10oclockdot:

On Universe-Simulation Computers, 10 points.

1. Nick Bostrom’s “Are You Living in a Computer Simulation?” discusses the possibility of a planet-sized computer which could run 10^42 operations per second.  This is an astronomical number.  He proposes that such a computer could simulate the entire history of mankind a million times over in the space of one second.
2. When I first read Bostrom’s article, I was already familiar with summaries of his basic argument; consequently, my mind wandered to something else.  How could such a planet-sized computer be powered?  Wouldn’t it require a planet-sized power source?  And wouldn’t that power source have to consume fuel with an incredibly high energy density?  Chemical reactions (such as burning coal or gasoline) would hardly cut it; this planet-sized computer would require nuclear, indeed probably thermonuclear power.  Otherwise, the power source would have to be prohibitively large compared to the array of computers.  Just as chemical rockets (fueled by ammonium perchlorate and a metal or liquid oxygen and liquid hydrogen) cannot transport cargo intergalactic distances (that is, while keeping the spaceship at a reasonable size), so also chemical reactions cannot provide power to planet-sized computers in any practical way.  And just as intergalactic space travel would only be practical with humongous solar sails, so also planet-sized computers could probably only be run with thermonuclear power.
3. This observation raises another question.  Even if power could be supplied to a planet-sized computer, how could such a massive computer be cooled?  Either the material would have to be fractally porous (possibly resembling a Menger sponge, or perhaps an animal’s circulatory system) to allow a remarkably efficient coolant to circulate, OR - and this seems more likely - the computer would have to be designed from components which could not overheat.  Or, better than that, it would have to designed to function optimally (or even solely) at extremely high temperatures.  Is liquid or gaseous computing possible?  It turns out that the answer is probably yes.
4. Such a computer would be more efficient if it didn’t have to sacrifice any of its power to cool itself.  It would be even more efficient if the power-generating thermonuclear reactions were distributed evenly throughout the computer, so as to reduce the energy loss which crops up whenever power is transmitted over long distances.  Such a computer would approach maximum efficiency if it was it wasn’t powered in the conventional sense at all (with wires and such), but was instead designed to operate in the presence of the extreme heat of the thermonuclear reactions.  At this stage, the computer’s material substrate would no longer be liquid or gaseous, but purely atomic plasma.
5. What would such a planet-sized computer look like from the outside?  Operating at such extreme temperatures, it would emit quite a lot of heat into the surrounding empty space; and a portion of that heat would likely radiate outward as visible light and many of the other wavelengths on the electromagnetic spectrum.  Imagine it - a vast spherical computer, the size of a planet or even larger, powered by a tumultuous cauldron of thermonuclear reactions, blazing forth against the darkness of space.
6. It would be indistinguishable from a star.  What if the sun is a computer?  What if all the stars in the sky are computers?
7. What if the big bang and the initial conditions of the universe were set up to create sextillions of computers?  What if the designers of our universe designed it only for this purpose?  What if the chaos of the cosmos was designed so that no two stars would form the same way, and thus no two stars would run the same simulation?  What if the Chandrasekhar limit (that is, the mass above which a star will collapse into a black hole), was also designed, so that stars which run sufficiently robust simulations will collapse on themselves when their simulation is completed, either sealing the data obtained by their simulations inside (for later harvesting), or perhaps opening up an output wormhole which sends their data back to the designers of the simulation?
8. But what about the other stars?  Well, they would do exactly as we see in the universe: lighter stars would burn out, unable to transmit their data.  When too-massive stars burn too quickly and go supernova, they would (as they do) emit the fusion products which they once forged in their core as an explosion of dust.  From this explosion, the dust coalesces into nebulae.  Perhaps, over time, other stars will form from this dust and run successful simulations.
9. But also over time, some of that dust may coalesce into planets.  And, in the fullness of time and novelty, life may emerge, as it did.  I don’t know what the beings in the next-universe-up may be trying to simulate, but what if it’s life?  Would it shock them to discover that within the bowels of their microcosmic universe, the refuse and byproducts of failed simulation computers accidentally banded together and actually made life?
10. Bostrom demonstrated that if it is possible for posthuman societies to run ancestor simulations, it is overwhelmingly probable that we are living in such a simulation.  I don’t dispute Bostrom’s math; most life probably is a simulation.  But what if when we look into the night sky, we’re not seeing stars simulated for our eyes?  What if in each stellar twinkling we actually behold a simulation computer at work, and inside it simulated minds and bodies experience first kisses, deathbed farewells, and the rise and fall of civilizations?  Those consciousnesses within the star-computers would accept all their experiences as reality, and they would be right to (as David Chalmers suggests) – but where would that leave us?  What if the beings in the next-universe-up have no idea that we exist, living on worlds and in bodies which self-assembled from their broken computer parts?  What if reality was programmed, “it from bit,” but we were not?  Would this account for our feelings of lostness, purposelessness, and abandonment?  Or might it mean that we are the only truly free beings, for we have escaped the eyes of the gods?