Notably, that field is powerful enough that microwave doors need to be about an inch thick. The rest of the inch is just empty space and a sheet of plastic to

Notably, that field is powerful enough that microwave doors need to be about an inch thick. The rest of the inch is just empty space and a sheet of plastic to stop you putting your fingers into the evanescent field. Unfortunately there were a few microwaves sold recently in Europe which forgot that design element, and if you pointed at food while cooking it, you would cook your fingers too.