From: Gina Miller (echoz@hotmail.com)
Date: Mon May 17 1999 - 21:27:39 MDT
>From Engines of creation (K. Eric Drexler)
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° Will the uncertainty principle of quantum physics make molecular machines
unworkable?
This principle states (among other things) that particles can't be pinned
down in an exact location for any length of time. It limits what molecular
machines can do, just as it limits what anything else can do. Nonetheless,
calculations show that the uncertainty principle places few important limits
on how well atoms can be held in place, at least for the purposes outlined
here. The uncertainty principle makes electron positions quite fuzzy, and in
fact this fuzziness determines the very size and structure of atoms. An atom
as a whole, however, has a comparatively definite position set by its
comparatively massive nucleus. If atoms didn't stay put fairly well,
molecules would not exist. One needn't study quantum mechanics to trust
these conclusions, because molecular machines in the cell demonstrate that
molecular machines work.
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Cells replicate. Their machines copy their DNA, which directs their
ribosomal machinery to build other machines from simpler molecules. These
machines and molecules are held in a fluid-filled bag. Its membrane lets in
fuel molecules and parts for more nanomachines, DNA, membrane, and so forth;
it lets out spent fuel and scrapped components. A cell replicates by copying
the parts inside its membrane bag, sorting them into two clumps, and then
pinching the bag in two. Artificial replicators could be built to work in a
similar way, but using assemblers instead of ribosomes. In this way, we
could build cell-like replicators that are not limited to molecular
machinery made from the soft, moist folds of protein molecules.
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Some of these replicators will not resemble cells at all, but will instead
resemble factories shrunk to cellular size. They will contain nanomachines
mounted on a molecular framework and conveyor belts to move parts from
machine to machine. Outside, they will have a set of assembler arms for
building replicas of themselves, an atom or a section at a time.
_______________________________________________________________________
Gina "Nanogirl" Miller
Nanotechnology Industries
Web Page
http://www.nanoindustries.com
E-mail
echoz@hotmail.com
Alternate E-mail
nanogirl@halcyon.com
"The science of nanotechnology, solutions for the future."
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