[extropy-chat] Re: Self replication again (was MARS: ...

[Chris Phoenix]

Mike Lorrey wrote:
 > Sorry, you were talking about making monolithic diamond and comparing
 > that to making nanites, implying that one started with a hunk of
 > diamond and chipped away at it. So we are a back to my original
 > argument about building parts and assemblies an atom or molecule at a
 > time.

I was saying that if we can make monolithic diamond by deposition 
reactions, then we can, by controlling the position and sequence of 
those reactions, make more complex parts.

 > It is entirely different to have a machine that is tied to a computer
 > database to not just tell it how to make one part, but every part that
 > the machine itself is made of, the computer itself, and the end product
 > the controller wants built is made of.

The complexity of such a machine is in the computer's software.  Not in 
the deposition machinery, or the actuators, or even the computer's 
hardware.  The assumption that a general-purpose manufacturing machine 
must be physically complex is common, but it's simply wrong.  The 
physical part doesn't necessarily have to be more complex than, say, an 
inkjet printer.

If you want to talk about the complexity of the software, that's fine. 
But start by addressing the relevant sections of my nanofactory paper: 
"8.1. File size and data distribution"
http://www.jetpress.org/volume13/Nanofactory.htm#s8.1 which builds on
"6 Control of the nanofactory"
http://www.jetpress.org/volume13/Nanofactory.htm#s6 and
"5 Product design"
http://www.jetpress.org/volume13/Nanofactory.htm#s5

 > I have serious questions about how easy it is to just assemble diamond
 > molecules at normal pressures. Admittedly I don't know much about this,
 > but it seems to me that something that requires a humongous press to
 > produce even artificial diamond at massive pressures and temps (and
 > can't actually replicate natural diamond) would cause significant
 > difficulties for you if your machine is trying to put diamond molecules
 > together at normal pressures and temps.

Your "serious questions" about mechanosynthesis do not reflect any 
actual problems with the proposal; they are easy to answer and have 
already been answered if you study the mechanochemistry literature.

A single bond, or two bonds, don't require much force.  The pressure in 
bulk diamond synthesis isn't to make reactions happen--it's to shift the 
equilibrium from graphite to diamond.

http://www.foresight.org/stage2/mechsynthbib.html
See especially the section "Diamond Mechanosynthesis Tools (Theory)"

Chris

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