Text 8. THE A TO Z OF ASTRONOMY

By Professor Chris Kitchin

Here are some simple difinitions of the more puzzling words commonly encountered in astronomy.

Meteorite The fragment of a meteoroid which has survived passage through the Earth's (or other planet's) atmosphere to reach the surface. Small meteorites impact at their terminal velocity, but larger ones may retain some of their cosmic velocity and hit at up to several tens of kilometres per second. In the latter cases an impact crater will be produced and the meteorite will survive only as thousands of tiny fragments. Most meteorites are found to be of rocky composition but about six percent are almost pure nickel-iron. About two percent are formed from mixtures of rock and iron.Two small but very significant sub-groups are the carbonaceous chondrites which contain some simple organic molecules and are thought to pre-date the formation of the Solar System, and the SNC meteorites which may have come from Mars.

Meteoroid A small body independently orbiting the Sun. The meteoroids merge into the asteroids at the larger end, and into the inter-planetary dust at the smaller end of the scale.

Meteor shower A series of meteors lasting from a few hours to several days which have parallel paths through space. Perspective means that the meteor tracks appear to diverge from a point in the sky called the radiant. The position of the radiant is often used to give the shower a name. Thus we have the Leonid (after the constellation Leo) and the Geminid (after Gemini) meteor showers amongst many others. The number of meteors in a shower can range from a few tens to hundreds of thousands per hour. The particles producing the meteors are thought to be debris from a comet which are continuing to follow the comet's orbit. The Leonids, for example, originate from comet Temple-Tuttle.

Metonic cycle The period required for the Moon's phases to repeat themselves on the same days of the month. Its value is 19 years.

Milky WayThe faint irregular glowing band which circles the sky. It is a small part of our own galaxy and comprises tens of millions of stars, each too faint to be seen with the naked eye individually, but clearly to be seen in aggregate. It gives its name to our galaxy; so that we are a part of the Milky Way Galaxy. Interstellar dust restricts our view of the galaxy to within a few thousand parsecs of the Sun, and so the Milky Way is just a small part of the whole galaxy.

Monopole An hypothetical magnetic equivalent to the electron. A monopole would be a sub-atomic particle with a single magnetic (north or south) pole. They are predicted to have been produced in huge numbers during the big bang but none has yet been detected. This scarcity of monopoles is one of the arguments supporting an inflationary period during the early stages of the formation of the Universe.

(ASTRONOMY NOW / SEP 1997)

I. Read the definitions and translate them into Russian.

Text 9. VIEWS OF UNIVERSE

Ancient men wondered why the sun, the moon and the stars moved as they do. For thousands of years men had watched the skies. They couldn't understand and made up myths to explain the movements of the heavenly bodies. Greek astronomers studied the heavens and finally most of them decided that the sun and stars travelled around the Earth.

In the 3d century B.C. the Greek astronomer, Aristarchus had some very different ideas. He wrote, "The Earth travels around the sun in a circle. This takes a year. The moon alone circles round the Earth. The stars are very far away. The Universe is very large." Other astronomers did not agree with him, and, of course, people didn't accept his ideas. They couldn't agree that the Earth was moving. For centuries, no one developed his ideas.

Nicolaus Copernicus was the Polishastronomer who began to study the Greek writings of the ancient astronomers. He checked them and found mistakes. Copernicus worked out formulas that seemed to prove that the Earth travelled around the Sun. Finally he decided the idea was right. The Earth and the planets did indeed circle the sun. Copernicus' formulas, however, still had the heavenly bodies travelling in epicycles.

In 1513, Copernicus wrote a book about his ideas. He showed it to some friends but never had it published. Year after year, he went on checking the orbits of the planets. In his studies, he used homemade instruments. Often he checked the stars' positions against those given in the ancient Greek astronomers' tables. He filled many pages with his findings, but he did not always trust them. He did not publish them.

Copernicus knew that people were not ready to accept the idea of a moving Earth. Copernicus did not want to go against his church's teaching, which declared that other planets moved round the Earth. Once a friend came to visit him. He talked with Copernicus and read many pages of his studies. He urged Copernicus to let him put the pages into order and publish them. Finally, Copernicus agreed. Copernicus did not live to read the printed copy of his book. It was placed in his hand as he lay dying on May 14, 1543.

Today, we honor Nicolaus Copernicus because he helped people accept the idea of the moving Earth. He dared to doubt the ideas held for centuries. He looked at the heavens with his own eyes. Using math, he tried to show how the Earth circled the sun. He was the first man to do this. Copernicus' book pointed the way to truth. Other astronomers began to explore the idea of the moving Earth.

Read the text and complete the sentences:

1. The myths about stars and the Universe were made ______.

a) to describe them

b) to explain the movement of the sun and the stars

c) to help Greek astronomers study the skies

d) to show them in a poetic way.

