About their problems. They try to find answers for their problems together. For example

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GEOTHERMAL ENERGY

It gets hotter and hotter as you go down towards the centre of the earth. This heat is geothermal energy. In some places the temperature increases as much as 40⁰C per kilometre, and this is a very good ‘heat gradient’. A normal heat gradient is 25⁰C per kilometre. Often if you make a deep hole in the ground, you will find hot water deep underground. For example, engineers drilled for hot water in Southampton, England. At 1500 metres they found water at 60⁰C. There is enough hot water there to heat a thousand houses for thirty or forty years.

In some places you do not have to drill to obtain geothermal energy. This is because hot water and steam are already coming out of the ground. The most famous examples of this are in California (USA) New Zealand, Italy and Icelande. In these places the water and steam are very hot. It is hot enough to heat most of the capital of Iceland, Reykjavik, or to drive, i.e. provide the power to work, electric generators in California.

There is not always hot water deep down, but there is often very hot dry rock. Of course, w₉ want to use this heat, but can we get it out? In Los Alamos, USA, scientists are trying to do this. They are drilling down to the hot rock. Then they are going to break the hot rock. They will then send cold water down to the bottom, and it will get hot there. This hot water will return to the top through another hole. The hot water will be useful for making electricity or heating houses.

Geothermal energy will never be an important source of energy. But there are many places where ft can be very useful.

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BALI
Bali is a beautiful island of mountains, forests and rice fields. It is also an island of artists. Almost everybody there is an artist of some kind. The people work all day at home, in the fields or in their boats, but in the evenings they make music, dance, paint or carve things out of wood and stone. There are thousands of temples in Bali, and there are festivals at these temples when people die, or get married, or when a child is borne

Until the 1950's the Balinese people did not worry about the outside world. For them Bali was the whole world. But in the 1950's tourists began to visit Bali, and since then tourism has become big business there. So the people have begun to sell their art to tourists. These days the Balinese produce more and more things for tourists; they make fewer things for their temples. They have less time for their gods, so there are fewer festivals.

Every year more tourists bring more money to the island. They also bring new ideas and a new way of life. The Balinese need money, and they need new ideas. Nowadays too many people live on the island, and they need to buy food and other things from abroad. The Balinese know that if fewer tourists come to the island, there will be less money, too. But they also know that if there are too many tourists, the Balinese way of life will change too quickly. So the authorities are trying to organise and control tourism very carefully. Bali should change; but they want to make sure that ft changes for the better, not for the worse.

LIFE IN SPACE

Hopes of finding life on other worlds have been raised by Canadian astronomers. Their observations of nearby stars have shown that half of them may have planets.

The discovery, announced at a recent meeting of the American Astronomical Society, provides important support for scientists who believe that planetary Systems, and life, are common in our galaxy.

"These observations suggest that half our galaxy's 100 000 million stars have planets - and that means we must have a good chance of finding life out there'," said Professor Archibald Roy of Glasgow University.

The research, carried out by Dr. Bruce Campbell of the Dominion Astronomical Observatory, Victoria, and Dr. Gordon Walker and Dr Stephenson Yang of the Univeryity of British Columbia, Vancouver employed a new astronomical measuring technique called high-resolution spectroscopy.

In the past, the search for other worlds has been limited by two factors. First, planets are tiny, i.e. very small, objects compared with stars; for instance, the sun, a typical star, is 300,000 times more massive or larger than the earth. Second, planets do not shine but only reflect (give back) light from stars.

But Dr. Campbell and his colleagues solved this problem by using high-resolution spectroscopy to measure variations in a star's light Small differences in a star's light showed that unseen planets pushed and pulled the stars ,out of their paths, in other words, their ways.

The astronomers results, published in the Science magazine showed that, of 16 nearby stars, two - Epsilon Eridani and Gamma Cephei -were definitely being affected by large bodies in orbit round them. Of the rest, five or six also appeared to have unseen companions.

The astronomers calculate that these unseen objects must be several hundred times more massive than Earth. However, they are almost certainly planets.

"There are about l00,000 million stars in our galaxy and about one fifth are stable; that is, unchanging and cool like our own sun." said Professor Roy. "Now it seems about half also have planets That leaves us with 10,000 million stars which might have life on them. It's very encouraging."

Further evidence should follow, because in a few years two important space projects – the Space Telescope and a European satellite called Hipparchus - will be introduced. Both will increase scientists'