Reading

The Origin of the Universe


Newton’s work gave a mathematical basis for the universe on a large scale. However, the data available at his time suggested a static unchanging universe. This could not be explained by the law of gravitation, since all bodies in the universe attract each other by the force of gravity. Newton realized there was only one solution to this problem: in a static universe matter must be uniformly spread throughout an infinitely large space. In 1826, Heinrich Olbers published a paper containing what is known as Olbers’ paradox: the universe had to be finite and uniform to avoid gravitational collapse. This assumption must have been wrong because it required perpetually bright sky on earth. Both Newton and Olbers incorrectly imagined space to be infinite and independent of the matter it contained. Einstein in his general theory of relativity (1915) proposed that the universe exists in four-dimensional space-time. This space-time is curved by the presence of matter and the matter moves following the resulting curves.

The discovery of expanding universe by Hubble in 1929 provided the starting point of our present understanding of the universe. Hubble made his discovery by analyzing the spectra of light from distant galaxies noting redshift, which he explained in terms of the Doppler effect: the sources were moving away from the observer. Moreover, he discovered a pattern in his data: the further away the galaxy, the greater the speed of away motion. This model may seem to place the Earth at the center of the universe again. However, it is the space itself that is expanding and the galaxies are situated in this space like dots in a ring. As the ring expands, the view from any dot is that other dots are moving away at a speed proportional to their distance. No single dot is at the center, but all dots see the same. Hubble’s discovery satisfies the cosmological principle that the universe should appear the same no matter where one is.

Expansion of the universe also implies that there once must have been a time when space and time were minutely small with all the matter and energy of the universe concentrated in this small volume.

Exercise 1.

In the above text find modal verbs which say that :

- something wasn’t possible

- something is possible now

- we are sure something is true now

• we are sure something happened
• something is obligatory

Exercise 2.

In which case does the modal verb express modality (M) and in which case does it express possibility (P) or certainty (C)?

Newton couldn’t use present-day technologies.

He had to rely on observation.

He must have been influenced by the data available at his time

He might have been mistaken.

Today we may rely on high-tech research procedures.

The expanding universe may be explained by big bang.

Exercise 3.

Put the sentences into Past Tense.

1. I must begin now.
2. You don’t have to come.
3. You can’t mean it.
4. You should help me.
5. The data must be wrong.
6. I can’t speak German.
7. We may use calculators at the exam.
8. You may be right.

Exercise 4.

Make the following text less resolute using may, might, can, could.

The universe originated as a minute but very hot body. The temperature has been continuously falling as the expansion has continued. Variations in background radiation discovered in 1992 explain why the universe formed into galaxies and stars. In a uniform universe there is no reason for a gravitational collapse at any point. The four fundamental forces in the universe originated from a single force. This force existed when the big bang occurred. As the universe cooled, the forces separated. Research into the future is only speculative. The universe will continue to expand indefinitely or an eventual contraction will occur.

Exercise 5.

Match sentences 1-5 with the explanations in a-e.

1. They couldn’t / can’t have done it.
2. They should have done it.
3. They needn’t have done it.
4. They might / may not have done it.
5. They must have done it.

1. They didn’t do it.
2. They did it but it wasn’t necessary.
3. I am sure they did it.
4. I don’t believe they did it.
5. I am not sure they did it or not.

Exercise 6.

Use suitable modal verbs to complete the sentences.

1. However angry you are, you ………………… never talk to people like that.
2. This report is urgent – you …………………. finish it by four o’clock.
3. …………………. I help you with the report?
4. John …………… have gone home, his PC is still on!
5. You …………….. have checked the data, I did it yesterday.
6. Something bad ……………. have happened to Joan, she has never been late like this.
7. You ………………….. have deleted the file, you ……………… need it later.
8. The secretary ………………… have already left, but I am not sure. Check her office.