# Re: Question?

Darin Sunley (rsunley@escape.ca)
Mon, 19 Jul 1999 20:43:36 -0500

Gina Miller wrote:

> Does any one here have any architectural insight to a question I have? If I
> were to begin building a simple structure merely to achieve it's epitome of
> height, what should it be built of, (not considering the future of
> nanotubes, but what could be used now) how high would it reach and how thick
> would the structure have to be in width?

>From what little I understand of large structure architecture/engineering, there
are several issues.

First, each given layer must be strong enough to support the weight of all the layers above.
Second, the entire structure must have a combination of strength and shape to resist the force generated by wind hitting it. this implies that each layer must be fastened to the layer beneath it with either enough force to resist this wind pressure (Sears Tower) , or enough flex to bend to it (reed in the swamp). Force due to Air pressure can be reduced by shaping the structure aerodynamically (at least along one axis) and allowing it to rotate so that the aerodynamics always face into the wind.

[Speculation: Can wind be used to strengthen a building?]

Given this, the structure would probably be shaped somewhat like an airplane's rudder, and would rotate freely around it's vertical axis (assuming height is the sole criterion we're building to). It would definitely taper from as large a base as practical to a whip antenna (or smaller) at the top. It would have to be stiff yet flexy, so I'm thinking some kinda diamondoid/buckytube composite.

Beats the heck outta me how tall you could make the thing. To invoke the lords of proctological numerology (pulling numbers out of an orifice that shall go unnamed), I'd say a fully optimized design a couple thousand feet across at ground level could top out at a whip antenna (waving wildly around, badly menacing local air travel but describing a lovely strange attractor) 30 to 50 kilometers up.

If we're stuck with reinforced concrete, I would say a kilometer, maybe two.

Be real pretty tho.

Darin Sunley
rsunley@escape.ca