scallions

[Allan Adler]

A little while ago, I took a scallion, washed it, cut it up into pieces
and put it in a dish in the microwave oven with no additional water
and set it for two minutes at the default setting of full power. After
a minute or so, I heard a buzzing coming from the microwave and then
saw what looked like flame. I stopped the cooking and took a look and
saw that some of the thin stems of the scallion had caught fire.
I suspect that after the stems got dry enough, there was somehow
arcing between the walls of the microwave and the stems. I know
enough not to put metal in the microwave and I've always considered
it safe to put vegetables in it, even if I don't add water.

Does that kind of arcing really happen? Or should I seek some other
kind of explanation, e.g. that scallions, like leeks, sometimes carry
within them a little bit of dirt, and that there was arcing between
the walls and the dirt?
--
Ignorantly,
Allan Adler <ara@zurich.csail.mit.edu>
* Disclaimer: I am a guest and *not* a member of the MIT CSAIL. My actions and
* comments do not reflect in any way on MIT. Also, I am nowhere near Boston.