[extropy-chat] 6 challenges to Drexlerian nanotech

Hal Finney hal at finney.org
Tue Jan 10 00:28:22 UTC 2006

I've mentioned before that an excellent nanotech Blog is Soft Machines,
by Richard Jones, <http://www.softmachines.org/wordpress/>.  Jones is a
British nanotech researcher and is active in the debates over nanotech
policy as chair of the Nanotech Engagement Group.  He is also a long-time
critic of the Drexlerian nanotech paradigm.  In his book Soft Machines
he advocates a biological model for atomic design and says that the
stiff diamondoid that Drexler relies on will not actually work the way
Drexler says.

(BTW although it is not what I want to comment on, take a look at
<http://www.softmachines.org/wordpress/?p=189> where Jones describes
research showing that buckyballs are not toxic to fish after all, in
fact they are protective!  Supposedly the earlier, widely publicised
results were due to sloppy experimental procedure.)

A recent blog posting described six "challenges" for the Drexlerian
molecular manufacturing paradigm.  These are problems which Jones feels
have not been clearly addressed by researchers in the field, problems
which could make the whole thing be a non-starter.  The challenges:


1. Stability of nanoclusters and surface reconstruction.
2. Thermal noise, Brownian motion and tolerance.
3. Friction and energy dissipation.
4. Design for a motor.
5. The eutactic environment and the feed-through problem.
6. Implementation path.

In listing them here I don't do justice to Jones' extensive elaborations
on each point and his demonstration of how they work together.
For example point 4, the need for a sound nanomechanical motor, points
out that Drexler's sketch of an electrostatic motor is likely to run into
problems either with surface reconstruction (point 1) or Brownian motion
(point 2).

Unfortunately, Jones well-though-out critiques, head and shoulders above
most of what you read about nanotech, have been met only with silence from
the Drexlerian advocacy camp.  Nanodot <http://www.foresight.org/nanodot/>
has not mentioned them, nor has CRN <http://crnano.typepad.com/crnblog/>.
In particular, CRN with their frequent claims that Drexler's Nanosystems
is inerrant, should note Jones' pointers to research showing that
nanoscale friction measurements are much greater that Drexler's
calculations, throwing many of his design techniques into question.

I find that this blog is a refreshing peek into the mainstream of
nanotech research and is free of the cultishness which sometimes attends
discussions of Drexler's ideas.  Reading this you see why Drexler is
seen from within the professional research community as something of a
wild card who is well outside the mainstream.  It is always good to see
as many viewpoints as possible so I strongly recommend reading Jones'
blog along with the others I listed above.

Hal Finney

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