Why don’t microwaves get stuck in the food we put in the microwave oven?
Microwaves are like light—both are electromagnetic waves and both move extremely quickly. While it is possible to trap a light wave briefly between two mirrors, that wave will eventually be absorbed or released. The same is true of a microwave. It’s almost impossible to trap a microwave for more than 1 second, even in very exotic enclosures, so you needn’t worry about them becoming trapped in food. The food simply absorbs them and turns their energy into thermal energy.