Making a Sundial

Before watches and clocks were invented, people used the position of the sun in the sky to guess the time of day, but this couldn’t be very accurate. The next step was the invention of the sundial, when someone noticed the way that shadows moved across the ground over the …

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What is Sand?

Sand is a mixture of small grains of rock, ranging in size from 0.0625 mm to 2 mm. Sand is made by erosion and weathering of rocks – seas or rivers carry pebbles that chip small pieces off rocks, and freezing and thawing during the winter breaks rocks up. Sand …

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Watching Clouds

Clouds are collections of very small drops of water or particles of ice and they form from water vapour in the air. Types of Clouds According to the World Meteorological Office, there are ten basic cloud types: Cirrus, cirrocumulus, cirrostratus, altocumulus, altostratus, nimbostratus, cumulus, cumulonimbus, stratocumulus and stratus. The names …

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Monitoring the Weather

Weather stations include different ways of measuring the weather. Meteorologists (people who study the weather) use weather stations to monitor the weather day by day, and use the results to make weather forecasts. Use a weather station to record the weather and see how it changes daily, weekly and monthly. …

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Looking at Soil Profiles

Soil is everywhere – in fields, gardens, woods. Even in pots in houses for house plants. It is what plants need for growth, but what is it actually made of? Soil is a mixture of small rock particles weathered away from rocks, with rotted (composted) vegetation, known as humus. Soil …

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Making Biospheres, Ecospheres and Bottle Gardens

In Edwardian times, growing plants in glass cases was very popular, especially because it protected delicate plants, such as ferns, from polluted air. These were generally bottle-sized or aquarium-sized, and were often called Wardian cases, after their inventor Dr Nathaniel Bagshaw Ward. Bottle Gardens A bottle garden or terrarium is …

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The Science of Recycling

Recycling is important because it saves energy and resources and reduces pollution, as well as creating jobs and keeping things out of landfill. Paper Paper is made of wood fibres. Over their lifetime, a family of four will use the equivalent of six trees in paper. Recycling paper uses 70% …

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Desalination of Water

Desalination means taking the salt out of salty water (from lakes or the sea) to make fresh, drinkable water. How Does Desalination Work? The two main ways to remove the salt (and other impurities) from water are through distillation and osmosis. In distillation, the water is heated to form a …

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Condensation and Dew

Condensation, on the inside of the kitchen window on a chilly morning or on a cold glass of water, and dew on the grass on a cool autumn evening, is a familiar sight, but what is it and what causes it? About Water Water molecules can be a solid (ice), …

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When the Wind Blows: Making a Wind Vane

Warm air is less dense than cold air, and so as air is warmed by the sun it rises (see ‘Warm and Cold: Expanding Air’ and ‘Floating and Sinking: Looking at Density’). Cold air then moves to replace the warm air. This movement of air is called ‘wind’. At the …

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