population is growing very fast and scientists believe that in a few decades it will be too big for the earth to support.
The Earth is being constantly damaged in different ways. Speaking about the growth of population we have to admit the increase of industries and their harmful effects on the environment — the pollution of air from choking factory chimneys and the pollution of water because of industrial wastes.
Among the other serious problems which our planet is facing are: the increasing consumption of energy and water, the pollution of air by car exhausts, the increasing hole in the atmospheric ozone layer, the rivers that are poisoned by industrial and agricultural chemicals, the forests that are felled and vast forest territories that are devastated by fire and acid rains.
Besides, armed conflicts and local wars add to the critical situation on the planet.
The Earth is just a huge spaceship and mankind is its crew. Can quarrels and killings among the crew be permitted? What will then happen to the spaceship? What will happen to mankind?
If we realize the coming danger, we'll see that we should find solutions to all the problems to survive.
What should be done to change the situation for the better?
• We must change people's attitude towards the environment.
• We should stop the pollution of air and water.
• We must save more energy and water and try to use other sources of energy (solar and tidal energy, the energy of the wind, subterranean hot waters, etc.).
• We must protect the ozone layer from harmful industrial products.
• We should prevent animals from extinction.
These and many other steps should be taken already now to make our planet a safer and better place to live in. We, human beings, must act.
TSIOLKOVSKY'S DREAM NEARS REALIZATION
The young man spent hours over ideas he had put down in a schoolboy's notebook. In a home-made machine he made lots of experiments to see how living things withstood the effects of gravity and acceleration. The date was 1879, in the small Russian village near Ryazan. Konstantin Tsiolkovsky was 22, waiting for a post of a schoolmaster.
The problem at which he worked was interplanetary travel. Though Tsiolkovsky soon began a long career as a teacher of mathematics, man's penetration into space remained his life-long study.
In 1883 he noted that the rocket would be the only man-made instrument able to reach space. The prediction was published only in 1954, when his collected works were printed by the Soviet Academy of Sciences.
The mathematical terms' of space travel were worked out by Tsiolkovsky as early as 1895 in a manuscript "The Exploration of Cosmic Space by Reaction-Propelled Apparatus". When it was published in 1903, Tsiolkovsky won immediate international recognition, especially among the pioneers of aviation science.
In order to get money for his researches Tsiolkovsky tried to publish his book "Outside the Earth" in 1916, in which he described the imaginary flight of a manned rocket ship in orbit about the earth.
It was only in 1920 that the book was published and it fired the imagination of other scientists in our country as well as abroad. In 1929 when Tsiolkovsky was 72, Professor Herman Obert, a German scientist, wrote to him: "You kindled this fire. We shall not let it die. It is necessary that man's greatest dream should be realized."2
In the book "Outside the Earth" Tsiolkovsky assembled a group of famous scientists in an imaginary mountain laboratory: Galileo, Newton, Laplace, Helmholz, Franklin and a modest Russian named Ivanov. At their disposal is an army of the world's best engineers and technicians. The year is 2017.
Together the scientists work out the theories of cosmic flight. They test rockets and fuels, discuss ways of living aboard a rocket, and design a 300-ton spaceship. The voyage that follows is described very vividly. Some of the details of this imaginary flight you have seen in reality on your own TV screen — weightless objects floating around a cosmonaut, the black sky of space, the blast-off of a man-carrying rocket.3
In. 1935 Tsiolkovsky wrote "All who are occupied with writing science fiction are doing good work; they excite interest, promote the working of the brain and bring into being people4 who will work on grand projects in the future."
1. mathematical terms — математические расчеты
2. that man's greatest dream should be realized — чтобы осуществилась величайшая мечта человека
3. the blast-off of a man-carrying rocket — запуск ракеты с человеком на борту
4. to promote the working of the brain and bring into being people — способствовать работе ума и появлению людей
ON THE ICE CONTINENT
Antarctica is the least known part of our planet. In contrast to the North Polar regions, where the Pole is surrounded by an ice-covered sea, the South Pole lies at the center of a great continent, with a coast line of about 14,000 (fourteen thousand) miles in length.
