I saw lots of videos on youtube were people but grapes in the microwave, and the grape shot plasma because of the electomagnetic feild. This link http://www.madsci.org/posts/archives/1997-12/882909591.Ph.r.html explains how it works. You know this is not a prank because on all of the prank videos, there are always other videos that explain how the pranks work. The link says nothing about heating the grape effects the plasma. My question is that if i put 2 sides of a grape in between an electromagnetic field made with magnets, how powerful/how big do the magnets have to be?