Re: A list of textbook misconceptions

[SCIAMANDA@edinboro.edu]

William Beaty wrote:
> (By "coherent" I mean "having large spatial coherence length.)
>
> William J. Beaty                                  SCIENCE HOBBYIST website

Bill,
Before this discussion gets mired in semantics, let me just point out 
that you seem to be confusing what I believe to be the common notions 
of spatial vs. temporal coherence:
"having large spatial coherence length" ALONG the direction of 
propagation is a measure of temporal coherence;  coherence in a 
direction perpendicular to the propagation direction is a measure of 
spatial coherence.  The first is examined in a Michelson type 
interferometer; the second in a Young's double slit type interference 
experiment.  I think you are at times calling both "spatial coherence".

-Bob

Bob Sciamanda           sciamanda@edinboro.edu
Dept of Physics         trebor@velocity.net
Edinboro Univ of PA     http://www.edinboro.edu/~sciamanda/home.html