Microwave is so popular nowadays and less serious accidents we hear today. Users MUST NOT microwave an egg is one of the most popular taboo because it bursts like a bomb. I don't know whether true story or not, a housewife microwaved her kitten to dry her after shampoo. She probably thought that a kind of a nice and gentle dryer or something.
The microwave oven heats the water inside food
The microwave oven doesn't heat the surface of food like the old-fashioned oven, so it never gets browned. It heats just water inside food.
Why shouldn't the egg be microwaved? Water expands with heat, but there is no extra room for expanded water inside the egg. It's inevitable that the egg bursts.
Tips on cooking with microwave
The microwave cooking becomes popular among busy people. New fast and easy cooking recipes are published every day. It's not easy to follow the recipe accurately because the ingredient you purchase may not be the same as what is written. Like, the cabbage you bought may be much lighter and have less moisture inside than expected. Some adjustments to the recipe are needed to use various conditions of ingredients and it may make a big difference at the finished dish. Cooks know unwritten know-how from many years of experience, while engineers know why the moisture of ingredients matters with microwave cooking from their technical perspective, they just don't write instructions from the perspective of the cook. If you understand the principle of the microwave at the engineering level, it makes sense at the earliest.
Technically speaking, What the microwave does to your dish is; the microwave heats the food material by activating water molecules inside the food. In other words, water is an essential component of microwave cooking. If you feel your ingredient is dry, it should be wetted with water. It should be wrapped with a cling film because water molecules leave the ingredient easily.
The microwave oven heats not only water but also metals
The microwave oven heats water. It is a quick understanding of the principle. Since it is related to safety, there is one more thing I want to add. The important thing is that the microwave does not only heat the metals, but it also causes sparkles which might spread to something else. Ceramicware and glass aren’t heated by the microwave. Just think for a sec, the turntable made of ceramic ware isn’t heated.
Trivia
Have you had experience of sudden worsening of WiFi connectivity while the microwave oven is working? Microwaves actually interfere with the WiFi signal at 2.4GHz. You can avoid this interfere using the WiFi signal at 5GHz.