English notes for class 12 Sindh Board Chapter 9 (An Astronomer’s View of The Universe) Second Year Karachi and Sindh board Question Answers English 12th class Notes, Composition, Exercise, Summary, Mcqs, Online Test, Guess Papers, and Past Papers.
English notes for class 12 Sindh Board Chapter 9 (An Astronomer’s View of The Universe)
Why is the origin of life still a riddle to the scientist?
According to Jeans’s perspective, the origin of life is still a riddle to the scientist. There still lies a great confusion in the minds of a number of scientists to find out whether the living cells of the mankind i.e. atoms hat atoms are merely atoms or they are atoms mingled with life. They are anxious enough to find the answer to the question that if a second accident appears then what would be the nature of the atoms which have been taken as the fundamental part for the origin of life.
Why does it seem incredible to Jeans that the universe was designed primarily to produce life-like our own?
It seems incredible to Jeans that the universe was designed primarily to produce life like our own. In his point of view, if it can be considered as one of the reasons then one has to keep the reality in mind that we should find a better proportion between the magnitude of the mechanism and the amount of the product in every part of this universe. It is also a fact that life may seem to be an absolutely trivial by-product.
What is the temperature of most of the space?
According to Sir James calculations, the temperature of most of space is some four degrees about absolute zero i.e. 273K. It is about 484 degrees of frost on our Fahrenheit scale of temperature and is even lower in the vast stretches of space which lie beyond the Milky Way.
Why does a planetary system seem to be the only kind of environment on which life could originate?
A planetary system seems to be the only kind of environment on which life could originate due to the factor of suitable physical conditions needed for the production of life. These perfect conditions are only available on the planets of a planetary system. Hence, the earth is the only planet of a planetary system where life exists in its true form in the whole of the universe.
How does Jeans justify his assertion that ‘the universe appears to be actively hostile to life like our own?
Sir James Jeans justifies his assertion that ‘the universe appears to be actively hostile to life like our own’ by giving the following points to ponder:
Vast and meaningless distances are present between the earth and the universe.
The universe seems quite terrifying because of its inconceivably long vistas of time which dwarf human history to the twinkling of an eye.
We as the residents of this planet earth feel a strong sense of loneliness as compared to the vastness of the universe.
The material substances lose their significance when compared to the total substances of the whole universe.
That’s not all; everything seems to be terrifying as our ambitions, achievements, emotions and even religion have nothing to do with the plan of the universe.
Why are our first impressions of an astronomer’s picture of the universe likely to make us feel that humanity is insignificant?
Our first impressions of an astronomer’s picture of the universe likely to make us feel that humanity is insignificant because it has given the information about the meaningless distances, vast duration of time which is much longer than the history of life on earth, complete loneliness of the earth and the hostile nature of the universe.
What does Jeans imagine the first forms of life on earth to have been like?
According to Jeans’ perspective, the first forms of life on earth came into existence from a very humble beginning. It started with the origin of simplest organisms that reproduced themselves and soon died. With the passage of time, this simplicity turns into complexity and then the life on the earth began to start with greater maturity and vigor.
How does a planet, such as the earth, derive its warmth?
A planet, such as the earth derives its warmth solely from the radiations that are poured down from the sun. As after separation from the sun, it gradually cooled down, now they have but little essential heat left.
What is Jeans’s explanation of how the planets came to be formed from the sun?
James Jean’s gives an awesome explanation about the formation of planets from the sun. According to him, the whole phenomena took place some two thousand million years ago. It occurred when a second star, wandering blindly through space came with in haling distance from the sun. It raised tides on the surface of the sun that formed a mountain of great height. Before this second star began to recede, its tidal pull was so powerful that the mountain was torn into pieces and threw small fragments of itself. These small fragments then took the form of planets.
Why is it improbable that one particular star will ever come close to another?
It is improbable that one particular star will ever come close to another as the universe in which they roam around is so spacious that it this act seldom happens in the lifetime of a star. Some stars like to move in the company whereas others love to roam in solitude.
Summarize the following passage in not more than 75 words:
A few stars are known which are hardly bigger than the earth, but the majority are so large that hundreds of thousands of earths could be packed inside each and leave room to spare; here and there we come upon a giant star large enough to contain millions and millions of earths. And the total number of stars in the universe is probably something like the total number of grains of sand on all the seashores of the world. Such is the littleness of our home in space when measured up against the total substance of the universe.
This vast multitude of stars is wandering about in space. A few form groups which journey in company, but the majority are solitary travelers. And they travel through a universe so spacious that it is an event of almost unimaginable rarity for a star to come anywhere near to another star. For the most part each voyage in splendid isolation, like a ship on an empty ocean. In a scale model in which the stars are ships, the average ship will be well over a million miles from its nearest neighbor, whence it is easy to understand why a ship seldom finds another within hailing distance.
Write your summary in one paragraph. The essential points to bring out are the great size of stars compared with the earth, the immense number of stars that exist their great isolation from each other, and the great rarity with which one star comes close to another.
The stars in space are so huge and spacious that millions and millions of earth can easily be folded into it. This shows the minuteness of earth in the whole universe. Some stars travel in groups whereas most being the solitary travelers loved to move in isolation. The stars are equal to the grains in sands of the whole world’s seashores. It rarely happens that one star could get a chance to meet another star.