[ExI] Inflatable tower could climb to the edge of space

spike spike66 at att.net
Thu Jun 11 01:23:19 UTC 2009


> -----Original Message-----
> Spike, regarding your idea of pressurizing to 20 times 
> atmospheric in a vertical tube, air has a mass of ~1kg/m3 at  
> STP.  The mass of your column of gas is going to be (very
> roughly) 75 million tonnes,
> with a footprint of over 100 tonne/m2. 
> I don't want to be near that balloon if it bursts.  :)
> -David

My goodness yes, the original notion is one hell of a bomb, way more
devastating than all our current nukes, but after I started doing the calcs,
I realized the original notion is not right anyways.  I had imagined a
hollow cone about a km diameter at the base, reaching to about 30 km, but
starting on a mountain, so the cone itself would be only about 23-ish km.
But after doing the calcs on the pressure at the base, it isn't clear to me
that any known soil or rock interface could bear that load.  In any case,
your point was that pressurizing 8 cubic kilmeters to 20 atm would store a
frightful amount of energy, and would just invite some reprehensible asshole
to try to pop your balloon.  Did we not all learn this grim aspect of
humanity in the early grades?

All is not lost however, for it is possible to construct the tower out of a
bunch of individually inflated blocks, but not inflate the tower itself.
This makes the tower itself far lighter, so that the interface between the
tower and underlying rock is within the confines of my fevered imagination.
It also allows internal structure, which will be necessary, as I will
discuss at another time.

The blocks: I have imagined them as hexagonal things, like those old
fashioned six sided wooden pencils that some of us used in school in our
misspent youths, so tragically many years ago.  These would be individually
pressurized to about 300 to 500 atmospheres, at least the lower ones would.
Less pressure is needed for the upper ones.  They would be stacked and
interlocked, such that it would look like an enormous beehive.

For illustration, oops gotta scoot, more later,


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