More on Irradiate-- vs Nuke or Mike..
Microwaves are radio/sound waves-- very high frequence-- if you start with waves (say on the ocean) and keep making the wave smaller and smaller... you eventually would get to 60 Hz-- or middle C-- and make them smaller and smaller-- and you get to micro waves-- (which you can neither see or hear..)
Mirco wave ovens use the same range of waves as radar systems... (hence a Amana's brand of Radar Ranges-- an early term for Micro waves..)
Some one in US first notice you could "see" an object in sound waves--and before WWII there was a crude Radar system set up (the german's had a lot of Radar) but it was pretty crude and couldn't tell a flock of birds from a B52-- so lots of false alarms.
The Brits actually came up with a very much improved system using a magnatron--but by then, where deep into WWII and didn't have the resource to develop a working product on a large scale.
They pretty much gave the technology to US, in return for us actually building a good quality working radar system that could be mounted in a plane..
During the war, pilots noted that coffee(tea) stores near the radar machine got/ stayed hot (in the unheated bombers) and learned to use the radar equipment to heat coffee and meals.
Post war, the technology was used to build Microwave ovens.. I saw my first in a VA hospital in the late 1960's...
I am sure there is a web site somewhere with the names of all the engineers, and the frequency range of a Microwave oven... You could LIU if you want more than this thumb nail history..