Jupiter brain

A Jupiter Brain is a theoretical computing megastructure the size of a planet. Unlike a Matrioshka brain, a Jupiter Brain is optimized for minimum signal propagation delay, and so has a compact structure. Power generation and heat dissipation are formidable concerns for a Jupiter Brain implementation.

While a rigid solid object the size and mass of a rocky planet or gas giant could not be built using any known material, such a structure could be built as a low-density lattice with a mass comparable to a large moon or a small rocky planet but a far larger volume, or as a solid but non-rigid structure with the mass and density of a planet (as long as the internal heat gradient is carefully controlled to prevent convection).

Fiction

• Earth is a form of Jupiter Brain in The Hitchhiker's Guide to the Galaxy by Douglas Adams. Built by the Magratheans and commissioned by mice, it is frequently mistaken for a planet by its inhabitants (who are part of the program to determine the question of "Life, the Universe and Everything", given the answer 42 found by Deep Thought).

• In Life, the Universe and Everything, also by Douglas Adams, Hactar is a planet-sized computer who was ordered to construct a weapon of universal destruction. However, he found the idea distasteful and deliberately introduced a flaw into the design he came up with. When his masters learned of this, they pulverized Hactar, greatly diminishing his powers but failing to destroy his consciousness in the process.

• One of the main "characters" in Ken MacLeod's The Cassini Division is the planet Jupiter, which is the home of transhumanists who uploaded their personalities.

• In The Well of Souls series by Jack L. Chalker, the Well of Souls is a Jupiter Brain which is tasked with maintaining the physical state of the current universe.

• In Revelation Space by Alastair Reynolds, the neutron star Hades is a Jupiter Brain which stored the minds of and so preserved the corporeally extinct race of the Amarantin.

See also

• Matrioshka brain
• computronium

References

• Sandberg, A (22 Dec. 1999). The Physics of Information Processing Superobjects: Daily Life Among the Jupiter Brains (non-refereed)