Our Picture of the Universe

-Stephen Hawking

Summary:

In the past, the world was considered as a flat plate supported by a big tortoise standing on an infinite tower of tortoises. People would take it as a ridiculous matter.  There were several questions related to the beginning, continuing and existence of the universe. New breakthroughs in physics would contribute more to solve these questions. The answers of these questions would be true as well as fantastic like the fact of earth orbiting the sun or as a tower of tortoise. Only time will tell regarding it.

The Greek philosopher Aristotle in his book On the Heavens put forward two arguments related to the shape of the earth. Firstly, he claimed that the eclipses occurred as the earth came in between the sun and the moon. When he saw the shadow of the earth spherical on the moon, he concluded that earth was round. Secondly, the North Star was nearby the earth in comparison to the stars seen on the equatorial side. It indicated the distance of the stars and earth is not same from all places.  

Aristotle thought that the earth was static; the sun, the moon, the planets and the stars orbited in circles around the earth. Ptolemy elaborated this idea in the 2^nd century AD. He also claimed that earth was the center of all the planets and he introduced some more planets like Mercury, Venus, Mars, Jupiter and Saturn rather than Aristotle. He claimed that the planets moved on smaller complicated circles in the space. Out of the circles of the planets some fixed stars would stay in fixed positions in the space. Beyond that their arguments remained silent as it was beyond the observation of the mankind of that time.

In 1514, Copernicus presented a simple model of the universe. He claimed that the sun was stationary at the center. The earth and other planets moved around in circular orbits. After a century passed, Kepler and Galileo supported the theory of Copernicus, yet they were wrong in the concept of orbits. Aristotelian-Ptolemaic theory was proved wrong when Galileo observed Jupiter with his telescope. Galileo found that several small satellites or moons orbited around the Jupiter. It proved that the earth was not the center of the universe. Later on Kepler modified the Copernican theory and suggested that planets moved in ellipses not in circles. However, Kepler couldn’t prove that the planets orbited the sun by magnetic forces. The detail explanation was given by Newton in 1687 that heavenly bodies moved in space and time in complicated circles. Newton introduced the theory of Gravitation which proved that each body attracted every other body by force which is stronger among massive bodies and in short distance. It was repulsive if the objects are farther. It was the same force that made things fell down to the earth. Newton also proved that moon and other planets went round the sun in an elliptical path due to gravitational force.

Newton also realized that stars would attract on another so they would move round the massive bodies at the center. There was suspicion that the planets and stars would fall together at the center with gravitational force. In response of it, Newton argued that there was no finite center in the space; the universe was divided into infinite number of stars; so there wouldn’t be any center.

There was some problem while talking about infinity. Every point can be regarded as center in an infinite universe. Every point has an infinite number of stars on each side of it. If we consider the finite universe in which all the stars would fall together, it would be wrong. There is a question what will happen if we add more stars in the universe? According to Newton’s theory it didn’t make any difference. We could add as many stars as we like because they would collapse within themselves. It is impossible to find infinite static model because gravity always affects them.

Till the 20^th century, there was debate among scientists whether the universe was expanding or contracting. There was also another argument either the universe existed forever or had it been created at a finite time in the past. The scholars who believed in Newton’s theory didn’t believe in that the world had been expanding. Rather they would try to prove that gravitational force would be repulsive if the bodies go far beyond. Such thought wouldn’t affect the predictions of the motions of the planets, but it established the belief that stars would remain in equilibrium. The attractive force would work with nearest bodies and the repulsive force worked with furthest bodies. Now we have advanced thought that the stars which are nearer to one another would work with attractive forces and they would collapse with one another. Similarly, stars which are farther away would be affected by repulsive forces and they would be driven farther away.

Theologians would believe in unchanging or static universe. According to these people the universe had created by the God and it would exist forever till the boon of God goes to humans. But in 1929, Edwin Hubble discovered that the distant galaxies are moving away from us. It meant that the universe has been expanding ever which meant that the universe was compact in the past. Before 10 or 20 thousand million years ago the density of the universe was infinite. This discovery introduced the beginning of the universe in the field of science.

Hubble named the time as Big Bang in which the earth was too small and too dense. Along with the introduction of Big Bang theory all the laws of science and predictions would break down. When we believed that time had begun at the time of Big Bang which was difficult to define. The beginning of time with the Big Bang was different from the concept developed previously. In the static universe, the beginning of time seemed to have imposed by some outside forces. Theologians could say that god created the universe in the past. On the other hand, physical reason of the earth needed the beginning of the universe. The writer argued that God’s creation of the universe was wrong. He also added that it was meaningless to imagine that the universe had been created before the Big Bang.

