I didnt say anything about radiation. When water is in a contained enviroment the proper amount of excitement to the water molecules will produce heat.
The expansion of water is only done by exciting the molecules so much that they need room to bounce around. Its this needed room from the excited water molecules that force the popcorn kernal to pop.
As I said before, the production of heat is a product of making the water molecules excited and you do not need heat to excite the water molecules.
You dont have to use radiation, heat, or microwaves to popcorn. Anything that excites the water molecules in the kernal can pop popcorn.
