Genetic Algorithm: Any algorithm which seeks to solve a problem by considering numerous possibilities at once, ranking them according to some standard of fitness, and then combining ("breeding") the fittest in some way. In other words, any algorithm which imitates natural selection. [AS]
GENIE: An AI combined with an assembler or other universal constructor, programmed to build anything the owner wishes. Sometimes called a Santa Machine. This assumes a very high level of AI and nanotechnology. [AS]
Giant Magnetoresistance: (GMR). It results from subtle electron-spin effects in ultra-thin 'multilayers' of magnetic materials, which cause huge changes in their electrical resistance when a magnetic field is applied. GMR is 200 times stronger than ordinary magnetoresistance. (See Spintronics and Giant Magneto Resistance) GMR enables sensing of significantly smaller magnetic fields, which in turn allows hard disk storage capacity to increase by a factor of 20.
GNR technologies: (Genetic Engineering, Nanotechnology, and Robotics)
Guy Fawkes Scenario: If nanotechnology becomes widely available, it might become trivial for anyone to commit acts of terrorism (such as making nanomachines build a large amount of explosives under government buildings a la Guy Fawkes). This would either force strict control over nanotechnology (hard) or a decentralised mode of organisation.