We need to be clear about the scientific theory to know about the beginning and end of the universe. The theory is just a model of the universe, or a restricted part, or a set of rules. It doesn’t have any other realities except to be existed in our mind. A good theory makes us satisfies in two ways: firstly, it must describe large number of observations with few arbitrary elements. Secondly, it must make definite predictions about future observations. Aristotle’s theory predicted that the earth was made up of earth, air, fire and water; so it didn’t make any definite predictions. Similarly, Newton’s theory was also simple but its predictions about gravitation were accurate.

The physical theories are provisional as they are hypothetical. Philosopher Karl Popper argued that a good theory is characterized by the facts that could be disproved or falsified by observations. New experiments would thrive on predictions that increased our confidence; if new observations would make it false we have to abandon or modify them. In practice, new theory is developed from the old one. For instance, Einstein’s theory of general relativity was developed from Newton’s theory of gravity.

The evaluation goal of science is to provide a single theory; but scientists would separate the problems into two parts. Firstly, there are the laws that tell us how the universe changes with time. Secondly, there is the question of the initial state of the universe. Some people would argue that science should follow the first question. They claimed that the initiation of the universe is the matter of religion. They also claimed that the omnipotent God had started the universe. These people would follow certain regular laws of the creator God. Certainly there are the laws that govern the initial state of the universe.

It is difficult to describe all the theories of the universe at a time. We need to break them apart and to develop partial theories. Each of these theories would describe certain limited class of observations with simple set of numbers. This approach is completely wrong because each part represents or solves single problem in isolation. Since universe depends on everything else we need to address all the issues together. We have made progression in the past regarding the theories of universe. The concept of Newtonian theory is that gravitational force depends on body; it’s mass but independent of what the bodies are made of. In the same way, we need not have the knowledge of structure and constitution of the sun and the planets to identify their orbits.

These days scientists describe the universe using the general theory of relativity and quantum mechanics. The general theory of relativity describes the force of gravity and the large-scale structure of the universe. The size of observable universe is million million million million miles in distance. Quantum mechanics deals with millionth of a millionth of an inch. These two theories are inconsistent with one other or both of them are not correct. One important endeavor in physics today is to incorporate them both. We don’t have a theory that can address all the issues related to the universe; it will have been developing till long in the future.

If you believe that the universe is arbitrary, it’s a different matter. We need to combine the partial theories into a unified theory that will solve all the problems. Partial theories of the past would make sufficient accurate predictions; however it’s difficult to unite them on practical grounds. The discovery of the unified theory may not contribute to the survival of our species, nor may it affect our lifestyle. However people won’t be contented with it as it has been happening since the dawn of civilization. We are keenly interested to know why we are here and where we came from. Humanity’s deepest desire is to quench the quest of their knowledge so that our goal should have been directed to get complete knowledge of the universe where we live.

Comprehension

A.    Read the given text carefully and answer the following questions briefly.

1.      What was Aristotle’s basis for believing that the earth was spherical?

He observed the eclipse of the moon at night time. It was spherical or round in shape so he concluded that the earth was spherical.

2.      What were Aristotle’s and Copernicus’ models of the universe and how was the latter supported by Galileo?

Aristotle’s model of universe was that the earth was the center of all the planets; the sun, the moon and other planets would go round the earth. Copernicus’ model was different than him and he claimed that sun was the center of the universe. The earth and other planets would move round the sun. Galileo supported the Copernicus when he observed Jupiter with his telescope he found that it was one of the planets in the solar system.

3.      What was the gist of Newton’s theory of gravity?

The magnetic force of gravity is attractive with bigger mass and short distance whereas it is repulsive with the distance of objects.

4.      Why does Stephen Hawking think there is need to develop a complete unified theory of the universe? Has it been done at all?

He argued that everything in this universe is related with everything else. The partial solution of such problem can’t address the collective problem. So the goal of science should be directed to develop a unified theory. It hasn’t been done till date.

5.      Which human yearning is justification enough for the continued search for this complete unified theory of the universe and why?

The yearning of knowledge from the beginning of human civilization has been the justification for the continued search of unified theory of the universe. It’s because human beings can’t be contented with limited means and resources.

