* Dan Asimov <dasimov@earthlink.net> [Nov 12. 2009 12:37]:
I believe I've seen paper catch fire in a microwave oven when it's been on too long and the water has evaporated away.
But how is this possible, considering that water boils at well below the kindling point of paper?
--Dan
semi off topic: If you run the microwave 'dry' (i.e. with next to nothing that absorbs the energy), you risk breaking the magnetron. This used to be a standard warning in all manuals, don't know whether this still applies with modern ovens. Even if the magnetron survives you might get more than you ask for. For example, a tiny flame will ionize the air, rendering it conductive and absorbent to the microwaves. Spectacular blazing flames may well follow. There are some web sites about these effects. The experiments are usually done outside the building, for very good reasons. cheers, jj (who reads manuals)