The metallic inner walls of a microwave oven are specifically designed to not affect its use and, in fact, play a crucial role in its operation. Microwave ovens are constructed with a metal cavity that helps contain the microwave radiation inside the oven and ensures that it is directed toward the food being cooked. There are a few reasons why metallic walls do not interfere with microwave cooking:
Reflective properties: Metals are highly reflective to microwave radiation. When microwaves encounter the metal walls, they are reflected back into the oven, helping to distribute the microwaves more evenly. This reflection prevents hot spots and ensures even cooking of the food.
Containment of microwaves: The metal cavity acts as a Faraday cage, which is an enclosure that prevents the escape of electromagnetic radiation. It keeps the microwaves confined inside the oven, so they do not pose any danger to the users and surrounding environment.
No absorption: Unlike the water, fats, and sugars present in the food, metal does not absorb microwaves. This lack of absorption means that the metal walls do not heat up during microwave operation and remain relatively cool.
Safety measures: Modern microwave ovens are designed with safety measures to prevent any potential issues with metallic walls. The oven's design ensures that the microwave radiation is directed into the cooking area and does not leak out through any gaps or openings.
It's essential to note that you should not put any metal objects inside a microwave oven during operation, as they can reflect the microwaves back to the magnetron, potentially damaging the oven or causing a fire hazard. However, the metallic walls of the oven itself are safe and necessary for efficient and even cooking while containing the microwaves within the cooking chamber.