B.     Choose from a, b or c and correct the endings to the following sentences.

1.      Aristotle realized that eclipses of the moon were caused by: the earth coming between the sun and the moon.

2.      Galileo’s observation of the planet Jupiter indicated that: the planets moved around Jupiter.

3.      Newton postulated a law of universal gravitation according to which: each body in the universe was attracted toward every other body by a strong force.

4.      A good theory must accurately describe a class of observations on the basis of a model and: it must be able to make observations based on past theories.

C.    Vocabulary

1.      List out antonyms of the following words that appear in the given text.

Perfect = imperfect           partial= full                 stationary= moving

Superior=inferior               major=minor                believing=distrust

Define=not define                        complicated=simple    expanding=contracting

Finite=infinite                   similar=different         accurately=inaccurately

Practical=impractical         general=specific          single=together          

2.      Write the pronunciation pattern and stress to the following words:

1.Fantastic=/fanˈtastɪk/; 2. tortoise/ˈtɔːtəs/; 3. Endeavour=/ɪnˈdɛvə/; 4. yearn

/’jəːn/; 5. Elliptical=/ɪˈlɪptɪk(ə)l/; 6. Principle=/ˈprɪnsɪp(ə)l/WORD 

3.      Fill in the blanks with the suitable words given below:

a.       Ahmed has run out of subjects to discuss with the man sitting next to him.

b.      The children’s imagination was run away with them, and their story sounded more and more incredible.

c.       Could this exercise be run through your language teacher, please?

d.      I run up against an interesting person today on my way to college.

e.       Shall we run across the schedule for the seminar before we leave?

f.       There are some of the problems that Sujata run by at the booking office tomorrow.

g.      The play runs on until very late last night.

-By Prem Prasad Sigdel

The Cost of Solar Heat

-H. A. Bethe

Summary:

The cost of solar heat is much expensive in a huge scale. It needs large field to set up mirrors to the central boiler. The mirrors would be controlled by computer and it would be like traditional method. ERDA has been working on this project. It needs $2500 to produce one Kilowatt power without adding interest and inflation. On the contrary, nuclear fission reactors need only $500 to produce a kilowatt of electricity. It is five times cheaper than solar power.

In this way, the cost is too high. For example the sun shines only one part of the day in 24 hours. It needs $250 million to produce 100 megawatt electricity on a sunny winter day in the Southern U.S. It needs to utilize the full sun power at a day. It would produce 400 megawatts at a day which would be less at morning and evening time. So we need 400 megawatts power plant to produce 100 megawatts of electricity. In this way, it needs four times more boilers and turbines to produce solar electricity in comparison to nuclear and fossil-fuel power plant. It needs even more money to establish storage equipments which would cost much higher or we can’t imagine at all to this cost.  

We need half of the cost for mirrors and electronic drive mechanisms. It needs $125 million to establish a plant of one square mile; or less than $5 per square foot. We can’t think that the cost could be less for mass production as well. On the contrary a house costs $30 a square foot. As a corollary, solar power is much expensive in comparison to nuclear or fossil-fuel power.

1.   Drawing your information from the passage given above, answer in your own words the following questions in complete sentences. Your answer to every question should not exceed 35 words.

a.       Describe the most practical proposal that has been made for the use of solar heat for power generation.

Answer: Solar power is much expensive in comparison to the nuclear and fossil-fuel power. So it would be better to adopt alternative ways to produce electricity.

b.      Why is it necessary to have solar equipment generating about 400 megawatts to get an average output of 100 megawatt?

Answer: The reason is that the sun shines only 12 hours a day. Moreover, at morning and evening time also the production is less than at daytime. So we need to establish 400 megawatts of power plant to distribute electricity for night time.  

c.       What would be the cost ratio of a solar power plant compared to a nuclear power plant?

Answer: The cost of Solar power plant is five times expensive than nuclear power plant.

d.      Does the author feel that the mirrors and their electronic drive mechanisms can be built for about $5 per square foot?

Answer: No, he has no such feelings. He has excluded the inflation and interest of the money. It needs more amount than $5 per square foot.

2.   Analyze paragraph 35 and say how the three principles of paragraph writing have been utilized.

Answer: The author has started the paragraph with a common statement. Then he has described in detail how the cost of solar heat costs high. For proof he has compared it with other costs. At last he has drawn conclusion that the solar cost is much more expensive in comparison to other alternatives.

3.   Analyze paragraph 33 and say what techniques has been utilized to write this introductory paragraph. Give reason for your answer.

