<Marianne Hu <hu@satchmo.virtualprototypes.ca> wrote: 
     <Bess, Ellen et al,
     <I once read that it's not advisable to microwave milk in the 
     <microwave.  Something about retaining some radioactivity!?  Has 
     <anyone else heard anything about this?
     Hi all,
     There are no radioactive substances ie uranium/plutonium used in 
     microwaves.  Just look at the back of your microwave.  Federal law 
     requires the yellow and black radiation sticker to be applied.
     Microwaves are electrical currents pulsed at a different frequency 
     than house current.  Electricity moving through a wire 'radiates' 
     energy in a circular pattern around the wire. 
     The microwave energy is transformed in the food/milk into heat energy. 
     So yes - all foods retain the radiated energy in the form of heat.
     Gerry