I don't believe that we live in a simulated universe, and I'm not convinced that we could know even if we did. However, the possibility of a simulated universe gives rise to some truly horrifying potential outcomes. To summarize the simulation hypothesis: If humanity survives, then advances in computing power and understanding of human brains may allow our descendants to simulate us, their ancestors, on computers of the future. If our descendants develop the ability and have the will to simulate their ancestors on computers of the future, then there would be one real universe and many simulated universes. In that case, it is highly probable that any given universe would be a simulated universe.
Here's where the horror comes in. Consider these possible simulated universes.
1) Fundamentalist Universe: Everyone who dies disbelieving in a particular god or set of religious beliefs experiences a simulation of hell at death. Everyone else experiences a simulation of heaven at death.
2) Skepticist Universe: Everyone who dies believing in any god or set of religious beliefs experiences hell at death. Everyone else gets annihilated at death.
3) Moralistic Universe: Everyone who dies after committing some amount of harm or evil experiences hell at death. Everyone else gets annihilated at death.
4) Inverted Universe: Everyone who dies after creating some amount of benefit or good experiences hell at death. Everyone else gets annihilated at death.
5) Tormented Universe: Everyone who dies experiences hell at death.
Having said all this, I strongly believe that these horrible simulations will always be impossible. To develop the planet-sized computers required for such a simulation in the first place, our descendants would have to evolve their ethics to the point that torturing other sentient beings would be unthinkable. Otherwise, our descendants necessarily would annihilate themselves or impede their own technological progress to the point that such a vast undertaking couldn't be organized and executed.
Here's where the horror comes in. Consider these possible simulated universes.
1) Fundamentalist Universe: Everyone who dies disbelieving in a particular god or set of religious beliefs experiences a simulation of hell at death. Everyone else experiences a simulation of heaven at death.
2) Skepticist Universe: Everyone who dies believing in any god or set of religious beliefs experiences hell at death. Everyone else gets annihilated at death.
3) Moralistic Universe: Everyone who dies after committing some amount of harm or evil experiences hell at death. Everyone else gets annihilated at death.
4) Inverted Universe: Everyone who dies after creating some amount of benefit or good experiences hell at death. Everyone else gets annihilated at death.
5) Tormented Universe: Everyone who dies experiences hell at death.
Having said all this, I strongly believe that these horrible simulations will always be impossible. To develop the planet-sized computers required for such a simulation in the first place, our descendants would have to evolve their ethics to the point that torturing other sentient beings would be unthinkable. Otherwise, our descendants necessarily would annihilate themselves or impede their own technological progress to the point that such a vast undertaking couldn't be organized and executed.
