Here's a detailed explanation to a simple question: how does a microwave oven work? Also covered: measuring wavelengths using cheese (!), what's in a magnetron, and why microwave ovens have "cold spots." Enjoy:

See also: Why Can't You Put Metal in the Microwave?

The video above is based in part on Bill Hammack's book, Eight Amazing Engineering Stories, if you prefer your engineering information in non-YouTube format.