This has been in my mind for a while... Well, actually everytime I heat any food with a greater amount of liquid in it:
- a microwave oven warms up food by inducing polar molecules in the food to rotate and produce thermal energy;
- it heat foods quickly and efficiently because excitation is fairly uniform in the outer 25–38 mm (1–1.5 inches) of a homogenous (high water content) food item. So, if there's an "heterogeneous, dense object" with liquid right in the center of it (beyond the 25-38mm margin they mentioned), that part won't be heated properly;
- however, the not so new ovens were added a disk at the bottom, so the food container can rotate while heating, I suppose for warming up the food uniformly, since the wave is guided in some pattern to the target;
- therefore, wouldn't the heating be more efficient if the container could be moved up, down or even sideways?