Revision as of 19:03, 11 July 2018

APM is a very novel area of research and development that dives into fields of knowledge that are yet pretty alien for most people including many "nanotechnology" experts. When encountering a new network of knowledge one usually tries to apply existing knowledge to judge statements and claims - what else can one do. Without deeper understanding of the relationships this can lead people into trapdoors. Some are so bad that almost everyone falls in. This page is intended to be a guide around those trapdoors.

No nanobots here

No self-replicating ones

This is not about nanobots (especially not the self replicating type).

While self replication nanobots (aka molecular assemblers) where an early idea that naturally suggested itself (it was originally presented in the book "Engines of Creation" 1986) slightly less old (and much less known) methodical work ("Nanosystems" 1992 - same author) strongly points to nanofactories as a much better target.

• The self-replicating molecular assembler concept is outdated.
  It was superseded by Nanofactories since before 1992!

(Details: Molecular assembler)

Associated traits that have nothing to do with advanced productive APM systems:

• swarms
• living & evolving
• insatiable, "metabolize" just about anything -- (see: Omnivorous nanobots)
• super dangerous - the accident is unavoidable and cataclysmic

Few non-self-replicating ones

Non self-replicating medical nanobots, utility fog and similar concepts are still not outdated but:

• As especially difficult to design systems the lie even beyond the far term target of Nanofactories (which are a main focus of this wiki).
• They make up only a very tiny part of the possible product space. Most products will be devices made from arrangements of highly specialized mechanical metamaterials. Just like computers do not consist out of "computronium" advanced products will not consist out of "nanofogonium".
  Advanced products out of complexly intertwined metamaterials rarely (if at all) make it into popular fiction probably because (a) the concept is barely known and (b) it would requires in depth explanations.

Related

• evolution

Macroscale style machinery at the nanoscale ?!

Physics changes when one scales down things. This may pose serious problems.

If you are educated in physics and nanotechnology you will likely be quick to point out that this will not work because of the effects of one or more of the following scaling laws (here listed in informal form):

• rising surface area (per volume)
  >> causing: rising friction; rising corrosion; clogging
• rising tendency towards thermodynamic equilibrium
• rising influence of thermal motion
• rising influence of quantum mechanics
• falling available space (obviously)
• falling material stiffness (less obvious)
• rising influence of intermolecular forces
• rising effect of viscosity

But: All of these potential concerns have been analyzed.
The result: In total things change for the better rather than for the worse. That is: For macroscale style machinery the changing of physics is actually an improving rather than a worsening. (Why nature does not do it this way albeit being better is a different topic (wiki-TODO: add link).)

It turns out that all the common assumptions:

• either do not hold at all under closer inspection
• or they are partially true but overcompensated by other less known factors.

Follow the links above for detailed explanations. (wiki-TODO: add those links)

It's called "nanotechnology" - not anymore

Due to the terms extreme generality it caused severe confusion and conflict. Hardening misconceprions causing unjustified discreditation going as far as career fear based self censorship and consequently a severe setback in development.

For details see main article: "The term nanotechnology" (and page: History).

It's seems best to refrain from using the term "nanotechnology" as much as possible (and the nano- prefix in general) when referring to APM related ideas.

Nature does it differently thus advanced APM must be flawed. – Faulty reasoning.

See main article: "Nature does it differently".

It will be enormously difficult to develop advanced APM possibly requiring super advanced AI – Wrong

• The biggest current challenges are of conceptual and institutional nature.
• What is not well know about advanced APM is that there is stuff that can be known.

Misled criticism about the fundamentals

Macro-scale style machinery isn't suitable for the quantum world one needs something more exotic instead - wrong

Via a very simple estimation it turns out that nanomechanics is actually barely mechanical quantum-mechanics. Baffling? The fact that quantum-mechanics is called quantum-mechanics is just a somewhat unlucky result of science history. Basically mechanics was generalized to the point where it also encompasses the behavior of electrons thus to the point where it encompasses what is in eveready language considered electronics. And electronics are pretty quantum mechanical at the nanoscale. Of course certain nanomechanic systems can be made quantum mechanical in behavior if the conditions are made extreme enough.

Actually under conditions expectable in advanced atomically precise production devices nanomechanics is pretty classical in behavior. Since the objective is to transport stuff from A to B in a controlled manner just like in makrotechnology using makro-style-machinery (with some minor tweaks) makes perfectly sense and has even advantages such as superlubrication and dissipation sharing.

Thermodynamics prevents one from having every atom at the place we want it - wrong for practical scales

See main article: "Thermodynamics".

Advanced APM systems are a "castle in the sky" with no way to built them - not quite

It has often be perceived that diamondoid molecular elements can only be synthesized by stiff tools made that themselves are made from diamondoid molecular elements. The incremental path avoids circular dependencies by continuously changing the method of assembly from self assembly to stereotactic control. (Radical Abundance - page 190)

The direct path tries to use bigger already stiff but not quite atomically precise slabs of material to build stiff atomically precise structures (e.g. in MEMS-AFMs). This is not fundamentally impossible but a much steeper slope judging from the progress rates.

Atoms can't be placed individually because of "fat and sticky fingers" - sticky is actually good fat is just untrue for the tips

Disproved by basic experimental and detailed theoretical work. See: Mechanosynthesis. It may get a bit more challenging when the mechanosynthesis of complex chain molecules is attempted. Which is not a requirement for gem-gum-factories.

See main articles: "Fat finger problem" and "Sticky finger problem".

Almost everything will be buildable - often misunderstood

It is often thought that APM is supposed to be able to produce almost anything (often formulated: all allowed structures permissible by physical law) including e.g. food, wood, plastics and metal parts but this is surely not the case.

