> I for one completely fail to see what such a huge brain
> would have to think about -- there's no way we could
> provide it with enough information to keep itself busy...
> (if only because of the maximum speed imposed by RLT)
Why not brute force causality computations.
Imagine our world, or at least human society, covered with nanites.
They're inside brains, monitoring neural activity, anticipating behavior, guiding human development according to first principles.
Now comes the fun part: what effect does this interaction have 20 years down the line? What if this person learns that or this rabbit doesn't cross the road just then, what difference will it make.
Pretty soon it's like a giant chess game where the outcome isn't checkmate, but instead some first principle goal state, like ecological balance, biodiversity, stimulating interaction and development, etc. So this planet sized brain just chugs away all day long calculating scenarios, with ever increasing degrees of detail.
So here we are.