Re: Smalley's Objection to MNT feasibility

Dan Fabulich (
Mon, 08 Dec 1997 21:20:06 -0500

At 08:07 PM 12/8/97 -0500, you wrote:

>Has anyone (Drexler, et al) addressed Dr. Smalley's objection to the

>feasibility of MNT?


>His problem is with thermal resolution and can be found at



>I'd appreciate anyone's informed opinion on Dr. Smalley's assertions.

He makes the point himself:


<excerpt>On the other hand, molecular assemblers certainly do exist. We
call them catalysts. Robert Weymouth, Mark Davis, and Gabor Somorjai were
invited to the conference to remind us of just how powerful modern
catalysts can be. These are not examples of the universal assemblers in
the Drexlerian dream. Instead, they are entirely ad hoc assemblers that
in their intimate, hyperdimensional, chemical way go about the business
of molecular assembly of just a particular product from just a particular
set of reactants. But in this specific, assigned task they are very
effective molecular assembly machines.


While a given protein makes only "a particular product from just a
particular set of reactants," DNA has much fewer such limitations.
Indeed, DNA is at the root of everything which we call "alive," including
cheeseburgers. If it happens in a cow, there's no law that says that we
can't, for example, rewrite the DNA of a bacteria and make it happen in a
test tube.

We can already rewrite DNA... we even know how it codes for proteins;
but those catalysts are nothing if not complicated. Writing our own is
hard, but possible,* if economically unfeasible (though this will

This is just one of the possible ways by which MNT could happen; it may
not be the best way. However, if it can happen *in any way at all*, then
I, along with many other future-minded scientists, will strive to make it

* DeGrado, W.F., L. Regan, and S. P. Ho. The Design of a Four-helix
Bundle Protein. _Cold Spring Harbor Symposia on Quantitative Biology,
Volume 52._ 1987, Cold Spring Harbor Laboratory. (There have very
likely been further advances since this, but this is the most convenient
reference I could lay my hands on.)