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What causes different skin colours?

It you walk down a street in any town or city, you will see lots of people with different coloured skin: white, black, yellow and coffee colours all appear. But why do people have different coloured skin? The reason is that in your skin you have substances which, under certain conditions and with the correct chemical processes, make colour – …

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What are wave snakes?

A Wave snakes are long red tubes that help convert the motion of waves into electricity and form part of a commercial wave power station. It was developed by a British company and took 10 years to create. Currently, the pilot wave-power project has been launched off the coast of a Portuguese town called Agucadoura, and aims to power 1,000 …

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What are Volcanic Tubeworms?

In order to raise chicks the farmer keeps the eggs warm and is careful not to crush them. But when scientists in the University of Southern California rear tubeworms, they keep the immature worms very cold and under high pressure. You would think the scientists are being cruel by subjecting these little worms to such extreme conditions. They are not. …

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What are T-rays?

T-rays stand for terahertz radiation. It is used to scan airline passengers for explosives and illegal drugs. The rays are particularly effective, as they can see through clothing, paper, leather, plastic, wood, and ceramics. They don’t penetrate as well as x-rays, but they also don’t damage living tissue. They can read spectroscopic signatures, detecting the difference between, say, hair gel …

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What are transparent soaps made of?

Transparent soaps are made of glycerin, and are partly soap and partly solvent. Sodium hydroxide causes crystals to form in soap, which is why the soap becomes opaque. In order to make it transparent, the soap has to be dissolved in enough solvent to make the crystals so small that light passes freely through, making the soap look transparent. There …

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What are thunder and lightning?

Some people become very frightened during a thunder storm, but there’s really nothing to worry about. Lightning is the result of a collision between two electrical charges one positive, and the other negative either in two clouds or in a cloud and the earth. When the difference between the two charges becomes great enough, a great spark the lightning jumps …

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What are the uses of the telephone?

Most of us find telephones extremely useful for talking to others, but the telephone has several other uses. The telephone network sends voices around the world in the form of electric signals. It can also send other kinds of electric signals that are not voice signals for example, computer signals. Computer networks are groups of computers connected together by telephone …

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