Answer: The author has begun the paragraph with general statement which stand as a hook. Then he has described the positive and negative aspects of his statement. He has presented the evidence for his statement as well. The conclusion is so much effective that he has given the gist of his statement. So the author has fully utilized the norms of paragraph writing.

4.   Analyze the following introductory paragraphs and say what techniques have been utilized in writing them, bearing in mind that there is a vital link between the introductory paragraph and the rest of the essay. Give reasons for your answer.

Answer: The first paragraph has used a general description as the beginning of the paragraph. Then the issue has been described. Rather than the hook the author has given plain introduction of the paragraph.

-By Prem Prasad Sigdel

Man and His Environment

-Robert Arvill

Summary:

To improve the quality of environment we need to improve our perception, education, economic strength, research, plus policies and proper administration. At first we need positive understanding and adjustment. New problems would arise as we solve the old ones. New discoveries would arise new problems as said by Goethe.

First we should understand the need of society; it should have addressed the contemporary situation of the society. People should widen their horizons to solve the problem of environment. They must have deeper understanding to identify the new relationship with environment. The challenge is that we should be able to keep on the new ideas with new context.

We need to understand many things at the same time. We should develop various ways to create new framework to save biotic and physical environment of us. We should understand that man is a part of nature and s/he can influence the natural processes as well. As man needs space and rest like other creatures and environment. Men should understand that their actions have far-reaching effects on other creatures.

Man has changed the earth with his primitive tools and limited knowledge. The question is that what man will have done with vast power and the explosion of knowledge. It is important to note that man has created better food, clothing, housing and hygiene for millions of people. Not only that they have also foiled the land, air, rivers, sea and wild life. He shouldn’t have done so as he could achieve the progress without getting destruction of the land and environment. Waste can be cleared away in the next century with alternative way without any harm. It needs creative solution of understanding national inheritance. As the understanding increases, more values will be established.

People should be aware about the result of their activities. They should be aware that vast quantities of newspapers destructs forests; veneering furniture also destructs trees; speck free fruits and vegetables needs to use pesticides; plastics cannot be disposed easily; coal fire produces more air pollution and so on. Neither people can demand it nor can oppose the production of these materials. It is not sufficient to know about it only. It will be better to develop some alternative ideas or ways to solve the problem. Men should be aware about the mismanagement of themselves.

1.   Drawing your information from the passage given above, answer the following questions in complete sentences using your own words. Your answer to every question should not exceed 35 words.

a.       What are the necessary factors which improve the quality of the surroundings that you live in?

Answer: They are better perception, education, economic strength, research, plus policies and administration geared to the right aims.

b.      What is the first step towards environment improvement?

Answer: It is to understand the need of society with the need of contemporary situation.

c.       What is man’s relationship with nature?

Answer: Man is a part of nature, yet they s/he can influence its processes.

d.      What happened to the environment during the second half of the nineteenth and the first half of the twentieth century?

Answer: Men created better food, clothing, housing, and hygiene for millions and they have contaminated the land, air, rivers, sea and wildlife.

e.       What will help the public decide which new products should be manufactured?

Answer: They should develop the alternative products to save the environment.

2.   Analyze paragraph 14 and say how the three principles of paragraph writing have been utilized.

Answer: The first line of this paragraph is a beginning or the hook of the sentence. The writer has given the examples as body of the paragraph. The last line of the paragraph is the ending which suggests humans to improve their mismanagement. In this way, this paragraph has employed the three principles of a paragraph writing.

-By Prem Prasad Sigdel

Man and Nature

-J. Bronowski

Summary:

The identity of a man is crucial in between either Self or Machine. It is the beginning of the essay as well as the basic condition of the writer. However, he believes that man is a part of nature.

His condition or question is innocent or neutral. All the persons like the Bible readers, agnostics, Sunday strollers, haunters of museums accept this fact. In the latter half of the 20^th century, men consider that they are also a part of nature like stone, cactus and camel. These things represent three categories of human being world like Animal, Vegetable or Mineral. This common condition has got explosive charge because it challenges the self-assurance of Western man.

Man would deny the fact of the writer thinking himself as unique. It can be a hidden fact, so they remain silent, because they have returned before 1600. In the same way, Giordano Bruno was asked to abandon his ideas that the earth was not only the planet in the universe. It was thought as wild belief at that time. The man should also realize that s/he isn’t only the creature in this multitude of the worlds.

