Has anyone out there actually tried the kitchen experiment of placing a continous line of meltable food (i.e. marshmellows/chocholate/cheese etc.) across the bottom of a microwave oven in hopes of finding the antinodes of a standing wave by looking for regions that melt while the rest of the line remains solid? I have, and while I did find random schorch marks, there was by no means a regular pattern of them (as you would hope from a standing wave). It seems to me that the experiment is doomed since the incoming waves are "bounced" first off a rotating fan blade to somewhat "randomize" the waves so that there are not going to nodes and antinodes. What puzzels me is that I still see this experiment on the Web as a way to determine the speed of light from this kitchen appliance. Am I missing something?