Humans are provably impossible to accurately simulate using our current theoretical models which treat time as continuous. If we could prove that there's some resolution, or minimum time step, (like Planck Time) below which time does not matter and we update our models accordingly, then that might change*. For now time is continuous in every physical model we have, and thus digital computers are not able to accurately simulate the physical world using any of our models.
Right now we can't outright dismiss that there might be some special sauce to the physical world that digital computers with their finite state cannot represent.
* A theory of quantum gravitation would likely have to give an answer to that question, so hold out for that.
(Aside from "explaining" why AI couldn't ever possibly be "really intelligent" for those who find this notion existentially offensive.)
It's a cult. Like many cults, it tries to latch on science to give itself legitimacy. In this case, mathematics. It has happened before many times.
You're trying to say that, because it's computers and stuff, it's science and therefore based on reason. Well, it's not. It's just a bunch of non sequitur.
Physics gives us a way to answer questions about nature, but it is not nature itself. It is also, so far (and probably forever), incomplete.
Math doesn't need to agree with nature, we can take it as far as we want, as long as it doesn't break its own rules. Physics uses it, but is not based on it.
The laws of physics can, as far as I can tell, be described using mathematics. That doesn't mean that we have a perfect mathematical model of the laws of physics yet, but I see no reason to believe that such a mathematical model shouldn't be possible. Existing models are already extremely good, and the only parts which we don't yet have essentially perfect mathematical models for yet are in areas which we don't yet have the equipment necessary to measure how the universe behaves. At no point have we encountered a sign that the universe is governed by laws which can't be expressed mathematically.
This necessarily means that everything in the universe can also be described mathematically. Since the human experience is entirely made up of material stuff governed by these mathematical laws (as per the assumption in the first paragraph), human intelligence can be described mathematically.
Now there's one possible counter to this: even if we can perfectly describe the universe using mathematics, we can't perfectly simulate those laws. Real simulations have limitations on precision, while the universe doesn't seem to. You could argue that intelligence somehow requires the universe's seemingly infinite precision, and that no finite-precision simulation could possibly give rise to intelligence. I would find that extremely weird, but I can't rule it out a priori.
I'm not a physicist, and I don't study machine intelligence, nor organic intelligence, so I may be missing something here, but this is my current view.
I'm just saying you're mistaking the thing for the the tool we use to describe the thing.
I'm also not talking about simulations.
Epistemologically, I'm talking about unknown unknowns. There are things we don't know, and we still don't know we don't know yet. Math and physics deal with known unknowns (we know we don't know) and known knowns (we know we know) only. Math and physics do not address unknown unknowns up until they become known unknowns (we did not tackle quantum up until we discover quantum).
We don't know how humans think. It is a known unknown, tackled by many sciences, but so far, incomplete in its description. We think we have a good description, but we don't know how good it is.
If you think there are potential flaws in this line of reasoning other than the ones I already covered, I'm interested to hear.
Also, a simulation is not the thing. It's a simulation of the thing. See? The same issue. You're mistaking the thing for the tool we use to simulate the thing.
You could argue that the universe _is_ a simulation, or computational in nature. But that's speculation, not very different epistemologically from saying that a magic wizard made everything.
I’ll read the paper but the title comes off as out of touch with reality.