In the confusion that surrounds the universe of microwave heating, perhaps it is better that mainstream consumers are happy to know that their kitchen microwave ovens respond to the button pushing—most of the time, at least—and heat the water for coffee, defrost the frozen entrees, and pop the popcorn. But, from our distant past come the definite messages that microwave energy will greatly expand its range of action and finally be applied to pasteurization and sterilization—pre and post packagin…