As far as kid-friendliness goes, Fastronauts have it all: bells and whistles (and lights), instant feedback, adorably round silhouettes and small stature -- they're only about 6 inches tall and 6 inches wide (15 by 15 centimeters) in their vehicles. But it's what's going on inside that sets Fastronauts apart from other toys.
Converting motion into electricity dates back to the 1830s, when English scientist Michael Faraday proved that you could, so to speak, reverse-engineer electricity. It was long known that electric current generates an electromagnetic field. But Faraday showed that you could use an electromagnetic field to generate electric current. And you can create an electromagnetic field by spinning a metal coil between two magnetic poles. So if you can get a coil to spin, you can create electricity.
In the Fastronauts, the core of the system is a dynamo. A dynamo is simply a generator -- a device that uses a rotating coil and magnets to establish an electromagnetic field that then generates electricity. It turns energy of motion into electrical energy, just like the generator for a wind turbine or hydroelectric dam. In a Fastronaut, the energy input is human motion, instead of wind or moving water. But it works in the same way: A spinning wheel turns a gear inside the Fastronaut rocket, and that gear spins the dynamo to generate an electric current.
Fastronauts are certainly not the only devices to harness human energy for electrical output. Kinetic-powered flashlights use the same type of dynamo setup, but instead of riding a bicycle, the user repeatedly presses a lever. And there are bigger projects, too, like the Hong Kong fitness center that wired a bunch of its elliptical machines and treadmills to move a dynamo that generates electricity to run the gym [source: So].
The Fastronaut electric current is applied on a much smaller, but perhaps more amusing, scale. It's the powered features that make the toy's alternative energy appealing to kids. So what can these things do?