India, Sept. 6 -- How can a stovetop be smooth, flat, and eternally cool?

Induction cooking feels like something out of a sci-fi movie, but the truth is, it has been around for almost a century.

The technology made its debut at the 1933 Chicago World's Fair (themed Century of Progress). A range of demonstrations, including one by General Motors, showed crowds how a pot of water could be made to boil on a stovetop that could be touched at all times.

This works because of a magnetic field that affects the metal of the pan, causing molecules to shift rapidly, which generates heat in the pan, but nowhere else. (More on that in a bit.)

The catch was the price. Induction cooktops require powerful copper coils, high-frequency electronics and...