Solar Airship, 3 m Long, Ø60 cm

A large cylindrical balloon made of thin black plastic, 3 m long and 60 cm in diameter. It is filled with air, sealed and tied off with the supplied cord to form its elongated shape; the black surface absorbs sunlight, heating the trapped air and creating lift just as in a hot-air balloon. In physics lessons it illustrates buoyancy, thermodynamics and solar energy, letting pupils investigate how the sun's energy is turned into motion and how temperature differences in the air produce lift. It also fits cross-curricular projects on renewable energy and climate, and makes a spectacular demonstration of solar energy creating movement with no fuel.