Stretch Vs.Temperament, (was Beat Rates)

[A440A@AOL.COM]

I wrotes: 
>>    With three strings struck, there is a tertiary transfer created which
>is far more complex and contains more resultant modes of vibration, and the
> three strings will never be totally in phase.
 
Ron writes: 
>Again, in theory, but I'm not sure that is the case in the piano. Of course
> they can be in phase and not be in acceptable  tune, but you already know
>that.

Um,  I am not sure I do know that.  If you have different rates of vibration, 
how are they going to be in phase? 
If the differences were large enough to form multiples of one another, I 
could see it, but if you have a string going at 500 Hz and another at 501, 
they won't have a very easy time of getting together, will they? 
Ed