[extropy-chat] Re: Nano-assembler feasibility

[Chris Phoenix]

This post will be about technology.

Brett Paatsch wrote:

> On Sunday, March 28   Chris Phoenix wrote:
>>...  Have you read Merkle's papers?
> 
> I have read some. But none contained a spec with a full set of 
> parts for an assembler.   Is there one that does?

No.  But that's not necessary for making preliminary estimates of 
performance.

>>The computer may or may not be nanoscale, depending 
>>entirely on what's easiest.
> 
> Sure attempts to design of a full set of components for a self 
> replicator at any scale would permit the chosen scale of the design
> itself to be one of the degrees of freedom.

What I mean is that the computer may or may not be at the same scale as 
the mechanical parts.  The first few nanofabricators can be controlled 
by a large computer.  Then you can use a lot of nanofabricators to build 
the nanocomputer quickly.  A tabletop integrated almost certainly needs 
nanocomputers, or at least nano-logic.  But the first, bootstrapped 
nanofabricators don't need a nanocomputer.

>>We have a specification that includes most functional components,
>>and supplemental information about range of motion, required 
>>stiffness, speed, etc.  We know the functions it must perform. 
> 
> Having less than 100% of the necessary parts in the system design
> for the first prototype amounts to having 0% of a designed (and 
> buildable) prototype.

Why are you talking about prototypes?  Lots of pre-prototype engineering 
work can be done, and some of it has to be done before a prototype can 
be designed.  We knew we could get to the moon before we finished the 
Saturn V design.  So why are you focusing on the 100% completed 
blueprints?  We don't have them, we can't have them yet, we don't need 
them.  Let's move on and talk about the interesting issues.

> If you don't know how many parts are needed to produce a
> full design spec for an assembler then how can you know that you
> have "most" of them? 

I said we know most functional components.  Not individual parts.  If I 
were talking about an internal combustion engine, I'd say we know it 
needs valves, a piston, a crankshaft.  But it's too early to talk about 
valve springs or crankshaft bearings.

> The question is is it possible? And the answer is we don't know
> until we see a systems specification that shows a full set of 
> components necessary to produce an assembler (at any scale
> would be a very good start)

As far as we can tell today, from all of the science and engineering 
work that's been done, it's more than possible.  It should have 
excellent performance numbers.  Feel free to address the engineering.

But "We don't know for sure until we've seen it done" is interesting 
politically but trivial scientifically.  So I won't try to answer it here.

> Without
> a list of components showing its possible any time and cost 
> numbers may as well be numerology "

No, the time and cost numbers *may be wrong.*  "Numerology" is 
name-calling.  Time and cost projections may always be wrong.  If 
there's an undiscovered error in the engineering, they may be very 
wrong.  This is a given.  So why are you saying it in an engineering post?

Chris

-- 
Chris Phoenix                                  cphoenix at CRNano.org
Director of Research
Center for Responsible Nanotechnology          http://CRNano.org