Text 4085, 39 rader
Skriven 2005-05-11 08:09:52 av Monte Davis (1:379/45)
   Kommentar till text 4081 av Geo (1:379/45)
Ärende: Re: Space Elevators in NJ
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From: Monte Davis <monte.davis@verizon.net>

"Geo" <georger@nls.net> wrote:

>I still have my doubts that we can
>build a ladder out of a gravity well. But I do think it's worth a try.

Oh, I have my doubts as well. The pessimist in me says that CNTs may turn out
like the existing high-strength graphite/carbon fibers, or synthetic diamond,
or some of the titanium-magnesium-roettgerium super-alloys: great properties,
but too hard/expensive to make, and/or work with, for more than relatively
small niche applications.

The optimist in me says that they're carbon nano*tubes* rather than nanolumps
or nanotangles precisely because the chemistry and thermodynamics of their
formation make them "want" to grow much, much longer than their diameter while
retaining perfect molecular structure (and strength). So all we have to do is
fine-tune the synthesis conditions to maximize that natural tendency.

For "all we have to do" substitute X years and $Y hundred million or billion.
The hope is that the payoffs along the way, in terrestrial applications for
fibers "merely" 2x, 5x, 10x... stronger than the current champs (steel, Kevlar,
Spectra, Kapton, Dyneema etc), will pay that freight.

Keep in mind that microelectronics companies are already putting a metric
buttload of R&D into CNTs for quantum wires within chips, Samsung's and
Motorola's flat field-emission displays, etc. They care about CNTs' electronic
properties at micron-to-mm lengths, rather than mechanical strength or mm-to-km
lengths in bulk quantities, but everything they learn can only help with the
latter. NASA just awarded Carbon Nanotechnologies Inc. a contract to develop
lightweight, low-loss CNT wiring for the proposed Crew Exploration Vehicle.

Ask me again after I finish the current series of lab tours and interviews --
including CNI and Rick Smalley, the buckyball Nobelist at Rice who spun it off.

-Monte <ah, Houston and Dallas in late June>

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