Most of the continent is covered with a great cap of ice in places more than 6,000 (six thousand) feet thick. It is a land of cold summers, violent winds and snowstorms. The temperature of the warmest month seldom rises above 0°C (zero degrees Centigrade) while the winter temperature varies from —36° (minus thirty six degrees) to — 76° (minus seventy six degrees).
It is believed that deep under the ice and snow of Antarctic-.ca lie the largest deposits of coal in the world, while its mountains contain over 140 (one hundred and forty) valuable minerals, including gold, silver, lead, iron and uranium.
The exploration of Antarctica that Reaches far back in time1 is full of struggle and hardships and daemands the fullest use of man's courage will and labour. To-day, however, planes, supply ships2 and well stocked bases open the way to Antarctica and explorers in increasing number are learning to live on the continent. As a result the polar ice became an everyday laboratory in the study of the earth.
Recently no less than 11 nations were taking part in the intensive scientific research of the region of which so little is known as yet. Research stations were set up all over the continent, some of them on high inland ice. For more than a year several hundred men from various countries of the world were living and working in close contact and co-operation.
Special equipment was used to make measurement sand study different phenomena from land, from ships at sea and from aircraft. These investigations were carried out daily good as well as in bad weather according to a carefully worked out plan.
They included measurements of the upper air, the intensity of cosmic radiation as well as the nature of the earth's magnetic field. Studies were also made of the thickness of ice, its formation and the speed of its movement.
For years to come4 scientists will be exploring Antarctica and making observations that will be of great practical importance5 to mankind. Hundreds of year-round bases will be set up over the whole of Antarctica. The work that scientists will be leading there will help to remove the last "blank spaces" from the map of the ice continent.
1. to reach far back in time — относиться к отдаленному прошлому
2. supply ships — транспортные суда
3. as yet — пока еще
4. for years to come — в последующие годы
5. to be of importance — представлять ценность
BETWEEN TWO CONTINENTS
For centuries two problems have dominated man: to learn to fly and -to learn how to change the climate. The first dream has been fully accomplished, the second requires a great effort on the part of mankind for its solution.
We should like to know what could be done to improve the climate of the Northern countries. To this end1 the water currents should be шеи for their influence upon the climate is well-known. Water is the most obedient, most compact and economical medium for transmitting warmth.
Man has long prepared for the decisive battle against cold, accumulating knowledge in the field of science and engineering all the time. Scientists have long tried to solve that problem and their thoughts more and more frequently turn to the Bering Strait. This strait is something like an open gate between two oceans: the largest and warmest — the Pacific—and the smallest and coldest — the Arctic.
A big engineering project —a combination of dam and bridge across the Bering Strait was suggested by the Russian engineer A. I. Shurnilin. This idea is quite realistic as the strait is only some 50 miles wide and on the average no more than 125 feet deep.
Over the dam a direct transport line could pass: London (via a tunnel under the English Channel) —Paris — Berlin — Warsaw —Moscow — Irkutsk —Bering Strait and Washington with a branch line to Peking along which atomic loco motives — engines of the future — could carry goods and passengers making long non-stop runs at high speeds. The gigantic dam that would separate the two oceans should keep the ice and cold waters of the Arctic out of3 the Pacific. How could this task be accomplished one-might ask.
Hundreds of powerful pumps installed in the darn could be operated by an atomic power station. Their application would create an artificial warm current almost equivalent to the Gulf Stream. The new Pacific Ocean current would warm successively the Bering Sea, the Bering Strait, the Sea of Chukotsk and the corresponding part of the Arctic Ocean.
This would make it possible to change the climate of the continents of Asia and North America, to approximate it to the climate of the corresponding parts of Europe. The artificial current would distribute Nature's heat more unonril1, and would conquer the eternal frost. The climate not only of Asia and North America but also of Europe, in part, might become much warmer. Of course, such a plan for a "climate factory" in the Bering Strait requires further studies and scientific calculations. Engineers and scientists of all countries concerned should take part in joint study for the time has come to put the idea of peaceful technical co-operation on a practical basis.
1. to this end —с этой целью
2. via — через
3. to keep... out of—закрыть... доступ в