It was Renaissance extravagance that human considered themselves neither slave nor master of fate. They were happy that they could enjoy with the nature of being free from boundaries. Neither was it true, nor it can be. The jealous man also wants to be immortal. They also want to get supernatural power which larger than life and nature. After all, it is impossible because they have boundaries. Man can’t be greater than nature. 

1.   Put the following five sentences in the right order to make them read like a paragraph.

a.       Bronowski says that man is a part of nature.

b.      He lost his self-assurance because this statement means that man is not unique.

c.       This is the statement which has made Western man lose his self-assurance.

d.      He also wants to feel that he has been, from the beginning, larger than nature.

e.       But man wants to feel unique and immortal.

2.   Drawing your information from the passage given above, answer in your own words the following questions in complete sentences. Your answer to every question should not exceed 35 words.

a.       What is the thrust of Bronowski’s argument throughout the paragraphs?

Answer: He argued that man is a part of nature. Man wants to be superior to nature but he can’t be. The Renaissance man believed that they would challenge the nature which wasn’t possible at all. They are also like other creatures of the world like stone, cactus and camel.

b.      What seems self-evident in the latter half of the twentieth century regarding man’s relationship with nature?

Answer: It was proved that man is a part of the nature. They are also like other things of the world. Man gets equal share like animal, vegetable and mineral.

c.       Why was Giordano Bruno burnt at the stake?

Answer: He challenged the ideas of the traditional man that the earth wasn’t only the planet in the universe. So he was burnt alive.

-By Prem Prasad Sigdel

Science and Survival

-Barry Commoner

Summary:

There is some disagreement about the effects of medical hazards and effects of DDT, smog and fallout. We have already used them without knowing the risk caused by these pollutants. As a result, we have loaded the substance in our blood that resists our blood circulation. People wanted to make bomb to kill mosquitoes. They have loaded their bodies with serontium-90 and DDT which is too much dangerous for us. People are conducting experiment on their own body these days. So these are the main components of public health hazards of present.

Some people may concern about the damage of environment; whereas others would argue that it is the achievement of science whether it is good or bad. They would argue that it would already happen in our life and if we don’t take risk the achievement of science and technology is useless. Possible errors may exist with the use of science and expansion of technology. In the past, the risk of science and technology was confined to a certain place. These days it has influenced the entire world. For example: air pollution is everywhere; fallout is worldwide; synthetic chemicals may remain under soil for many years; a radioactive pollutant is everywhere; and the effect of carbon-14 will affect for thousands of years. The excessive use of carbon dioxide could cause floods which could cover much of the earth’s surface.

Nowadays, the errors have been growing. When there was a boiler explosion, it was taken as an art of science. If a single nuclear power would burst, it will turn the whole area uninhabitable. We can’t imagine the negative effect of it as it is beyond imagination. Hence modern scientific experiments have been conducted in a trial-and-error approach.

Some may argue that the hazards of modern pollutants are small in comparison to other human activities. For example the fallout hazard is much smaller in comparison to the road or plane accidents. We should think about the future generations. The effect of fallout, smog or chemical is so serious that we would realize it only after the consequence is too serious. Science has forgotten the duty of prediction and control on human activities to save people from pollutants. The true ratio of danger isn’t represented by the present condition. We will surely feel its result in the future if we don’t correct this basic fault of the scientific enterprise in time.

1.   Match the segments in Section A with the correct corresponding segments from Section B. Make sure that the resulting sentence corresponds with the author’s point of view on the subject.

a.       A single explosion in a nuclear power plant ….. might kill thousands of people.

b.      Extra carbon dioxide from fuel combustion ….. might eventually cause floods.

c.       DDT and strontium-90 in the air …. may interfere with the functioning of the blood.

d.      Carbon-14 …. will remain on the earth’s surface for thousands of years.

e.       The effect of smog, fallout or chemical pollutants…. may be extremely harmful for future generations.

f.       Synthetic chemicals …..may remain in the soil for years.

2.   Drawing your information from the passage given above, answer the following questions in complete sentences. Your answer to every question should not exceed 25 words.

a.       Name three pollutants with which man has loaded the atmosphere.

Answer: They are smog, fallout and chemical pollutants.

b.      What would happen if there was an explosion in a nuclear power plant?

Answer: It would kill thousands of people and the area will be uninhabitable.

c.       What is one of the major duties of science that the author writes about?

Answer: Science should predict about the dangers and control of human intervention into nature.

d.      What is the true measure of the danger of modern pollutants?

Answer: It will certainly affect our life in the future so we should correct the basic fault on time.

-By Prem Prasad Sigdel