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 …

Read more

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 …

Read more

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 …

Read more

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. …

Read more

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 …

Read more

Cooking With the Sun

Cooking with the sun (solar cooking) provides free, safe, clean heat energy that preserves nutrients in food. Cooking with the Sun On a clear, bright, sunny day, line a mixing bowl or colander with aluminium foil (shiny side up), and smooth it as much as possible, to make a solar …

Read more

Seeing Soil Erosion

Soil erosion is the loss of healthy and fertile topsoil through water or wind, leaving behind poorer quality subsoil. Soil erosion can lead to famine in developing countries, because the poorer soil means that crops are not as good, or might fail completely. Different Soils and Water Erosion Fill shallow …

Read more

Tracking Sunspots Across the Sun

A sunspot is a cooler area on the surface of the sun, which shows up as a patch that is darker than the rest of the sun’s surface. A sunspot generally lasts for about two weeks. Sunspots usually happen in groups. Sunspot activity happens in cycles that peak about every …

Read more

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 …

Read more

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 …

Read more