Why a microwave has hot and cold spots
A microwave oven heats food with electromagnetic waves that make certain molecules—especially water molecules—move and transfer energy as heat. Inside the metal oven, those waves bounce off the walls and overlap. In some places they reinforce one another; in others they partly cancel. The result is a changing pattern of stronger and weaker heating, not a perfectly uniform field.
That is why one part of a dish can be steaming while another is still cool, even when both sat in the oven for the same amount of time.
The turntable spreads the exposure
The rotating tray carries the food through different parts of that pattern. A section that begins in a weaker-heating area may pass through a stronger one as the tray turns. This averages out some of the unevenness, so the food is more likely to warm consistently than if it stayed in one position.
The tray does not make the waves uniform or guarantee that every bite reaches the same temperature. Thick portions, dense ingredients, and food piled unevenly can still heat at different rates. Stirring or rearranging food helps expose its cooler parts, while a brief rest after heating lets warmth spread from hotter areas into cooler ones.
So the spinning is not just a display of activity: it is a simple mechanical way to give more of the meal a turn through the oven’s uneven heating zones.
