Reality+: Virtual Worlds and the Problems of Philosophy

by David J. Chalmers

From the inside, SimUniverse will be indistinguishable from the universe it’s a simulation of. Suppose that we’re simulating a possible universe containing ten billion people; in that case, SimUniverse will contain a simulated person—a pure sim—for each of them. After a while, every teenager may be running SimUniverse on a mobile device. Even if the use of the technology is restricted, we can imagine researchers running many simulated universes for scientific, historical, financial, and military purposes. Within a century or two, this could easily lead to millions or billions of different copies of Sim Universe running here and there. As a result, there will be vastly more sims than nonsims. Across history, sims may outnumber nonsims by at least a million to one. The same goes for intelligent beings anywhere in the cosmos. If any aliens have human-level intelligence, they should eventually develop computers and program them. If these alien civilizations survive long enough, they’ll likely create simulated universes. Let’s run some numbers, using small numbers to keep things simple. Any nonsim population that survives long enough will eventually be able to create (let’s say) at least a thousand sim populations, each with about as many sims as the original nonsim population. It’s arguable that at least one in ten human-level nonsim populations will eventually do this. If one in ten nonsim populations creates at least a thousand sim populations each (as depicted in figure 14)...