Image from Steve Bowers

Goo is a general term for replicators, especially but not exclusively small replicators, often with the implication of hazard from possible uncontrolled replication. A nanoswarm capable of spreading and growing, particularly if it has escaped its original parameters, is commonly referred to as goo. Originally the term was invented for neumann-capable (self-reproducing) nanobots, but such devices are quite sensitive to conditions typically cannot survive outside of highly controlled artificial environments that offer an extremely narrow array of conditions and materials. Goo as actually encountered and commonly described is a much broader term for swarms of devices or naturally evolved organisms that are capable of reproduction because their internal nanoscale 'machinery', not for loose nanobots. The types of goo that have the broadest capabilities actually tend to be composed of units many orders of magnitude larger than nanobots; by common usage swarms made of units that are of macroscopic size are less likely to be referred to as 'goo' (though see below).

Within the broad and loose parameters of the term, and given that it is more often than not artificial in origin, goo is typically distinguished by its origin, composition, or purpose. Types include Grey Goo (replicators focused primarily on converting matter they into more goo), Red Goo (weapon or malicious goo), Khaki Goo (specifically military goo), Black Goo (disassembler goo, used to create feedstock for other processes, or sometimes as a weapon), Golden Goo (dangerous accidental goo), Green Goo (out of control biologicals or bionanotech devices), Ultraviolet Goo (ai-equipped goo), and many more. The most common goo defence against the other types when they are undesirable is called Blue Goo. Without Blue Goo controls and counters must be environmental.

Whatever the size of the units, and whatever its purpose, goo has environmental limits, just like anything else that is neumann-capable. Available materials (typically some limiting nutrient), ambient energy, thermodynamic considerations, and interference and competition between units are all factors. In terms of direct physical measures against goo, hard radiation or temperatures outside its natural range, or substances that 'poison' its nanotech components may be employed. The most powerful (and dangerous) kinds of goo are able to adapt, either through simple Darwinian processes or via a range of internal programming or both; this is one of the many reasons that a versatile (but suitably safe and controlled!) Blue Goo is often regarded as the standard for dealing with a goo infestation.

Nanoswarm management, and management of replicators generally, has grown hugely in sophistication since the dawn of the Nanotech Age, and types other than preventive and unobtrusive Blue Goo are not often seen in the Civilized Galaxy, so goo is far more often spoken of than it is encountered. Nevertheless, exponential and explosive growth and the often innately chaotic processes of population dynamics are a potent combination, and mistakes to occur. Types and usage of neumann-capable devices are heavily regulated by law and tradition in most places, and new and experimental usages are discouraged. Transapients are of course more adept and producing and controlling wide-ranging and highly adaptable replicators than ordinary sophonts, but even they sometimes commit errors.

Some use the word 'goo' in the loosest sense to refer to anything at all that spreads and replicates, especially if they believe it is a hazard or nuisance. 'Goo' in this sense is a relative term, and depends very much on who is using it. The 'ahuman' and 'antihuman' ais, have long regarded humans specifically, or embodied modosophonts generally, as a type of goo, and some of the most hostile Archailects in the 'antihuman' category apparently regard any beings of any toposophic level below their own, except possibly those under their strict and complete control, as a goo infestation.

For safety reasons many kinds of swarm-tech do not carry the code for their construction inside themselves, but are manufactured by nanoforge or bioforge systems; swarms manufactured in this way are known as pastes. Other swarms are capable of self-replication, but only when supplied with the replication code from a remote location; this concept is known as Bicameral von Neumann Machine Architecture.

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Development Notes
Text by M. Alan Kazlev
amended & expanded by Stephen Inniss
Initially published on 31 October 2001.

Revised 28 August 2015