CLASS EXERCISES
Exercise 1 (in groups)
Checking up understanding
1.What does the expansion of the universe mean?
2.Is this expansion smooth or chaotic?
3.What is background microwave radiation?
4.What are some flecks on the TV screen due to?
5.How can one describe the expansion of the universe?
6.Why can one describe the expansion of the universe in terms of a single number?
7.How does the gravitational attraction affect the rate of the expan-
sion?
8.In what case will gravitational attraction eventually stop the expansion?
9.How would the universe behave in this case?
10.What would the big crunch be like?
11.What is a singularity?
12.What is the crucial question for the future of the universe?
13.How would the universe behave in case the average density of the universe is less than the critical value?
14.How would the universe behave in case the average density of the universe is greater than the critical value?
Exercise 2 (do it yourself)
Translate the parts of sentences using One as the subject + a modal verb (can, can’t, should, have to, needn’t).
1.Можно описать расширение вселенной на основании одного числа − расстояния между двумя галактиками.
2.Можно предположить
3.Можно увеличить
4.Можно замедлить
5.Можно сжать
6.Можно расширить
7.Можно предсказать
8.Можно сделать вывод (to conclude)
9.Нужно объяснить
10.Можно подумать
31
11.Нужно быть очень осторожным (to be careful)
12.Можно начертить график скорости галактик в зависимости от их яркости (to plot a graph of something against something).
13.Нельзя терять надежду.
Exercise 3 (do it yourself)
Translate the sentences. Then check up your translation against the original sentences in the passage and correct your mistakes, if any.
1.Расширение вселенной можно описать на основании расстояния между двумя галактиками.
2.В настоящее время это расстояние увеличивается.
3.Но можно предположить, что силы притяжения между галактиками будут замедлять скорость расширения.
4.Сингулярность – это звезда с бесконечной величиной плотности, при которой законы физики не действуют.
5.У меня есть определенные преимущества перед другими пророками.
UNIT 6
ON THE DARK MATTER
“As much as 90 percent of the matter in the universe is invisible. Detecting dark matter will help astronomers better comprehend the universe’s destiny.”
Vera Rubin
PRE - READING TASK Study some grammar points.
I. Modal verbs show the attitude of the speaker to the idea he expresses.
We use must + Vo to say we are sure that something is true for the present or the future = most probably.
Study the sentences.
1.The universe must contain the dark matter, which we cannot observe directly.
2.There must be some unseen form of matter.
3.There must be extra dark matter present in clusters of galaxies.
32
4. The universe must contain enough dark matter to bring the density up to the critical density.
II. We use special tenses with if when we are talking about imaginary situations.
To talk about imaginary present or future situations we use:
If S + V2, S + would + Vo
Study the sentences.
1.Collections of stars and gas would fly apart if they contained only the stars and gas that we observe directly.
2.The speeds at which individual galaxies are moving in the clusters are so high that the clusters would fly apart, unless they were held by gravitational attraction.
III. The participle
The English verb changes in four forms:
I II III
to estimate (the infinitive) − estimated (the past simple) − estimated
(the passive participle) − |
IV |
|
estimating (the active participle) |
N + Ving or Ved clause − определительное придаточное предло-
жение (Russian − который).
Study the sentences.
1.Not all the scientists working in this field share this idea.
2.The speed of a pulse of light is the distance it travels between two events, divided by the time interval between the events.
3.A shock wave, called Cerenkov radiation, can be detected from the ground as a flash of visible light.
4.One can draw a graph showing the amount of light elements vertically and the amount of normal matter in the universe along the horizontal axis.
5.The Dirac equation, as Dirac himself pointed out, was the basis of most of physics and all chemistry. However, we have been able to solve the equation only for the very simplest system, the hydrogen atom, consisting of one proton and one electron.
Note:
N + V3 (the past participle)
33
We do not always put participles as adjectives before nouns. It is not always easy to explain why one participle can be used before a noun but another one cannot.
Study the sentences.
1.The mass required is considerably greater than the masses of all the galaxies.
2.The rate needed was very low.
3.The heat released generates a pressure that enables the sun to resist the attraction of its own gravity.
IV. S + is supposed (is considered, is believed, is supposed, is expected, is assumed) + toV. These verbs express generally accepted opi-
nion and correspond to Russian – Считают, что; Полагают, что;
Ожидают, что; Допускают, что
Study the sentences.
1.General relativity can’t be considered to be a complete theory.
2.The so-called missing matter is believed (is considered, is supposed, is assumed) to reside within clusters of galaxies.
3.The neutrino was believed to have no mass of its own, but some recent observations have suggested that the neutrino may have a small mass.
We use two variants. Study the sentences.
1.It was found that the nucleus was composed of the so-called ele-
mentary particles.
2. The nucleus was found to be composed of the so-called elementary particles.
1.It was considered that Democritus had a universal mind.
2.Democritus was considered to have a universal mind.
1.It was believed that everything was composed of indivisible and indestructible atoms.
2.Everything was believed to be composed of indivisible and indestructible atoms.
V. Would is used to talk about the natural course and behavior of things and events as a result of some action. It is the less definite form of will.
Study the sentences.
1. A lighter planet would have a smaller escape velocity than a more massive one.
34
2. The white hole could be in another part of the universe. This would offer the possibility of rapid intergalactic travel.
Give Russian correspondence:
unless (if not), from (on the basis of), even if, directly (here - with a telescope), as (here - while), considerably greater (much greater), another (a second), unless (if not), a few (some, several), it follows, therefore (so, thus), specific (particular, specified), close to something (near something), the only (single), a way (a method, a technique), actually (really), an effect (an influence)
UNSEEN FORM OF MATTER
Study the passage. Translate the sentences marked with asterisks in writing.
We can try to estimate the average density of the universe from observations. If you count the stars that we can see and add up their masses, we get less than one per cent of the critical density. Even if we add in the masses of the clouds of gas that we observe in the universe, the total still makes up only about one per cent of the critical value.
We know, however, that the universe must also contain what is called the dark matter, which we cannot observe directly. One piece of evidence comes from the spiral galaxies. These are enormous pancakeshaped collections of stars and gas. We observe that they are rotating about their centres, but the rate of rotation is so high that they would fly apart if they contained only the stars and gas that we observe directly. *There must be some unseen form of gravitational attraction whose matter is great enough to hold the galaxies together as they rotate.*
Another piece of evidence for dark matter comes from clusters of galaxies. We observe that galaxies are not uniformly distributed throughout space; they are gathered together in clusters that range from a few galaxies to millions. Presumably these clusters are formed because the galaxies attract each other into groups. However, we can measure the speeds at which individual galaxies are moving in these clusters. *We find they are so high that the clusters would fly apart unless they were held together by gravitational attraction. The mass required is considerably greater than the masses of all the galaxies. It fol-
35