Re: Are there any Space Elevator experts here?

From: John Sefton (john_at_petcom.com)
Date: 07/31/04 

Date: Sat, 31 Jul 2004 09:49:54 -0600

Uncle Al wrote:
> George wrote:
>
>>Sorry if this has been discussed.
>>
>>Every time I read an Arther C. Clarke novel with his Space Elevator
>>in it, this question comes to mind, but I've never seen it
>>specifically analyzed.
>>
>>I'm talking about the change in orbital velocity which the object
>>being raised or lowered must experience. At the earth's surface on
>>the equator, an object at the bottom of the elevator has an
>>orbital velocity of about 1038 mph (3693mi * 2pi / 24hrs). But by
>>the time this object has been raised to geosynchronous orbit
>>directly above that point on the equator, it's orbital velocity must
>>have been increased to about 6859 mph (26200mi * 2pi /24hrs).
>>Something has to impart the needed "sideways" acceleration to
>>achieve a delta-V of about 5821mph. Otherwise, the elevator cable
>>or shaft will bow backward (Westward) as the payload climbs the
>>cable, and bow forward as it climbs back down to earth.
>>
>>It may be that the bowing just happens, but isn't big enough to
>>matter. Of course that would depend on the size of the payload
>>going up or down the cable, and possibly on the speed of ascent or
>>descent. But I just wondered if anyone can point me to a source
>>where this problem has really been addressed. I assume this
>>problem isn't a fatal flaw in the concept, but I would like to see
>>where someone has run the numbers to prove that.
>>
>>Arthur, are you out there?
>
>
> It won't work. The minimum energy curve from surface to
> geosynchronous orbit is not a straight line. The added tensile
> stress and length dooms a construct that cannot be built because
> of its tensile stress and length. It must be constructed of
> dielectrics or the Earth's billowing magnetosphere will roman
> candle it by induction. If it is non-conductive, what powers the
> gondola up and down? A funicular is asinine - the weight. The
> stretch can only propagate at the speed of sound. 24,000 miles
> is hours of delay. Cable inertia alone is damning.
>
> NASA, "we will launch the Space Scuttle 5000 times to build the
> Beanstalk."
>
> Right. Uncle Al bets 2 and out.
>
> --
> Uncle Al
> http://www.mazepath.com/uncleal/
> (Toxic URL! Unsafe for children and most mammals)
> http://www.mazepath.com/uncleal/qz.pdf

This is one area where I agree with Al.
He can't see how stupid a BH is, but a
Space Elevator is even stupider, and
somehow he senses that.
John

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