Posted by HuenYK on September 01, 19101 at 04:37:57:
In Reply to: Re: Vacuum balloons posted by Anders Sandberg on January 14, 19100 at 18:39:15:
:
: : Do the any of the folks in BIGV (particularly the New Americans) have advanced enough materials technology to make a vaccuum balloon, a la Neal Stephenson's Diamond Age?
: I did not think of it, but they would definitely fit in on NA. I'm not sure about the necessary material strength, I always thought that you would need nanotech to make sufficiently light and stiff materials, but maybe it would be possible using the admittedly good engineering abilities of NA (and especially noew with nanotech spreading). I like the idea, they might be a new development that is rapidly spreading. One can imagine races in Floating California between the "vaccies" and "airers", each promoting their own kind of balloons.
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HYK: I recently have been pondering over it because helium balloons are
very leaky. That is why there are some very elaborate configurations
with two helium balloons enclosed by another outer diaphragm of hotair
balloon. Also helium is not readily available outside America.
Stadnard air density is 1.29 kg/m3. If one has a stiff enough enclosure
(quite a structural challenge but I think can be done) and reduce the
air pressure by 1%, the lifting force can be computed for a tetrahedron:
Side = 15 meters:
lifting force = float(vol_pyramid3(15)*1.29*0.1); 51.3094 kg
Side = 20 meters:
lifting force = float(vol_pyramid3(20)*1.29*0.1); = 121.622 kg
I think it is feasible and I am starting to build a prototype with
side of 2 meter to lift 0.12162 kg. The total weight of the
vacuum balloon and the internal stiffener must be less than 0.12162
kg. I will try to use drinking draws for these stiffeners and
create the slight vacuum by sucking with a straw and sealing it.
A tetrahedran is formed of regular triangles and so the structure is
quite stiff for the volume although the balloon will be heavier
volume for volume against an inflated sphere. I suggest you try it
also. Let's compare results.
HuenYK
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