From: Mark VandeWettering 
To: "clement.focuser" 
CC: atm{at}shore.net
Reply-To: Mark VandeWettering 




clement.focuser wrote:

> In the Feb 2003 issue of Scientific American  the article of Evolving
> Inventions
> By John R. Koza, Martin A. Keane and Matthew J. Streeter presents an
> interesting concept of design by computer. Optimization programs found in
> some ray tracing software and electrical simulation (spice) work only on a
> range of values of a predefined optical or electrical design. The new type
> of software presented in this article actual mimics the process of
> evolution. The design itself, components type, component placement and range
> of values, are allowed to change and “evolve” and produce new combinations
> in the design. Some of the examples in the article are of analog filter
> circuits that were not only optimized, but, new and better circuit
> topologies emerged. The same could be applied to optical design…perhaps an
> all- spherical large easily built scope design might be realized.


Well, perhaps, but the design space of telescopes (especially those
suitable for amateur construction) are fairly limited, mostly because of
the limits on the number of surfaces.  For one and two mirror telescopes,
the design space is covered pretty completely by traditional Newtonians,
Herschelians, Cassegrains
and Schiefspieglers and Yolos.   Reasonable performance can be had from
each of these (admittedly, with aspheric surfaces).  When you add more
surfaces (either refracting or reflecting) you do gain some freedom, but
the additional cost of figuring additional surfaces isn't insignificant.

Sasian had some nice TCT designs that were scalable to 20" size, but
if my memory
serves, also had toroidal optics.  Bob Schalk had his Schalk-Newtonian, which was
all spherical and suitable for 12.5" designs (and probably could
scale), but it had a three element corrector.

I'm uncertain that any miracles of compactness and economy are waiting for us.

        Mark


>
>
>
> Don Clement
>
> Running Springs, California
>
> http://www.clementfocuser.com
>
>
>

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