Perhaps the pitch residue from smoking contributes to wild imagination.
I am an old fart in materials science (first degree in 1053, over 40
years ago), and get put off easily by "NEWCOMER blissful ignorance and
In sci.space.policy, on Tue, 31 Aug 2004 19:12:54 -0500,
` I am an old fart in materials science (first degree in 1053, over 40
` years ago), and get put off easily by "NEWCOMER blissful ignorance and
OK, I'll play, in what culture is the current year around 1095? And
what event are they countng from? Or is this just a case of double
transpose typo, and that should have been 1963 - not nearly so
Well it might hurt to plan for someday that never comes. However, it
is a lot of fun to dream (and I do so as much as I can afford to).
Space elevators, if in the end profitable, is only the tip of the
iceburg for super fibers. The feller who makes this possible would be
as important as Bessemer (and hopefully as rich or richer).
If you ever want to say, can you give me change for this million
dollar bill, I suggest figuring out how to make cheap ultra strong
I have devised several methods of manufaturing Ultra Lng carbon nanotubes.
This is disussed in greater detail on
's process worked in the laboratory but it is not practical. Vulvox
Nano/Biotechnology is researching and developing practical processes to
manufacture ULNTs (Ultra Long Carbon Nanotubes) Vulvox also has plans to
make HTS superconducting nanotube cables and generators. Read my interview
published by Nano Investors News the link is on the homepage of the above
The space elevator may be the biggest environmental disaster ever waiting to
happen. If an airplane hit the space elevator cable it might drag it into an
orbit that causes it to hit the ground. The asteroid that keeps the space
elvator in place by centrifiugal force might cause a tidal wave or hit a
city with greater energy than a thermonuclear bomb. We should model the
space elvator on computers a long time before we can say whether it is a
safe project or a disaster movie come true.
"Neil Farbste> The space elevator may be the biggest environmental disaster ever waiting to
If it snaps then it will fall under the 'what happens if the cable snaps'
which has been thoroughly considered here* and elsewhere. If it's strong
enough to not snap then I'd guess that it could be easily shown to be
necessarily too stable to do anything more than 'twang'.
It's only when an asteroid is being manoeuvred towards Earth for
capture that it poses any possible threat. Once it's attached the only way
it can go (if the elevator snaps) is _out_. Not every design requires an
asteroid and I'm sure that any maneuver systems will be very carefully
planned to fail 'miss' rather than fail 'hit'.
Interesting that you mention disaster movies - one thing they often have in
common is a very loose grasp on facts and an over sensationalist
* sci.space.policy in my case.
1) The space elevator design most frequently discussed these days is
that associated with Brad Edwards -- see "The Space Elevator" (book)
on Amazon or an earlier version online at
It is much less massive (~800 tons total) than earlier versions such
as that in Kim Stanley Robinson's _Red Mars_ (6 *billion* tons). So it
doesn't require an asteroid either as source for cable material or as
counterweight... and the worst-case disaster scenarios are nothing
like what you're describing.
Vulvox Nano/Biotechnology Corporation is developing the world's toughest,
strongest composites to use in the aerospace and other industries. Visit the
it into your address book. We are soliciting investments, strategic
partners to jointly research bucktubes, and processes to manufacture them on
a large scale. No practical technology of manufactuirng buckytubes exists.
We are also developing ultra long carbon nanotubes. This month Dr. Y.T. Zhu
at Los Alamos Laboratory published an article in Nature Materials about a
brekthrough method of growing ultra long carbon nanotubes. Vulvox is
planning to modify Zhu's process to increase its' productivity and to reduce
the expense of manuafacturing ULNTs (ultra long carbon nanotubes.)
I found out the calculation of the nanotubes tensile strength is
based on using as the cross-sectional area only the single molecule
layer of the nanotube as a hollow tube. Note that tensile strength is
given in units of pressure, i.e., Force/Area. So using the thickness
of the shell of the tube for the area rather than viewing the base of
the tube as a filled in disk results in a much higher estimate of the
This has consequences for estimating the strength of the tubes when
scaled up to macroscopic sizes. For example suppose you wanted to
create a cable 10cm wide out of nanotubes bundled together. The weight
this cable could support would not be found simply by multiplying the
cross-sectional area of the cable Pi*(10cm)^2 times the tensile
strength. The reason being the nanotubes are hollow resulting in a
much smaller actual total cross-sectional area, and therefore also a
much lower strength.
So I'm wondering can the nanotubes width be scaled up to macroscopic
sizes as is the length? If so, you could have many layers of the tubes
one inside the other, fitting close together so there is little empty
space, all the way up to centimeter scale widths. Then a 10cm wide
cable could be formed in this way and now the cable's cross-section
would be filled in and the weight it could support really would be
given by multiplying the area of a 10cm wide disk times the tensile
However, I've only seen reports of single walled nanotubes at widths
up to around 10 nm. Can single walled nanotubes be made arbitrarily