[extropy-chat] Did Smalley change his mind?

Robert J. Bradbury bradbury at aeiveos.com
Thu Jan 1 18:29:05 UTC 2004


On Thu, 1 Jan 2004, Brett Paatsch wrote:

> [2389]. R.E. Smalley, "Chemistry on the Nanometer Scale --
> Introductory Remarks," 1996 Welch Conference in Chemistry,
> at: http://cnst.rice.edu/NanoWelch.html

Interesting.  The WayBack machine does have copies.

The full quote is:
"On a length scale of more than one nanometer, the mechanical robot
 assembler metaphor envisioned by Drexler almost certainly will work,
 but within the 1 nm3 volume surrounding the reaction site there is a
 subtlety and complexity that is often not fully appreciated even by
 practicing chemists."

He then goes on to complain about the small volume and the need to
control the motion of the atoms (similar to his Sci. Am. and C&EN
positions) and ends with:
"Since the manipulator "fingers" of the robot would have to be made
 of atoms as well, there appears to be at least one fatal problem
 with the concept of a universal assembler: there simply is not enough
 room inside the 1 nm3 reaction volume both for the atoms desired in the
 final structure and the atomic fingers necessary to control their movement."

So we are back to the fat fingers problem again.  It is an interesting
article.

One of the WayBack URLs is:
  http://web.archive.org/web/20020127070232/http://cnst.rice.edu/NanoWelch.html

It existed in their archives from:
  Jan. 9, 1998 to Jan. 27, 2002

So it is interesting that Robert F. is selectively quoting Smalley with respect
to what works and ignoring what Smalley thinks will not work.  I think this
may be due to the fact that Smalley has a mental framework that is based
entirely on solution phase chemistry (as do almost all chemists) and have
not done their homework to see whether it really is possible to have the
positional accuracies that are discussed in Nanosystems without having to
grab onto each and every atom at the assembly site.  The entire process
of mechanosynthesis is almost antiethical to what chemists normally do
which is to heat things up to get them to move faster to increase the
probabilities that things will come into proper alignment to react
at some reasonable rate.

One thing I don't know is whether the assembler chemistry, esp. free radical
chemistry, changes with temperature.  If it doesn't then the obvious counter
argument to Smalley is simply to cool everything to a few degrees K.

Robert





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