[emddudley]

Most of the microwave power does not deeply penetrate something like a whole ham. The microwaves are mostly absorbed by the outer layers and then the heat conducts through the inner portions.

The journal article below contains lots of detail. It claims that microwaves penetrate about 3.8 mm in cooked ham and 9.9 mm in cooked beef.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4657497/

[rixed]

> The microwaves are mostly absorbed by the > outer layers and then the heat conducts > through the inner portions.

Then why does the plate have to be slowly rotated within the oven? I used to believe that it was for the waves peaks (distant from one another by a pair of centimeters) to be able to reach every point of the inside.

But if the inside is heated by conduction, which propagates evenly in all directions, then why care rotating the plate?

[canhascodez]

Microwave ovens do indeed have hot spots[0]. Conduction doesn't propagate evenly in very many foodstuffs, and you still want to avoid overheating any one spot.

  [0] https://www.evilmadscientist.com/2011/microwave-oven-diagnostics-with-indian-snack-food/