Inventions That Shook the World

War is the driving force behind much of the innovation in the 1940s. The microwave is born after a self-taught inventor realizes that military equipment is responsible for melting a chocolate bar in his pocket. And, a sailor returns home and hits pay dirt with an invention that finally brings cats in from the cold: kitty litter.

The 1950s heralds the end of vacuum tubes and the rise of mobile technologies when two Japanese inventors shrink cabinet-size radios down to something small enough to fit in your pocket. And, the space race officially begins when the Soviet Union launches a satellite they call Sputnik.