Re: dispersion at Chichenitza

[brian whatcott <inet@INTELLISYS.NET>]

At 10:07 1/10/00 -0800, Leigh wrote:
> You are standing in front of an acoustic echelle grating. This can be
> demonstrated on any suitably long-tread concrete stairway (there are
> some here at SFU that will do it).
>
> Leigh

I hoped that a glance through an Atlas of Optical Transforms would trigger
my imagination. But it did not. It is the time dispersion that calls for an
explanation. Echelon gratings show up in texts in much the same physical
configuration as a ziggurat or Castillo.

  One speculates that the low frequency components can take the shortest
path because they suffer least diffraction. The highest frequencies,
with most deviation, travel the longest path.


brian whatcott <inet@intellisys.net>
Altus OK