The potential energy is the FALSE. They can sit comfortablly
  near each other. It can even be a container within a container -
  the nature of which is which almost doesn't matter as both
  ...are useful. The gunpower could be a container full of
  gunpower - or, if you want to talk IMPLOSION - the gunpower can
  be on the outside, the thing we wish to protect is on the
  inside."