Re: Alternative mirror technologies, WAS ATM Liquid-mirror telescopes

[Kurt Hillig <khillig@Chem.LSA.UMich.Edu>]

On Tue, 24 Jun 1997, Chuck Knight wrote:

> > I could probably build a mylar
> > mirror for even less!  (Say, have you actually tried that vacuum
> > technique, or is it just theory?  I have a 14" embroidery hoop
> > that's just "screaming" for an experiment!  Why would it form a
> > parabola, specifically, instead of a spherical mirror?)
> 
> I've got a question.  I've seen occasional references to mylar 
> film mirrors...pulled into a parabola with a vacuum.  What
> makes it take on a parabolic shape?  

That's the problem: it doesn't.  But I don't have ready access to a finite
element program (or expertise with the math) to calculate just what shape
it does take.  Maybe there's an ME out there who needs a little project?

(And I have yet to find an embroidery hoop that will hold a vacuum!) 

                            Dr. Kurt Hillig
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Ann Arbor, MI  48109-3297    as I see it.    X.500 khillig@umich.edu

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