Timothy Blee has a lot more to say about Robin Hanson's thesis of simulated people. Namely, Mr. Blee asserts that it is not possible.
Brains work in a very different manner than silicon chips. Silicon chips have a central processor, that can store data on temporary storage, like RAM, or permanent storage like hard drives. It cycles very very quickly. I recently bought a 3.2 GhZ processor. It cycles 3.2 billion times per second.
Brains, however, are a massive network of neurons that signal each other They cycle slowly, only 30 times per second, and can connect to many other neurons at any given time, and are always reconfiguring each other.
Mr. Blee then points out that emulation works in computers works because we know how both the target and host computer operate, and by Dr. Turing's theorem can restructure the directives to match the host computer's operation. We at this point have only a fuzzy idea of how the bran works, and our theories on it are constantly being proven wrong.
I think that it's hypothetically possible to emulate the brain -- but it may require radically different hardware. A massive memristor mesh would be a closer approximation than the machine on your desk (or lap). The hardest part is that the brain literally rewires itself as you learn things, and so far no hardware we have ever built does that.
I thought of this because of Mr. Hanson's previous rants about emulated people, and thinking how an emulated version of me could be handy at work. While I'm stressing and frazzled, I could pass messages to him and he could help me. (Which would probably even be easy for him...the world would move quite slowly from his perspective.)