2 karma · joined June 20, 2014
The only way to simulate accurately on a classical computer is to use global state but this goes against the instruction that the devices must be isolated from each other.
> This is immaterial, however. It is a well known fact that BQP is in PSPACE and Clifford circuits (a subclass of quantum circuits) can not only be simulated classically, but done so efficiently. It is not controversial.
Yes, BQP problems are solvable and a "subclass" of quantum circuits can be simulated efficiently. But the fact is there are known aspects of reality that cannot be simulated on a classical computer.
> In the current paper, we make use of the recently published work in quantum information theory by Candela to have students write code to simulate the operation of the device in that article. Analysis of the device has significant pedagogical value—a fact recognized by Feynman—and simulation of its operation provides students a unique window into quantum mechanics without prior knowledge of the theory.
This is a very strong argument. Certainly all the ingredients to replicate a mind must exist within our physical reality.
But does an algorithm running on a computer have access to all the physics required?
For example, there are known physical phenomena, such as quantum entanglement, that are not possible to emulate with classical physics. How do we know our brains are not exploiting these, and possibly even yet unknown, physical phenomena?
An algorithm running on a classical computer is executing in a very different environment than a brain that is directly part of physical reality.