The range of materials and structures targeted actually lies in a very narrow range (see: "mechanosynthesis"-page).
The magic lies in the diamondoid metamaterials that emulate properties above the atomic level.

This is not to say it will be impossible for all times to assemble materials (or rather compounds) lying outside the narrow set of now targeted materials. When the technology will have been around for quite a while very advanced extensions may be able to do this but this is way beyond the scope of any current day APM attainment project because it is beyond the horizon of useful exploratory engineering.

No food from gem-gum factories

Future gem-gum factories are not in any way intended to be usable for food production. Structures out of solvated weakly linked non stiff proteins and lipid layers are a good example of "anti-diamondoid" materials. Specialized devices will be capable of some limited form of synthesis of food.

Attempting to create genetic twin tissue (avoiding the need for a complete scan) has the problem that information extraction from DNA to a spacial (not only typological) atom and molecule configuration is not straightforward to say the least. There's not only the forward protein folding problem but also the yet unsolved riddle how body shape at all scales is encoded.

Why an perfect 1:1 copy of a steak is and will stay impossible

Attempting to create exact copies down to positional atomic presicion of an original tissue at this point seems ridiculously complex. Some kind of very advanced scan (atomically precise disassembly) of the original would be needed to be performed in advance. Trying to compress quasi-random atom configurations data hierarchically like in diamondoid APM systems would probably lead to strange unnatural compression artifacts. The need to produce everything in a frozen state (ice crystals) might be a hard problem but one of the most minute ones.

Tasty "meta-food" may be creatable (given sufficient design effort in chain molecule mechanosynthesis capabilities)

Creating something edible by mixing pure synthesizes molecules together (quite a lot of sloppy molecules need to be synthesizable thus not something to expect early on) together would produce something like an advanced nourishment dough. One may be able to fake familiar food for the human senses or make something else heterogeneous and tasty but it's questionable whether we really desire to fool ourselves. At some ends deficiencies through lopsided nutrition may arise while at other ends food might get a lot healthier. A mixed nutrition with natural food will probably be best.

Competing with cheap potatoes is hard

Note: Plants are already self replicating and thus cheap. Most people just don't grow all of the plants they consume because they need space, sun, soil, and often industrial post processing. Advanced (technical) APM will bring all the other stuff to the same or lower price level per mass. Including means for easier plant breeding.

To be competitive with the cheap self replicating food that we eat today tissue construction via advanced mechanosynthetic means (e.g. a pie like this hoax [1]) must be quite a bit faster than biological machinery. This may be expectable but at this point the highly diverse tool-tip chemistry at cryogenic temperatures and at the threshold of stability needed poses a prohibitively high barrier. That is barely any exploratory engineering can be applied here. Further some kind of hierarchical assembly that completely replaces the natural system would be needed.

Other sources of synthetic food

Also other technology branches (bio-nanotechnology ...) unrelated to APM may be able to produce edible tissues before of after we attain advanced APM capabilities.

Minor ones

Gemstones are inherently scarce and valuable (and will always be) - wrong

Many gemstones are made of very common elements. Its just a question of manufacturing capabilities. In this case capabilities in mechanosynthesis.

Gemstones are inherently brittle - wrong

(Or: One can't make soft materials from diamond - wrong)

What makes gemstones brittle are faults.

Faults are unavoidable in macroscopic gemstones.

• Todays (2017) synthetic gems have faults right from birth due to their thermodynamic production route.
• Tomorrows mechanosynthesized gems will quickly gain faults through natural ionizing radiation originating from the environment (or even from within in the likely case that radioactive isotopes where included)

Faults are with a very high rate avoidable in nanoscale gemstones (crystolecules) though. Most of a whole lot of identical crystolecules are perfectly flawlwess. Due to lack of any flaws these crystolecules are bendable to a pretty high degree. Well, not as extreme like rubber (several 100%) but still easily up to a two digit percentage range. A macroscopic block composed out of interlocking crystolecules does catch the cracks of the few unavoidably broken crystolecules at the clean unconnected borders between crystolecules. This makes the macroscopic block much less brittle than a single crystal. (Side-note: Crystolecules do not only feature a perfectly flawless interior but also atomically precise surfaces.) Adding a more sophisticated metamaterial structure allows even emulation off rubber like properties (reversible strainability to several 100%) but with much higher tensile strength (and heat resistance).

APM can make precious metals from dirt - wrong

APM is all about (non statistical) chemistry. Chemistry cannot make elements. (See "femtotechnology" for more details why).

Elements can only be made with nuclear technology (really big power-plants). This is called (nuclear) transmutation. It is (and likely will remain) way too inefficient to be economic. A better option may be to get scarce elements from space (asteroid mining) in case the really will be needed in great amounts.
Side-note: Not that its important in face of the other problems but, unlike chemical APM, nuclear technology seems to be fundamentally statistical in nature. At least if one does not want to go to extremely speculative areas.

Of course it will be possible to use APM to build nuclear power-plants en masse. But this is a whole nother topic.

Diamond has a much lower density than silicon (which has identical structure) - wrong

Quite the opposite actually - diamond is pretty heavy for its volume:

• Diamond: 3.5–3.53 g/cm³
• "(Diamond+Silicon)/2" ~= Moissanite: 3.218–3.22 g/cm³ (heavier than the average density)
• Silicon: 2.3290 g/cm³
• Quartz: 2.65 g/cm³ (denser than silicon although there are voids and lighter oxygen interspersed - how??)

Related

• Common critiques towards atomically precise manufacturing