Another thing to keep in mind when trying to think about
radio waves and why they do the things they do is to know
that radio waves are exactly the same kind of energy as
visible light. It took some of the best brains in the world to
confirm this back a little over 100 years ago, but a few folks
thought radio signals were related to light but weren't really sure.
	Light has color which is just different frequencies of
radio as perceived by the human eye. It is perfectly safe to say
that working eyes are just radios built for the band whose low
end is around 800 nanometers and whose high end is around 350 to
400 nanometers. If you transmit on 800 NM, most people will say
they saw a red light. If the frequency is around 400 or so
nanometers, they will say they saw blue or violet.
	What confuses people is that frequencies longer or
shorter than the visible light band don't behave like visible
light seems to behave. The truth is that they can be reflected,
refracted and absorbed just like visible light but it may
require different materials to achieve the same effect.
"Dr. Ronald E. Milliman" writes:
> Joe, you ask some very good and most interesting questions. I strongly
> recommend that you do a little investigating on the topic of radio
> propagation. There are several excellent, basic informational pieces on 
> this
> topic. It is an extremely interesting topic and a topic that is very
> fundamental to how hams communicate over various distances on different 
> ham
> bands and at different times of the day and year.