Pathways to advanced APM systems

A possible map for incremental pathways and mixed pathways.
Left axis: technology levels
Right axis see: convergent assembly comparison and hierarchical self-assembly.
The direct path starts top left (3,0) right away facing the challenge of more difficult scaling of system complexity rather than getting the challenge to get to better i.e. stiffer materials.
The red stars indicate challenging blockades:
(1,0) Positional assembly redundancy blockade and
(0,5) Thermal driven selfassembly diffusion speed slowdown blockade.

the steep direct path

the long incremental path

• The Incremental path
• The Direct path
• The Mixed path
• The historic Feynman path
• The paths that aren't paths: Brownian Path => Accidental Path

(wiki-TODO: Needs a basic introduction.)

Its not a binary either or question whether the direct or the incremental path will be taken its more that the two represent extreme ends of a spectrum of possible development progressions. Both types of paths will likely heavily borrow from the non mechanical technology path.

There seems to be a peaceful internal conflict.
See also: Pathway controversy.

Views of the paths from the proponents of different viewpoints

Critiques:

• incremental path (Ralph Merkle & co): slow and aimless little targeted effort ...
  (wiki-TODO: collect their arguments)
• direct path (E.Drexler & co): too hard to access experimentally, slow experimental progress, little research motivation (funds)

Relation to speed of introduction of advanced productive nanosystems

It seems any bets are off here. It is worth to note that the usual association of the direct path with sudden and rapid changes and the indirect path with slow and progressive changes might be not incorrect.

• (wiki-TODO: treat benefits and risks of fast vs slow changes)

Related

• Bootstrapping methods for productive nanosystems
• Spectrum of pathways
• Pathway controversy
• Bridging the gaps
• Up: Where to start targeted development

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(wiki-TODO: These following pages need some review.)

• Non mechanical technology path
• Brownian technology path

External links

Citation from the article "From Here to Nanofactories" (crnano blog – Posted on September 24, 2006):
"..., advances in one dimension will synergize with advances in other dimensions, so it may be more efficient to go straight to a new technology that makes bigger leaps forward in several dimensions at once. But if such a technology can't be found for a particular leap, it can be done in a series of incremental steps. ..."