[makomk]

Actually, they didn't appear to investigate the cause at all - they just assumed one cut surface must have been contaminated more than the other and changed the experiment to remove the cut surface altogether. Since the mold on the non-pyramid apple only survived on the cut surface, not cutting the apples made sure no mold grew on any of them, and all bar one of the apples (the one from the cube) was perfectly preserved at the end of the experiment.

Was kind of annoying actually; the Mythbusters got so pissed off that their experiment appeared to show pyramids working that they set up their next test in such a way it'd give the same result regardless of whether pyramids or contamination had caused one apple to rot faster before, then held it up as proof pyramids were bunk. While it's really unlikely pyramids can magically preserve food, they should still have been honest and fair in their testing.