10 experiments found
Clear filtersFertilisers raise yields only up to a point; extra nitrogen washes into rivers and harms them, and pesticides harm useful creatures too
Decide how much fertiliser to put on a rice field, chemical or compost, whether to spray pesticide, and see the effects on the harvest, the soil and the river.
Greenhouse gases such as carbon dioxide let sunlight in but trap heat radiated from the ground, warming the Earth
Shine a lamp on an open jar, a covered jar and a covered jar of extra carbon dioxide, and compare how warm each gets.
Renewable sources vary with the seasons; Nepal's rivers make micro-hydro powerful, while solar and wind can fill gaps
Choose solar panels, wind turbines or a micro-hydro plant for a 60-home village in Nepal's hills, and see how much energy each gives in winter, the dry spring and the monsoon.
Running water carries soil away fastest on steep, bare slopes; plant cover, mulch and terraces slow the water and hold the soil
Pour rain onto trays of soil on different slopes, bare or protected by grass, mulch or terraces, and weigh the soil washed away.
Many of Nepal's animals and herbs are endangered by habitat loss, hunting, over-collection and climate change and are protected by law, while common herbs grown at home are used in traditional remedies; conserving them keeps nature in balance
Meet sixteen animals and plants of Nepal, from the red panda and the gharial to satuwa, jatamasi and tulsi. Find out where each lives and why it matters, then sort them.
Electricity and fuel cost money and resources, and making them often pollutes the air; small habits, such as switching off, using LED bulbs and covering pots, save energy, while leaving things on or open wastes it
Look at twelve everyday habits, from switching off lights and cooking with a lid to leaving the TV on standby. Find out why each one saves or wastes energy, and sort them.
1 mm of rain on 1 m² of roof is 1 litre of water, so a roof collects area × rain × 0.8 litres (some splashes or soaks away): even a small roof can store a lot of water in the monsoon
Choose the size of a roof and the rain in a month, and work out how many litres of rainwater a family could collect in a tank, and for how many days it would give a family of five their water.
Trees take carbon dioxide from the air by photosynthesis and store the carbon in their wood: a grown tree takes about 21 kg of CO₂ a year, while a car gives out about 0.17 kg every kilometre
Plant 1, 10 or 100 trees and let them grow for 1 to 20 years. Find how much carbon dioxide they take from the air, and how many kilometres a car could drive to give out the same amount.
Burning petrol and diesel gives carbon dioxide, a greenhouse gas: kg of CO₂ = km travelled × kg per km per person, so walking or cycling gives none, a shared bus gives little, and a car gives the most for each student
Choose how you get to school, how far it is, and for how many days. See how many kilograms of carbon dioxide the trips put into the air, and how many trees it would take a year to soak it up.
The Earth turns 360° in 24 hours, so 15° of longitude is 1 hour: places to the east see the sun first and their clocks are ahead; each country sets its standard time from a longitude near its middle
It is noon in Kathmandu. What time is it in London, Delhi, Tokyo or New York? Pick two cities and see how the turning Earth gives every country its own clock time, and why Nepal is 5 hours 45 minutes ahead of London.