I was following the discussion about the "Why" and "How" questions, feeling
myself unable to add anything that had not been already said.
But yesterday I encountered an episode that turned my attention to one of more
practical aspects of "Why" and "How".
Namely, during my lunch, an empty, closed, and TURNED OFF microwave oven right
near me suddenly exploded with a loud "Bang!".
It was only by a lucky coincidence that I was not hurt by flying splinters of
microwave door. On immediate examination, I found the door still closed but
broken with large holes in it, and the rest of it all cracked. The microwave was
about 5 years old, and had been functioning all that time (including the
previous evening) without any problems.
I had never before experienced (or heard of) this kind of spontaneous
explosion of a disconnected device. My first (human) question was "What the heck
is going on?" My next, more scientific (and more polite) was "Why and How this
could have happened?". Just describing "What happened" would not add much to
what I observed, unless it gave a full description of some unnoticeable
preceding internal structural changes or unnoticeable external influences with
their explanation. But to me, the latter would amount to explaining "Why" and
"How".
I personally have no idea of "Why" and "How" this happened. Of course, I could
resort to considering this as a divine message from some mysterious headquarters
that it is time for me to switch from pure theoretical to applied physics, but I
so far decided to keep such possibility as a last resort. Meanwhile, I
immediately called to a colleague - a professional experimental physicist with
30 year experience. He came over, looked at the scene and said that he has never
encountered or heard of this kind of event. His only suggestion was that the
cause might be a gradually accumulated strain or stress in the microwave door,
or explosion (rather, implosion?) of the vacuum tube in the internal magnetron.
Neither of which explains much to me. On his insistence (he said there might be
some toxic output) we wrapped the thing into a plastic bag and disposed of it,
and now I regret this since I cannot anymore do a more thorough examination.
I have done some search on the Internet, but did not find anything similar
except for SHC (spontaneous human combustion) (never before heard about that,
either), and again, without any satisfactory explanation or even proof that all
described cases were not some artifacts.
So my question to this Forum is: Has anyone any viable idea or information
about this kind of effect? If yes, that would be a good answer to the "Why" and
"How" question.