Why should you never cook an egg in a microwave?
The microwave is a marvellous invention: those in a hurry won't disagree! Practical, it lets you heat or reheat any dish or food in no time at all!
Any food? No, no, no, some foods are ESPECIALLY NOT to be put in the microwave, and that's the case with eggs!
"Here, why don't I cook a whole egg in the microwave to make a hard-boiled egg?"
If you've asked yourself this question, stop the experiment right now: what you're about to do is DANGEROUS!
In fact, with the heat, the yolk inside the egg will swell, swell, swell... But the shell will not. After cooking, when you pick up your egg to remove its shell, it will explode into a thousand pieces (if it hasn't already exploded in your microwave and covered its entire surface...).
If you don't want to end up with egg all over your kitchen, and don't want to injure your hands or eyes, NEVER cook a whole egg in the microwave.
Instead, use a saucepan and water, or opt for another, much safer cooking method!