Proto-assembler (outdated)
Proto-assembler: The basic idea is/was to create a machine with side-lengths of one to a few hundred nanometers which
packages all the functionality to produce useful products and also make copies of itself (directly with diamondoid mechanosynthesis).
This way one would get an exponential rate of replication and can
eventually switch from replication to production of macroscopic goods withinin reasonable amounts of time.
There's a lot of collary falling out from this premise. One thing that everyone immediately jumps at:
What if the switch from replication to production fails and these assembles never stop replication?
Wahaaa panic!! 😱😱😱
See: Grey goo horror fable, Reproduction hexagon & Replication pentagon
The three problems
There are three main problems with molecular assemblers.
- their inefficiency
- the difficulty in reaching them
- their undesirability
Inefficiency
For a proto-assembler inefficiency can be an excusable issue
so long that inefficiency is not impacting feasibility.
For more on the several inefficiency issues of molecular assembles see page:
Molecular assemblers as advanced productive nanosystem (outdated)
Difficulty
High difficulty is a serious problem and was (and still is 2023)
a big critique point regarding the direct path.
(wiki-TODO: factor following out to: Direct path atom manipulation difficulties)
Doing single atomic manipulation with scanning probe microscopy is a very hard problem.
– Especially when going only a bit out of 2D into 3D.
– Especially materials (like diamond) that …
- feature strong covalent room temperature stable bonds
- are non conductive
- have small crystal lattice spacing
- don't like to form large scale atomically flat surfaces
– Plus atom placement needs to be done in sufficient fast succession to form a proto-system in reasonable time …
- either by frequency (very difficult with macroscale tips pushing around nanoscale atoms)
- or by parallelism (multiple needle tips) other challenges here
Undesirability
Reasons for undesirably were clearly over-hyped. See: Grey goo horror fable
But it's clear that they came from overused misleading insidiously self suggesting biological analogies.
For "Molecular assemblers as advanced productive nanosystem (outdated)" it eventually became clear that
following this immediately self suggesting bio-analogy to living cells leads to a massively sub-optimal system.
For a proto-assembler that sub-optimality may be acceptable but there is still the matter of difficulty.
Optimal systems look very different. See: gemstone metamaterial on-chip factories