I had a Professor (42+ years ago) who explained it thus: If is smells bad it's chemistry, if it's green and squishy it's biology, and if it doesn't work it's physics.
Regards, GtG
82 posted on 08/19/2009 7:36:34 AM PDT by Gandalf_The_Gray
(I live in my own little world, I like it 'cuz they know me here.)