A radio can NEVER work without a ground?

[hal feinstein]

Another of those glaringly obvious questions:

Proposition:  In an idea system we know that radio reception can only  
occur when  a receiving apparatus conducts radio signals
from its antenna, through intermediate circuits, to ground.

Then:  Removing either or both the antenna or ground renders the  
receiver non-functional.

Conclusion:   No matter in what form, all radio receivers (and  
transmitters)  must be grounded even if no attachment to the "earth  
return"
is obvious.  A ground  must exist if the receiver functions.  Where  
is the ground?

Here I have a Sony 2010 tuned to a local station.  It uses  batteries  
and has no attachment to the power distribution system
and thereby is not grounded through it.  How does the radio signal  
"return"  to the transmitter?

A space probe in deep space sends a signal back to its Earth  
controllers.  Since the signal is received
we know there must be a "ground."     Where is the "ground?"


--hal f