[extropy-chat] Fwd: KSRM now available online

Jeff Davis jrd1415 at yahoo.com
Fri Oct 28 02:30:39 UTC 2005


--- Brett Paatsch <bpaatsch at bigpond.net.au> wrote:

> jrd1415 wrote:
> > --- In nanotech at yahoogroups.com, "Gina Miller"
> <nanogirl at h...> wrote:
> > 
> > Kinematic Self-Replicating Machines Now Freely
> Available Online
> > 
> > The most comprehensive review of the field of
> Kinematic Self-
> > Replicating
> > Machines (KSRM), the title of a book co-authored
> by Robert A. Freitas 
> > Jr.
> > (http://www.rfreitas.com) and Ralph C. Merkle 
> > (http://www.merkle.com), was
> > published in hardback in late 2004.  The book is
> still available in 
> > print
> >
> (http://www.amazon.com/exec/obidos/ASIN/1570596905),
> but KSRM is now 
> > freely
> > accessible online at
> http://www.MolecularAssembler.com/KSRM.htm.  
> > With 200+
> > illustrations and 3200+ literature references,
> KSRM describes all 
> > proposed
> > and experimentally realized self-replicating
> systems that were 
> > publicly
> > known as of 2004, ranging from nanoscale to
> macroscale systems.  The 
> > book
> > extensively describes the historical development
> of the field.  It 
> > presents
> > for the first time a detailed 137-dimensional map
> of the entire 
> > kinematic
> > replicator design space to assist future
> engineering efforts.  KSRM 
> > has been
> > cited in two articles appearing in Nature this
> year (Zykov et al, 
> > Nature
> > 435, 163 (12 May 2005) and Griffith et al, Nature
> 437, 636 (29 
> > September
> > 2005)) and appears well on its way to becoming the
> classic reference 
> > in this
> > field.
> Are any readers of this list familiar enough with
> the contents
> of  this book to tell me if it contains even a
> single instance of 
> a full set of component parts that would together
> make up 
> the first self replication device? 

I pre-ordered a copy from the publisher, and got it
hot off the presses.  I read it cover to cover on my
winter sojourn to Baja last year.  Lovely read.  For
an über nerd.

The short answer to your question is no.  There's the
trivial case, but it's, well, trivial.  (Two robots,
one with an uninstalled fuse. The working robot
completes the "replication" of robot #2 by installing
the fuse.)  Then there are conceptual but fairly
complete designs for "cellular" replicators, such as
Forest Bishop's XY Active Cell (See Figure 3.18). 
This design approach is a mechanical parallel to
biology.  A minimum parts list makes a "cellular"
building block.  By connecting a multitude of these
blocks in different configurations one constructs the
various machines necessary to perform all the tasks
necessary to reproduce and assemble, in quantity, the
component parts of the cellular building blocks.    

The design space for machine self-replication is
deliciously complex (yet oddly simple ;-})with a
multitude of approaches.  F&M (the authors) have
described the design space by breaking it down into
four principle categories; 12 sub-categories; and
finally 137 practical multi-valued design properties.
(See figure 5.5)

> It seems to me that a full parts list would be
> needed before 
> those parts could be intentionally assembled by any
> means
> into a first instantiation of a self-replicator.

Agreed.  But if your point is that it's a difficult
problem, far from a solution due to it's exceeding
depth and complexity, (This I conclude from your
comments below), I don't agree.  I seem to be rather
lonely in my view that it's actually rather
straightforward -- big, but not hard -- a clear cut
case of "Everything's hard till you know how to do
it.", or, to be just a tad more pointed, directly at
the nature of THIS particular problem, "Anything 
conventionally and mistakenly seen as hard will
continue to be presumed so until someone gets off
their ass and does it."  Or more succinctly, "A thing
is impossible until it isn't."
> Nature does self assembly with biological cells, so
> with biological
> cells we know self-replication is possible but we
> don't know
> exactly how. That is, to the best of my knowledge no
> scientist
> knows even the full list of molecular parts for a
> biological cell
> capable of replication yet.

It may very well be that the absolutely
comprehensively complete parts list is not known, but
I think we're closing in on it rapidly.  And I think
we know enough, to say we know how it works.  We've
passed from "It's a mystery." to "There are gaps in
our understanding."  My opinion.  No doubt there will
be smarter folks who disagree.

> Knowing the 960 odd
> genes of 
> simple creatures doesn't of itself give us the set
> of their protein
> structures and the other component molecules. 
> To the best of my knowledge it is a simple statement
> of
> the truth that we do not know how nature does self 
> replication at the molecular level that it must do
> it. 

It surely does do it.  We're all replicators on the

We have been supremely lucky to have been born into
this precise moment in history.  It is with an
ever-cresting crescendo of wonder and enthusiasm that
I commend you to the great adventure and the great
adventure to you.  

Best, Jeff Davis

   "Everything's hard till you know how to do it."
                           Ray Charles

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