Gaia is a fictional planet described in the book Foundation's Edge (1982) and referred to in Foundation and Earth (1986) by Isaac Asimov. The name is derived from the Gaia hypothesis, which is itself eponymous to Gaia, the Earth Goddess.
Gaia is located in the Sayshell Sector, about ten parsecs (32 light years) from the system Sayshell itself. It orbits a G-4 class star, and has one natural satellite (50 km or 31 miles in diameter). Its axial inclination is 12°, and a Gaian day lasts 0.92 Galactic Standard Days.
In its course of settlement, the human beings on Gaia, under robotic guidance, not only evolved their ability to form an ongoing group consciousness, but also extended this consciousness to the fauna and flora of the planet itself, even including inanimate matter. As a result the entire planet became a super-organism.
Because of the size of the consciousness involved, Gaia's mental powers are significantly greater than those of any other mentalics encountered before in previous books. Where Second Foundationers generally required eye contact to alter emotions, Gaia could detect and alter minds without this constraint within a limited range. Gaia's influence is spread throughout the Galaxy, through a web of agents who are capable of instantaneous communication via hyperspace with the group mind as a whole.
Gaia is able to channel the kinetic energy of its matter, a phenomenon Asimov calls transduction. Transduction allowed Gaia to provide limited electrical power, move objects as large as starships, or take over the computer control system of a space vessel. It may also be capable of obliterating large sections of matter, though this ability is never discussed by Gaia; the Solarians (much more powerful transducers) were capable of destroying objects at least as large as space vessels.
Gaia's ability to store data does away with information technology. Gaia has no written records; every amount of information is stored in the collective consciousness. Naturally, a good deal of this is stored in humans and other large-brained animals, but some is stored in inanimate objects such as water, geological features, or trees. Historical records are based on the memories of individuals stored forever in the collective consciousness. Any part of Gaia can access these memories directly, as if they were just another part of their own mind. Because Galaxia will also include stars, black holes, uninhabited planets, and cosmic debris, the powers of data storage will be enhanced significantly. One drawback however, is that all historical information prior to the completion of Gaia's collective consciousness has been lost, as they cannot recall a memory that predates them, and early written records were not saved. It is also mentioned that drawing information from inanimate objects, such as a rock, requires more time than from a living organism.
Because of the nature of Gaia, natural disasters can be regulated. The collective consciousness can be alerted to an impending volcanic eruption because of the consciousness of the inanimate matter involved, and take the necessary precautions. Likewise, weather can also be carefully controlled.
Despite the enormous powers of Gaia, they are a relatively local phenomenon at the time of Foundation's Edge. This is because mentalic effects occur at the speed of light. To have them happen more quickly, Gaia must act through hyperspace, which takes a good deal more energy. However, once Galaxia is accomplished, these problems will be somewhat reduced, because all matter in the Galaxy will be part of Galaxia.
Gaians have long names; the longer the name, the higher their status. They are generally addressed by only one syllable of their name, depending on who they are communicating with.
Gaia was founded by R. Daneel Olivaw during the Empire's reign. Even then, the galaxy left it alone and it evaded taxes. By 498 F.E., Gaia had a population of one billion, a high population for a planet at that time. The inhabitants hoped eventually to create a complex ecology; all human-settled planets in the Galaxy — except Earth — had simple ecologies. The inhabitants of Gaia were all tied together into a telepathic group consciousness when it was founded; this consciousness was eventually extended to the non-human life, and later to the inorganic material of the planet. This would explain The Mule's incredible psychic powers, as Gaia was said to be his home planet.
At the time of the two books dealing with Gaia, Foundation's Edge and Foundation and Earth, Galaxia is conceived as a living organism which contains all the lifeforms and other non-living material in the galaxy. It is a utopia; the successor of Gaia. Olivaw founded Gaia with the purpose of Galaxia in mind, in order to be able to alter humanity for the better. However, since he could not tell whether this move would eventually hurt humanity, itself of almost unpredictable nature, and he therefore could not tell whether the Zeroth Law permitted it, he could not by himself make the decision to implement Galaxia. Hari Seldon's Psychohistory Project was a 'backup' initiated by Olivaw in the event that Galaxia was not determined to be the ideal course of action.
In 498 F.E., the time of Foundation's Edge, councilman Golan Trevize and historian Janov Pelorat, the protagonists, are maneuvered to Gaia so Trevize can decide whether the future of the Galaxy is to be guided by the First Foundation, Second Foundation, or Gaia. Trevize is stated to have the unique ability to deduce the correct solution to a problem, even with little or no information on the nature of problem itself. The book portrays it as a higher form of intuition, though Trevize has no actual psychic abilities. Trevize chooses Gaia, therefore Galaxia. This was done because Olivaw could not proceed with Galaxia for risk of harming humanity in the process.
In the novel Foundation and Earth, Golan Trevize, Janov Pelorat, and Blissenobiarella set out on a journey to find humanity's ancestral planet — Earth. The purpose of the journey is to settle Trevize's doubt with his decision at the end of Foundation's Edge to embrace the all-encompassing supermind of Galaxia.
From Foundation's Edge it can be surmised that Galaxia culminates in about FE 800-900 (or more precisely - R. Daneel Olivaw declines to merge with Janov Pelorat's mind as he is too old and will die in 30-40years and elects instead to merge with Fallom's who being from Solaria will live another 300-400 years which will be enough for the completion of Galaxia), allowing for further Foundation stories to be interesting until that date, if the Estate of Isaac Asimov were to authorize further stories (vis-a-vis Donald Kingsbury's novel, Psychohistorical Crisis). However, it is noted by R. Daneel Olivaw in Foundation and Earth that it would take several more centuries to bring Galaxia about.