I imagine this is what plays when you put the cup slightly off center on the microwave turntable so it starts drifting in wide circles when you turn it on.
The em waves in a microwave are standing waves, meaning energy is deposited in the food only on some spots, and the spots remain static as the microwave is running. Therefore, positioning food to the outside of the tray will make it move through these spots more vs if it was only rotating at the center.
Tldr drift your food for maximum heat distribution.
Seems plausible: the wavelength is in a good size range for such an effect to be noticeable.
I found that in a typical microwave oven, the frequency is about 2450 MHz. Using the formula, velocity = frequency × wavelength and knowing that the velocity of an electromagnetic wave is about 3.0 × 108 m/s, gives a wavelength of about 12 cm.
I imagine this is what plays when you put the cup slightly off center on the microwave turntable so it starts drifting in wide circles when you turn it on.
The em waves in a microwave are standing waves, meaning energy is deposited in the food only on some spots, and the spots remain static as the microwave is running. Therefore, positioning food to the outside of the tray will make it move through these spots more vs if it was only rotating at the center.
Tldr drift your food for maximum heat distribution.
Seems plausible: the wavelength is in a good size range for such an effect to be noticeable.
Same thing happens in chemical mixing in a vat. You want it off center. I might have a diagram in one of my old textbooks if you want.