On 30/12/2018 05:47, Johnny B Good wrote:

The microwave energy doesn't magically focus in the deep interior of the
food and heat it from the inside outwards. The microwaves only penetrate
the first centimetre or two before losing sufficient of their energy in
this process so as to have insignificant effect on the deeper interior
which therefore relies upon conduction from the hotter outer portions to
raise its temperature sufficiently to kill any pathogenic micro-organisms
so as to eliminate the risk of food poisoning.

"What's he on about Grandad?"

"Well, he says when you put stuff in the micro it gets hot more on the
outside than on the inside. Microwaves work by invisible waves, little
tiny ones."

"Could I see them with my microscope?"

"Well no because as well as being tiny they're invisible."

"How do people know they're there then?"

"Err, because they warm food up, for one thing."

"What else?"

"Well, erm, they make television work. That's why we have aerials, to
pick the waves up."

"Do the aerials get warmed up by the waves then?"

"No."

"Why not? If the food gets warmed up..."

"Look, let's get back to the microwave oven. You see, the waves can only
go into the food about half an inch..."

"Is that about ten centimeters?"

"Tell you what. How about if you have another go on your X Box?"

******

The microwave energy doesn't magically focus in the deep interior of
the food and heat it from the inside outwards. The microwaves only
penetrate the first centimetre or two before losing sufficient of their
energy in this process so as to have insignificant effect on the deeper
interior which therefore relies upon conduction from the hotter outer
portions to raise its temperature sufficiently to kill any pathogenic
micro-organisms so as to eliminate the risk of food poisoning. (77
words; many of them long)


Shorter version for those who fall asleep half way through long paragraphs:
The microwaves heat food from the outside. They don't penetrate very
far, so the inner parts of the food are cooked by conduction. If these
parts get hot enough the germs are killed. (33 words)

Bill