From: Patrick Salsbury (salsbury_at_sculptors.com)
Date: 05/11/99
Message-Id: <199905110904.CAA30313@bootstrap.sculptors.com> Subject: Re: Alternate tech and questions Date: Tue, 11 May 1999 02:04:55 -0700 From: Patrick Salsbury <salsbury_at_sculptors.com>
> > > like a giant geodesic bubble (think EPCOT Center dome, on
>
> > be buoyant. Not in water...but in air! You wouldn't need heavy
>
> > Well, yes, actually. That's the theory. I've been talking
> > about this on and off since 1989. It's beginning to sound more
> > feasible as we move forward. :-)
>
> Why would we build it as a geodesic, though? Why build with discrete
> components, when Monolithic Domes has perfected the sprayed concrete
> "bubble?" Reinforced concrete might be easier to use...an inflated
> balloon would be easier to build as a mega-structure too.
>
> -- Chuck Knight
According to the equations I've seen, you wouldn't see
anything begin to float until it was about 1/2 mile across. Have you
considered just how to spray that much concrete, or where to get a
balloon that big? And actually, with that much weight from the
concrete, I doubt it would float until it was more like 1 or 1.5 miles
across.
Geodesics get stronger the larger you build them. The more
pieces there are, the more ways it has to distribute loads across the
structure. Concrete is not flexible, and doesn't dissapate force all
that well. (Masonry also has a dismal tension rating of about 50
lbs/in^2, and a floating sphere would have half of its structure
"hanging" from the upper half.) If anything were to crack that 1 mile
"eggshell", it would propagate that crack throughout the structure
much like...well...a real eggshell.
Pat
___________________Think For Yourself____________________
Patrick G. Salsbury - http://reality.sculptors.com/~salsbury/
Check out the Reality Sculptors Project: http://reality.sculptors.com/
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