On not simulating a universe
"What if we are just a simulation?" is an idea with a long
history, from Lewis Carroll (the Red King's dream) through Raymond Queneau
("Les Fleurs Bleues") to modern cinema ("The Matrix").
It fits well with the complacent nihilism of modern culture, but now that
simulation-based philosophical arguments seem to be attaining respectability
(J.D. Barrow, "Living in a Simulated Universe"; N. Bostrom,
"Are You Living in a Computer Simulation?") it is time to examine
the ontological implications of simulations.
Contemporary simulation arguments pay great attention to the computing
power needed to simulate (for example) a human brain. I argue that such considerations
are irrelevant. Starting from some straightforward premisses about what happens
when we do arithmetic, I show that from the point of view of the inhabitants
of a simulated universe it makes no difference whether anyone actually ever
runs their simulation. In fact, their lives will be the same even if the
simulation program is never written; possibly even if it is never thought
of. As a result some of the more science-fictional theories of recent years
(such as Tipler's "resurrection-by-computation" eschatology) completely
lose their point.
If we accept that the inhabitants of a simulated universe walk, talk, eat,
think, fight, and have souls just like us, we are faced with a problem. Specifically,
we have a more-than-Borgesian embarras de richesse: every possible universe
exists, however strange it may seem to us, and a world in which Boyle's Law
is different on Thursdays exists in just the same sense as our own.
An argument that leads to such a superabundance
is equally problematic
for theists and for atheists and a response of some kind is needed from both. One
answer, I suggest, may lie in worrying
the act of simulation and
- giving our own universe more "reality" than the
ones we simulate. But even this answer is vulnerable to paradox.
Simulation arguments raise further interesting parallels between God's
creation of a real universe and our own creation of a simulated
of the respective roles of creator/simulator and creature/simulation
lead to some fruitful and stimulating discourse between science and theology.
Keywords: simulation, creation, science fiction, ontology, computation,