[Aztlan] Plaster & Echoe

[Sid Hollander]

I feel obliged to reply now that some of my off-list comments were brought
on list.

It appears that of the three points that you brought to the list that none
were really answered. IE.

#1.  Unit of measure. I asked for one and did not get one.  Instead I got
that in ONE building there seems to be a "measurement" that is a common to
some measurements used it THAT construction.  To me, a unit of measure is
wide spread.  It is not OK to say that a measured room etc. of l,w and h
there is a common multiple of 7.5 inches in each dimension therefore the
Maya had a standard unit of measurement equivalent to 7.5 of our inches.

#2 when I commented on, "and appeared to have specific shape requirements"
instead of getting those requirements I was presented with the argument that
'they must have'.  And I agree, the Maya didn't just haphazardly toss shaped
stones about.  They planned and I agree that they planned.  But this only
give support that they planned not that they planned with acoustic design
principals in mind.  It appears that the argument for acoustical design is
proceeding along the lines of proving the existence of Acoustic Design  by
the theory of Intelligent Design.  I don't buy either.

#3. "I do believe there is a strong possibility the Quetzal-chirping design
was intended."  Sid:  What leads you to believing that? And in the cases
where there are other sounds (i.e. non Quetzal sounding) do you believe the
non-case was intended?  You didn't address the question.  Instead you
mentioned, "The inefficiency of use of materials in building a stepped
pyramid such as the Castillo or Pyramid of Kulkulcan in Chichen Itza is one
indicator." (On one hand you argue for intelligent acoustical design
considerations and now "inefficiency of use of materials in building" the
same structure.  I don't get the point.  You mention and are critical of the
non-vertical risers, why when, by your own admission, they have nothing to
do with the proposed acoustical phenomena are you critical of the
particular?  The reasoning you use ie. If the Maya only intended (this too
is not resolved) to make a equinox shadow show they didn't need to inlude
acoustic .....  Too much assumption here and the reasoning is flawed because
it is circular.

At the end you said,
                "I'm not saying other structures had acoustic design, but
this one may.
                 Note I used the  words, "do believe," and not "am sure."

 It is with these words that I am having trouble. I would not have trouble
if you said this on the streets but under the circumstance you are a
professional acoustical engineer posting on a scholarly board, give an
opinion in your area of expertise without corresponding justification.

Since you are limiting the acoustical phenomena to one building perhaps it
would be helpful to agree on a working hypothesis.  So far I "hear" you
saying the following:

   - Because the echoed sound of well-directed hand clap(ping) off the steps
   of the Castillo very closely approximates the chirped sound of a diving
   Quetzal bird I propose that the Maya had and purposely used acoustic design
   principals in the planning and construction of the Castillo stairs in order
   to produce those echoes.

If you would modify the above and offer:

   1.  some of your reason(s) for same and
   2.  how you are going to advance your hypothesis
   3.  How professional and others on the list can advance the hypothesis

It would go a long way towards resolving the question in this particular
structure.

Sid Hollander
Merida, Yucatan