Most people take reheating their food for granted. But there was a time, 30 years ago, when people were amazed by a new machine's ability to instantly turn cold leftovers into a warm treat. The microwave is celebrating its 30th anniversary, and while more than ninety-percent of American households own one, some questions about it remain unanswered. Minnesota Public Radio's Joe Fryer spoke with visitors at the Science Museum of Minnesota, and got answers from Jay Newlin, the museum's head of Physical Sciences.