Revision as of 14:30, 4 June 2014

Definition

The widespread knoweledge about the hypothetical gray goo scenario was born from the gonzo image that some "nanobot" like form of productive nanosystem fails to stop replication and consumes the whole surface of the earth leaving only grey goo behind. This superficial idea self replicated in the public mind like a virus. It can thus be called a successful meme. It did quite some unjustified reputation damage (see: History).

Current expert knowledge is:

• An accident like this is with a probability bordering on certainty imposible in the early development stages.
• Deliberate development will first likely then certainly bring limited forms of this problem.
• If official development will not be prohibited, there will be means for easy containment in place.

One must not forget that there are other dangers that are equally or more dangerous than uncontrolled replication. If it is so dangerous why APM then?
Simply because there's a huge list of opportunities and products potentially improving our and restoring natures world.

Factors for large scale unbounded replication

There are several factors which all must be true at the same time for an accelerating chain reaction to occur. In the fire departement there one has the combustion triangle. With replicators one can do a similar thing and create an replication hexagon (since there are around six requirements which must hold simultaneously.

replicativity

In T.Level I self replicapility could be avoided by building many active components in parallel onto a chips surface.
Wether it is easier to create a T.Level I Nanofactory with replicativity or parallelity remains to be seen. 

In T.Level III productive nanosystems of the classic (deprecated) assembler type need to be replicative to produce macroscopic amounts of material.
Advanced nanofactories (in form of solid bricks) will almost certainly have self replication capability (think of 3D printing a printer chip).

Medical tools (in form of dispersed nanomachines) can be nonreplicative products this is the best security measure one can get. It may be reasonable to in general prohibit dispersion of nanosystems with replicative capability in liquids or gasses, but at some arbitrary size level here has to be drawn a line.

resources

• In technology level I it is quite hard to produce the building blocks. The simple assembler mechanisms (at this stage one can think of them as linkages) can only put those whole preproduced blocks together.
• In technology level II It's not yet clear which resources will be used.
• In technology level III the not natural occuring ethine (= welding gas = HCCH) among other unnatural resource materials will be used.

Disassembly of nonstiff disordered natural substances is way harder then assembly of carefully choosen synthetic ones. In fact in many cases it's as good as impossible at room temperature. The humic substances [TODO add picture] for example are hopelessly to complex to use them as resource material. Certain minerals may be directly disassemblable with substantial effort in the not so near future. The carbon dioxide in the air constitutes a vast reservoir of easily attainable building material. This source could pose a threat. To investigate: minimal atmosphere-floating solar replicators (speculativity warning!)

energy

Productive nanosystems will likely get their energy from the chips surface - a good security measure.

mobiliy

Productive nanosystems will always have their components firmly linked together in machine phase. Only macroscopic blocks will seperate.
[todo: describe: policy exceptions limits]

Exponential assembly puts an absolute insurmountable limit to spacial spread of replicated structure.

mutations

AP systems don not evolve by themselves. A mutation of a productive nanosystem to a new ecosystem is as likely as that firefox mutates to firegodzilla and infiltrates new operating systems. Due to the very different architecture of living organisms and APM systems radiation has a completely different effect on them.

Productive nanosystems may loose efficiency or function. Logical errors (which still are functional) are extremely unlikely.
Biological systems also loose efficiency and function but have a non neglectable chance to suffer still functional logical errors aka mutation instead

A good description of part of the situation: alive-ness of computer viruses
Also: can computer viruses evolve
Or: "Nanofuture" chapter 8 self replication by J. Storr Hall

replication data

Is likely to be stored semi locally (millimeter scale) since it's conevient and disaster proof.

Examples for replicators from deliberate malicous intent

Microscale airborn carbon dioxide utilizing replicators

A form of those is called aerovores (name coined by J. Storrs Hall). They are solar powered air "breathing / eating (vore)" replicators. Note the (mis)use of biological analogy here.

• much desin effort needed: minimal nanofactory grains will probably be too big more assember like system need to be developed
• much desin effort needed: restriction to atmospheric elements H C N O and traces of others
• brown movement allows small particles to fall very slowly slight (solar) heating lets them rise
• when they emerge countermeasures will be in place (e.g. skysweepers - J. Storrs Hall) that is effects of malicious AP systems must not be considered in context of todays technology. (unilateral disarmment through suppression of research imaginable)
• there is a serious health hazard of breathing even a vew of them in
• they can be rained out and washed into the ground
• effect of radiation to time of operationality [Todo: analysis]
• self delimiting process - dangerous CO2 depletion
• lack of adaptability - brittleness of artificial systems
• spill - misconceptions

Other

(speculativity warning!)

• Atmospheric units that use CO2 as building material and sunlight as energy source potentially endangering plant life. In the worst case those thing could silently create huge amounts of Hydrogen Cyanide or NOx and release it in one blow.
  
• Some form of green goo medical tools with replicative capabilities that uses sugar and other common bio-molecules as resource. Medical tools will by definition be in form of seperated particles suspended in fluid phase and thus much more mobile. There are no known investigations to break up sugar for this process.
  
• When there is a whole global network of an AP system the hole system could be infected by a computer virus creating all sorts of strange effects from useful or funny over weird to really bad stuff. (Related: techno plants)

Similar phenomena

In the case of the existance of a global microcomponent redistribution system there could be something happening that amounts to a software based pipe breach. The cause could be a software bug on top of very flawed software design or some malicious computer virus. Any non mobile stuff thats expulsed may eventually sooner or later clog the outlet. Specifically programmed utility fog though could flood a wide area. As long as the foglets don't leave one connected machine phase they may be easily retractable when the software problem is resolved. Pushout force safety limits should prevent mountain high pileup of material till it crushes under it's own weight.

External links

• Some Limits to Global Ecophagy by Biovorous Nanoreplicators, with Public Policy Recommendations by Robert A. Freitas Jr.
• Safe exponential manufacturing - Abstract