code: def turn_physical_off(Pot):
      
      if isinstance(Pot,list):
          for pot in Pot:
              turn_physical_off(pot)
      else:
          Pot.turn_physical_off()
      return None
docs: NAME:
      
         turn_physical_off
  
      PURPOSE:
  
         turn off automatic returning of outputs in physical units
  
      INPUT:
  
         (none)
  
      OUTPUT:
  
         (none)
  
      HISTORY:
  
         2016-01-30 - Written - Bovy (UofT)