2. Aristarchus was the only astronomer who _______

a) never read myths

b) wrote a book that is recognised nowadays

c) declared that the Earth moved around the sun and the moon travelled round the Earth

d) made other astronomers agree the Earth was moving

3. Nicholas Copernicus proved that

a) the sun travelled round the Earth

b) other ancient astronomers were right

c) his own formulas were wrong

d) that the Earth moved round the sun

4. Copernicus explored the Universe using ______

a) homemade instruments

b) a telescope

c) Greek astronomers' tables

d) a microscope

5. Copernicus didn't want to publish his ideas because _______

a) his friend was against them

b) Copernicus supported the church's view

c) people were not ready to understand them

d) Copernicus was going to die

6. We honour Copernicus because _______

a) he was an astronomer

b) his ideas encouraged other astronomers

c) he supported the ideas of the Greek astronomers

d) he always helped people

Text 10. LONDON BRIDGE

When the Roman Empire crumbled, most of the arts of civilization started to disappear with it. They might have been lost altogether, had it not been for the monks who preserved as much of the learning of the past as they could by writing it down.

The six centuries between 300 A.D. and 900 A.D. were grim and lawless times for most people. Robbers, cutthroats, and highwaymen swarmed the roads, and they were especially dangerous at river crossings. Travelers had all they could do to manage their horses while crossing, and they found it hard to defend themselves against attack, so the monks began to build bridges at such places. Gradually, during the Middle Ages, they taught others how to build.

The new medieval bridges were not as grand as the Roman bridges. Early ones were of the wooden-beam type, built on stone piers or wooden piles. War and religion both had their effect on most medieval bridges. Chapels were often built close to bridges, fortresslike towers guarded the bridges' approaches, and the roadway was narrowed at strategic points to make defense easier.

By the twelfth century, some people were once again beginning to experiment with different kinds of bridge building, and in London an ambitious builder named Peter Colechurch was planning one of the most famous of all bridges - Old London Bridge.

Timber bridges spanning the Thames River at London had been alternately constructed and destroyed ever since the tenth century, when Norsemen .sailed up the Thames, fastened their lines to a bridge’s piling, then rowed downstream and pulled the bridge down.

Toward the end of the twelfth century, however, such invasions were no longer a threat, and London was becoming an increasingly important city. When Colechurch put forward his plans for a masonry arch bridge, it was exactly what the Londoners wanted. A fund drive was an immediate success, with subscriptions pouring in from rich and poor alike. Building began in 1176, and the bridge was finished thirty-four years later.

The old nursery rhyme says:

London Bridge is falling down,

Falling down,

Falling down...

Amazingly, it didn't! London Bridge was crude and clumsy looking — just over 936 feet long, with 19 pointed arches that varied in width from 15 feet to 34 feet, 5 inches. Not one of the piers matched any other, and all were more than half as wide as the arches that sprang from them.

This meant that the openings through which the waters of the tidal river rushed were relatively small. Water funneled through them with great velocity, making the passage of boats about as chancy as shooting the rapids in a mountain stream. In fact, maneuvering a boat through one of these arches was called “shooting the bridge” and a popular saying was “London Bridge is made for wise men to go over and fools to go under.”

Almost every kind of structure one can think of was built on London Bridge. There were gateways at each end and a chapel on the central pier. Houses were added, built on supports over the piers; there were a hundred of them, including buildings that straddled the roadway. In most of the buildings, merchants had shops on the roadway level and lived in the upper floors.

The seventh span from the south bank was a drawbridge. Upon the drawbridge pier, which was one of the larger piers, Nonesuch House was erected. It was called Nonesuch because nothing like it had been seen before. This four-story house was brought in pieces from Holland and then fastened together with wooden pegs. During the reign of Queen Elizabeth I. it became one of the most fashionable addresses in London.

The south gateway of the bridge was strongly fortified, and when traitors were beheaded, their heads were displayed on the battlements of this gateway. It soon gained the popular name of Traitor’s Gate.

For most of its six hundred years, London Bridge was the only bridge across the Thames. Its construction and upkeep were paid for by rents and tolls, and in time these amounted to a great deal of money. Tolls were even collected for “shooting the bridge,” which must have specially angered the boatmen who wished the structure had never been built in the first place.

By the seventeenth century, Old London Bridge was no longer a fashionable address. Many of the houses had fallen into disrepair, and in 1831 when construction began on New London Bridge, Old London Bridge was taken down. By that time several other bridges had been built at London.

Scott Corbett

From "Cricket"

I. Read the text ‘London Bridge’. Say which of the facts seems to you the most striking.

II. Find in the text the conditional sentence. Analyze and translate it.

III. Translate the text.