> Please note that rivers don't always branch ... there is the Colorado in 
> the grand canyon ... Rivers branch because at some point the bottom becomes 
> harder then the banks. 
Actually this isn't correct either (so much supposition and so little
time!).  Rivers branch because they "need"[1] to increase their length in
relation to their speed and slope (Geology 101).  The only way of doing
that is either to built a huge delta (Nile, Mississippi) or trace a more
winding path.
-Prof. Tim
Who is as amazed as everyone else that he is seen as a
scientific-rationalist by anyone in this group