[thedoc (OP)]

Zev  asked the Naked Scientists:
   
It has baffled me that a garage door can open without being mechanically lifted. I hope you can explain this phenomenon.
 
How do electrons cross from their position around an atom towards an available receiver?
 
What enables the electrons to move through space and sustain this movement until they reach a wireless target such as a garage door?
 
How does emitting a subsonic (it must be subsonic, because I can't hear anything) sound sustain contact through open space without diminishing its reach toward the receiver?
 
And why does only the garage door open?
 
What do you think?