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Can you ever hurt a robot?

We think of robots as perfect machines that never do anything wrong, let alone get hurt. However, there are some robots whose whole purpose is to get hurt and to say ‘ouch’. These robots are dummy patients for dentists. They have a model human head, and student dentists practise doing fillings and other kinds of dental work on the robot’s …

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Can there be light without heat?

Yes, we can have light without heat. The light from such reactions is called cool light. Many chemical reactions produce both light and heat. A burning candle is such a reaction. It is much less common for a chemical reaction to produce light without heat. Such chemical reactions are called chemiluminescent reactions, the most familiar of which occur in living …

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Can sunlight be stored?

Plants take in sunlight and combine it with carbon dioxide from the air and water and minerals from the ground. The energy of sunlight is stored in the leaves. Some of the sunlight gets stored underground. This stored sunlight is in the form of fossil fuels like coal and petroleum. Solar energy can be stored at high temperatures using molten …

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Can people create deserts?

Bordering the southern edge of the Sahara is a region called the Sahel. It extends from Mauritania and northern Senegal through Mail, Burkina Faso, Niger and Chad into Sudan. The Sahel has an average annual rainfall of between 100 and 400 mm (4-16in) and, in the past, it was grazing land. From the 1960s, this zone has suffered droughts, so …

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Can people be born in space?

It is possible that people will be born in space and live their whole lives there. These space people will be human beings who have left Earth to live in space colonies. The colonies will be gigantic spacecraft, many kilometers across, in which there could be whole cities, together with fields and lakes. The colonies would grow their own food …

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