Previously unknown to me, microwave ovens (originally invented in the late 1940's, but more commonly used and affordable in the 70's) have a variety of operational strategies, along with wattages. I was recently regaled with a 20 minute story of the fascinating tricks of the trade for one specific 700 watt microwave that left me considering slamming my head in a microwave to deafen me to further chapters in that book.