It's thermodynamic science made simple! Crookes Radiometer is an amazing desktop gadget that spins when exposed to sunlight. Inside the airtight glass bulb are silver and black vanes. When these vanes are exposed to sunlight the lack of air-resistance allows them to spin, powered by the sun. As the light becomes more intense the vanes will spin faster and faster.
Forget the hard work and complicated stuff, this radiometer is a visual experiment that allows you to witness the power of solar energy. Simply set it down on your desk, windowsill, table or bench top to watch it spin into action. An education and unique gift for all ages.