[extropy-chat] Why no assembler design?

[Eugen Leitl]

On Sat, Nov 15, 2003 at 06:03:33PM -0800, Hal Finney wrote:
> 
> Here are a few possible but mutually exclusive answers:

Not necessarily. The world doesn't like boolean logic. 
 
> 1. There is still considerable science to be done in order to learn how
> atoms and molecules behave in the detail necessary to design an assembler.

Yes. No new physics is involved, but creating and breaking bonds at a high
rate and good control is not something well studied. In fact, a large
fraction of chemists and physicists would deny it's even possible. Not
everybody reads widely outside of their speciality.
 
> 2. The science is known, but designing an assembler would be an enormous
> task due to its incredible complexity, taking hundreds or thousands of
> man years, and no one can afford to expend that effort.

How can you design something you can't validate? We don't have a simulator
precise enough to build the assembler in a virtual dry dock which would work
flawlessly once fabbed for the first time. The simulator/model will need
iterative refinement, using input from real-world data.
 
> 3. Designing an assembler would not be enormously complex, but it would
> still require a considerable investment in state of the art hardware
> and software tools, as well as engineering manpower, and no company
> has been willing to do that.

99.9% of potential designers aren't even aware that there's a whole new world
of design waiting to be discovered. Even if they did, the amount of R&D
required with a decade-delayed ROI would make that not a viable proposition
for the most of corporate industry (but for a few giants, which also tend to
have less resources for R&D and accordingly harsher internal evaluation
cycles).
 
> 4. Designing an assembler is relatively straightforward and it is clear
> that it could be done today with a modest effort, but since there is no
> way to build the resulting device, no one wants to go to the effort of
> coming up with a complete assembler design.

An assembler without a bootstrap route is worthless. Luckily, polymer
electronics (via inkjet) as top-down and self-assembly (as bottom-up) are
bound to meet somewhere in the middle.
 
> Answers 3 and 4 assume that merely designing an assembler is pointless;
> rather, effort should be devoted to designing an assembler which can be
> built from simpler tools, which is much more difficult.  Nevertheless it
> would seem that if the situation were close to case 4, it might be a
> worthwhile exercise just to make the technological potential more obvious.

A considerable desideratum is an interactive nanoscale simulator, with more
or less accurate forcefields and a good approximation of bond
breaking/formation (Brenner's potential is too specialized and too coarse,
but it's a step in the right direction).

We're having some promising packages in MMTK, PyMOL and VMD/NAMD,
unfortunately these are geared towards biomolecules. The mainstream is
apparently not interested in interactive build and simulation packages for
machine-phase suitable systems.

Remember, how NanoCAD tanked so pitifully? The reason is that the community
interested in the matter doesn't have enough skills and critical mass to
even write software.
 
> I'd be interested to hear opinions about where we actually are along
> this spectrum, or other possibilities that I haven't considered.

-- Eugen* Leitl <a href="http://leitl.org">leitl</a>
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ICBM: 48.07078, 11.61144 http://www.leitl.org
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