
The physics of information processing superobjects: Jupiter brains (1999) [pdf] - inlineint
http://www.jetpress.org/volume5/Brains2.pdf
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gwern
see also [http://aleph.se/andart2/megascale/just-how-efficient-can-
a-j...](http://aleph.se/andart2/megascale/just-how-efficient-can-a-jupiter-
brain-be/) and [https://www.gwern.net/docs/1999-bradbury-
matrioshkabrains.pd...](https://www.gwern.net/docs/1999-bradbury-
matrioshkabrains.pdf) [http://aleph.se/andart2/megascale/energy-requirements-
of-the...](http://aleph.se/andart2/megascale/energy-requirements-of-the-
singularity/)

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nabla9
Jupiter brains must be hollow spheres.

Reason for this: Volume grows cubically, surrounding area has just quadratic
growth. Fusion power generation in the core of the Sun is just 270 watts/m^3
similar to human metabolism, but but because the area grows much slower,
getting rid of the heat makes the sun very hot.

\---

What is the computational complexity for Jupiter brain thinking process?

Few options:

1\. Tightly connected (like a neural network). O(n^2.373) ... O(n^3) Best
modeled as distributed dense matrix multiplication. I think these algorithms
are processing time limited, so the communication latency is not a problem.
Node to node communication trough hollow sphere helps to remove physical
communication bottlenecks.

2\. MapReduce like. O(n*log n).

3\. Chaotic scale‐free networks. O(n) I think.

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idlewords
Power per cubic centimeter in the sun's core is even lower than that, similar
to reptile metabolism. Think of the sun as a giant glowing space lizard.

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M_Grey
...And that lizard is only as warm as it is because of quantum effects
(tunneling).

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zeroer
Could you elaborate?

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Baeocystin
He's referring to overcoming the Coulomb Barrier in stars that allows fusion
to happen at temperatures/pressures that are otherwise too low to fuse.

[https://en.wikipedia.org/wiki/Quantum_tunnelling#Nuclear_fus...](https://en.wikipedia.org/wiki/Quantum_tunnelling#Nuclear_fusion_in_stars)

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M_Grey
Thanks, that's exactly what I was referring to, I should have been more clear.

